{-# LANGUAGE DataKinds #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE TypeOperators #-}
{-# LANGUAGE NoImplicitPrelude #-}

-- : dep warp
-- : dep servant-server
-- : dep lucid
-- : dep servant-lucid
-- : dep http-api-data
-- : dep process
-- : dep clay
module Omni.Jr.Web
  ( run,
    defaultPort,
  )
where

import Alpha
import qualified Data.List as List
import qualified Data.Text as Text
import qualified Data.Text.Lazy as LazyText
import qualified Data.Text.Lazy.Encoding as LazyText
import Data.Time (UTCTime, defaultTimeLocale, diffUTCTime, formatTime)
import qualified Lucid
import qualified Lucid.Base as Lucid
import qualified Network.Wai.Handler.Warp as Warp
import Numeric (showFFloat)
import qualified Omni.Jr.Web.Style as Style
import qualified Omni.Task.Core as TaskCore
import Servant
import qualified Servant.HTML.Lucid as Lucid
import qualified System.Exit as Exit
import qualified System.Process as Process
import Web.FormUrlEncoded (FromForm (..), lookupUnique, parseUnique)

type PostRedirect = Verb 'POST 303 '[Lucid.HTML] (Headers '[Header "Location" Text] NoContent)

defaultPort :: Warp.Port
defaultPort = 8080

data TaskFilters = TaskFilters
  { filterStatus :: Maybe TaskCore.Status,
    filterPriority :: Maybe TaskCore.Priority,
    filterNamespace :: Maybe Text,
    filterType :: Maybe TaskCore.TaskType
  }
  deriving (Show, Eq)

type API =
  Get '[Lucid.HTML] HomePage
    :<|> "style.css" :> Get '[CSS] LazyText.Text
    :<|> "ready" :> Get '[Lucid.HTML] ReadyQueuePage
    :<|> "blocked" :> Get '[Lucid.HTML] BlockedPage
    :<|> "intervention" :> Get '[Lucid.HTML] InterventionPage
    :<|> "stats" :> QueryParam "epic" Text :> Get '[Lucid.HTML] StatsPage
    :<|> "tasks"
      :> QueryParam "status" Text
      :> QueryParam "priority" Text
      :> QueryParam "namespace" Text
      :> QueryParam "type" Text
      :> Get '[Lucid.HTML] TaskListPage
    :<|> "kb" :> Get '[Lucid.HTML] KBPage
    :<|> "epics" :> Get '[Lucid.HTML] EpicsPage
    :<|> "tasks" :> Capture "id" Text :> Get '[Lucid.HTML] TaskDetailPage
    :<|> "tasks" :> Capture "id" Text :> "status" :> ReqBody '[FormUrlEncoded] StatusForm :> Post '[Lucid.HTML] StatusBadgePartial
    :<|> "tasks" :> Capture "id" Text :> "description" :> ReqBody '[FormUrlEncoded] DescriptionForm :> PostRedirect
    :<|> "tasks" :> Capture "id" Text :> "notes" :> ReqBody '[FormUrlEncoded] NotesForm :> PostRedirect
    :<|> "tasks" :> Capture "id" Text :> "review" :> Get '[Lucid.HTML] TaskReviewPage
    :<|> "tasks" :> Capture "id" Text :> "diff" :> Capture "commit" Text :> Get '[Lucid.HTML] TaskDiffPage
    :<|> "tasks" :> Capture "id" Text :> "accept" :> PostRedirect
    :<|> "tasks" :> Capture "id" Text :> "reject" :> ReqBody '[FormUrlEncoded] RejectForm :> PostRedirect
    :<|> "tasks" :> Capture "id" Text :> "reset-retries" :> PostRedirect
    :<|> "partials" :> "recent-activity" :> Get '[Lucid.HTML] RecentActivityPartial
    :<|> "partials" :> "ready-count" :> Get '[Lucid.HTML] ReadyCountPartial
    :<|> "partials"
      :> "task-list"
      :> QueryParam "status" Text
      :> QueryParam "priority" Text
      :> QueryParam "namespace" Text
      :> QueryParam "type" Text
      :> Get '[Lucid.HTML] TaskListPartial
    :<|> "partials" :> "task" :> Capture "id" Text :> "metrics" :> Get '[Lucid.HTML] TaskMetricsPartial

data CSS

instance Accept CSS where
  contentType _ = "text/css"

instance MimeRender CSS LazyText.Text where
  mimeRender _ = LazyText.encodeUtf8

data HomePage = HomePage TaskCore.TaskStats [TaskCore.Task] [TaskCore.Task]

newtype ReadyQueuePage = ReadyQueuePage [TaskCore.Task]

newtype BlockedPage = BlockedPage [TaskCore.Task]

newtype InterventionPage = InterventionPage [TaskCore.Task]

data TaskListPage = TaskListPage [TaskCore.Task] TaskFilters

data TaskDetailPage
  = TaskDetailFound TaskCore.Task [TaskCore.Task] [TaskCore.TaskActivity] (Maybe TaskCore.RetryContext) [GitCommit]
  | TaskDetailNotFound Text

data GitCommit = GitCommit
  { commitHash :: Text,
    commitShortHash :: Text,
    commitSummary :: Text,
    commitAuthor :: Text,
    commitRelativeDate :: Text,
    commitFilesChanged :: Int
  }
  deriving (Show, Eq)

data TaskReviewPage
  = ReviewPageFound TaskCore.Task ReviewInfo
  | ReviewPageNotFound Text

data ReviewInfo
  = ReviewNoCommit
  | ReviewMergeConflict Text [Text]
  | ReviewReady Text Text

data TaskDiffPage
  = DiffPageFound Text Text Text
  | DiffPageNotFound Text Text

data StatsPage = StatsPage TaskCore.TaskStats (Maybe Text)

newtype KBPage = KBPage [TaskCore.Task]

data EpicsPage = EpicsPage [TaskCore.Task] [TaskCore.Task]

newtype RecentActivityPartial = RecentActivityPartial [TaskCore.Task]

newtype ReadyCountPartial = ReadyCountPartial Int

data StatusBadgePartial = StatusBadgePartial TaskCore.Status Text

newtype TaskListPartial = TaskListPartial [TaskCore.Task]

data TaskMetricsPartial = TaskMetricsPartial Text [TaskCore.TaskActivity] (Maybe TaskCore.RetryContext)

newtype RejectForm = RejectForm (Maybe Text)

instance FromForm RejectForm where
  fromForm form = Right (RejectForm (either (const Nothing) Just (lookupUnique "notes" form)))

newtype StatusForm = StatusForm TaskCore.Status

instance FromForm StatusForm where
  fromForm form = do
    statusText <- parseUnique "status" form
    case readMaybe (Text.unpack statusText) of
      Just s -> Right (StatusForm s)
      Nothing -> Left "Invalid status"

newtype DescriptionForm = DescriptionForm Text

instance FromForm DescriptionForm where
  fromForm form = do
    desc <- parseUnique "description" form
    Right (DescriptionForm desc)

newtype NotesForm = NotesForm Text

instance FromForm NotesForm where
  fromForm form = do
    notes <- parseUnique "notes" form
    Right (NotesForm notes)

pageHead :: (Monad m) => Text -> Lucid.HtmlT m ()
pageHead title =
  Lucid.head_ <| do
    Lucid.title_ (Lucid.toHtml title)
    Lucid.meta_ [Lucid.charset_ "utf-8"]
    Lucid.meta_
      [ Lucid.name_ "viewport",
        Lucid.content_ "width=device-width, initial-scale=1"
      ]
    Lucid.link_ [Lucid.rel_ "stylesheet", Lucid.href_ "/style.css"]
    Lucid.script_
      [ Lucid.src_ "https://unpkg.com/htmx.org@2.0.4",
        Lucid.integrity_ "sha384-HGfztofotfshcF7+8n44JQL2oJmowVChPTg48S+jvZoztPfvwD79OC/LTtG6dMp+",
        Lucid.crossorigin_ "anonymous"
      ]
      ("" :: Text)

navbar :: (Monad m) => Lucid.HtmlT m ()
navbar =
  Lucid.nav_ [Lucid.class_ "navbar"] <| do
    Lucid.a_ [Lucid.href_ "/", Lucid.class_ "navbar-brand"] "Jr"
    Lucid.input_
      [ Lucid.type_ "checkbox",
        Lucid.id_ "navbar-toggle",
        Lucid.class_ "navbar-toggle-checkbox"
      ]
    Lucid.label_
      [ Lucid.for_ "navbar-toggle",
        Lucid.class_ "navbar-hamburger"
      ]
      <| do
        Lucid.span_ [Lucid.class_ "hamburger-line"] ""
        Lucid.span_ [Lucid.class_ "hamburger-line"] ""
        Lucid.span_ [Lucid.class_ "hamburger-line"] ""
    Lucid.div_ [Lucid.class_ "navbar-links"] <| do
      Lucid.a_ [Lucid.href_ "/", Lucid.class_ "navbar-link"] "Dashboard"
      Lucid.div_ [Lucid.class_ "navbar-dropdown"] <| do
        Lucid.button_ [Lucid.class_ "navbar-dropdown-btn"] "Tasks ▾"
        Lucid.div_ [Lucid.class_ "navbar-dropdown-content"] <| do
          Lucid.a_ [Lucid.href_ "/ready", Lucid.class_ "navbar-dropdown-item"] "Ready"
          Lucid.a_ [Lucid.href_ "/blocked", Lucid.class_ "navbar-dropdown-item"] "Blocked"
          Lucid.a_ [Lucid.href_ "/intervention", Lucid.class_ "navbar-dropdown-item"] "Intervention"
          Lucid.a_ [Lucid.href_ "/tasks", Lucid.class_ "navbar-dropdown-item"] "All"
      Lucid.div_ [Lucid.class_ "navbar-dropdown"] <| do
        Lucid.button_ [Lucid.class_ "navbar-dropdown-btn"] "Plans ▾"
        Lucid.div_ [Lucid.class_ "navbar-dropdown-content"] <| do
          Lucid.a_ [Lucid.href_ "/epics", Lucid.class_ "navbar-dropdown-item"] "Epics"
          Lucid.a_ [Lucid.href_ "/kb", Lucid.class_ "navbar-dropdown-item"] "KB"
      Lucid.a_ [Lucid.href_ "/stats", Lucid.class_ "navbar-link"] "Stats"

statusBadge :: (Monad m) => TaskCore.Status -> Lucid.HtmlT m ()
statusBadge status =
  let (cls, label) = case status of
        TaskCore.Open -> ("badge badge-open", "Open")
        TaskCore.InProgress -> ("badge badge-inprogress", "In Progress")
        TaskCore.Review -> ("badge badge-review", "Review")
        TaskCore.Approved -> ("badge badge-approved", "Approved")
        TaskCore.Done -> ("badge badge-done", "Done")
   in Lucid.span_ [Lucid.class_ cls] label

multiColorProgressBar :: (Monad m) => TaskCore.TaskStats -> Lucid.HtmlT m ()
multiColorProgressBar stats =
  let total = TaskCore.totalTasks stats
      doneCount = TaskCore.doneTasks stats
      inProgressCount = TaskCore.inProgressTasks stats
      openCount = TaskCore.openTasks stats + TaskCore.reviewTasks stats + TaskCore.approvedTasks stats
      donePct = if total == 0 then 0 else (doneCount * 100) `div` total
      inProgressPct = if total == 0 then 0 else (inProgressCount * 100) `div` total
      openPct = if total == 0 then 0 else (openCount * 100) `div` total
   in Lucid.div_ [Lucid.class_ "multi-progress-container"] <| do
        Lucid.div_ [Lucid.class_ "multi-progress-bar"] <| do
          when (donePct > 0)
            <| Lucid.div_
              [ Lucid.class_ "multi-progress-segment progress-done",
                Lucid.style_ ("width: " <> tshow donePct <> "%"),
                Lucid.title_ (tshow doneCount <> " done")
              ]
              ""
          when (inProgressPct > 0)
            <| Lucid.div_
              [ Lucid.class_ "multi-progress-segment progress-inprogress",
                Lucid.style_ ("width: " <> tshow inProgressPct <> "%"),
                Lucid.title_ (tshow inProgressCount <> " in progress")
              ]
              ""
          when (openPct > 0)
            <| Lucid.div_
              [ Lucid.class_ "multi-progress-segment progress-open",
                Lucid.style_ ("width: " <> tshow openPct <> "%"),
                Lucid.title_ (tshow openCount <> " open")
              ]
              ""
        Lucid.div_ [Lucid.class_ "progress-legend"] <| do
          Lucid.span_ [Lucid.class_ "legend-item"] <| do
            Lucid.span_ [Lucid.class_ "legend-dot legend-done"] ""
            Lucid.toHtml ("Done " <> tshow doneCount)
          Lucid.span_ [Lucid.class_ "legend-item"] <| do
            Lucid.span_ [Lucid.class_ "legend-dot legend-inprogress"] ""
            Lucid.toHtml ("In Progress " <> tshow inProgressCount)
          Lucid.span_ [Lucid.class_ "legend-item"] <| do
            Lucid.span_ [Lucid.class_ "legend-dot legend-open"] ""
            Lucid.toHtml ("Open " <> tshow openCount)

statusBadgeWithForm :: (Monad m) => TaskCore.Status -> Text -> Lucid.HtmlT m ()
statusBadgeWithForm status tid =
  Lucid.div_ [Lucid.id_ "status-badge-container", Lucid.class_ "status-badge-container"] <| do
    statusBadge status
    Lucid.select_
      [ Lucid.name_ "status",
        Lucid.class_ "status-select-inline",
        Lucid.makeAttribute "hx-post" ("/tasks/" <> tid <> "/status"),
        Lucid.makeAttribute "hx-target" "#status-badge-container",
        Lucid.makeAttribute "hx-swap" "outerHTML"
      ]
      <| do
        statusOptionHtmx TaskCore.Open status
        statusOptionHtmx TaskCore.InProgress status
        statusOptionHtmx TaskCore.Review status
        statusOptionHtmx TaskCore.Approved status
        statusOptionHtmx TaskCore.Done status
  where
    statusOptionHtmx :: (Monad m2) => TaskCore.Status -> TaskCore.Status -> Lucid.HtmlT m2 ()
    statusOptionHtmx opt current =
      let attrs = [Lucid.value_ (tshow opt)] <> [Lucid.selected_ "selected" | opt == current]
       in Lucid.option_ attrs (Lucid.toHtml (tshow opt))

renderTaskCard :: (Monad m) => TaskCore.Task -> Lucid.HtmlT m ()
renderTaskCard t =
  Lucid.a_
    [ Lucid.class_ "task-card task-card-link",
      Lucid.href_ ("/tasks/" <> TaskCore.taskId t)
    ]
    <| do
      Lucid.div_ [Lucid.class_ "task-header"] <| do
        Lucid.span_ [Lucid.class_ "task-id"] (Lucid.toHtml (TaskCore.taskId t))
        statusBadge (TaskCore.taskStatus t)
        Lucid.span_ [Lucid.class_ "priority"] (Lucid.toHtml (tshow (TaskCore.taskPriority t)))
      Lucid.p_ [Lucid.class_ "task-title"] (Lucid.toHtml (TaskCore.taskTitle t))

renderListGroupItem :: (Monad m) => TaskCore.Task -> Lucid.HtmlT m ()
renderListGroupItem t =
  Lucid.a_
    [ Lucid.class_ "list-group-item",
      Lucid.href_ ("/tasks/" <> TaskCore.taskId t)
    ]
    <| do
      Lucid.div_ [Lucid.class_ "list-group-item-content"] <| do
        Lucid.span_ [Lucid.class_ "list-group-item-id"] (Lucid.toHtml (TaskCore.taskId t))
        Lucid.span_ [Lucid.class_ "list-group-item-title"] (Lucid.toHtml (TaskCore.taskTitle t))
      Lucid.div_ [Lucid.class_ "list-group-item-meta"] <| do
        statusBadge (TaskCore.taskStatus t)
        Lucid.span_ [Lucid.class_ "priority"] (Lucid.toHtml (tshow (TaskCore.taskPriority t)))

instance Lucid.ToHtml HomePage where
  toHtmlRaw = Lucid.toHtml
  toHtml (HomePage stats readyTasks recentTasks) =
    Lucid.doctypehtml_ <| do
      pageHead "Jr Dashboard"
      Lucid.body_ <| do
        navbar
        Lucid.div_ [Lucid.class_ "container"] <| do
          Lucid.h1_ "Jr Dashboard"

          Lucid.h2_ "Task Status"
          multiColorProgressBar stats
          Lucid.div_ [Lucid.class_ "stats-grid"] <| do
            statCard "Open" (TaskCore.openTasks stats) "badge-open" "/tasks?status=Open"
            statCard "In Progress" (TaskCore.inProgressTasks stats) "badge-inprogress" "/tasks?status=InProgress"
            statCard "Review" (TaskCore.reviewTasks stats) "badge-review" "/tasks?status=Review"
            statCard "Approved" (TaskCore.approvedTasks stats) "badge-approved" "/tasks?status=Approved"
            statCard "Done" (TaskCore.doneTasks stats) "badge-done" "/tasks?status=Done"

          Lucid.h2_ <| do
            "Ready Queue "
            Lucid.span_
              [ Lucid.class_ "ready-count",
                Lucid.makeAttribute "hx-get" "/partials/ready-count",
                Lucid.makeAttribute "hx-trigger" "every 5s"
              ]
              <| do
                Lucid.a_ [Lucid.href_ "/ready", Lucid.class_ "ready-link"]
                  <| Lucid.toHtml ("(" <> tshow (length readyTasks) <> " tasks)")
          if null readyTasks
            then Lucid.p_ [Lucid.class_ "empty-msg"] "No tasks ready for work."
            else
              Lucid.div_ [Lucid.class_ "list-group"]
                <| traverse_ renderListGroupItem (take 5 readyTasks)

          Lucid.h2_ "Recent Activity"
          Lucid.div_
            [ Lucid.class_ "recent-activity",
              Lucid.makeAttribute "hx-get" "/partials/recent-activity",
              Lucid.makeAttribute "hx-trigger" "every 10s"
            ]
            <| if null recentTasks
              then Lucid.p_ [Lucid.class_ "empty-msg"] "No recent tasks."
              else
                Lucid.div_ [Lucid.class_ "list-group"]
                  <| traverse_ renderListGroupItem recentTasks
    where
      statCard :: (Monad m) => Text -> Int -> Text -> Text -> Lucid.HtmlT m ()
      statCard label count badgeClass href =
        Lucid.a_ [Lucid.href_ href, Lucid.class_ ("stat-card " <> badgeClass)] <| do
          Lucid.div_ [Lucid.class_ "stat-count"] (Lucid.toHtml (tshow count))
          Lucid.div_ [Lucid.class_ "stat-label"] (Lucid.toHtml label)

instance Lucid.ToHtml ReadyQueuePage where
  toHtmlRaw = Lucid.toHtml
  toHtml (ReadyQueuePage tasks) =
    Lucid.doctypehtml_ <| do
      pageHead "Ready Queue - Jr"
      Lucid.body_ <| do
        navbar
        Lucid.div_ [Lucid.class_ "container"] <| do
          Lucid.h1_ <| Lucid.toHtml ("Ready Queue (" <> tshow (length tasks) <> " tasks)")
          if null tasks
            then Lucid.p_ [Lucid.class_ "empty-msg"] "No tasks are ready for work."
            else Lucid.div_ [Lucid.class_ "task-list"] <| traverse_ renderTaskCard tasks

instance Lucid.ToHtml BlockedPage where
  toHtmlRaw = Lucid.toHtml
  toHtml (BlockedPage tasks) =
    Lucid.doctypehtml_ <| do
      pageHead "Blocked Tasks - Jr"
      Lucid.body_ <| do
        navbar
        Lucid.div_ [Lucid.class_ "container"] <| do
          Lucid.h1_ <| Lucid.toHtml ("Blocked Tasks (" <> tshow (length tasks) <> " tasks)")
          Lucid.p_ [Lucid.class_ "info-msg"] "Tasks with unmet blocking dependencies."
          if null tasks
            then Lucid.p_ [Lucid.class_ "empty-msg"] "No blocked tasks."
            else Lucid.div_ [Lucid.class_ "task-list"] <| traverse_ renderTaskCard tasks

instance Lucid.ToHtml InterventionPage where
  toHtmlRaw = Lucid.toHtml
  toHtml (InterventionPage tasks) =
    Lucid.doctypehtml_ <| do
      pageHead "Needs Intervention - Jr"
      Lucid.body_ <| do
        navbar
        Lucid.div_ [Lucid.class_ "container"] <| do
          Lucid.h1_ <| Lucid.toHtml ("Needs Intervention (" <> tshow (length tasks) <> " tasks)")
          Lucid.p_ [Lucid.class_ "info-msg"] "Tasks that have failed 3+ times and need human help."
          if null tasks
            then Lucid.p_ [Lucid.class_ "empty-msg"] "No tasks need intervention."
            else Lucid.div_ [Lucid.class_ "task-list"] <| traverse_ renderTaskCard tasks

instance Lucid.ToHtml KBPage where
  toHtmlRaw = Lucid.toHtml
  toHtml (KBPage tasks) =
    Lucid.doctypehtml_ <| do
      pageHead "Knowledge Base - Jr"
      Lucid.body_ <| do
        navbar
        Lucid.div_ [Lucid.class_ "container"] <| do
          Lucid.h1_ "Knowledge Base"
          Lucid.p_ [Lucid.class_ "info-msg"] "Epic design documents and project knowledge."
          if null tasks
            then Lucid.p_ [Lucid.class_ "empty-msg"] "No epics with designs yet."
            else Lucid.div_ [Lucid.class_ "task-list"] <| traverse_ renderEpicCard tasks
    where
      renderEpicCard :: (Monad m) => TaskCore.Task -> Lucid.HtmlT m ()
      renderEpicCard t =
        Lucid.a_
          [ Lucid.class_ "task-card task-card-link",
            Lucid.href_ ("/tasks/" <> TaskCore.taskId t)
          ]
          <| do
            Lucid.div_ [Lucid.class_ "task-header"] <| do
              Lucid.span_ [Lucid.class_ "task-id"] (Lucid.toHtml (TaskCore.taskId t))
              statusBadge (TaskCore.taskStatus t)
            Lucid.p_ [Lucid.class_ "task-title"] (Lucid.toHtml (TaskCore.taskTitle t))
            case TaskCore.taskDescription t of
              Nothing -> pure ()
              Just desc ->
                Lucid.p_ [Lucid.class_ "kb-preview"] (Lucid.toHtml (Text.take 200 desc <> "..."))

instance Lucid.ToHtml EpicsPage where
  toHtmlRaw = Lucid.toHtml
  toHtml (EpicsPage epics allTasks) =
    Lucid.doctypehtml_ <| do
      pageHead "Epics - Jr"
      Lucid.body_ <| do
        navbar
        Lucid.div_ [Lucid.class_ "container"] <| do
          Lucid.h1_ <| Lucid.toHtml ("Epics (" <> tshow (length epics) <> ")")
          Lucid.p_ [Lucid.class_ "info-msg"] "All epics (large, multi-task projects)."
          if null epics
            then Lucid.p_ [Lucid.class_ "empty-msg"] "No epics found."
            else Lucid.div_ [Lucid.class_ "task-list"] <| traverse_ (renderEpicCardWithStats allTasks) epics

renderEpicCardWithStats :: (Monad m) => [TaskCore.Task] -> TaskCore.Task -> Lucid.HtmlT m ()
renderEpicCardWithStats allTasks t =
  let children = getDescendants allTasks (TaskCore.taskId t)
      openCount = length [c | c <- children, TaskCore.taskStatus c == TaskCore.Open]
      inProgressCount = length [c | c <- children, TaskCore.taskStatus c == TaskCore.InProgress]
      reviewCount = length [c | c <- children, TaskCore.taskStatus c == TaskCore.Review]
      doneCount = length [c | c <- children, TaskCore.taskStatus c == TaskCore.Done]
      totalCount = length children
   in Lucid.a_
        [ Lucid.class_ "task-card task-card-link",
          Lucid.href_ ("/tasks/" <> TaskCore.taskId t)
        ]
        <| do
          Lucid.div_ [Lucid.class_ "task-header"] <| do
            Lucid.span_ [Lucid.class_ "task-id"] (Lucid.toHtml (TaskCore.taskId t))
            statusBadge (TaskCore.taskStatus t)
            Lucid.span_ [Lucid.class_ "priority"] (Lucid.toHtml (tshow (TaskCore.taskPriority t)))
          Lucid.p_ [Lucid.class_ "task-title"] (Lucid.toHtml (TaskCore.taskTitle t))
          when (totalCount > 0) <| do
            Lucid.div_ [Lucid.class_ "epic-status-breakdown"] <| do
              Lucid.span_ [Lucid.class_ "breakdown-label"] (Lucid.toHtml (tshow totalCount <> " tasks: "))
              when (doneCount > 0)
                <| Lucid.span_ [Lucid.class_ "badge badge-done breakdown-badge"] (Lucid.toHtml (tshow doneCount <> " done"))
              when (inProgressCount > 0)
                <| Lucid.span_ [Lucid.class_ "badge badge-inprogress breakdown-badge"] (Lucid.toHtml (tshow inProgressCount <> " in progress"))
              when (reviewCount > 0)
                <| Lucid.span_ [Lucid.class_ "badge badge-review breakdown-badge"] (Lucid.toHtml (tshow reviewCount <> " review"))
              when (openCount > 0)
                <| Lucid.span_ [Lucid.class_ "badge badge-open breakdown-badge"] (Lucid.toHtml (tshow openCount <> " open"))
          case TaskCore.taskDescription t of
            Nothing -> pure ()
            Just desc ->
              Lucid.p_ [Lucid.class_ "kb-preview"] (Lucid.toHtml (Text.take 200 desc <> "..."))

getDescendants :: [TaskCore.Task] -> Text -> [TaskCore.Task]
getDescendants allTasks parentId =
  let children = [c | c <- allTasks, maybe False (TaskCore.matchesId parentId) (TaskCore.taskParent c)]
   in children ++ concatMap (getDescendants allTasks <. TaskCore.taskId) children

instance Lucid.ToHtml TaskListPage where
  toHtmlRaw = Lucid.toHtml
  toHtml (TaskListPage tasks filters) =
    Lucid.doctypehtml_ <| do
      pageHead "Tasks - Jr"
      Lucid.body_ <| do
        navbar
        Lucid.div_ [Lucid.class_ "container"] <| do
          Lucid.h1_ <| Lucid.toHtml ("Tasks (" <> tshow (length tasks) <> ")")

          Lucid.div_ [Lucid.class_ "filter-form"] <| do
            Lucid.form_
              [ Lucid.method_ "GET",
                Lucid.action_ "/tasks",
                Lucid.makeAttribute "hx-get" "/partials/task-list",
                Lucid.makeAttribute "hx-target" "#task-list",
                Lucid.makeAttribute "hx-push-url" "/tasks",
                Lucid.makeAttribute "hx-trigger" "submit, change from:select"
              ]
              <| do
                Lucid.div_ [Lucid.class_ "filter-row"] <| do
                  Lucid.div_ [Lucid.class_ "filter-group"] <| do
                    Lucid.label_ [Lucid.for_ "status"] "Status:"
                    Lucid.select_ [Lucid.name_ "status", Lucid.id_ "status", Lucid.class_ "filter-select"] <| do
                      Lucid.option_ ([Lucid.value_ ""] <> maybeSelected Nothing (filterStatus filters)) "All"
                      statusFilterOption TaskCore.Open (filterStatus filters)
                      statusFilterOption TaskCore.InProgress (filterStatus filters)
                      statusFilterOption TaskCore.Review (filterStatus filters)
                      statusFilterOption TaskCore.Approved (filterStatus filters)
                      statusFilterOption TaskCore.Done (filterStatus filters)

                  Lucid.div_ [Lucid.class_ "filter-group"] <| do
                    Lucid.label_ [Lucid.for_ "priority"] "Priority:"
                    Lucid.select_ [Lucid.name_ "priority", Lucid.id_ "priority", Lucid.class_ "filter-select"] <| do
                      Lucid.option_ ([Lucid.value_ ""] <> maybeSelected Nothing (filterPriority filters)) "All"
                      priorityFilterOption TaskCore.P0 (filterPriority filters)
                      priorityFilterOption TaskCore.P1 (filterPriority filters)
                      priorityFilterOption TaskCore.P2 (filterPriority filters)
                      priorityFilterOption TaskCore.P3 (filterPriority filters)
                      priorityFilterOption TaskCore.P4 (filterPriority filters)

                  Lucid.div_ [Lucid.class_ "filter-group"] <| do
                    Lucid.label_ [Lucid.for_ "namespace"] "Namespace:"
                    Lucid.input_
                      [ Lucid.type_ "text",
                        Lucid.name_ "namespace",
                        Lucid.id_ "namespace",
                        Lucid.class_ "filter-input",
                        Lucid.placeholder_ "e.g. Omni/Jr",
                        Lucid.value_ (fromMaybe "" (filterNamespace filters))
                      ]

                  Lucid.button_ [Lucid.type_ "submit", Lucid.class_ "filter-btn"] "Filter"
                  Lucid.a_
                    [ Lucid.href_ "/tasks",
                      Lucid.class_ "clear-btn",
                      Lucid.makeAttribute "hx-get" "/partials/task-list",
                      Lucid.makeAttribute "hx-target" "#task-list",
                      Lucid.makeAttribute "hx-push-url" "/tasks"
                    ]
                    "Clear"

          Lucid.div_ [Lucid.id_ "task-list"] <| do
            if null tasks
              then Lucid.p_ [Lucid.class_ "empty-msg"] "No tasks match the current filters."
              else Lucid.div_ [Lucid.class_ "task-list"] <| traverse_ renderTaskCard tasks
    where
      maybeSelected :: (Eq a) => Maybe a -> Maybe a -> [Lucid.Attribute]
      maybeSelected opt current = [Lucid.selected_ "selected" | opt == current]

      statusFilterOption :: (Monad m) => TaskCore.Status -> Maybe TaskCore.Status -> Lucid.HtmlT m ()
      statusFilterOption s current =
        let attrs = [Lucid.value_ (tshow s)] <> [Lucid.selected_ "selected" | Just s == current]
         in Lucid.option_ attrs (Lucid.toHtml (tshow s))

      priorityFilterOption :: (Monad m) => TaskCore.Priority -> Maybe TaskCore.Priority -> Lucid.HtmlT m ()
      priorityFilterOption p current =
        let attrs = [Lucid.value_ (tshow p)] <> [Lucid.selected_ "selected" | Just p == current]
         in Lucid.option_ attrs (Lucid.toHtml (tshow p))

instance Lucid.ToHtml TaskDetailPage where
  toHtmlRaw = Lucid.toHtml
  toHtml (TaskDetailNotFound tid) =
    Lucid.doctypehtml_ <| do
      pageHead "Task Not Found - Jr"
      Lucid.body_ <| do
        navbar
        Lucid.div_ [Lucid.class_ "container"] <| do
          Lucid.h1_ "Task Not Found"
          Lucid.p_ <| do
            "The task "
            Lucid.code_ (Lucid.toHtml tid)
            " could not be found."
  toHtml (TaskDetailFound task allTasks activities maybeRetry commits) =
    Lucid.doctypehtml_ <| do
      pageHead (TaskCore.taskId task <> " - Jr")
      Lucid.body_ <| do
        navbar
        Lucid.div_ [Lucid.class_ "container"] <| do
          Lucid.h1_ <| Lucid.toHtml (TaskCore.taskTitle task)

          renderRetryContextBanner (TaskCore.taskId task) maybeRetry

          Lucid.div_ [Lucid.class_ "task-detail"] <| do
            Lucid.div_ [Lucid.class_ "detail-row"] <| do
              Lucid.span_ [Lucid.class_ "detail-label"] "ID:"
              Lucid.code_ [Lucid.class_ "detail-value"] (Lucid.toHtml (TaskCore.taskId task))

            Lucid.div_ [Lucid.class_ "detail-row"] <| do
              Lucid.span_ [Lucid.class_ "detail-label"] "Type:"
              Lucid.span_ [Lucid.class_ "detail-value"] (Lucid.toHtml (tshow (TaskCore.taskType task)))

            Lucid.div_ [Lucid.class_ "detail-row"] <| do
              Lucid.span_ [Lucid.class_ "detail-label"] "Status:"
              Lucid.span_ [Lucid.class_ "detail-value"] <| statusBadgeWithForm (TaskCore.taskStatus task) (TaskCore.taskId task)

            Lucid.div_ [Lucid.class_ "detail-row"] <| do
              Lucid.span_ [Lucid.class_ "detail-label"] "Priority:"
              Lucid.span_ [Lucid.class_ "detail-value"] <| do
                Lucid.toHtml (tshow (TaskCore.taskPriority task))
                Lucid.span_ [Lucid.class_ "priority-desc"] (Lucid.toHtml (priorityDesc (TaskCore.taskPriority task)))

            case TaskCore.taskNamespace task of
              Nothing -> pure ()
              Just ns ->
                Lucid.div_ [Lucid.class_ "detail-row"] <| do
                  Lucid.span_ [Lucid.class_ "detail-label"] "Namespace:"
                  Lucid.span_ [Lucid.class_ "detail-value"] (Lucid.toHtml ns)

            case TaskCore.taskParent task of
              Nothing -> pure ()
              Just pid ->
                Lucid.div_ [Lucid.class_ "detail-row"] <| do
                  Lucid.span_ [Lucid.class_ "detail-label"] "Parent:"
                  Lucid.a_ [Lucid.href_ ("/tasks/" <> pid), Lucid.class_ "detail-value task-link"] (Lucid.toHtml pid)

            Lucid.div_ [Lucid.class_ "detail-row"] <| do
              Lucid.span_ [Lucid.class_ "detail-label"] "Created:"
              Lucid.span_ [Lucid.class_ "detail-value"] (Lucid.toHtml (tshow (TaskCore.taskCreatedAt task)))

            Lucid.div_ [Lucid.class_ "detail-row"] <| do
              Lucid.span_ [Lucid.class_ "detail-label"] "Updated:"
              Lucid.span_ [Lucid.class_ "detail-value"] (Lucid.toHtml (tshow (TaskCore.taskUpdatedAt task)))

            let deps = TaskCore.taskDependencies task
            unless (null deps) <| do
              Lucid.div_ [Lucid.class_ "detail-section"] <| do
                Lucid.h3_ "Dependencies"
                Lucid.ul_ [Lucid.class_ "dep-list"] <| do
                  traverse_ renderDependency deps

            case TaskCore.taskType task of
              TaskCore.Epic -> do
                Lucid.div_ [Lucid.class_ "detail-section"] <| do
                  Lucid.h3_ "Design"
                  case TaskCore.taskDescription task of
                    Nothing -> Lucid.p_ [Lucid.class_ "empty-msg"] "No design document yet."
                    Just desc -> Lucid.div_ [Lucid.class_ "markdown-content"] (renderMarkdown desc)
                  Lucid.details_ [Lucid.class_ "edit-description"] <| do
                    Lucid.summary_ "Edit Design"
                    Lucid.form_ [Lucid.method_ "POST", Lucid.action_ ("/tasks/" <> TaskCore.taskId task <> "/description")] <| do
                      Lucid.textarea_
                        [ Lucid.name_ "description",
                          Lucid.class_ "description-textarea",
                          Lucid.rows_ "15",
                          Lucid.placeholder_ "Enter design in Markdown format..."
                        ]
                        (Lucid.toHtml (fromMaybe "" (TaskCore.taskDescription task)))
                      Lucid.div_ [Lucid.class_ "form-actions"] <| do
                        Lucid.button_ [Lucid.type_ "submit", Lucid.class_ "submit-btn"] "Save Design"
              _ ->
                case TaskCore.taskDescription task of
                  Nothing -> pure ()
                  Just desc ->
                    Lucid.div_ [Lucid.class_ "detail-section"] <| do
                      Lucid.h3_ "Description"
                      Lucid.pre_ [Lucid.class_ "description"] (Lucid.toHtml desc)

            let children = filter (maybe False (TaskCore.matchesId (TaskCore.taskId task)) <. TaskCore.taskParent) allTasks
            unless (null children) <| do
              Lucid.div_ [Lucid.class_ "detail-section"] <| do
                Lucid.h3_ "Child Tasks"
                Lucid.ul_ [Lucid.class_ "child-list"] <| do
                  traverse_ renderChild children

            unless (null commits) <| do
              Lucid.div_ [Lucid.class_ "detail-section"] <| do
                Lucid.h3_ "Git Commits"
                Lucid.div_ [Lucid.class_ "commit-list"] <| do
                  traverse_ (renderCommit (TaskCore.taskId task)) commits

          let hasRunningActivity = any (\a -> TaskCore.activityStage a == TaskCore.Running) activities
          when hasRunningActivity <| do
            let isInProgress = TaskCore.taskStatus task == TaskCore.InProgress
                htmxAttrs =
                  [ Lucid.makeAttribute "hx-get" ("/partials/task/" <> TaskCore.taskId task <> "/metrics"),
                    Lucid.makeAttribute "hx-trigger" "every 5s",
                    Lucid.makeAttribute "hx-swap" "innerHTML"
                  ]
                sectionAttrs =
                  [Lucid.class_ "execution-section", Lucid.id_ "execution-details"]
                    <> [attr | isInProgress, attr <- htmxAttrs]
            Lucid.div_ sectionAttrs <| do
              Lucid.h3_ "Execution Details"
              renderExecutionDetails (TaskCore.taskId task) activities maybeRetry

          when (TaskCore.taskStatus task == TaskCore.InProgress && not (null activities)) <| do
            Lucid.div_ [Lucid.class_ "activity-section"] <| do
              Lucid.h3_ "Activity Timeline"
              Lucid.div_ [Lucid.class_ "activity-timeline"] <| do
                traverse_ renderActivity activities

          when (TaskCore.taskStatus task == TaskCore.Review) <| do
            Lucid.div_ [Lucid.class_ "review-link-section"] <| do
              Lucid.a_
                [ Lucid.href_ ("/tasks/" <> TaskCore.taskId task <> "/review"),
                  Lucid.class_ "review-link-btn"
                ]
                "Review This Task"
    where
      priorityDesc :: TaskCore.Priority -> Text
      priorityDesc p = case p of
        TaskCore.P0 -> " (Critical)"
        TaskCore.P1 -> " (High)"
        TaskCore.P2 -> " (Medium)"
        TaskCore.P3 -> " (Low)"
        TaskCore.P4 -> " (Backlog)"

      renderDependency :: (Monad m) => TaskCore.Dependency -> Lucid.HtmlT m ()
      renderDependency dep =
        Lucid.li_ <| do
          Lucid.a_ [Lucid.href_ ("/tasks/" <> TaskCore.depId dep), Lucid.class_ "task-link"] (Lucid.toHtml (TaskCore.depId dep))
          Lucid.span_ [Lucid.class_ "dep-type"] <| Lucid.toHtml (" [" <> tshow (TaskCore.depType dep) <> "]")

      renderChild :: (Monad m) => TaskCore.Task -> Lucid.HtmlT m ()
      renderChild child =
        Lucid.li_ <| do
          Lucid.a_ [Lucid.href_ ("/tasks/" <> TaskCore.taskId child), Lucid.class_ "task-link"] (Lucid.toHtml (TaskCore.taskId child))
          Lucid.span_ [Lucid.class_ "child-title"] <| Lucid.toHtml (" - " <> TaskCore.taskTitle child)
          Lucid.span_ [Lucid.class_ "child-status"] <| Lucid.toHtml (" [" <> tshow (TaskCore.taskStatus child) <> "]")

      renderCommit :: (Monad m) => Text -> GitCommit -> Lucid.HtmlT m ()
      renderCommit tid c =
        Lucid.div_ [Lucid.class_ "commit-item"] <| do
          Lucid.div_ [Lucid.class_ "commit-header"] <| do
            Lucid.a_
              [ Lucid.href_ ("/tasks/" <> tid <> "/diff/" <> commitHash c),
                Lucid.class_ "commit-hash"
              ]
              (Lucid.toHtml (commitShortHash c))
            Lucid.span_ [Lucid.class_ "commit-summary"] (Lucid.toHtml (commitSummary c))
          Lucid.div_ [Lucid.class_ "commit-meta"] <| do
            Lucid.span_ [Lucid.class_ "commit-author"] (Lucid.toHtml (commitAuthor c))
            Lucid.span_ [Lucid.class_ "commit-date"] (Lucid.toHtml (commitRelativeDate c))
            Lucid.span_ [Lucid.class_ "commit-files"] (Lucid.toHtml (tshow (commitFilesChanged c) <> " files"))

      renderActivity :: (Monad m) => TaskCore.TaskActivity -> Lucid.HtmlT m ()
      renderActivity act =
        Lucid.div_ [Lucid.class_ ("activity-item " <> stageClass (TaskCore.activityStage act))] <| do
          Lucid.div_ [Lucid.class_ "activity-icon"] (stageIcon (TaskCore.activityStage act))
          Lucid.div_ [Lucid.class_ "activity-content"] <| do
            Lucid.div_ [Lucid.class_ "activity-header"] <| do
              Lucid.span_ [Lucid.class_ "activity-stage"] (Lucid.toHtml (tshow (TaskCore.activityStage act)))
              Lucid.span_ [Lucid.class_ "activity-time"] (Lucid.toHtml (formatTimestamp (TaskCore.activityTimestamp act)))
            case TaskCore.activityMessage act of
              Nothing -> pure ()
              Just msg -> Lucid.p_ [Lucid.class_ "activity-message"] (Lucid.toHtml msg)
            case TaskCore.activityMetadata act of
              Nothing -> pure ()
              Just meta ->
                Lucid.details_ [Lucid.class_ "activity-metadata"] <| do
                  Lucid.summary_ "Metadata"
                  Lucid.pre_ [Lucid.class_ "metadata-json"] (Lucid.toHtml meta)

      stageClass :: TaskCore.ActivityStage -> Text
      stageClass stage = case stage of
        TaskCore.Claiming -> "stage-claiming"
        TaskCore.Running -> "stage-running"
        TaskCore.Reviewing -> "stage-reviewing"
        TaskCore.Retrying -> "stage-retrying"
        TaskCore.Completed -> "stage-completed"
        TaskCore.Failed -> "stage-failed"

      stageIcon :: (Monad m) => TaskCore.ActivityStage -> Lucid.HtmlT m ()
      stageIcon stage = case stage of
        TaskCore.Claiming -> "●"
        TaskCore.Running -> "▶"
        TaskCore.Reviewing -> "◎"
        TaskCore.Retrying -> "↻"
        TaskCore.Completed -> "✓"
        TaskCore.Failed -> "✗"

      formatTimestamp :: UTCTime -> Text
      formatTimestamp = Text.pack <. formatTime defaultTimeLocale "%Y-%m-%d %H:%M:%S"

      renderExecutionDetails :: (Monad m) => Text -> [TaskCore.TaskActivity] -> Maybe TaskCore.RetryContext -> Lucid.HtmlT m ()
      renderExecutionDetails _ acts retryCtx =
        case findRunningAct acts of
          Nothing -> Lucid.p_ [Lucid.class_ "empty-msg"] "No worker execution data available."
          Just act ->
            Lucid.div_ [Lucid.class_ "execution-details"] <| do
              case TaskCore.activityAmpThreadUrl act of
                Nothing -> pure ()
                Just url ->
                  Lucid.div_ [Lucid.class_ "metric-row"] <| do
                    Lucid.span_ [Lucid.class_ "metric-label"] "Amp Thread:"
                    Lucid.a_ [Lucid.href_ url, Lucid.target_ "_blank", Lucid.class_ "amp-thread-btn"] "View in Amp ↗"

              case (TaskCore.activityStartedAt act, TaskCore.activityCompletedAt act) of
                (Just start, Just end) ->
                  Lucid.div_ [Lucid.class_ "metric-row"] <| do
                    Lucid.span_ [Lucid.class_ "metric-label"] "Duration:"
                    Lucid.span_ [Lucid.class_ "metric-value"] (Lucid.toHtml (formatDur start end))
                (Just start, Nothing) ->
                  Lucid.div_ [Lucid.class_ "metric-row"] <| do
                    Lucid.span_ [Lucid.class_ "metric-label"] "Started:"
                    Lucid.span_ [Lucid.class_ "metric-value"] (Lucid.toHtml (formatTimestamp start))
                _ -> pure ()

              case TaskCore.activityCostCents act of
                Nothing -> pure ()
                Just cents ->
                  Lucid.div_ [Lucid.class_ "metric-row"] <| do
                    Lucid.span_ [Lucid.class_ "metric-label"] "Cost:"
                    Lucid.span_ [Lucid.class_ "metric-value"] (Lucid.toHtml (formatCostVal cents))

              case retryCtx of
                Nothing -> pure ()
                Just ctx ->
                  Lucid.div_ [Lucid.class_ "metric-row"] <| do
                    Lucid.span_ [Lucid.class_ "metric-label"] "Retry Attempt:"
                    Lucid.span_ [Lucid.class_ "metric-value retry-count"] (Lucid.toHtml (tshow (TaskCore.retryAttempt ctx) <> "/3"))

              Lucid.div_ [Lucid.class_ "metric-row"] <| do
                Lucid.span_ [Lucid.class_ "metric-label"] "Last Activity:"
                Lucid.span_ [Lucid.class_ "metric-value"] (Lucid.toHtml (formatTimestamp (TaskCore.activityTimestamp act)))
        where
          findRunningAct = List.find (\a -> TaskCore.activityStage a == TaskCore.Running)

          formatDur :: UTCTime -> UTCTime -> Text
          formatDur start end =
            let diffSecs = floor (diffUTCTime end start) :: Int
                mins = diffSecs `div` 60
                secs = diffSecs `mod` 60
             in if mins > 0
                  then tshow mins <> "m " <> tshow secs <> "s"
                  else tshow secs <> "s"

          formatCostVal :: Int -> Text
          formatCostVal cents =
            let dollars = fromIntegral cents / 100.0 :: Double
             in "$" <> Text.pack (showFFloat (Just 2) dollars "")

renderRetryContextBanner :: (Monad m) => Text -> Maybe TaskCore.RetryContext -> Lucid.HtmlT m ()
renderRetryContextBanner _ Nothing = pure ()
renderRetryContextBanner tid (Just ctx) =
  Lucid.div_ [Lucid.class_ bannerClass] <| do
    Lucid.div_ [Lucid.class_ "retry-banner-header"] <| do
      Lucid.span_ [Lucid.class_ "retry-icon"] retryIcon
      Lucid.span_ [Lucid.class_ "retry-attempt"] (Lucid.toHtml attemptText)
      when maxRetriesExceeded
        <| Lucid.span_ [Lucid.class_ "retry-warning-badge"] "Needs Human Intervention"

    Lucid.div_ [Lucid.class_ "retry-banner-details"] <| do
      Lucid.div_ [Lucid.class_ "retry-detail-row"] <| do
        Lucid.span_ [Lucid.class_ "retry-label"] "Failure Reason:"
        Lucid.span_ [Lucid.class_ "retry-value"] (Lucid.toHtml (summarizeReason (TaskCore.retryReason ctx)))

      let commit = TaskCore.retryOriginalCommit ctx
      unless (Text.null commit) <| do
        Lucid.div_ [Lucid.class_ "retry-detail-row"] <| do
          Lucid.span_ [Lucid.class_ "retry-label"] "Original Commit:"
          Lucid.code_ [Lucid.class_ "retry-commit"] (Lucid.toHtml (Text.take 8 commit))

      let conflicts = TaskCore.retryConflictFiles ctx
      unless (null conflicts) <| do
        Lucid.div_ [Lucid.class_ "retry-detail-row"] <| do
          Lucid.span_ [Lucid.class_ "retry-label"] "Conflict Files:"
          Lucid.ul_ [Lucid.class_ "retry-conflict-list"]
            <| traverse_ (Lucid.li_ <. Lucid.toHtml) conflicts

    when maxRetriesExceeded <| do
      Lucid.div_
        [Lucid.class_ "retry-warning-message"]
        "This task has exceeded the maximum number of retries. A human must review the failure and either fix the issue manually or reset the retry count."

      Lucid.div_ [Lucid.class_ "retry-notes-section"] <| do
        Lucid.h4_ "Human Notes/Guidance"
        Lucid.p_ [Lucid.class_ "notes-help"] "Add notes to guide the worker on the next retry attempt:"
        Lucid.form_ [Lucid.method_ "POST", Lucid.action_ ("/tasks/" <> tid <> "/notes")] <| do
          Lucid.textarea_
            [ Lucid.name_ "notes",
              Lucid.class_ "notes-textarea",
              Lucid.rows_ "6",
              Lucid.placeholder_ "Provide guidance for the worker: what to fix, which approach to use, or what to avoid..."
            ]
            (Lucid.toHtml (fromMaybe "" (TaskCore.retryNotes ctx)))
          Lucid.div_ [Lucid.class_ "form-actions"] <| do
            Lucid.button_ [Lucid.type_ "submit", Lucid.class_ "submit-btn"] "Save Notes"

      Lucid.div_ [Lucid.class_ "retry-reset-section"] <| do
        Lucid.h4_ "Reset Retries"
        Lucid.p_ [Lucid.class_ "notes-help"] "Clear retry context and give task a fresh start:"
        Lucid.form_ [Lucid.method_ "POST", Lucid.action_ ("/tasks/" <> tid <> "/reset-retries")] <| do
          Lucid.button_ [Lucid.type_ "submit", Lucid.class_ "reset-btn"] "Reset Retries"

    case TaskCore.retryNotes ctx of
      Nothing -> pure ()
      Just notes ->
        unless maxRetriesExceeded <| do
          Lucid.div_ [Lucid.class_ "retry-notes-display"] <| do
            Lucid.h4_ "Human Notes"
            Lucid.div_ [Lucid.class_ "notes-content"] (Lucid.toHtml notes)
  where
    attempt = TaskCore.retryAttempt ctx
    maxRetriesExceeded = attempt >= 3
    bannerClass = if maxRetriesExceeded then "retry-banner retry-banner-critical" else "retry-banner retry-banner-warning"
    retryIcon = if maxRetriesExceeded then "⚠" else "↻"
    attemptText = "Attempt " <> tshow attempt <> " of 3"

    summarizeReason :: Text -> Text
    summarizeReason reason
      | "rejected:" `Text.isPrefixOf` reason = "Rejected: " <> Text.strip (Text.drop 9 reason)
      | "Test failure:" `Text.isPrefixOf` reason = "Test failure (see details below)"
      | "MERGE CONFLICT" `Text.isPrefixOf` reason = "Merge conflict with concurrent changes"
      | otherwise = Text.take 100 reason <> if Text.length reason > 100 then "..." else ""

instance Lucid.ToHtml TaskReviewPage where
  toHtmlRaw = Lucid.toHtml
  toHtml (ReviewPageNotFound tid) =
    Lucid.doctypehtml_ <| do
      pageHead "Task Not Found - Jr Review"
      Lucid.body_ <| do
        navbar
        Lucid.div_ [Lucid.class_ "container"] <| do
          Lucid.h1_ "Task Not Found"
          Lucid.p_ <| do
            "The task "
            Lucid.code_ (Lucid.toHtml tid)
            " could not be found."
  toHtml (ReviewPageFound task reviewInfo) =
    Lucid.doctypehtml_ <| do
      pageHead ("Review: " <> TaskCore.taskId task <> " - Jr")
      Lucid.body_ <| do
        navbar
        Lucid.div_ [Lucid.class_ "container"] <| do
          Lucid.h1_ "Review Task"

          Lucid.div_ [Lucid.class_ "task-summary"] <| do
            Lucid.div_ [Lucid.class_ "detail-row"] <| do
              Lucid.span_ [Lucid.class_ "detail-label"] "ID:"
              Lucid.code_ [Lucid.class_ "detail-value"] (Lucid.toHtml (TaskCore.taskId task))
            Lucid.div_ [Lucid.class_ "detail-row"] <| do
              Lucid.span_ [Lucid.class_ "detail-label"] "Title:"
              Lucid.span_ [Lucid.class_ "detail-value"] (Lucid.toHtml (TaskCore.taskTitle task))
            Lucid.div_ [Lucid.class_ "detail-row"] <| do
              Lucid.span_ [Lucid.class_ "detail-label"] "Status:"
              Lucid.span_ [Lucid.class_ "detail-value"] <| statusBadge (TaskCore.taskStatus task)

          case reviewInfo of
            ReviewNoCommit ->
              Lucid.div_ [Lucid.class_ "no-commit-msg"] <| do
                Lucid.h3_ "No Commit Found"
                Lucid.p_ "No commit with this task ID was found in the git history."
                Lucid.p_ "The worker may not have completed yet, or the commit message doesn't include the task ID."
            ReviewMergeConflict commitSha conflictFiles ->
              Lucid.div_ [Lucid.class_ "conflict-warning"] <| do
                Lucid.h3_ "Merge Conflict Detected"
                Lucid.p_ <| do
                  "Commit "
                  Lucid.code_ (Lucid.toHtml (Text.take 8 commitSha))
                  " cannot be cleanly merged."
                Lucid.p_ "Conflicting files:"
                Lucid.ul_ <| traverse_ (Lucid.li_ <. Lucid.toHtml) conflictFiles
            ReviewReady commitSha diffText -> do
              Lucid.div_ [Lucid.class_ "diff-section"] <| do
                Lucid.h3_ <| do
                  "Commit: "
                  Lucid.code_ (Lucid.toHtml (Text.take 8 commitSha))
                Lucid.pre_ [Lucid.class_ "diff-block"] (Lucid.toHtml diffText)

              Lucid.div_ [Lucid.class_ "review-actions"] <| do
                Lucid.form_
                  [ Lucid.method_ "POST",
                    Lucid.action_ ("/tasks/" <> TaskCore.taskId task <> "/accept"),
                    Lucid.class_ "inline-form"
                  ]
                  <| do
                    Lucid.button_ [Lucid.type_ "submit", Lucid.class_ "accept-btn"] "Accept"

                Lucid.form_
                  [ Lucid.method_ "POST",
                    Lucid.action_ ("/tasks/" <> TaskCore.taskId task <> "/reject"),
                    Lucid.class_ "reject-form"
                  ]
                  <| do
                    Lucid.textarea_
                      [ Lucid.name_ "notes",
                        Lucid.class_ "reject-notes",
                        Lucid.placeholder_ "Rejection notes (optional)"
                      ]
                      ""
                    Lucid.button_ [Lucid.type_ "submit", Lucid.class_ "reject-btn"] "Reject"

instance Lucid.ToHtml TaskDiffPage where
  toHtmlRaw = Lucid.toHtml
  toHtml (DiffPageNotFound tid commitHash') =
    Lucid.doctypehtml_ <| do
      pageHead "Commit Not Found - Jr"
      Lucid.body_ <| do
        navbar
        Lucid.div_ [Lucid.class_ "container"] <| do
          Lucid.h1_ "Commit Not Found"
          Lucid.p_ <| do
            "Could not find commit "
            Lucid.code_ (Lucid.toHtml commitHash')
          Lucid.a_ [Lucid.href_ ("/tasks/" <> tid), Lucid.class_ "back-link"] "← Back to task"
  toHtml (DiffPageFound tid commitHash' diffOutput) =
    Lucid.doctypehtml_ <| do
      pageHead ("Diff " <> Text.take 8 commitHash' <> " - Jr")
      Lucid.body_ <| do
        navbar
        Lucid.div_ [Lucid.class_ "container"] <| do
          Lucid.div_ [Lucid.class_ "diff-header"] <| do
            Lucid.a_ [Lucid.href_ ("/tasks/" <> tid), Lucid.class_ "back-link"] "← Back to task"
            Lucid.h1_ <| do
              "Commit "
              Lucid.code_ (Lucid.toHtml (Text.take 8 commitHash'))
          Lucid.pre_ [Lucid.class_ "diff-block"] (Lucid.toHtml diffOutput)

instance Lucid.ToHtml StatsPage where
  toHtmlRaw = Lucid.toHtml
  toHtml (StatsPage stats maybeEpic) =
    Lucid.doctypehtml_ <| do
      pageHead "Task Statistics - Jr"
      Lucid.body_ <| do
        navbar
        Lucid.div_ [Lucid.class_ "container"] <| do
          Lucid.h1_ <| case maybeEpic of
            Nothing -> "Task Statistics"
            Just epicId -> Lucid.toHtml ("Statistics for Epic: " <> epicId)

          Lucid.form_ [Lucid.method_ "GET", Lucid.action_ "/stats", Lucid.class_ "filter-form"] <| do
            Lucid.div_ [Lucid.class_ "filter-row"] <| do
              Lucid.div_ [Lucid.class_ "filter-group"] <| do
                Lucid.label_ [Lucid.for_ "epic"] "Epic:"
                Lucid.input_
                  [ Lucid.type_ "text",
                    Lucid.name_ "epic",
                    Lucid.id_ "epic",
                    Lucid.class_ "filter-input",
                    Lucid.placeholder_ "Epic ID (optional)",
                    Lucid.value_ (fromMaybe "" maybeEpic)
                  ]
              Lucid.button_ [Lucid.type_ "submit", Lucid.class_ "filter-btn"] "Filter"
              Lucid.a_ [Lucid.href_ "/stats", Lucid.class_ "clear-btn"] "Clear"

          Lucid.h2_ "By Status"
          multiColorProgressBar stats
          Lucid.div_ [Lucid.class_ "stats-grid"] <| do
            statCard "Open" (TaskCore.openTasks stats) (TaskCore.totalTasks stats)
            statCard "In Progress" (TaskCore.inProgressTasks stats) (TaskCore.totalTasks stats)
            statCard "Review" (TaskCore.reviewTasks stats) (TaskCore.totalTasks stats)
            statCard "Approved" (TaskCore.approvedTasks stats) (TaskCore.totalTasks stats)
            statCard "Done" (TaskCore.doneTasks stats) (TaskCore.totalTasks stats)

          Lucid.h2_ "By Priority"
          Lucid.div_ [Lucid.class_ "stats-section"] <| do
            traverse_ (uncurry renderPriorityRow) (TaskCore.tasksByPriority stats)

          Lucid.h2_ "By Namespace"
          Lucid.div_ [Lucid.class_ "stats-section"] <| do
            if null (TaskCore.tasksByNamespace stats)
              then Lucid.p_ [Lucid.class_ "empty-msg"] "No namespaces found."
              else traverse_ (uncurry (renderNamespaceRow (TaskCore.totalTasks stats))) (TaskCore.tasksByNamespace stats)

          Lucid.h2_ "Summary"
          Lucid.div_ [Lucid.class_ "summary-section"] <| do
            Lucid.div_ [Lucid.class_ "detail-row"] <| do
              Lucid.span_ [Lucid.class_ "detail-label"] "Total Tasks:"
              Lucid.span_ [Lucid.class_ "detail-value"] (Lucid.toHtml (tshow (TaskCore.totalTasks stats)))
            Lucid.div_ [Lucid.class_ "detail-row"] <| do
              Lucid.span_ [Lucid.class_ "detail-label"] "Epics:"
              Lucid.span_ [Lucid.class_ "detail-value"] (Lucid.toHtml (tshow (TaskCore.totalEpics stats)))
            Lucid.div_ [Lucid.class_ "detail-row"] <| do
              Lucid.span_ [Lucid.class_ "detail-label"] "Ready:"
              Lucid.span_ [Lucid.class_ "detail-value"] (Lucid.toHtml (tshow (TaskCore.readyTasks stats)))
            Lucid.div_ [Lucid.class_ "detail-row"] <| do
              Lucid.span_ [Lucid.class_ "detail-label"] "Blocked:"
              Lucid.span_ [Lucid.class_ "detail-value"] (Lucid.toHtml (tshow (TaskCore.blockedTasks stats)))
    where
      statCard :: (Monad m) => Text -> Int -> Int -> Lucid.HtmlT m ()
      statCard label count total =
        let pct = if total == 0 then 0 else (count * 100) `div` total
         in Lucid.div_ [Lucid.class_ "stat-card"] <| do
              Lucid.div_ [Lucid.class_ "stat-count"] (Lucid.toHtml (tshow count))
              Lucid.div_ [Lucid.class_ "stat-label"] (Lucid.toHtml label)
              Lucid.div_ [Lucid.class_ "progress-bar"] <| do
                Lucid.div_
                  [ Lucid.class_ "progress-fill",
                    Lucid.style_ ("width: " <> tshow pct <> "%")
                  ]
                  ""

      renderPriorityRow :: (Monad m) => TaskCore.Priority -> Int -> Lucid.HtmlT m ()
      renderPriorityRow priority count =
        let total = TaskCore.totalTasks stats
            pct = if total == 0 then 0 else (count * 100) `div` total
         in Lucid.div_ [Lucid.class_ "stats-row"] <| do
              Lucid.span_ [Lucid.class_ "stats-label"] (Lucid.toHtml (tshow priority))
              Lucid.div_ [Lucid.class_ "stats-bar-container"] <| do
                Lucid.div_ [Lucid.class_ "progress-bar"] <| do
                  Lucid.div_
                    [ Lucid.class_ "progress-fill",
                      Lucid.style_ ("width: " <> tshow pct <> "%")
                    ]
                    ""
              Lucid.span_ [Lucid.class_ "stats-count"] (Lucid.toHtml (tshow count))

      renderNamespaceRow :: (Monad m) => Int -> Text -> Int -> Lucid.HtmlT m ()
      renderNamespaceRow total ns count =
        let pct = if total == 0 then 0 else (count * 100) `div` total
         in Lucid.div_ [Lucid.class_ "stats-row"] <| do
              Lucid.span_ [Lucid.class_ "stats-label"] (Lucid.toHtml ns)
              Lucid.div_ [Lucid.class_ "stats-bar-container"] <| do
                Lucid.div_ [Lucid.class_ "progress-bar"] <| do
                  Lucid.div_
                    [ Lucid.class_ "progress-fill",
                      Lucid.style_ ("width: " <> tshow pct <> "%")
                    ]
                    ""
              Lucid.span_ [Lucid.class_ "stats-count"] (Lucid.toHtml (tshow count))

instance Lucid.ToHtml RecentActivityPartial where
  toHtmlRaw = Lucid.toHtml
  toHtml (RecentActivityPartial recentTasks) =
    if null recentTasks
      then Lucid.p_ [Lucid.class_ "empty-msg"] "No recent tasks."
      else
        Lucid.div_ [Lucid.class_ "list-group"]
          <| traverse_ renderListGroupItem recentTasks

instance Lucid.ToHtml ReadyCountPartial where
  toHtmlRaw = Lucid.toHtml
  toHtml (ReadyCountPartial count) =
    Lucid.a_ [Lucid.href_ "/ready", Lucid.class_ "ready-link"]
      <| Lucid.toHtml ("(" <> tshow count <> " tasks)")

instance Lucid.ToHtml StatusBadgePartial where
  toHtmlRaw = Lucid.toHtml
  toHtml (StatusBadgePartial status tid) =
    statusBadgeWithForm status tid

instance Lucid.ToHtml TaskListPartial where
  toHtmlRaw = Lucid.toHtml
  toHtml (TaskListPartial tasks) =
    if null tasks
      then Lucid.p_ [Lucid.class_ "empty-msg"] "No tasks match the current filters."
      else Lucid.div_ [Lucid.class_ "task-list"] <| traverse_ renderTaskCard tasks

instance Lucid.ToHtml TaskMetricsPartial where
  toHtmlRaw = Lucid.toHtml
  toHtml (TaskMetricsPartial _tid activities maybeRetry) =
    Lucid.div_ [Lucid.class_ "execution-details"] <| do
      case findRunningActivity activities of
        Nothing -> Lucid.p_ [Lucid.class_ "empty-msg"] "No worker execution data available."
        Just act -> do
          case TaskCore.activityAmpThreadUrl act of
            Nothing -> pure ()
            Just url ->
              Lucid.div_ [Lucid.class_ "metric-row"] <| do
                Lucid.span_ [Lucid.class_ "metric-label"] "Amp Thread:"
                Lucid.a_ [Lucid.href_ url, Lucid.target_ "_blank", Lucid.class_ "amp-thread-btn"] "View in Amp ↗"

          case (TaskCore.activityStartedAt act, TaskCore.activityCompletedAt act) of
            (Just start, Just end) ->
              Lucid.div_ [Lucid.class_ "metric-row"] <| do
                Lucid.span_ [Lucid.class_ "metric-label"] "Duration:"
                Lucid.span_ [Lucid.class_ "metric-value"] (Lucid.toHtml (formatDuration start end))
            (Just start, Nothing) ->
              Lucid.div_ [Lucid.class_ "metric-row"] <| do
                Lucid.span_ [Lucid.class_ "metric-label"] "Started:"
                Lucid.span_ [Lucid.class_ "metric-value"] (Lucid.toHtml (formatTimestamp start))
            _ -> pure ()

          case TaskCore.activityCostCents act of
            Nothing -> pure ()
            Just cents ->
              Lucid.div_ [Lucid.class_ "metric-row"] <| do
                Lucid.span_ [Lucid.class_ "metric-label"] "Cost:"
                Lucid.span_ [Lucid.class_ "metric-value"] (Lucid.toHtml (formatCost cents))

          case TaskCore.activityTokensUsed act of
            Nothing -> pure ()
            Just tokens ->
              Lucid.div_ [Lucid.class_ "metric-row"] <| do
                Lucid.span_ [Lucid.class_ "metric-label"] "Tokens:"
                Lucid.span_ [Lucid.class_ "metric-value"] (Lucid.toHtml (tshow tokens))

          case maybeRetry of
            Nothing -> pure ()
            Just ctx ->
              Lucid.div_ [Lucid.class_ "metric-row"] <| do
                Lucid.span_ [Lucid.class_ "metric-label"] "Retry Attempt:"
                Lucid.span_ [Lucid.class_ "metric-value retry-count"] (Lucid.toHtml (tshow (TaskCore.retryAttempt ctx) <> "/3"))

          Lucid.div_ [Lucid.class_ "metric-row"] <| do
            Lucid.span_ [Lucid.class_ "metric-label"] "Last Activity:"
            Lucid.span_ [Lucid.class_ "metric-value"] (Lucid.toHtml (formatTimestamp (TaskCore.activityTimestamp act)))
    where
      findRunningActivity = List.find (\a -> TaskCore.activityStage a == TaskCore.Running)

      formatTimestamp :: UTCTime -> Text
      formatTimestamp = Text.pack <. formatTime defaultTimeLocale "%Y-%m-%d %H:%M:%S"

      formatDuration :: UTCTime -> UTCTime -> Text
      formatDuration start end =
        let diffSecs = floor (diffUTCTime end start) :: Int
            mins = diffSecs `div` 60
            secs = diffSecs `mod` 60
         in if mins > 0
              then tshow mins <> "m " <> tshow secs <> "s"
              else tshow secs <> "s"

      formatCost :: Int -> Text
      formatCost cents =
        let dollars = fromIntegral cents / 100.0 :: Double
         in "$" <> Text.pack (showFFloat (Just 2) dollars "")

-- | Simple markdown renderer for epic descriptions
-- Supports: headers (#, ##, ###), lists (- or *), code blocks (```), inline code (`)
renderMarkdown :: (Monad m) => Text -> Lucid.HtmlT m ()
renderMarkdown input = renderBlocks (parseBlocks (Text.lines input))

data MarkdownBlock
  = MdHeader Int Text
  | MdParagraph [Text]
  | MdCodeBlock [Text]
  | MdList [Text]
  deriving (Show, Eq)

parseBlocks :: [Text] -> [MarkdownBlock]
parseBlocks [] = []
parseBlocks lns = case lns of
  (l : rest)
    | "```" `Text.isPrefixOf` l ->
        let (codeLines, afterCode) = List.span (not <. Text.isPrefixOf "```") rest
            remaining = List.drop 1 afterCode
         in MdCodeBlock codeLines : parseBlocks remaining
    | "### " `Text.isPrefixOf` l ->
        MdHeader 3 (Text.drop 4 l) : parseBlocks rest
    | "## " `Text.isPrefixOf` l ->
        MdHeader 2 (Text.drop 3 l) : parseBlocks rest
    | "# " `Text.isPrefixOf` l ->
        MdHeader 1 (Text.drop 2 l) : parseBlocks rest
    | isListItem l ->
        let (listLines, afterList) = List.span isListItem lns
         in MdList (map stripListPrefix listLines) : parseBlocks afterList
    | Text.null (Text.strip l) ->
        parseBlocks rest
    | otherwise ->
        let (paraLines, afterPara) = List.span isParagraphLine lns
         in MdParagraph paraLines : parseBlocks afterPara
  where
    isListItem t =
      let stripped = Text.stripStart t
       in "- " `Text.isPrefixOf` stripped || "* " `Text.isPrefixOf` stripped
    stripListPrefix t =
      let stripped = Text.stripStart t
       in Text.drop 2 stripped
    isParagraphLine t =
      not (Text.null (Text.strip t))
        && not ("```" `Text.isPrefixOf` t)
        && not ("#" `Text.isPrefixOf` t)
        && not (isListItem t)

renderBlocks :: (Monad m) => [MarkdownBlock] -> Lucid.HtmlT m ()
renderBlocks = traverse_ renderBlock

renderBlock :: (Monad m) => MarkdownBlock -> Lucid.HtmlT m ()
renderBlock block = case block of
  MdHeader 1 txt -> Lucid.h2_ [Lucid.class_ "md-h1"] (renderInline txt)
  MdHeader 2 txt -> Lucid.h3_ [Lucid.class_ "md-h2"] (renderInline txt)
  MdHeader 3 txt -> Lucid.h4_ [Lucid.class_ "md-h3"] (renderInline txt)
  MdHeader _ txt -> Lucid.h4_ (renderInline txt)
  MdParagraph lns -> Lucid.p_ [Lucid.class_ "md-para"] (renderInline (Text.unlines lns))
  MdCodeBlock lns -> Lucid.pre_ [Lucid.class_ "md-code"] (Lucid.code_ (Lucid.toHtml (Text.unlines lns)))
  MdList items -> Lucid.ul_ [Lucid.class_ "md-list"] (traverse_ renderListItem items)

renderListItem :: (Monad m) => Text -> Lucid.HtmlT m ()
renderListItem txt = Lucid.li_ (renderInline txt)

-- | Render inline markdown (backtick code, bold, italic)
renderInline :: (Monad m) => Text -> Lucid.HtmlT m ()
renderInline txt = renderInlineParts (parseInline txt)

data InlinePart = PlainText Text | InlineCode Text | BoldText Text
  deriving (Show, Eq)

parseInline :: Text -> [InlinePart]
parseInline t
  | Text.null t = []
  | otherwise = case Text.breakOn "`" t of
      (before, rest)
        | Text.null rest -> parseBold before
        | otherwise ->
            let afterTick = Text.drop 1 rest
             in case Text.breakOn "`" afterTick of
                  (code, rest2)
                    | Text.null rest2 ->
                        parseBold before ++ [PlainText ("`" <> afterTick)]
                    | otherwise ->
                        parseBold before ++ [InlineCode code] ++ parseInline (Text.drop 1 rest2)

parseBold :: Text -> [InlinePart]
parseBold t
  | Text.null t = []
  | otherwise = case Text.breakOn "**" t of
      (before, rest)
        | Text.null rest -> [PlainText before | not (Text.null before)]
        | otherwise ->
            let afterBold = Text.drop 2 rest
             in case Text.breakOn "**" afterBold of
                  (boldText, rest2)
                    | Text.null rest2 ->
                        [PlainText before | not (Text.null before)] ++ [PlainText ("**" <> afterBold)]
                    | otherwise ->
                        [PlainText before | not (Text.null before)]
                          ++ [BoldText boldText]
                          ++ parseBold (Text.drop 2 rest2)

renderInlineParts :: (Monad m) => [InlinePart] -> Lucid.HtmlT m ()
renderInlineParts = traverse_ renderInlinePart

renderInlinePart :: (Monad m) => InlinePart -> Lucid.HtmlT m ()
renderInlinePart part = case part of
  PlainText txt -> Lucid.toHtml txt
  InlineCode txt -> Lucid.code_ [Lucid.class_ "md-inline-code"] (Lucid.toHtml txt)
  BoldText txt -> Lucid.strong_ (Lucid.toHtml txt)

api :: Proxy API
api = Proxy

server :: Server API
server =
  homeHandler
    :<|> styleHandler
    :<|> readyQueueHandler
    :<|> blockedHandler
    :<|> interventionHandler
    :<|> statsHandler
    :<|> taskListHandler
    :<|> kbHandler
    :<|> epicsHandler
    :<|> taskDetailHandler
    :<|> taskStatusHandler
    :<|> taskDescriptionHandler
    :<|> taskNotesHandler
    :<|> taskReviewHandler
    :<|> taskDiffHandler
    :<|> taskAcceptHandler
    :<|> taskRejectHandler
    :<|> taskResetRetriesHandler
    :<|> recentActivityHandler
    :<|> readyCountHandler
    :<|> taskListPartialHandler
    :<|> taskMetricsPartialHandler
  where
    styleHandler :: Servant.Handler LazyText.Text
    styleHandler = pure Style.css

    homeHandler :: Servant.Handler HomePage
    homeHandler = do
      stats <- liftIO <| TaskCore.getTaskStats Nothing
      readyTasks <- liftIO TaskCore.getReadyTasks
      allTasks <- liftIO TaskCore.loadTasks
      let recentTasks = take 5 <| List.sortBy (flip compare `on` TaskCore.taskUpdatedAt) allTasks
      pure (HomePage stats readyTasks recentTasks)

    readyQueueHandler :: Servant.Handler ReadyQueuePage
    readyQueueHandler = do
      readyTasks <- liftIO TaskCore.getReadyTasks
      let sortedTasks = List.sortBy (compare `on` TaskCore.taskPriority) readyTasks
      pure (ReadyQueuePage sortedTasks)

    blockedHandler :: Servant.Handler BlockedPage
    blockedHandler = do
      blockedTasks <- liftIO TaskCore.getBlockedTasks
      let sortedTasks = List.sortBy (compare `on` TaskCore.taskPriority) blockedTasks
      pure (BlockedPage sortedTasks)

    interventionHandler :: Servant.Handler InterventionPage
    interventionHandler = do
      interventionTasks <- liftIO TaskCore.getInterventionTasks
      let sortedTasks = List.sortBy (compare `on` TaskCore.taskPriority) interventionTasks
      pure (InterventionPage sortedTasks)

    statsHandler :: Maybe Text -> Servant.Handler StatsPage
    statsHandler maybeEpic = do
      let epicId = emptyToNothing maybeEpic
      stats <- liftIO <| TaskCore.getTaskStats epicId
      pure (StatsPage stats epicId)

    taskListHandler :: Maybe Text -> Maybe Text -> Maybe Text -> Maybe Text -> Servant.Handler TaskListPage
    taskListHandler maybeStatusText maybePriorityText maybeNamespace maybeTypeText = do
      allTasks <- liftIO TaskCore.loadTasks
      let maybeStatus = parseStatus =<< emptyToNothing maybeStatusText
          maybePriority = parsePriority =<< emptyToNothing maybePriorityText
          maybeType = parseTaskType =<< emptyToNothing maybeTypeText
          filters = TaskFilters maybeStatus maybePriority (emptyToNothing maybeNamespace) maybeType
          filteredTasks = applyFilters filters allTasks
      pure (TaskListPage filteredTasks filters)

    kbHandler :: Servant.Handler KBPage
    kbHandler = do
      allTasks <- liftIO TaskCore.loadTasks
      let epicTasks = filter (\t -> TaskCore.taskType t == TaskCore.Epic) allTasks
      pure (KBPage epicTasks)

    epicsHandler :: Servant.Handler EpicsPage
    epicsHandler = do
      allTasks <- liftIO TaskCore.loadTasks
      let epicTasks = filter (\t -> TaskCore.taskType t == TaskCore.Epic) allTasks
          sortedEpics = List.sortBy (compare `on` TaskCore.taskPriority) epicTasks
      pure (EpicsPage sortedEpics allTasks)

    parseStatus :: Text -> Maybe TaskCore.Status
    parseStatus = readMaybe <. Text.unpack

    parsePriority :: Text -> Maybe TaskCore.Priority
    parsePriority = readMaybe <. Text.unpack

    parseTaskType :: Text -> Maybe TaskCore.TaskType
    parseTaskType = readMaybe <. Text.unpack

    emptyToNothing :: Maybe Text -> Maybe Text
    emptyToNothing (Just t) | Text.null (Text.strip t) = Nothing
    emptyToNothing x = x

    applyFilters :: TaskFilters -> [TaskCore.Task] -> [TaskCore.Task]
    applyFilters filters = filter matchesAllFilters
      where
        matchesAllFilters task =
          matchesStatus task
            && matchesPriority task
            && matchesNamespace task
            && matchesType task

        matchesStatus task = case filterStatus filters of
          Nothing -> True
          Just s -> TaskCore.taskStatus task == s

        matchesPriority task = case filterPriority filters of
          Nothing -> True
          Just p -> TaskCore.taskPriority task == p

        matchesNamespace task = case filterNamespace filters of
          Nothing -> True
          Just ns -> case TaskCore.taskNamespace task of
            Nothing -> False
            Just taskNs -> ns `Text.isPrefixOf` taskNs

        matchesType task = case filterType filters of
          Nothing -> True
          Just t -> TaskCore.taskType task == t

    taskDetailHandler :: Text -> Servant.Handler TaskDetailPage
    taskDetailHandler tid = do
      tasks <- liftIO TaskCore.loadTasks
      case TaskCore.findTask tid tasks of
        Nothing -> pure (TaskDetailNotFound tid)
        Just task -> do
          activities <- liftIO (TaskCore.getActivitiesForTask tid)
          retryCtx <- liftIO (TaskCore.getRetryContext tid)
          commits <- liftIO (getCommitsForTask tid)
          pure (TaskDetailFound task tasks activities retryCtx commits)

    taskStatusHandler :: Text -> StatusForm -> Servant.Handler StatusBadgePartial
    taskStatusHandler tid (StatusForm newStatus) = do
      liftIO <| TaskCore.updateTaskStatus tid newStatus []
      pure (StatusBadgePartial newStatus tid)

    taskDescriptionHandler :: Text -> DescriptionForm -> Servant.Handler (Headers '[Header "Location" Text] NoContent)
    taskDescriptionHandler tid (DescriptionForm desc) = do
      let descMaybe = if Text.null (Text.strip desc) then Nothing else Just desc
      _ <- liftIO <| TaskCore.editTask tid (\t -> t {TaskCore.taskDescription = descMaybe})
      pure <| addHeader ("/tasks/" <> tid) NoContent

    taskNotesHandler :: Text -> NotesForm -> Servant.Handler (Headers '[Header "Location" Text] NoContent)
    taskNotesHandler tid (NotesForm notes) = do
      liftIO <| TaskCore.updateRetryNotes tid notes
      pure <| addHeader ("/tasks/" <> tid) NoContent

    taskReviewHandler :: Text -> Servant.Handler TaskReviewPage
    taskReviewHandler tid = do
      tasks <- liftIO TaskCore.loadTasks
      case TaskCore.findTask tid tasks of
        Nothing -> pure (ReviewPageNotFound tid)
        Just task -> do
          reviewInfo <- liftIO <| getReviewInfo tid
          pure (ReviewPageFound task reviewInfo)

    taskDiffHandler :: Text -> Text -> Servant.Handler TaskDiffPage
    taskDiffHandler tid commitSha = do
      diffOutput <- liftIO <| getDiffForCommit commitSha
      case diffOutput of
        Nothing -> pure (DiffPageNotFound tid commitSha)
        Just output -> pure (DiffPageFound tid commitSha output)

    taskAcceptHandler :: Text -> Servant.Handler (Headers '[Header "Location" Text] NoContent)
    taskAcceptHandler tid = do
      liftIO <| do
        TaskCore.clearRetryContext tid
        TaskCore.updateTaskStatus tid TaskCore.Done []
      pure <| addHeader ("/tasks/" <> tid) NoContent

    taskRejectHandler :: Text -> RejectForm -> Servant.Handler (Headers '[Header "Location" Text] NoContent)
    taskRejectHandler tid (RejectForm maybeNotes) = do
      liftIO <| do
        maybeCommit <- findCommitForTask tid
        let commitSha = fromMaybe "" maybeCommit
        maybeCtx <- TaskCore.getRetryContext tid
        let attempt = maybe 1 (\ctx -> TaskCore.retryAttempt ctx + 1) maybeCtx
        let reason = "rejected: " <> fromMaybe "(no notes)" maybeNotes
        TaskCore.setRetryContext
          TaskCore.RetryContext
            { TaskCore.retryTaskId = tid,
              TaskCore.retryOriginalCommit = commitSha,
              TaskCore.retryConflictFiles = [],
              TaskCore.retryAttempt = attempt,
              TaskCore.retryReason = reason,
              TaskCore.retryNotes = maybeCtx +> TaskCore.retryNotes
            }
        TaskCore.updateTaskStatus tid TaskCore.Open []
      pure <| addHeader ("/tasks/" <> tid) NoContent

    taskResetRetriesHandler :: Text -> Servant.Handler (Headers '[Header "Location" Text] NoContent)
    taskResetRetriesHandler tid = do
      liftIO <| do
        TaskCore.clearRetryContext tid
        TaskCore.updateTaskStatus tid TaskCore.Open []
      pure <| addHeader ("/tasks/" <> tid) NoContent

    recentActivityHandler :: Servant.Handler RecentActivityPartial
    recentActivityHandler = do
      allTasks <- liftIO TaskCore.loadTasks
      let recentTasks = take 5 <| List.sortBy (flip compare `on` TaskCore.taskUpdatedAt) allTasks
      pure (RecentActivityPartial recentTasks)

    readyCountHandler :: Servant.Handler ReadyCountPartial
    readyCountHandler = do
      readyTasks <- liftIO TaskCore.getReadyTasks
      pure (ReadyCountPartial (length readyTasks))

    taskListPartialHandler :: Maybe Text -> Maybe Text -> Maybe Text -> Maybe Text -> Servant.Handler TaskListPartial
    taskListPartialHandler maybeStatusText maybePriorityText maybeNamespace maybeTypeText = do
      allTasks <- liftIO TaskCore.loadTasks
      let maybeStatus = parseStatus =<< emptyToNothing maybeStatusText
          maybePriority = parsePriority =<< emptyToNothing maybePriorityText
          maybeType = parseTaskType =<< emptyToNothing maybeTypeText
          filters = TaskFilters maybeStatus maybePriority (emptyToNothing maybeNamespace) maybeType
          filteredTasks = applyFilters filters allTasks
      pure (TaskListPartial filteredTasks)

    taskMetricsPartialHandler :: Text -> Servant.Handler TaskMetricsPartial
    taskMetricsPartialHandler tid = do
      activities <- liftIO (TaskCore.getActivitiesForTask tid)
      maybeRetry <- liftIO (TaskCore.getRetryContext tid)
      pure (TaskMetricsPartial tid activities maybeRetry)

getReviewInfo :: Text -> IO ReviewInfo
getReviewInfo tid = do
  maybeCommit <- findCommitForTask tid
  case maybeCommit of
    Nothing -> pure ReviewNoCommit
    Just commitSha -> do
      conflictResult <- checkMergeConflict (Text.unpack commitSha)
      case conflictResult of
        Just conflictFiles -> pure (ReviewMergeConflict commitSha conflictFiles)
        Nothing -> do
          (_, diffOut, _) <-
            Process.readProcessWithExitCode
              "git"
              ["show", Text.unpack commitSha]
              ""
          pure (ReviewReady commitSha (Text.pack diffOut))

getDiffForCommit :: Text -> IO (Maybe Text)
getDiffForCommit commitSha = do
  (code, diffOut, _) <-
    Process.readProcessWithExitCode
      "git"
      ["show", Text.unpack commitSha]
      ""
  case code of
    Exit.ExitSuccess -> pure (Just (Text.pack diffOut))
    Exit.ExitFailure _ -> pure Nothing

findCommitForTask :: Text -> IO (Maybe Text)
findCommitForTask tid = do
  let grepArg = "--grep=" <> Text.unpack tid
  (code, shaOut, _) <-
    Process.readProcessWithExitCode
      "git"
      ["log", "--pretty=format:%H", "-n", "1", grepArg]
      ""
  if code /= Exit.ExitSuccess || null shaOut
    then pure Nothing
    else case List.lines shaOut of
      (x : _) -> pure (Just (Text.pack x))
      [] -> pure Nothing

getCommitsForTask :: Text -> IO [GitCommit]
getCommitsForTask tid = do
  let grepArg = "--grep=Task-Id: " <> Text.unpack tid
  (code, out, _) <-
    Process.readProcessWithExitCode
      "git"
      ["log", "--pretty=format:%H|%h|%s|%an|%ar", grepArg]
      ""
  if code /= Exit.ExitSuccess || null out
    then pure []
    else do
      let commitLines = filter (not <. null) (List.lines out)
      traverse parseCommitLine commitLines
  where
    parseCommitLine :: String -> IO GitCommit
    parseCommitLine line =
      case Text.splitOn "|" (Text.pack line) of
        [sha, shortSha, summary, author, relDate] -> do
          filesCount <- getFilesChangedCount (Text.unpack sha)
          pure
            GitCommit
              { commitHash = sha,
                commitShortHash = shortSha,
                commitSummary = summary,
                commitAuthor = author,
                commitRelativeDate = relDate,
                commitFilesChanged = filesCount
              }
        _ ->
          pure
            GitCommit
              { commitHash = Text.pack line,
                commitShortHash = Text.take 7 (Text.pack line),
                commitSummary = "(parse error)",
                commitAuthor = "",
                commitRelativeDate = "",
                commitFilesChanged = 0
              }

    getFilesChangedCount :: String -> IO Int
    getFilesChangedCount sha = do
      (code', out', _) <-
        Process.readProcessWithExitCode
          "git"
          ["show", "--stat", "--format=", sha]
          ""
      pure
        <| if code' /= Exit.ExitSuccess
          then 0
          else
            let statLines = filter (not <. null) (List.lines out')
             in max 0 (length statLines - 1)

checkMergeConflict :: String -> IO (Maybe [Text])
checkMergeConflict commitSha = do
  (_, origHead, _) <- Process.readProcessWithExitCode "git" ["rev-parse", "HEAD"] ""

  (cpCode, _, cpErr) <-
    Process.readProcessWithExitCode
      "git"
      ["cherry-pick", "--no-commit", commitSha]
      ""

  _ <- Process.readProcessWithExitCode "git" ["cherry-pick", "--abort"] ""
  _ <- Process.readProcessWithExitCode "git" ["reset", "--hard", List.head (List.lines origHead)] ""

  case cpCode of
    Exit.ExitSuccess -> pure Nothing
    Exit.ExitFailure _ -> do
      let errLines = Text.lines (Text.pack cpErr)
          conflictLines = filter (Text.isPrefixOf "CONFLICT") errLines
          files = mapMaybe extractConflictFile conflictLines
      pure (Just (if null files then ["(unknown files)"] else files))

extractConflictFile :: Text -> Maybe Text
extractConflictFile line =
  case Text.breakOn "Merge conflict in " line of
    (_, rest)
      | not (Text.null rest) -> Just (Text.strip (Text.drop 18 rest))
    _ -> case Text.breakOn "in " line of
      (_, rest)
        | not (Text.null rest) -> Just (Text.strip (Text.drop 3 rest))
      _ -> Nothing

app :: Application
app = serve api server

run :: Warp.Port -> IO ()
run port = do
  TaskCore.initTaskDb
  putText <| "Starting Jr web server on port " <> tshow port
  Warp.run port app