// 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'

    var listRE = /^(\s*)(>[> ]*|[*+-] \[[x ]\]\s|[*+-]\s|(\d+)([.)]))(\s*)/,
        emptyListRE = /^(\s*)(>[> ]*|[*+-] \[[x ]\]|[*+-]|(\d+)[.)])(\s*)$/,
        unorderedListRE = /[*+-]\s/

    CodeMirror.commands.newlineAndIndentContinueMarkdownList = function (cm) {
        if (cm.getOption('disableInput')) return CodeMirror.Pass
        var ranges = cm.listSelections(),
            replacements = []
        for (var i = 0; i < ranges.length; i++) {
            var pos = ranges[i].head

            // If we're not in Markdown mode, fall back to normal newlineAndIndent
            var eolState = cm.getStateAfter(pos.line)
            var inner = CodeMirror.innerMode(cm.getMode(), eolState)
            if (inner.mode.name !== 'markdown' && inner.mode.helperType !== 'markdown') {
                cm.execCommand('newlineAndIndent')
                return
            } else {
                eolState = inner.state
            }

            var inList = eolState.list !== false
            var inQuote = eolState.quote !== 0

            var line = cm.getLine(pos.line),
                match = listRE.exec(line)
            var cursorBeforeBullet = /^\s*$/.test(line.slice(0, pos.ch))
            if (!ranges[i].empty() || (!inList && !inQuote) || !match || cursorBeforeBullet) {
                cm.execCommand('newlineAndIndent')
                return
            }
            if (emptyListRE.test(line)) {
                var endOfQuote = inQuote && />\s*$/.test(line)
                var endOfList = !/>\s*$/.test(line)
                if (endOfQuote || endOfList)
                    cm.replaceRange(
                        '',
                        {
                            line: pos.line,
                            ch: 0,
                        },
                        {
                            line: pos.line,
                            ch: pos.ch + 1,
                        }
                    )
                replacements[i] = '\n'
            } else {
                var indent = match[1],
                    after = match[5]
                var numbered = !(unorderedListRE.test(match[2]) || match[2].indexOf('>') >= 0)
                var bullet = numbered ? parseInt(match[3], 10) + 1 + match[4] : match[2].replace('x', ' ')
                replacements[i] = '\n' + indent + bullet + after

                if (numbered) incrementRemainingMarkdownListNumbers(cm, pos)
            }
        }

        cm.replaceSelections(replacements)
    }

    // Auto-updating Markdown list numbers when a new item is added to the
    // middle of a list
    function incrementRemainingMarkdownListNumbers(cm, pos) {
        var startLine = pos.line,
            lookAhead = 0,
            skipCount = 0
        var startItem = listRE.exec(cm.getLine(startLine)),
            startIndent = startItem[1]

        do {
            lookAhead += 1
            var nextLineNumber = startLine + lookAhead
            var nextLine = cm.getLine(nextLineNumber),
                nextItem = listRE.exec(nextLine)

            if (nextItem) {
                var nextIndent = nextItem[1]
                var newNumber = parseInt(startItem[3], 10) + lookAhead - skipCount
                var nextNumber = parseInt(nextItem[3], 10),
                    itemNumber = nextNumber

                if (startIndent === nextIndent && !isNaN(nextNumber)) {
                    if (newNumber === nextNumber) itemNumber = nextNumber + 1
                    if (newNumber > nextNumber) itemNumber = newNumber + 1
                    cm.replaceRange(
                        nextLine.replace(listRE, nextIndent + itemNumber + nextItem[4] + nextItem[5]),
                        {
                            line: nextLineNumber,
                            ch: 0,
                        },
                        {
                            line: nextLineNumber,
                            ch: nextLine.length,
                        }
                    )
                } else {
                    if (startIndent.length > nextIndent.length) return
                    // This doesn't run if the next line immediately indents, as it is
                    // not clear of the users intention (new indented item or same level)
                    if (startIndent.length < nextIndent.length && lookAhead === 1) return
                    skipCount += 1
                }
            }
        } while (nextItem)
    }
})