{-|
Description:    Tokenization rules for characters within @\<[CDATA[@ ... @]]\>@ sections.

Copyright:      (c) 2020-2021 Sam May
License:        MPL-2.0
Maintainer:     ag.eitilt@gmail.com

Stability:      stable
Portability:    portable
-}
module Web.Mangrove.Parse.Tokenize.CData
    ( tokenCDataSection
    ) where


import Web.Mangrove.Parse.Common.Error
import Web.Mangrove.Parse.Tokenize.Common


-- | __HTML:__
--      @[CDATA section state]
--      (https://html.spec.whatwg.org/multipage/parsing.html#cdata-section-state)@
-- 
-- The parsing instructions rooted in the 'CDataState' section of the state
-- machine.
tokenCDataSection :: Tokenizer [TokenizerOutput Token]
tokenCDataSection = tokenizers (Just [([EOFInCData], EndOfStream)])
    [ ifs_ (== ']') tokenCDataSectionBracket
    , elsesChar $ \c -> emit' ([], Character c)
    ]

-- | __HTML:__
--      @[CDATA section bracket state]
--      (https://html.spec.whatwg.org/multipage/parsing.html#cdata-section-bracket-state)@
-- 
-- The parsing instructions for after reading @"]"@ in the 'CDataState' section
-- of the state machine.
tokenCDataSectionBracket :: Tokenizer [TokenizerOutput Token]
tokenCDataSectionBracket = tokenizers (Just [([], Character ']'), ([EOFInCData], EndOfStream)])
    [ ifs_ (== ']') tokenCDataSectionEnd
    , elsePush_ $ emit' ([], Character ']')
    ]

-- | __HTML:__
--      @[CDATA section end state]
--      (https://html.spec.whatwg.org/multipage/parsing.html#cdata-section-end-state)@
-- 
-- The parsing instructions for after reading @"]]"@ in the 'CDataState'
-- section of the state machine.
tokenCDataSectionEnd :: Tokenizer [TokenizerOutput Token]
tokenCDataSectionEnd = tokenCDataSectionEnd' >>= \ts -> case tokenizedOut ts of
    [] -> return []
    (t':ts') -> emits (tokenizedState ts) $
        (tokenizedErrs ts, Character t') : [([], Character t) | t <- ts']
  where emits state ts = finalStateList state <$> mapM emit ts

-- | Loop within the __HTML__ @[CDATA section end state]
-- (https://html.spec.whatwg.org/multipage/parsing.html#cdata-section-end-state)@
-- to read and re-emit any number of @']'@ 'Char's before the closing @"]]\>"@.
tokenCDataSectionEnd' :: Tokenizer (TokenizerOutput String)
tokenCDataSectionEnd' = tokenizer (Just ([EOFInCData], "]]"))
    [ if_ (== ']') $ consOut ']' <$> tokenCDataSectionEnd'
    , if_ (== '>') $ changeState DataState *> packToken ([], "")
    , elsePush_ $ packToken ([], "]]")
    ]