// CodeMirror, copyright (c) by Marijn Haverbeke and others
// Distributed under an MIT license: https://codemirror.net/LICENSE

;(function (mod) {
    if (typeof exports == 'object' && typeof module == 'object')
        // CommonJS
        mod(require('../../lib/codemirror'))
    else if (typeof define == 'function' && define.amd)
        // AMD
        define(['../../lib/codemirror'], mod)
    // Plain browser env
    else mod(CodeMirror)
})(function (CodeMirror) {
    'use strict'

    CodeMirror.defineMode('haskell', function (_config, modeConfig) {
        function switchState(source, setState, f) {
            setState(f)
            return f(source, setState)
        }

        // These should all be Unicode extended, as per the Haskell 2010 report
        var smallRE = /[a-z_]/
        var largeRE = /[A-Z]/
        var digitRE = /\d/
        var hexitRE = /[0-9A-Fa-f]/
        var octitRE = /[0-7]/
        var idRE = /[a-z_A-Z0-9'\xa1-\uffff]/
        var symbolRE = /[-!#$%&*+.\/<=>?@\\^|~:]/
        var specialRE = /[(),;[\]`{}]/
        var whiteCharRE = /[ \t\v\f]/ // newlines are handled in tokenizer

        function normal(source, setState) {
            if (source.eatWhile(whiteCharRE)) {
                return null
            }

            var ch = source.next()
            if (specialRE.test(ch)) {
                if (ch == '{' && source.eat('-')) {
                    var t = 'comment'
                    if (source.eat('#')) {
                        t = 'meta'
                    }
                    return switchState(source, setState, ncomment(t, 1))
                }
                return null
            }

            if (ch == "'") {
                if (source.eat('\\')) {
                    source.next() // should handle other escapes here
                } else {
                    source.next()
                }
                if (source.eat("'")) {
                    return 'string'
                }
                return 'string error'
            }

            if (ch == '"') {
                return switchState(source, setState, stringLiteral)
            }

            if (largeRE.test(ch)) {
                source.eatWhile(idRE)
                if (source.eat('.')) {
                    return 'qualifier'
                }
                return 'variable-2'
            }

            if (smallRE.test(ch)) {
                source.eatWhile(idRE)
                return 'variable'
            }

            if (digitRE.test(ch)) {
                if (ch == '0') {
                    if (source.eat(/[xX]/)) {
                        source.eatWhile(hexitRE) // should require at least 1
                        return 'integer'
                    }
                    if (source.eat(/[oO]/)) {
                        source.eatWhile(octitRE) // should require at least 1
                        return 'number'
                    }
                }
                source.eatWhile(digitRE)
                var t = 'number'
                if (source.match(/^\.\d+/)) {
                    t = 'number'
                }
                if (source.eat(/[eE]/)) {
                    t = 'number'
                    source.eat(/[-+]/)
                    source.eatWhile(digitRE) // should require at least 1
                }
                return t
            }

            if (ch == '.' && source.eat('.')) return 'keyword'

            if (symbolRE.test(ch)) {
                if (ch == '-' && source.eat(/-/)) {
                    source.eatWhile(/-/)
                    if (!source.eat(symbolRE)) {
                        source.skipToEnd()
                        return 'comment'
                    }
                }
                var t = 'variable'
                if (ch == ':') {
                    t = 'variable-2'
                }
                source.eatWhile(symbolRE)
                return t
            }

            return 'error'
        }

        function ncomment(type, nest) {
            if (nest == 0) {
                return normal
            }
            return function (source, setState) {
                var currNest = nest
                while (!source.eol()) {
                    var ch = source.next()
                    if (ch == '{' && source.eat('-')) {
                        ++currNest
                    } else if (ch == '-' && source.eat('}')) {
                        --currNest
                        if (currNest == 0) {
                            setState(normal)
                            return type
                        }
                    }
                }
                setState(ncomment(type, currNest))
                return type
            }
        }

        function stringLiteral(source, setState) {
            while (!source.eol()) {
                var ch = source.next()
                if (ch == '"') {
                    setState(normal)
                    return 'string'
                }
                if (ch == '\\') {
                    if (source.eol() || source.eat(whiteCharRE)) {
                        setState(stringGap)
                        return 'string'
                    }
                    if (source.eat('&')) {
                    } else {
                        source.next() // should handle other escapes here
                    }
                }
            }
            setState(normal)
            return 'string error'
        }

        function stringGap(source, setState) {
            if (source.eat('\\')) {
                return switchState(source, setState, stringLiteral)
            }
            source.next()
            setState(normal)
            return 'error'
        }

        var wellKnownWords = (function () {
            var wkw = {}
            function setType(t) {
                return function () {
                    for (var i = 0; i < arguments.length; i++) wkw[arguments[i]] = t
                }
            }

            setType('keyword')(
                'case',
                'class',
                'data',
                'default',
                'deriving',
                'do',
                'else',
                'foreign',
                'if',
                'import',
                'in',
                'infix',
                'infixl',
                'infixr',
                'instance',
                'let',
                'module',
                'newtype',
                'of',
                'then',
                'type',
                'where',
                '_'
            )

            setType('keyword')('..', ':', '::', '=', '\\', '<-', '->', '@', '~', '=>')

            setType('builtin')('!!', '$!', '$', '&&', '+', '++', '-', '.', '/', '/=', '<', '<*', '<=', '<$>', '<*>', '=<<', '==', '>', '>=', '>>', '>>=', '^', '^^', '||', '*', '*>', '**')

            setType('builtin')(
                'Applicative',
                'Bool',
                'Bounded',
                'Char',
                'Double',
                'EQ',
                'Either',
                'Enum',
                'Eq',
                'False',
                'FilePath',
                'Float',
                'Floating',
                'Fractional',
                'Functor',
                'GT',
                'IO',
                'IOError',
                'Int',
                'Integer',
                'Integral',
                'Just',
                'LT',
                'Left',
                'Maybe',
                'Monad',
                'Nothing',
                'Num',
                'Ord',
                'Ordering',
                'Rational',
                'Read',
                'ReadS',
                'Real',
                'RealFloat',
                'RealFrac',
                'Right',
                'Show',
                'ShowS',
                'String',
                'True'
            )

            setType('builtin')(
                'abs',
                'acos',
                'acosh',
                'all',
                'and',
                'any',
                'appendFile',
                'asTypeOf',
                'asin',
                'asinh',
                'atan',
                'atan2',
                'atanh',
                'break',
                'catch',
                'ceiling',
                'compare',
                'concat',
                'concatMap',
                'const',
                'cos',
                'cosh',
                'curry',
                'cycle',
                'decodeFloat',
                'div',
                'divMod',
                'drop',
                'dropWhile',
                'either',
                'elem',
                'encodeFloat',
                'enumFrom',
                'enumFromThen',
                'enumFromThenTo',
                'enumFromTo',
                'error',
                'even',
                'exp',
                'exponent',
                'fail',
                'filter',
                'flip',
                'floatDigits',
                'floatRadix',
                'floatRange',
                'floor',
                'fmap',
                'foldl',
                'foldl1',
                'foldr',
                'foldr1',
                'fromEnum',
                'fromInteger',
                'fromIntegral',
                'fromRational',
                'fst',
                'gcd',
                'getChar',
                'getContents',
                'getLine',
                'head',
                'id',
                'init',
                'interact',
                'ioError',
                'isDenormalized',
                'isIEEE',
                'isInfinite',
                'isNaN',
                'isNegativeZero',
                'iterate',
                'last',
                'lcm',
                'length',
                'lex',
                'lines',
                'log',
                'logBase',
                'lookup',
                'map',
                'mapM',
                'mapM_',
                'max',
                'maxBound',
                'maximum',
                'maybe',
                'min',
                'minBound',
                'minimum',
                'mod',
                'negate',
                'not',
                'notElem',
                'null',
                'odd',
                'or',
                'otherwise',
                'pi',
                'pred',
                'print',
                'product',
                'properFraction',
                'pure',
                'putChar',
                'putStr',
                'putStrLn',
                'quot',
                'quotRem',
                'read',
                'readFile',
                'readIO',
                'readList',
                'readLn',
                'readParen',
                'reads',
                'readsPrec',
                'realToFrac',
                'recip',
                'rem',
                'repeat',
                'replicate',
                'return',
                'reverse',
                'round',
                'scaleFloat',
                'scanl',
                'scanl1',
                'scanr',
                'scanr1',
                'seq',
                'sequence',
                'sequence_',
                'show',
                'showChar',
                'showList',
                'showParen',
                'showString',
                'shows',
                'showsPrec',
                'significand',
                'signum',
                'sin',
                'sinh',
                'snd',
                'span',
                'splitAt',
                'sqrt',
                'subtract',
                'succ',
                'sum',
                'tail',
                'take',
                'takeWhile',
                'tan',
                'tanh',
                'toEnum',
                'toInteger',
                'toRational',
                'truncate',
                'uncurry',
                'undefined',
                'unlines',
                'until',
                'unwords',
                'unzip',
                'unzip3',
                'userError',
                'words',
                'writeFile',
                'zip',
                'zip3',
                'zipWith',
                'zipWith3'
            )

            var override = modeConfig.overrideKeywords
            if (override) for (var word in override) if (override.hasOwnProperty(word)) wkw[word] = override[word]

            return wkw
        })()

        return {
            startState: function () {
                return { f: normal }
            },
            copyState: function (s) {
                return { f: s.f }
            },

            token: function (stream, state) {
                var t = state.f(stream, function (s) {
                    state.f = s
                })
                var w = stream.current()
                return wellKnownWords.hasOwnProperty(w) ? wellKnownWords[w] : t
            },

            blockCommentStart: '{-',
            blockCommentEnd: '-}',
            lineComment: '--',
        }
    })

    CodeMirror.defineMIME('text/x-haskell', 'haskell')
})