/**
 * @typedef {import('micromark-util-types').Construct} Construct
 * @typedef {import('micromark-util-types').Tokenizer} Tokenizer
 * @typedef {import('micromark-util-types').Token} Token
 * @typedef {import('micromark-util-types').State} State
 * @typedef {import('micromark-util-types').Code} Code
 */
import {decodeNamedCharacterReference} from 'decode-named-character-reference'
import {
  asciiAlphanumeric,
  asciiDigit,
  asciiHexDigit
} from 'micromark-util-character'

/** @type {Construct} */
export const characterReference = {
  name: 'characterReference',
  tokenize: tokenizeCharacterReference
}
/** @type {Tokenizer} */

function tokenizeCharacterReference(effects, ok, nok) {
  const self = this
  let size = 0
  /** @type {number} */

  let max
  /** @type {(code: Code) => code is number} */

  let test
  return start
  /** @type {State} */

  function start(code) {
    effects.enter('characterReference')
    effects.enter('characterReferenceMarker')
    effects.consume(code)
    effects.exit('characterReferenceMarker')
    return open
  }
  /** @type {State} */

  function open(code) {
    if (code === 35) {
      effects.enter('characterReferenceMarkerNumeric')
      effects.consume(code)
      effects.exit('characterReferenceMarkerNumeric')
      return numeric
    }

    effects.enter('characterReferenceValue')
    max = 31
    test = asciiAlphanumeric
    return value(code)
  }
  /** @type {State} */

  function numeric(code) {
    if (code === 88 || code === 120) {
      effects.enter('characterReferenceMarkerHexadecimal')
      effects.consume(code)
      effects.exit('characterReferenceMarkerHexadecimal')
      effects.enter('characterReferenceValue')
      max = 6
      test = asciiHexDigit
      return value
    }

    effects.enter('characterReferenceValue')
    max = 7
    test = asciiDigit
    return value(code)
  }
  /** @type {State} */

  function value(code) {
    /** @type {Token} */
    let token

    if (code === 59 && size) {
      token = effects.exit('characterReferenceValue')

      if (
        test === asciiAlphanumeric &&
        !decodeNamedCharacterReference(self.sliceSerialize(token))
      ) {
        return nok(code)
      }

      effects.enter('characterReferenceMarker')
      effects.consume(code)
      effects.exit('characterReferenceMarker')
      effects.exit('characterReference')
      return ok
    }

    if (test(code) && size++ < max) {
      effects.consume(code)
      return value
    }

    return nok(code)
  }
}