// 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 nonspace = /\S/g
    var repeat =
        String.prototype.repeat ||
        function (n) {
            return Array(n + 1).join(this)
        }
    function continueComment(cm) {
        if (cm.getOption('disableInput')) return CodeMirror.Pass
        var ranges = cm.listSelections(),
            mode,
            inserts = []
        for (var i = 0; i < ranges.length; i++) {
            var pos = ranges[i].head
            if (!/\bcomment\b/.test(cm.getTokenTypeAt(pos))) return CodeMirror.Pass
            var modeHere = cm.getModeAt(pos)
            if (!mode) mode = modeHere
            else if (mode != modeHere) return CodeMirror.Pass

            var insert = null,
                line,
                found
            var blockStart = mode.blockCommentStart,
                lineCmt = mode.lineComment
            if (blockStart && mode.blockCommentContinue) {
                line = cm.getLine(pos.line)
                var end = line.lastIndexOf(mode.blockCommentEnd, pos.ch - mode.blockCommentEnd.length)
                // 1. if this block comment ended
                // 2. if this is actually inside a line comment
                if (
                    (end != -1 && end == pos.ch - mode.blockCommentEnd.length) ||
                    (lineCmt && (found = line.lastIndexOf(lineCmt, pos.ch - 1)) > -1 && /\bcomment\b/.test(cm.getTokenTypeAt({ line: pos.line, ch: found + 1 })))
                ) {
                    // ...then don't continue it
                } else if (pos.ch >= blockStart.length && (found = line.lastIndexOf(blockStart, pos.ch - blockStart.length)) > -1 && found > end) {
                    // reuse the existing leading spaces/tabs/mixed
                    // or build the correct indent using CM's tab/indent options
                    if (nonspaceAfter(0, line) >= found) {
                        insert = line.slice(0, found)
                    } else {
                        var tabSize = cm.options.tabSize,
                            numTabs
                        found = CodeMirror.countColumn(line, found, tabSize)
                        insert = !cm.options.indentWithTabs ? repeat.call(' ', found) : repeat.call('\t', (numTabs = Math.floor(found / tabSize))) + repeat.call(' ', found - tabSize * numTabs)
                    }
                } else if ((found = line.indexOf(mode.blockCommentContinue)) > -1 && found <= pos.ch && found <= nonspaceAfter(0, line)) {
                    insert = line.slice(0, found)
                }
                if (insert != null) insert += mode.blockCommentContinue
            }
            if (insert == null && lineCmt && continueLineCommentEnabled(cm)) {
                if (line == null) line = cm.getLine(pos.line)
                found = line.indexOf(lineCmt)
                // cursor at pos 0, line comment also at pos 0 => shift it down, don't continue
                if (!pos.ch && !found) insert = ''
                // continue only if the line starts with an optional space + line comment
                else if (found > -1 && nonspaceAfter(0, line) >= found) {
                    // don't continue if there's only space(s) after cursor or the end of the line
                    insert = nonspaceAfter(pos.ch, line) > -1
                    // but always continue if the next line starts with a line comment too
                    if (!insert) {
                        var next = cm.getLine(pos.line + 1) || '',
                            nextFound = next.indexOf(lineCmt)
                        insert = (nextFound > -1 && nonspaceAfter(0, next) >= nextFound) || null
                    }
                    if (insert) {
                        insert = line.slice(0, found) + lineCmt + line.slice(found + lineCmt.length).match(/^\s*/)[0]
                    }
                }
            }
            if (insert == null) return CodeMirror.Pass
            inserts[i] = '\n' + insert
        }

        cm.operation(function () {
            for (var i = ranges.length - 1; i >= 0; i--) cm.replaceRange(inserts[i], ranges[i].from(), ranges[i].to(), '+insert')
        })
    }

    function nonspaceAfter(ch, str) {
        nonspace.lastIndex = ch
        var m = nonspace.exec(str)
        return m ? m.index : -1
    }

    function continueLineCommentEnabled(cm) {
        var opt = cm.getOption('continueComments')
        if (opt && typeof opt == 'object') return opt.continueLineComment !== false
        return true
    }

    CodeMirror.defineOption('continueComments', null, function (cm, val, prev) {
        if (prev && prev != CodeMirror.Init) cm.removeKeyMap('continueComment')
        if (val) {
            var key = 'Enter'
            if (typeof val == 'string') key = val
            else if (typeof val == 'object' && val.key) key = val.key
            var map = { name: 'continueComment' }
            map[key] = continueComment
            cm.addKeyMap(map)
        }
    })
})