{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE QuasiQuotes #-}
{-# LANGUAGE RecordWildCards #-}
{-# LANGUAGE NoImplicitPrelude #-}

-- : out task
module Omni.Task where

import Alpha
import qualified Data.Text as T
import qualified Omni.Cli as Cli
import qualified Omni.Namespace as Namespace
import Omni.Task.Core
import qualified Omni.Test as Test
import System.Directory (doesFileExist, removeFile)

main :: IO ()
main = Cli.main plan

plan :: Cli.Plan ()
plan =
  Cli.Plan
    { help = help,
      move = move,
      test = test,
      tidy = \_ -> pure ()
    }

help :: Cli.Docopt
help =
  [Cli.docopt|
task

Usage:
  task init
  task create <title> [--type=<type>] [--parent=<id>] [--deps=<ids>] [--dep-type=<type>] [--discovered-from=<id>] [--namespace=<ns>]
  task list [--type=<type>] [--parent=<id>]
  task ready
  task update <id> <status>
  task deps <id>
  task export [--flush]
  task import -i <file>
  task test
  task (-h | --help)

Commands:
  init                          Initialize task database
  create                        Create a new task or epic
  list                          List all tasks
  ready                         Show ready tasks (not blocked)
  update                        Update task status
  deps                          Show dependency tree
  export                        Export and consolidate tasks to JSONL
  import                        Import tasks from JSONL file
  test                          Run tests

Options:
  -h --help                     Show this help
  --type=<type>                 Task type: epic or task (default: task)
  --parent=<id>                 Parent epic ID
  --deps=<ids>                  Comma-separated list of dependency IDs
  --dep-type=<type>             Dependency type: blocks, discovered-from, parent-child, related (default: blocks)
  --discovered-from=<id>        Shortcut for --deps=<id> --dep-type=discovered-from
  --namespace=<ns>              Optional namespace (e.g., Omni/Task, Biz/Cloud)
  --flush                       Force immediate export
  -i <file>                     Input file for import

Arguments:
  <title>                       Task title
  <id>                          Task ID
  <status>                      Task status (open, in-progress, done)
  <file>                        JSONL file to import
|]

move :: Cli.Arguments -> IO ()
move args
  | args `Cli.has` Cli.command "init" = initTaskDb
  | args `Cli.has` Cli.command "create" = do
      title <- getArgText args "title"
      taskType <- case Cli.getArg args (Cli.longOption "type") of
        Nothing -> pure WorkTask
        Just "epic" -> pure Epic
        Just "task" -> pure WorkTask
        Just other -> panic <| "Invalid task type: " <> T.pack other <> ". Use: epic or task"
      parent <- case Cli.getArg args (Cli.longOption "parent") of
        Nothing -> pure Nothing
        Just p -> pure <| Just (T.pack p)

      -- Handle --discovered-from as shortcut
      (depIds, depType) <- case Cli.getArg args (Cli.longOption "discovered-from") of
        Just discoveredId -> pure ([T.pack discoveredId], DiscoveredFrom)
        Nothing -> do
          -- Parse regular --deps and --dep-type
          ids <- case Cli.getArg args (Cli.longOption "deps") of
            Nothing -> pure []
            Just depStr -> pure <| T.splitOn "," (T.pack depStr)
          dtype <- case Cli.getArg args (Cli.longOption "dep-type") of
            Nothing -> pure Blocks
            Just "blocks" -> pure Blocks
            Just "discovered-from" -> pure DiscoveredFrom
            Just "parent-child" -> pure ParentChild
            Just "related" -> pure Related
            Just other -> panic <| "Invalid dependency type: " <> T.pack other <> ". Use: blocks, discovered-from, parent-child, or related"
          pure (ids, dtype)

      let deps = map (\did -> Dependency {depId = did, depType = depType}) depIds

      namespace <- case Cli.getArg args (Cli.longOption "namespace") of
        Nothing -> pure Nothing
        Just ns -> do
          -- Validate it's a proper namespace by parsing it
          let validNs = Namespace.fromHaskellModule ns
              nsPath = T.pack <| Namespace.toPath validNs
          pure <| Just nsPath
      createdTask <- createTask title taskType parent namespace deps
      putStrLn <| "Created task: " <> T.unpack (taskId createdTask)
  | args `Cli.has` Cli.command "list" = do
      maybeType <- case Cli.getArg args (Cli.longOption "type") of
        Nothing -> pure Nothing
        Just "epic" -> pure <| Just Epic
        Just "task" -> pure <| Just WorkTask
        Just other -> panic <| "Invalid task type: " <> T.pack other
      maybeParent <- case Cli.getArg args (Cli.longOption "parent") of
        Nothing -> pure Nothing
        Just p -> pure <| Just (T.pack p)
      tasks <- listTasks maybeType maybeParent
      traverse_ printTask tasks
  | args `Cli.has` Cli.command "ready" = do
      tasks <- getReadyTasks
      putText "Ready tasks:"
      traverse_ printTask tasks
  | args `Cli.has` Cli.command "update" = do
      tid <- getArgText args "id"
      statusStr <- getArgText args "status"
      let newStatus = case statusStr of
            "open" -> Open
            "in-progress" -> InProgress
            "done" -> Done
            _ -> panic "Invalid status. Use: open, in-progress, or done"
      updateTaskStatus tid newStatus
      putStrLn <| "Updated task " <> T.unpack tid
  | args `Cli.has` Cli.command "deps" = do
      tid <- getArgText args "id"
      showDependencyTree tid
  | args `Cli.has` Cli.command "export" = do
      exportTasks
      putText "Exported and consolidated tasks to .tasks/tasks.jsonl"
  | args `Cli.has` Cli.command "import" = do
      file <- getArgText args "file"
      importTasks (T.unpack file)
      putText <| "Imported tasks from " <> file
  | otherwise = putText (T.pack <| Cli.usage help)
  where
    getArgText :: Cli.Arguments -> String -> IO Text
    getArgText argz name = do
      maybeArg <- pure <| Cli.getArg argz (Cli.argument name)
      case maybeArg of
        Nothing -> panic (T.pack name <> " required")
        Just val -> pure (T.pack val)

test :: Test.Tree
test = Test.group "Omni.Task" [unitTests]

unitTests :: Test.Tree
unitTests =
  Test.group
    "Unit tests"
    [ Test.unit "can create task" <| do
        -- Clean up before test
        exists <- doesFileExist ".tasks/tasks.jsonl"
        when exists <| removeFile ".tasks/tasks.jsonl"

        initTaskDb
        task <- createTask "Test task" WorkTask Nothing Nothing []
        taskTitle task Test.@?= "Test task"
        taskType task Test.@?= WorkTask
        taskStatus task Test.@?= Open
        null (taskDependencies task) Test.@?= True,
      Test.unit "can list tasks" <| do
        tasks <- listTasks Nothing Nothing
        not (null tasks) Test.@?= True,
      Test.unit "ready tasks exclude blocked ones" <| do
        task1 <- createTask "First task" WorkTask Nothing Nothing []
        let blockingDep = Dependency {depId = taskId task1, depType = Blocks}
        task2 <- createTask "Blocked task" WorkTask Nothing Nothing [blockingDep]
        ready <- getReadyTasks
        (taskId task1 `elem` map taskId ready) Test.@?= True
        (taskId task2 `notElem` map taskId ready) Test.@?= True,
      Test.unit "discovered-from dependencies don't block" <| do
        task1 <- createTask "Original task" WorkTask Nothing Nothing []
        let discDep = Dependency {depId = taskId task1, depType = DiscoveredFrom}
        task2 <- createTask "Discovered work" WorkTask Nothing Nothing [discDep]
        ready <- getReadyTasks
        -- Both should be ready since DiscoveredFrom doesn't block
        (taskId task1 `elem` map taskId ready) Test.@?= True
        (taskId task2 `elem` map taskId ready) Test.@?= True,
      Test.unit "related dependencies don't block" <| do
        task1 <- createTask "Task A" WorkTask Nothing Nothing []
        let relDep = Dependency {depId = taskId task1, depType = Related}
        task2 <- createTask "Task B" WorkTask Nothing Nothing [relDep]
        ready <- getReadyTasks
        -- Both should be ready since Related doesn't block
        (taskId task1 `elem` map taskId ready) Test.@?= True
        (taskId task2 `elem` map taskId ready) Test.@?= True
    ]