// 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) {
    var defaults = {
        pairs: '()[]{}\'\'""',
        closeBefore: ')]}\'":;>',
        triples: '',
        explode: '[]{}',
    }

    var Pos = CodeMirror.Pos

    CodeMirror.defineOption('autoCloseBrackets', false, function (cm, val, old) {
        if (old && old != CodeMirror.Init) {
            cm.removeKeyMap(keyMap)
            cm.state.closeBrackets = null
        }
        if (val) {
            ensureBound(getOption(val, 'pairs'))
            cm.state.closeBrackets = val
            cm.addKeyMap(keyMap)
        }
    })

    function getOption(conf, name) {
        if (name == 'pairs' && typeof conf == 'string') return conf
        if (typeof conf == 'object' && conf[name] != null) return conf[name]
        return defaults[name]
    }

    var keyMap = { Backspace: handleBackspace, Enter: handleEnter }
    function ensureBound(chars) {
        for (var i = 0; i < chars.length; i++) {
            var ch = chars.charAt(i),
                key = "'" + ch + "'"
            if (!keyMap[key]) keyMap[key] = handler(ch)
        }
    }
    ensureBound(defaults.pairs + '`')

    function handler(ch) {
        return function (cm) {
            return handleChar(cm, ch)
        }
    }

    function getConfig(cm) {
        var deflt = cm.state.closeBrackets
        if (!deflt || deflt.override) return deflt
        var mode = cm.getModeAt(cm.getCursor())
        return mode.closeBrackets || deflt
    }

    function handleBackspace(cm) {
        var conf = getConfig(cm)
        if (!conf || cm.getOption('disableInput')) return CodeMirror.Pass

        var pairs = getOption(conf, 'pairs')
        var ranges = cm.listSelections()
        for (var i = 0; i < ranges.length; i++) {
            if (!ranges[i].empty()) return CodeMirror.Pass
            var around = charsAround(cm, ranges[i].head)
            if (!around || pairs.indexOf(around) % 2 != 0) return CodeMirror.Pass
        }
        for (var i = ranges.length - 1; i >= 0; i--) {
            var cur = ranges[i].head
            cm.replaceRange('', Pos(cur.line, cur.ch - 1), Pos(cur.line, cur.ch + 1), '+delete')
        }
    }

    function handleEnter(cm) {
        var conf = getConfig(cm)
        var explode = conf && getOption(conf, 'explode')
        if (!explode || cm.getOption('disableInput')) return CodeMirror.Pass

        var ranges = cm.listSelections()
        for (var i = 0; i < ranges.length; i++) {
            if (!ranges[i].empty()) return CodeMirror.Pass
            var around = charsAround(cm, ranges[i].head)
            if (!around || explode.indexOf(around) % 2 != 0) return CodeMirror.Pass
        }
        cm.operation(function () {
            var linesep = cm.lineSeparator() || '\n'
            cm.replaceSelection(linesep + linesep, null)
            moveSel(cm, -1)
            ranges = cm.listSelections()
            for (var i = 0; i < ranges.length; i++) {
                var line = ranges[i].head.line
                cm.indentLine(line, null, true)
                cm.indentLine(line + 1, null, true)
            }
        })
    }

    function moveSel(cm, dir) {
        var newRanges = [],
            ranges = cm.listSelections(),
            primary = 0
        for (var i = 0; i < ranges.length; i++) {
            var range = ranges[i]
            if (range.head == cm.getCursor()) primary = i
            var pos = range.head.ch || dir > 0 ? { line: range.head.line, ch: range.head.ch + dir } : { line: range.head.line - 1 }
            newRanges.push({ anchor: pos, head: pos })
        }
        cm.setSelections(newRanges, primary)
    }

    function contractSelection(sel) {
        var inverted = CodeMirror.cmpPos(sel.anchor, sel.head) > 0
        return { anchor: new Pos(sel.anchor.line, sel.anchor.ch + (inverted ? -1 : 1)), head: new Pos(sel.head.line, sel.head.ch + (inverted ? 1 : -1)) }
    }

    function handleChar(cm, ch) {
        var conf = getConfig(cm)
        if (!conf || cm.getOption('disableInput')) return CodeMirror.Pass

        var pairs = getOption(conf, 'pairs')
        var pos = pairs.indexOf(ch)
        if (pos == -1) return CodeMirror.Pass

        var closeBefore = getOption(conf, 'closeBefore')

        var triples = getOption(conf, 'triples')

        var identical = pairs.charAt(pos + 1) == ch
        var ranges = cm.listSelections()
        var opening = pos % 2 == 0

        var type
        for (var i = 0; i < ranges.length; i++) {
            var range = ranges[i],
                cur = range.head,
                curType
            var next = cm.getRange(cur, Pos(cur.line, cur.ch + 1))
            if (opening && !range.empty()) {
                curType = 'surround'
            } else if ((identical || !opening) && next == ch) {
                if (identical && stringStartsAfter(cm, cur)) curType = 'both'
                else if (triples.indexOf(ch) >= 0 && cm.getRange(cur, Pos(cur.line, cur.ch + 3)) == ch + ch + ch) curType = 'skipThree'
                else curType = 'skip'
            } else if (identical && cur.ch > 1 && triples.indexOf(ch) >= 0 && cm.getRange(Pos(cur.line, cur.ch - 2), cur) == ch + ch) {
                if (cur.ch > 2 && /\bstring/.test(cm.getTokenTypeAt(Pos(cur.line, cur.ch - 2)))) return CodeMirror.Pass
                curType = 'addFour'
            } else if (identical) {
                var prev = cur.ch == 0 ? ' ' : cm.getRange(Pos(cur.line, cur.ch - 1), cur)
                if (!CodeMirror.isWordChar(next) && prev != ch && !CodeMirror.isWordChar(prev)) curType = 'both'
                else return CodeMirror.Pass
            } else if (opening && (next.length === 0 || /\s/.test(next) || closeBefore.indexOf(next) > -1)) {
                curType = 'both'
            } else {
                return CodeMirror.Pass
            }
            if (!type) type = curType
            else if (type != curType) return CodeMirror.Pass
        }

        var left = pos % 2 ? pairs.charAt(pos - 1) : ch
        var right = pos % 2 ? ch : pairs.charAt(pos + 1)
        cm.operation(function () {
            if (type == 'skip') {
                moveSel(cm, 1)
            } else if (type == 'skipThree') {
                moveSel(cm, 3)
            } else if (type == 'surround') {
                var sels = cm.getSelections()
                for (var i = 0; i < sels.length; i++) sels[i] = left + sels[i] + right
                cm.replaceSelections(sels, 'around')
                sels = cm.listSelections().slice()
                for (var i = 0; i < sels.length; i++) sels[i] = contractSelection(sels[i])
                cm.setSelections(sels)
            } else if (type == 'both') {
                cm.replaceSelection(left + right, null)
                cm.triggerElectric(left + right)
                moveSel(cm, -1)
            } else if (type == 'addFour') {
                cm.replaceSelection(left + left + left + left, 'before')
                moveSel(cm, 1)
            }
        })
    }

    function charsAround(cm, pos) {
        var str = cm.getRange(Pos(pos.line, pos.ch - 1), Pos(pos.line, pos.ch + 1))
        return str.length == 2 ? str : null
    }

    function stringStartsAfter(cm, pos) {
        var token = cm.getTokenAt(Pos(pos.line, pos.ch + 1))
        return /\bstring/.test(token.type) && token.start == pos.ch && (pos.ch == 0 || !/\bstring/.test(cm.getTokenTypeAt(pos)))
    }
})