{-# 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)
import System.Environment (setEnv)

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>] [--status=<status>] [--namespace=<ns>]
  task ready
  task update <id> <status>
  task deps <id>
  task tree [<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
  tree                          Show task tree (epics with children, or all epics if no ID given)
  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
  --status=<status>             Filter by status: open, in-progress, done
  --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)
      maybeStatus <- case Cli.getArg args (Cli.longOption "status") of
        Nothing -> pure Nothing
        Just "open" -> pure <| Just Open
        Just "in-progress" -> pure <| Just InProgress
        Just "done" -> pure <| Just Done
        Just other -> panic <| "Invalid status: " <> T.pack other <> ". Use: open, in-progress, or done"
      maybeNamespace <- case Cli.getArg args (Cli.longOption "namespace") of
        Nothing -> pure Nothing
        Just ns -> do
          let validNs = Namespace.fromHaskellModule ns
              nsPath = T.pack <| Namespace.toPath validNs
          pure <| Just nsPath
      tasks <- listTasks maybeType maybeParent maybeStatus maybeNamespace
      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
      -- Remind user to commit changes (pre-commit hook will auto-export)
      putText "Note: Task changes will be committed automatically on your next git commit."
  | args `Cli.has` Cli.command "deps" = do
      tid <- getArgText args "id"
      showDependencyTree tid
  | args `Cli.has` Cli.command "tree" = do
      maybeId <- case Cli.getArg args (Cli.argument "id") of
        Nothing -> pure Nothing
        Just idStr -> pure <| Just (T.pack idStr)
      showTaskTree maybeId
  | 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 "setup test database" <| do
        -- Set up test mode for all tests
        setEnv "TASK_TEST_MODE" "1"

        -- Clean up test database before all tests
        let testFile = ".tasks/tasks-test.jsonl"
        exists <- doesFileExist testFile
        when exists <| removeFile testFile
        initTaskDb
        True Test.@?= True,
      Test.unit "can create task" <| do
        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
        _ <- createTask "Test task for list" WorkTask Nothing Nothing []
        tasks <- listTasks Nothing Nothing 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
    ]