{-# LANGUAGE OverloadedStrings #-}

{-|
Description:    Token processing rules within a @\<colgroup\>@ markup section.

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

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


import Web.Mangrove.Parse.Common.Error
import Web.Mangrove.Parse.Tree.Common
import Web.Mangrove.Parse.Tree.InBody
import Web.Mangrove.Parse.Tree.InHead
import Web.Mangrove.Parse.Tree.Patch
import Web.Willow.Common.Parser
import Web.Willow.Common.Parser.Switch


-- | __HTML:__
--      @[the "in column group" insertion mode]
--      (https://html.spec.whatwg.org/multipage/parsing.html#parsing-main-incolgroup)@
-- 
-- The parsing instructions corresponding to the 'InColumnGroup' section of the
-- state machine.
treeInColumnGroup :: TreeBuilder TreeOutput
treeInColumnGroup = next >>= switch
    [ If isWhitespace insertCharacter
    , If isComment insertComment
    , If isDoctype $ \t' ->
        packTreeErrors [UnexpectedDoctype $ tokenDocumentType t'] t'
    , If (isStartTag ["html"]) $ \t' -> do
        push t'
        treeInBody
    , If (isStartTag ["col"]) insertNullElement
    , If (isEndTag ["colgroup"]) $ \t' -> do
        current <- currentNode
        if maybe False (nodeIsElement "colgroup") current
            then do
                switchMode InTable
                closeCurrentNode t'
            else packTreeErrors [UnmatchedEndTag $ tokenElement t'] t'
    , If (isEndTag ["col"]) $ packTreeErrors [UnexpectedEndColInColumnGroup]
    , If (isStartTag ["template"]) $ \t' -> do
        push t'
        treeInHead
    , If (isEndTag ["template"]) $ \t' -> do
        push t'
        treeInHead
    , If isEOF $ \t' -> do
        push t'
        treeInBody
    , Else $ \t' -> do
        current <- currentNode
        if maybe False (nodeIsElement "colgroup") current
            then do
                push t'
                switchMode InTable
                close <- closeCurrentNode_
                packTree_ close
            else packTreeErrors [UnexpectedElementWithImpliedEndTag] t'
    ]