module Hadolint.Rule.DL3057 (rule) where

import qualified Data.Sequence as Seq
import qualified Data.Set as Set
import qualified Data.Text as Text
import Hadolint.Rule
import Language.Docker.Syntax


data StageID = StageID
  { name :: Text.Text,
    line :: Linenumber
  } deriving (Show, Eq, Ord)

data Acc
  = Acc StageID (Set.Set StageID) (Set.Set StageID)
  | Empty
  deriving (Show)

rule :: Rule args
rule = veryCustomRule check (emptyState Empty) markFailures
  where
    code = "DL3057"
    severity = DLIgnoreC
    message = "`HEALTHCHECK` instruction missing."

    check line state (From BaseImage {image, alias = Just als}) =
      state |> modify (currentStage (imageName image) (StageID (unImageAlias als) line))
    check line state (From BaseImage {image, alias = Nothing}) =
      state |> modify (currentStage (imageName image) (StageID (imageName image) line))
    check _ state (Healthcheck _) = state |> modify goodStage
    check _ state _ = state

    markFailures :: State Acc -> Failures
    markFailures (State fails (Acc _ _ b)) = Set.foldl' (Seq.|>) fails (Set.map makeFail b)
    markFailures st = failures st
    makeFail (StageID _ line) = CheckFailure {..}
{-# INLINEABLE rule #-}

currentStage :: Text.Text -> StageID -> Acc -> Acc
currentStage src stageid (Acc _ g b)
    | not $ Set.null (Set.filter (predicate src) g) = Acc stageid (g |> Set.insert stageid) b
    | otherwise = Acc stageid g (b |> Set.insert stageid)
  where
    predicate n0 StageID {name = n1} = n1 == n0
currentStage _ stageid Empty = Acc stageid Set.empty (Set.singleton stageid)

goodStage :: Acc -> Acc
goodStage (Acc stageid g b) = Acc stageid (g |> Set.insert stageid) (b |> Set.delete stageid)
goodStage Empty = Empty