CheckoutSync.hs

module Seihou.CLI.CheckoutSync
  ( CheckoutSyncResult (..),
    runCheckoutSync,
    checkoutReportJSON,
    renderCheckoutPlan,
    renderCheckoutStatus,
    checkoutFailureJSON,
  )
where

import Control.Exception (IOException, displayException, try)
import Data.Aeson qualified as A
import Data.ByteString.Lazy qualified as LBS
import Data.Generics.Labels ()
import Data.Map.Strict qualified as Map
import Data.Text qualified as T
import Data.Text.Encoding qualified as TE
import Seihou.Core.Checkout
import Seihou.Core.Types
import Seihou.Effect.Filesystem hiding (CreateDirectoryLink)
import Seihou.Effect.FilesystemInterp (runFilesystem)
import Seihou.Effect.ProcessInterp (runProcessIO)
import Seihou.Engine.Checkout
import Seihou.Manifest.Types (manifestFromJSON)
import Seihou.Prelude

-- | Planning and execution remain separate so dry-run never reports writes.
data CheckoutSyncResult = CheckoutSyncResult
  { root :: !FilePath,
    dryRun :: !Bool,
    plan :: !CheckoutPlan,
    execution :: !CheckoutExecution,
    notices :: ![Text]
  }
  deriving stock (Eq, Show, Generic)

runCheckoutSync :: Bool -> IO (Either CheckoutError CheckoutSyncResult)
runCheckoutSync dryRun = do
  result <- try @IOException $ runEff $ runFilesystem $ runProcessIO $ do
    root <- normalizePath =<< getCurrentDirectory
    gitRoot <- checkoutGitRoot root
    case gitRoot of
      Nothing -> pure (Left (checkoutError "checkout_git_required" "seihou sync requires a Git working tree; run it from the working-tree root"))
      Just gitRoot | gitRoot /= root -> pure (Left (checkoutError "checkout_wrong_root" ("change directory to the Git working-tree root: " <> T.pack gitRoot)))
      _ -> do
        safe <- safeCheckoutManifest root
        case safe of
          Left err -> pure (Left err)
          Right () -> do
            bytes <- readFileText (root </> ".seihou/manifest.json")
            case manifestFromJSON (LBS.fromStrict (TE.encodeUtf8 bytes)) of
              Left err -> pure (Left (checkoutError "checkout_manifest_invalid" (T.pack err <> "; use seihou manifest upgrade for an older manifest, or a newer seihou for a newer schema")))
              Right manifest -> do
                planned <- prepareCheckoutPlan Rebuild SyncIgnoredOnly root manifest manifest []
                case planned of
                  Left err -> pure (Left err)
                  Right plan -> do
                    execution <- if dryRun then pure (CheckoutExecution Map.empty [] Nothing) else applyCheckoutPlan SyncIgnoredOnly root plan
                    let notices = ["No checkout declarations. Apply a declaring module release once before future clones can use seihou sync." | Map.null (manifest ^. #checkoutOutputs)]
                    pure (Right (CheckoutSyncResult root dryRun plan execution notices))
  pure $ case result of
    Left err -> Left (checkoutError "checkout_io_failed" ("cannot inspect checkout: " <> T.pack (displayException err)))
    Right value -> value

checkoutFailureJSON :: Bool -> CheckoutError -> A.Value
checkoutFailureJSON dryRun err = A.object ["mode" A..= mode dryRun, "outputs" A..= ([] :: [A.Value]), "errors" A..= [errorJSON err], "summary" A..= A.object ["planned" A..= counts [], "applied" A..= counts []]]

checkoutReportJSON :: CheckoutSyncResult -> A.Value
checkoutReportJSON result =
  A.object
    [ "mode" A..= mode (result ^. #dryRun),
      "root" A..= (result ^. #root),
      "applicable" A..= checkoutApplicable (result ^. #plan),
      "outputs" A..= map entryJSON entries,
      "errors" A..= map errorJSON (maybe [] pure (result ^. #execution . #failure)),
      "notices" A..= (result ^. #notices),
      "summary"
        A..= A.object
          [ "planned" A..= counts (map (^. #action) entries),
            "applied" A..= counts [entry ^. #action | entry <- entries, Map.lookup (entry ^. #dest) (result ^. #execution . #outcomes) == Just "applied"]
          ]
    ]
  where
    entries = result ^. #plan . #entries
    entryJSON entry =
      A.object
        [ "destination" A..= (entry ^. #dest),
          "kind" A..= ("directory-symlink" :: Text),
          "plannedAction" A..= actionText (entry ^. #action),
          "observation" A..= observationJSON (entry ^. #observation),
          "outcome" A..= Map.findWithDefault "not-applied" (entry ^. #dest) (result ^. #execution . #outcomes),
          "errors" A..= map errorJSON (entry ^. #errors),
          "warnings" A..= (entry ^. #warnings)
        ]

mode :: Bool -> Text
mode True = "dry-run"
mode False = "apply"

counts :: [CheckoutAction] -> A.Value
counts actions = A.object ["created" A..= count CreateLink, "replaced" A..= count ReplaceLink, "retired" A..= count RetireLink, "unchanged" A..= count UnchangedLink, "refused" A..= count RefusedLink]
  where
    count action = length (filter (== action) actions)

errorJSON :: CheckoutError -> A.Value
errorJSON err = A.object ["code" A..= (err ^. #code), "message" A..= (err ^. #message)]

observationJSON :: CheckoutObservation -> A.Value
observationJSON observation =
  A.object
    [ "entry" A..= kind,
      "target" A..= target,
      "sourceDirectory" A..= (observation ^. #sourceDirectory),
      "gitAvailable" A..= (observation ^. #gitAvailable),
      "ignored" A..= (observation ^. #ignored)
    ]
  where
    (kind, target) = case observation ^. #entry of
      EntryMissing -> ("missing" :: Text, Nothing)
      EntryFile -> ("file", Nothing)
      EntryDirectory -> ("directory", Nothing)
      EntrySymlink target -> ("symlink", Just target)

actionText :: CheckoutAction -> Text
actionText CreateLink = "create"
actionText ReplaceLink = "replace-link"
actionText RetireLink = "retire-matching-link"
actionText UnchangedLink = "unchanged"
actionText AlreadyAbsent = "already-absent"
actionText PreserveModified = "preserve-modified"
actionText RefusedLink = "refused"

renderCheckoutPlan :: Bool -> CheckoutPlan -> Text
renderCheckoutPlan dryRun plan =
  T.unlines
    [ (if dryRun && entry ^. #action `elem` [CreateLink, ReplaceLink, RetireLink] then "would-" else "")
        <> actionText (entry ^. #action)
        <> " "
        <> T.pack (entry ^. #dest)
        <> T.concat [": " <> err ^. #message | err <- entry ^. #errors]
        <> T.concat ["; " <> warning | warning <- entry ^. #warnings]
    | entry <- plan ^. #entries
    ]

renderCheckoutStatus :: CheckoutPlan -> Text
renderCheckoutStatus plan =
  let affected = filter ((/= UnchangedLink) . (^. #action)) (plan ^. #entries)
      count = length affected
   in "Checkout outputs: "
        <> T.pack (show (length (plan ^. #entries)))
        <> " declared, "
        <> T.pack (show count)
        <> " need attention.\n"
        <> T.concat ["  " <> T.pack (entry ^. #dest) <> ": " <> reason entry <> "\n" | entry <- take 10 affected]
        <> (if count > 10 then "  … " <> T.pack (show (count - 10)) <> " more affected paths\n" else "")
  where
    reason entry = case entry ^. #errors of
      err : _ -> err ^. #message
      [] -> case entry ^. #action of
        CreateLink -> "missing link; run seihou sync"
        ReplaceLink -> "wrong link target; run seihou sync"
        RetireLink -> "retirement pending"
        AlreadyAbsent -> "already absent"
        PreserveModified -> "modified entry preserved"
        UnchangedLink -> "correct"
        RefusedLink -> "repair refused; inspect this path"