{-# LANGUAGE OverloadedStrings #-}

{-|
Description:    Token processing rules within non-HTML content.

Copyright:      (c) 2020 Sam May
License:        MPL-2.0
Maintainer:     ag.eitilt@gmail.com

Stability:      stable
Portability:    portable
-}
module Web.Mangrove.Parse.Tree.Foreign
    ( treeForeign
    ) where


import qualified Control.Monad.Trans.State as N.S

import qualified Data.HashMap.Strict as M
import qualified Data.Maybe as Y
import qualified Data.Text as T

import Web.Willow.DOM

import Web.Mangrove.Parse.Common.Error
import Web.Mangrove.Parse.Tokenize.Common
import Web.Mangrove.Parse.Tree.Common
import Web.Mangrove.Parse.Tree.InBody
import Web.Mangrove.Parse.Tree.Patch
import Web.Willow.Common.Encoding.Character
import Web.Willow.Common.Parser
import Web.Willow.Common.Parser.Switch

import {-# SOURCE #-} Web.Mangrove.Parse.Tree.Dispatcher


-- | __HTML:__
--      @[the rules for parsing tokens in foreign content]
--      (https://html.spec.whatwg.org/multipage/parsing.html#parsing-main-inforeign)@
-- 
-- The parsing instructions for non-HTML content, which follows a simpler
-- recovery model more in line with HTML.
treeForeign :: TreeBuilder TreeOutput
treeForeign = next >>= switch
    [ If isNull $ \t' ->
        consTreeError UnexpectedNullCharacter <$> insertCharacter (mapTokenOut (const $ Character replacementChar) t')
    , If isWhitespace insertCharacter
    , If isCharacter $ \t' -> setFramesetNotOk *> insertCharacter t'
    , If isComment insertComment
    , If isDoctype $ \t' ->
        packTreeErrors [UnexpectedDoctype $ tokenDocumentType t'] t'
    , If isEOF $ \t' -> push t' *> treeInBody
    , If (isStartTag
        [ "b"
        , "big"
        , "blockquote"
        , "body"
        , "br"
        , "center"
        , "code"
        , "dd"
        , "div"
        , "dl"
        , "dt"
        , "em"
        , "embed"
        , "h1"
        , "h2"
        , "h3"
        , "h4"
        , "h5"
        , "h6"
        , "head"
        , "hr"
        , "i"
        , "img"
        , "li"
        , "listing"
        , "menu"
        , "meta"
        , "nobr"
        , "ol"
        , "p"
        , "pre"
        , "ruby"
        , "s"
        , "small"
        , "span"
        , "strong"
        , "strike"
        , "sub"
        , "sup"
        , "table"
        , "tt"
        , "u"
        , "ul"
        , "var"
        ]) htmlStartTag
    , If (isStartTag ["font"]) $ \t' ->
        if any (`elem` ["color", "face", "size"]) (map fst . M.toList . tokenAttributes $ tokenOut t')
            then htmlStartTag t'
            else anyOtherStartTag t'
    , If isAnyStartTag anyOtherStartTag
    , If (isEndTag ["script"]) $ \t' -> do
        current <- currentNode
        state <- N.S.get
        if (current >>= elementNamespace) == Just mathMLNamespace
            then closeCurrentNode t' <* closeSvgScript
            else anyOtherEndTag (openElements state) t'
    , If isAnyEndTag $ \t' -> do
        state <- N.S.get
        anyOtherEndTag (openElements state) t'
    ]
  where anyOtherStartTag t' = case tokenOut t' of
            StartTag d -> do
                current <- adjustedCurrentNode
                let ns = Y.fromMaybe htmlNamespace $ current >>= elementNamespace
                    d' = case ns of
                        ns' | mathMLNamespace == ns' -> adjustMathMLAttributes d
                        ns' | svgNamespace == ns' -> adjustSvgAttributes $ case tagName d of
                            "altglyph" -> d { tagName = "altGlyph" }
                            "altglyphdef" -> d { tagName = "altGlyphDef" }
                            "altglyphitem" -> d { tagName = "altGlyphItem" }
                            "animatecolor" -> d { tagName = "animateColor" }
                            "animatemotion" -> d { tagName = "animateMotion" }
                            "animatetransform" -> d { tagName = "animateTransform" }
                            "clippath" -> d { tagName = "clipPath" }
                            "feblend" -> d { tagName = "feBlend" }
                            "fecolormatrix" -> d { tagName = "feColorMatrix" }
                            "fecomponenttransfer" -> d { tagName = "feComponentTransfer" }
                            "fecomposite" -> d { tagName = "feComposite" }
                            "feconvolvematrix" -> d { tagName = "feConvolveMatrix" }
                            "fediffuselighting" -> d { tagName = "feDiffuseLighting" }
                            "fedisplacementmap" -> d { tagName = "feDisplacementMap" }
                            "fedistantlight" -> d { tagName = "feDistantLight" }
                            "fedropshadow" -> d { tagName = "feDropShadow" }
                            "feflood" -> d { tagName = "feFlood" }
                            "fefunca" -> d { tagName = "feFuncA" }
                            "fefuncb" -> d { tagName = "feFuncB" }
                            "fefuncg" -> d { tagName = "feFuncG" }
                            "fefuncr" -> d { tagName = "feFuncR" }
                            "fegaussianblur" -> d { tagName = "feGaussianBlur" }
                            "feimage" -> d { tagName = "feImage" }
                            "femerge" -> d { tagName = "feMerge" }
                            "femergenode" -> d { tagName = "feMergeNode" }
                            "femorphology" -> d { tagName = "feMorphology" }
                            "feoffset" -> d { tagName = "feOffset" }
                            "fepointlight" -> d { tagName = "fePointLight" }
                            "fespecularlighting" -> d { tagName = "feSpecularLighting" }
                            "fespotlight" -> d { tagName = "feSpotLight" }
                            "fetile" -> d { tagName = "feTile" }
                            "feturbulence" -> d { tagName = "feTurbulence" }
                            "foreignobject" -> d { tagName = "foreignObject" }
                            "glyphref" -> d { tagName = "glyphRef" }
                            "lineargradient" -> d { tagName = "linearGradient" }
                            "radialgradient" -> d { tagName = "radialGradient" }
                            "textpath" -> d { tagName = "textPath" }
                            _ -> d
                        _ -> d
                    t'' = mapTokenOut (const $ StartTag d') t'
                if tagIsSelfClosing d'
                    then if tagName d' == "script" && ns == svgNamespace
                            then insertForeignNullElement ns t'' <* closeSvgScript
                            else insertForeignNullElement ns t''
                    else insertForeignElement ns t''
            _ -> packTreeErrors [] t'
        anyOtherEndTag [] t' = packTreeErrors [] t'
        anyOtherEndTag es@(e:_) t' = case tokenOut t' of
            EndTag d -> if T.map toAsciiLower (elementName $ snd e) == tagName d
                then loopEndTag d es t'
                else consTreeError UnexpectedElementWithImpliedEndTag <$> loopEndTag d es t'
            _ -> packTreeErrors [] t'
        loopEndTag d es t' = either id id <$> loopEndTag' d es t'
        loopEndTag' _ [] t' = Left <$> packTreeErrors [] t'
        loopEndTag' _ [_] t' = Left <$> packTreeErrors [] t'
        loopEndTag' d (e:es) t'
            | T.map toAsciiLower (elementName $ snd e) == tagName d =
                Right <$> closeCurrentNode t'
            | otherwise = case es of
                (e':_) | elementNamespace (snd e') == Just htmlNamespace -> push t' *> fmap Left dispatchHtml
                _ -> do
                    recurse <- loopEndTag' d es t'
                    case recurse of
                        l@(Left _) -> return l
                        Right clear -> do
                            close <- closeCurrentNode_
                            return . Right $ close ++| clear
        tokenAttributes (StartTag d) = tagAttributes d
        tokenAttributes (EndTag d) = tagAttributes d
        tokenAttributes _ = M.empty
        htmlStartTag t' = do
            isFragment <- inFragment
            consTreeError UnexpectedHtmlElementInForeignContent <$> if isFragment
                then anyOtherStartTag t'
                else do
                    push t'
                    close <- closeCurrentNode_
                    clear <- clearToIntegration
                    packTree_ $ close ++ clear
        clearToIntegration = do
            current <- currentNode
            let mathML = maybe False atMathMLIntegration current
                html = maybe False atHtmlIntegration current
                ns = Y.fromMaybe htmlNamespace $ current >>= elementNamespace
            if mathML || html || ns == htmlNamespace
                then return []
                else do
                    close <- closeCurrentNode_
                    clear <- clearToIntegration
                    return $ close ++ clear
        closeSvgScript = undefined