{-# LANGUAGE GeneralizedNewtypeDeriving #-}
{-# LANGUAGE InstanceSigs #-}

module ShellCommands
  ( ShellCommand,
    ShellCommandContext (..),
    ShellCommandBuilder (..),
    runShellCommandBuilder,
    combineShellCommands,
    cdIntoCurrentProject,
    appendToWaspFile,
    createFile,
    setDbToPSQL,
    waspCliNew,
    waspCliCompile,
    waspCliMigrate,
    waspCliBuild,
    dockerBuild,
    insertCodeIntoWaspFileAtLineNumber,
  )
where

import Control.Monad.Reader (MonadReader (ask), Reader, runReader)
import Data.List (intercalate)
import System.FilePath (joinPath, (</>))

-- NOTE: Should we consider separating shell parts, Wasp CLI parts, and test helper parts in the future?
--       This would likely reqiure adoption of some library, and creating new layers of abstraction.
--       Deemed not worth it right now by all.

-- NOTE: Using `wasp-cli` herein so we can assume using latest `stack install` in CI and locally.

-- TODO: In future, find a good way to test `wasp-cli start`.

type ShellCommand = String

-- Each shell command gets access to the current project name, and maybe other things in future.
data ShellCommandContext = ShellCommandContext
  { _ctxtCurrentProjectName :: String
  }
  deriving (Show)

-- Used to construct shell commands, while still giving access to the context (if needed).
newtype ShellCommandBuilder a = ShellCommandBuilder {_runShellCommandBuilder :: Reader ShellCommandContext a}
  deriving (Functor, Applicative, Monad, MonadReader ShellCommandContext)

runShellCommandBuilder :: ShellCommandBuilder a -> ShellCommandContext -> a
runShellCommandBuilder shellCommandBuilder context =
  runReader (_runShellCommandBuilder shellCommandBuilder) context

combineShellCommands :: [ShellCommand] -> ShellCommand
combineShellCommands = intercalate " && "

cdIntoCurrentProject :: ShellCommandBuilder ShellCommand
cdIntoCurrentProject = do
  context <- ask
  return $ "cd " ++ _ctxtCurrentProjectName context

appendToWaspFile :: String -> ShellCommandBuilder ShellCommand
appendToWaspFile content =
  -- NOTE: Using `show` to preserve newlines in string.
  return $ "printf " ++ show (content ++ "\n") ++ " >> main.wasp"

-- NOTE: Pretty fragile. Can't handle spaces in args, *nix only, etc.
createFile :: String -> FilePath -> String -> ShellCommandBuilder ShellCommand
createFile content relDirFp filename = return $ combineShellCommands [createParentDir, writeContentsToFile]
  where
    createParentDir = "mkdir -p ./" ++ relDirFp
    destinationFile = "./" ++ relDirFp ++ "/" ++ filename
    contents = show (content ++ "\n")
    writeContentsToFile = unwords ["printf", contents, ">", destinationFile]

-- NOTE: This is fragile and will likely break in future. Assumes `app` decl is first line and by default
--       we do not have a `db` field. Consider better alternatives.
setDbToPSQL :: ShellCommandBuilder ShellCommand
-- Change DB to postgres by adding string at specific line so it still parses.
setDbToPSQL = insertCodeIntoWaspFileAtLineNumber 2 "  db: { system: PostgreSQL },"

insertCodeIntoWaspFileAtLineNumber :: Int -> String -> ShellCommandBuilder ShellCommand
insertCodeIntoWaspFileAtLineNumber atLineNumber line =
  return $
    combineShellCommands
      [ "awk 'NR==" ++ show atLineNumber ++ "{print " ++ show line ++ "}1' main.wasp > main.wasp.tmp",
        "mv main.wasp.tmp main.wasp"
      ]

waspCliNew :: ShellCommandBuilder ShellCommand
waspCliNew = do
  context <- ask
  return $ "wasp-cli new " ++ _ctxtCurrentProjectName context

waspCliCompile :: ShellCommandBuilder ShellCommand
waspCliCompile = return "wasp-cli compile"

-- TODO: We need to be careful what migration names we accept here, as Prisma will
--       normalize a migration name containing spaces/dashes to underscores (and maybe other rules).
--       This will impact our ability to move directories around if the names do not match exactly.
--       Put in some check eventually.
waspCliMigrate :: String -> ShellCommandBuilder ShellCommand
waspCliMigrate migrationName =
  let generatedMigrationsDir = joinPath [".wasp", "out", "db", "migrations"]
      waspMigrationsDir = "migrations"
   in return $
        combineShellCommands
          [ -- Migrate using a migration name to avoid Prisma asking via CLI.
            "wasp-cli db migrate-dev --name " ++ migrationName,
            -- Rename both migrations to remove the date-specific portion of the directory to something static.
            "mv " ++ (waspMigrationsDir </> ("*" ++ migrationName)) ++ " " ++ (waspMigrationsDir </> ("no-date-" ++ migrationName)),
            "mv " ++ (generatedMigrationsDir </> ("*" ++ migrationName)) ++ " " ++ (generatedMigrationsDir </> ("no-date-" ++ migrationName))
          ]

waspCliBuild :: ShellCommandBuilder ShellCommand
waspCliBuild = return "wasp-cli build"

dockerBuild :: ShellCommandBuilder ShellCommand
dockerBuild =
  return
    "[ -z \"$WASP_E2E_TESTS_SKIP_DOCKER\" ] && cd .wasp/build && docker build . && cd ../.. || true"