module Hadolint.Rule.DL3000 (rule) where

import qualified Data.Char as Char
import qualified Data.Text as Text
import Hadolint.Rule
import Language.Docker.Syntax (Instruction (..))

rule :: Rule args
rule = simpleRule code severity message check
  where
    code = "DL3000"
    severity = DLErrorC
    message = "Use absolute WORKDIR"
    check (Workdir loc)
      | "$" `Text.isPrefixOf` Text.dropAround dropQuotes loc = True
      | "/" `Text.isPrefixOf` Text.dropAround dropQuotes loc = True
      | isWindowsAbsolute (Text.dropAround dropQuotes loc) = True
      | otherwise = False
    check _ = True
{-# INLINEABLE rule #-}

dropQuotes :: Char -> Bool
dropQuotes chr
  | chr == '\"' = True
  | chr == '\'' = True
  | otherwise = False

isWindowsAbsolute :: Text.Text -> Bool
isWindowsAbsolute path
  | Char.isLetter (Text.index path 0) && (':' == Text.index path 1) = True
  | otherwise = False