{-# LANGUAGE LambdaCase        #-}
{-# LANGUAGE MultiWayIf        #-}
{-# LANGUAGE NamedFieldPuns    #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE TypeApplications  #-}

-- | Contains checks for custom ties of the map json
{-# LANGUAGE DataKinds         #-}
module Properties (checkMap, checkTileset, checkLayer) where


import           Control.Monad (unless, when)
import           Data.Text     (Text, isPrefixOf)
import           Tiled2        (HasProperties (adjustProperties, getProperties),
                                IsProperty (asProperty), Layer (..),
                                Property (..), PropertyValue (..),
                                Tiledmap (..), Tileset (..))
import           Util          (layerIsEmpty, prettyprint, showText)

import           Data.Data     (Proxy (Proxy))
import           Data.Maybe    (fromMaybe, isJust)
import           GHC.TypeLits  (KnownSymbol)
import           LintConfig    (LintConfig (..))
import           LintWriter    (LintWriter, adjust, askContext, askFileDepth,
                                complain, dependsOn, forbid, lintConfig,
                                offersEntrypoint, suggest, warn)
import           Paths         (PathResult (..), RelPath (..), parsePath)
import           Types         (Dep (Link, Local, LocalMap, MapLink))
import           Uris          (SubstError (..), applySubst)
import Data.Functor ((<&>))


-- | Checks an entire map for "general" lints.
--
-- Note that it does /not/ call checkMapProperty; this is handled
-- seperately in CheckMap.hs, since these lints go into a different
-- field of the resulting json.
checkMap :: LintWriter Tiledmap
checkMap = do
  tiledmap <- askContext

  -- test other things
  mapM_ checkMapProperty (fromMaybe [] $ tiledmapProperties tiledmap)

  -- some layers should exist
  hasLayerNamed "start" (const True)
    "The map must have one layer named \"start\"."
  hasLayerNamed "floorLayer" ((==) "objectgroup" . layerType)
    "The map must have one layer named \"floorLayer\" of type \"objectgroup\"."
  hasLayer (flip containsProperty "exitUrl" . getProperties)
    "The map must contain at least one layer with the property \"exitUrl\" set."

  -- reject maps not suitable for workadventure
  unless (tiledmapOrientation tiledmap == "orthogonal")
    $ complain "The map's orientation must be set to \"orthogonal\"."
  unless (tiledmapTileheight tiledmap == 32 && tiledmapTilewidth tiledmap == 32)
    $ complain "The map's tile size must be 32 by 32 pixels."
  where
    hasLayerNamed name p = hasLayer (\l -> layerName l == name && p l)
    hasLayer p err = do
      tiledmap <- askContext
      unless (any p (tiledmapLayers tiledmap))
        $ complain err


-- | Checks a single property of a map.
--
-- Doesn't really do all that much, but could in theory be expanded into a
-- longer function same as checkLayerProperty.
checkMapProperty :: Property -> LintWriter Tiledmap
checkMapProperty (Property name _value) = case name of
  "script" -> do
    -- this is kind of stupid, since if we also inject script this
    -- will be overriden anyways, but it also doesn't really hurt I guess
    -- TODO: perhaps include an explanation in the lint, or allow
    -- exactly that one value?
    lintConfig configAllowScripts >>= \case
      False -> isForbidden
      True  -> pure ()
    lintConfig configScriptInject >>= \case
      Nothing  -> pure ()
      Just url -> setProperty "script" url
  "mapName" -> pure ()
  "mapLink" -> pure ()
  "mapImage" -> pure ()
  "mapDescription" -> pure ()
  "mapCopyright" -> pure ()

  _        -> complain $ "unknown map property " <> prettyprint name
  where
    -- | this property is forbidden and should not be used
    isForbidden = forbid $ "property " <> prettyprint name <> " should not be used"


-- | check an embedded tile set.
--
-- Important to collect dependency files
checkTileset ::  LintWriter Tileset
checkTileset = do
  tileset <- askContext
  -- TODO: can tilesets be non-local dependencies?
  unwrapPath (tilesetImage tileset) (dependsOn . Local)

  -- reject tilesets unsuitable for workadventure
  unless (tilesetTilewidth tileset == 32 && tilesetTileheight tileset == 32)
    $ complain "Tilesets must have tile size 32×32."

  unless (tilesetImageheight tileset < 4096 && tilesetImagewidth tileset < 4096)
    $ warn "Tilesets should not be larger than 4096×4096 pixels in total."

  when (isJust (tilesetSource tileset))
    $ complain "Tilesets must be embedded and cannot be loaded from external files."
  -- TODO: check copyright!
  unlessHasProperty "copyright"
    $ forbid "property \"copyright\" is required for tilesets."


  mapM_ checkTilesetProperty (fromMaybe [] $ tilesetProperties tileset)

checkTilesetProperty :: Property -> LintWriter Tileset
checkTilesetProperty (Property name _value) = case name of
  "copyright" -> pure () -- only allow some licenses?
  _           -> pure () -- are there any other properties?


-- | collect lints on a single map layer
checkLayer :: LintWriter Layer
checkLayer = do
  layer <- askContext
  when (isJust (layerImage layer))
    $ complain "imagelayer are not supported."

  case layerType layer of
    "tilelayer" -> mapM_ checkLayerProperty (getProperties layer)
    "group" -> pure ()
    ty -> unless (layerName layer == "floorLayer" && ty == "objectgroup")
          $ complain "only group and tilelayer are supported."

  if layerType layer == "group"
    then when (null (layerLayers layer))
    $ warn "Empty group layers are pointless."
    else when (isJust (layerLayers layer))
    $ complain "Layer is not of type \"group\", but has sublayers."


-- | Checks a single (custom) property of a layer
--
-- It gets a reference to its own layer since sometimes the presence
-- of one property implies the presence or absense of another.
checkLayerProperty :: Property -> LintWriter Layer
checkLayerProperty p@(Property name _value) = case name of
    "jitsiRoom" -> do
      lintConfig configAssemblyTag
        >>= setProperty "jitsiRoomAdminTag"
        . ("assembly-" <>) -- prepend "assembly-" to avoid namespace clashes
      uselessEmptyLayer
      unwrapString p $ \jitsiRoom -> do
        suggestProperty $ Property "jitsiTrigger" "onaction"

        -- prepend jitsi room names to avoid name clashes
        unless ("shared-" `isPrefixOf` jitsiRoom) $ do
          assemblyname <- lintConfig configAssemblyTag
          setProperty "jitsiRoom" (assemblyname <> "-" <> jitsiRoom)
    "jitsiTrigger" -> do
      isString p
      unlessHasProperty "jitsiTriggerMessage"
       $ suggest "set \"jitsiTriggerMessage\" to a custom message to overwrite the default \"press SPACE to enter in jitsi meet room\"."
      requireProperty "jitsiRoom"
    "jitsiTriggerMessage" -> do
      isString p
      requireProperty "jitsiTrigger"
    "jitsiUrl" -> isForbidden
    "jitsiConfig" -> isForbidden
    "jitsiClientConfig" -> isForbidden
    "jitsiRoomAdminTag" -> isForbidden
    "jitsiInterfaceConfig" -> isForbidden
    "jitsiWidth" ->
      isIntInRange 0 100 p
    "bbbRoom" -> do
      removeProperty "bbbRoom"
      unwrapURI (Proxy @"bbb") p
        (\link -> do
            dependsOn (Link link)
            setProperty "openWebsite" link
            setProperty "openWebsitePolicy"
              ("fullscreen;camera;microphone;display-capture" :: Text)
        )
        (const $ complain "property \"bbbRoom\" cannot be used with local links.")
    "bbbTrigger" -> do
      removeProperty "bbbTrigger"
      requireProperty "bbbRoom"
      unwrapString p
        (setProperty "openWebsiteTrigger")
      unlessHasProperty "bbbTriggerMessage" $ do
       suggest "set \"bbbTriggerMessage\" to a custom message to overwrite the default \"press SPACE to enter the bbb room\""
       setProperty "openWebsiteTriggerMessage"
         ("press SPACE to enter bbb room" :: Text)
    "bbbTriggerMessage" -> do
      removeProperty "bbbTriggerMessage"
      requireProperty "bbbRoom"
      unwrapString p
        (setProperty "openWebsiteTriggerMessage")
    "playAudio" -> do
      uselessEmptyLayer
      unwrapLink p $ \link -> if "https://" `isPrefixOf` link
        then dependsOn $ Link link
        else unwrapPath link (dependsOn . Local)
    "audioLoop" -> do
      isBool p
      requireProperty "playAudio"
    "playAudioLoop" ->
      deprecatedUseInstead "audioLoop"
    "audioVolume" -> do
      isBool p
      requireProperty "playAudio"
    "openWebsite" -> do
      uselessEmptyLayer
      suggestProperty $ Property "openWebsiteTrigger" (StrProp "onaction")
      unwrapURI (Proxy @"website") p
        (dependsOn . Link)
        (dependsOn . Local)
    "openWebsiteTrigger" -> do
      isString p
      unlessHasProperty "openWebsiteTriggerMessage"
        $ suggest "set \"openWebsiteTriggerMessage\" to a custom message to overwrite the default \"press SPACE to open Website\"."
      requireProperty "openWebsite"
    "openWebsiteTriggerMessage" -> do
      isString p
      requireProperty "openWebsiteTrigger"
    "openWebsitePolicy" -> isForbidden
    "openWebsiteAllowApi" -> isForbidden
    "openTab" -> do
      isString p
      requireProperty "openWebsite"
    "url" -> isForbidden
    "allowApi" -> isForbidden
    "exitUrl" -> do
      forbidEmptyLayer
      unwrapURI (Proxy @"map") p
        (dependsOn . MapLink)
        (dependsOn . LocalMap)
    "exitSceneUrl" ->
      deprecatedUseInstead "exitUrl"
    "exitInstance" ->
      deprecatedUseInstead "exitUrl"
    "startLayer" -> do
      forbidEmptyLayer
      layer <- askContext
      offersEntrypoint $ layerName layer
      unwrapBool p $ \case
        True  -> pure ()
        False -> complain "property \"startLayer\" must be set to true."
    "silent" -> do
      isBool p
      uselessEmptyLayer
    "collides" ->
      unwrapBool p $ \case
        True  -> pure ()
        False -> warn "property \"collides\" set to 'false' is useless."
    "name" -> isUnsupported
    -- all properties relating to scripting are handled the same
    _ ->
        warn $ "unknown property type " <> prettyprint name
    where
      isForbidden = forbidProperty name
      requireProperty req = propertyRequiredBy req name
      isUnsupported = warn $ "property " <> name <> " is not (yet) supported by walint."
      deprecatedUseInstead instead =
        warn $ "property \"" <> name <> "\" is deprecated. Use \"" <> instead <> "\" instead."


      -- | this property can only be used on a layer that contains at least one tiles
      forbidEmptyLayer = do
        layer <- askContext
        when (layerIsEmpty layer)
          $ complain ("property " <> prettyprint name <> " should not be set on an empty layer.")
      -- | this layer is allowed, but also useless on a layer that contains no tiles
      uselessEmptyLayer = do
        layer <- askContext
        when (layerIsEmpty layer)
          $ warn ("property " <> prettyprint name <> " set on an empty layer is useless.")





--------- Helper functions & stuff ---------

unlessHasProperty :: HasProperties a => Text -> LintWriter a -> LintWriter a
unlessHasProperty name andthen = do
  layer <- askContext
  let hasprop = any (\(Property name' _) -> name == name') (getProperties layer)
  unless hasprop andthen


-- | this property is forbidden and should not be used
forbidProperty :: Text -> LintWriter Layer
forbidProperty name = do
  forbid $ "property " <> prettyprint name <> " should not be used."

propertyRequiredBy :: HasProperties a => Text -> Text -> LintWriter a
propertyRequiredBy req by =
  unlessHasProperty req
  $ complain $ "property "<>prettyprint req<>" is required by property "<> prettyprint by<>"."

-- | suggest some value for another property if that property does not
-- also already exist
suggestProperty :: Property -> LintWriter Layer
suggestProperty (Property name value) =
  unlessHasProperty name
  $ suggest $ "set property " <> prettyprint name <> " to " <> prettyprint value<>"."

-- | set a property, overwriting whatever value it had previously
setProperty :: (IsProperty prop, HasProperties ctxt)
  => Text -> prop -> LintWriter ctxt
setProperty name value = adjust $ \ctxt ->
  flip adjustProperties ctxt
  $ \ps -> Just $ Property name (asProperty value) : filter sameName ps
  where sameName (Property name' _) = name /= name'

removeProperty :: HasProperties ctxt => Text -> LintWriter ctxt
removeProperty name = adjust $ \ctxt ->
  flip adjustProperties ctxt
  $ \ps -> Just $ filter (\(Property name' _) -> name' /= name) ps


-- | does this layer have the given property?
containsProperty :: Foldable t => t Property -> Text -> Bool
containsProperty props name = any
  (\(Property name' _) -> name' == name) props


-- | asserts that this property is a string, and unwraps it
unwrapString :: Property -> (Text -> LintWriter a) -> LintWriter a
unwrapString (Property name value) f = case value of
  StrProp str -> f str
  _ -> complain $ "type error: property " <> prettyprint name <> " should be of type string."

unwrapString' :: Property -> LintWriter a -> LintWriter a
unwrapString' prop f = unwrapString prop (const f)

-- | same as unwrapString, but also forbids http:// as prefix
unwrapLink :: Property -> (Text -> LintWriter a) -> LintWriter a
unwrapLink (Property name value) f = case value of
  StrProp str -> if "http://" `isPrefixOf` str
    then complain "cannot access content via http; either use https or include it locally instead."
    else f str
  _ -> complain $ "type error: property " <> prettyprint name <> " should be of type string and contain a valid uri."

-- | asserts that this property is a boolean, and unwraps it
unwrapBool :: Property -> (Bool -> LintWriter a) -> LintWriter a
unwrapBool (Property name value) f = case value of
  BoolProp b -> f b
  _ -> complain $ "type error: property " <> prettyprint name <> " should be of type bool."

unwrapInt :: Property -> (Int -> LintWriter a) -> LintWriter a
unwrapInt (Property name value) f = case value of
  IntProp float -> f float
  _ -> complain $ "type error: property " <> prettyprint name <> " should be of type int."

unwrapPath :: Text -> (RelPath -> LintWriter a) -> LintWriter a
unwrapPath str f = case parsePath str of
  OkRelPath p@(Path up _ _) -> do
    depth <- askFileDepth
    if up <= depth
      then f p
      else complain $ "cannot acess paths \"" <> str <> "\" which is outside your repository."
  NotAPath -> complain $ "path \"" <> str <> "\" is invalid."
  AbsolutePath -> complain "absolute paths are disallowed. Use world:// instead."
  UnderscoreMapLink -> complain "map links using /_/ are disallowed. Use world:// instead."
  AtMapLink -> complain "map links using /@/ are disallowed. Use world:// instead."

-- | just asserts that this is a string
isString :: Property -> LintWriter a
isString = flip unwrapString (const $ pure ())

-- | just asserts that this is a boolean
isBool :: Property -> LintWriter a
isBool = flip unwrapBool (const $ pure ())

isIntInRange :: Int -> Int -> Property -> LintWriter a
isIntInRange l r p@(Property name _) = unwrapInt p $ \int ->
  if l < int && int < r then pure ()
  else complain $ "Property " <> prettyprint name <> " should be between" <> showText l <> " and " <> showText r<>"."


unwrapURI :: (KnownSymbol s, HasProperties a)
  => Proxy s -> Property -> (Text -> LintWriter a) -> (RelPath -> LintWriter a) -> LintWriter a
unwrapURI sym p@(Property name _) f g = unwrapLink p $ \link -> do
  subst <- lintConfig configUriSchemas
  case applySubst sym subst link of
    Right uri -> do
      setProperty name uri
      f uri
    Left NotALink -> unwrapPath link g
    Left err -> complain $ case err of
      IsBlocked -> link <> " is a blocked site."
      InvalidLink -> link <> " is invalid."
      SchemaDoesNotExist schema ->
        "the URI schema " <> schema <> ":// does not exist."
      WrongScope schema ->
        "the URI schema " <> schema <> ":// cannot be used on \""<>name<>"\"."