"use strict";

// Helper function to produce an XML tag.
var tag = function(name, attrs, selfclosing) {
    var result = '<' + name;
    if (attrs && attrs.length > 0) {
        var i = 0;
        var attrib;
        while ((attrib = attrs[i]) !== undefined) {
            result = result.concat(' ', attrib[0], '="', attrib[1], '"');
            i++;
        }
    }
    if (selfclosing) {
        result += ' /';
    }

    result += '>';
    return result;
};

var reXMLTag = /\<[^>]*\>/;

var toTagName = function(s) {
    return s.replace(/([a-z])([A-Z])/g, "$1_$2").toLowerCase();
};

var renderNodes = function(block) {

    var attrs;
    var info_words;
    var tagname;
    var walker = block.walker();
    var event, node, entering;
    var buffer = "";
    var lastOut = "\n";
    var disableTags = 0;
    var indentLevel = 0;
    var indent = '  ';
    var grandparent;
    var unescapedContents;
    var container;
    var selfClosing;

    var out = function(s) {
        if (disableTags > 0) {
            buffer += s.replace(reXMLTag, '');
        } else {
            buffer += s;
        }
        lastOut = s;
    };
    var esc = this.escape;
    var cr = function() {
        if (lastOut !== '\n') {
            buffer += '\n';
            lastOut = '\n';
            for (var i = indentLevel; i--;) {
                buffer += indent;
            }
        }
    };

    var options = this.options;

    if (options.time) { console.time("rendering"); }

    buffer += '<?xml version="1.0" encoding="UTF-8"?>\n';
    buffer += '<!DOCTYPE CommonMark SYSTEM "CommonMark.dtd">\n';

    while ((event = walker.next())) {
        entering = event.entering;
        node = event.node;

        if (node.t === 'ReferenceDef') {
            continue;
        }

        container = node.isContainer();
        selfClosing = node.t === 'HorizontalRule' || node.t === 'Hardbreak' ||
            node.t === 'Softbreak' || node.t === 'Image';
        unescapedContents = node.t === 'Html' || node.t === 'HtmlInline';
        tagname = toTagName(node.t);

        if (entering) {

            attrs = [];

            if (node.list_data) {
                var data = node.list_data;
                if (data.type !== undefined) {
                    attrs.push(['type', data.type.toLowerCase()]);
                }
                if (data.start !== undefined) {
                    attrs.push(['start', String(data.start)]);
                }
                if (data.tight !== undefined) {
                    attrs.push(['tight', (data.tight ? 'true' : 'false')]);
                }
                if (data.delimiter !== undefined) {
                    var delimword = '';
                    if (data.delimiter === '.') {
                        delimword = 'period';
                    } else {
                        delimword = 'paren';
                    }
                    attrs.push(['delimiter', delimword]);
                }
            }

            if (node.info !== undefined) {
                attrs.push(['info', node.info]);
            }
            if (node.level !== undefined) {
                attrs.push(['level', String(node.level)]);
            }
            if (node.destination !== undefined) {
                attrs.push(['destination', node.destination]);
            }
            if (node.title !== undefined) {
                attrs.push(['title', node.title]);
            }

            if (options.sourcepos) {
                var pos = node.sourcepos;
                if (pos !== undefined) {
                    attrs.push(['data-sourcepos', String(pos[0][0]) + ':' +
                                String(pos[0][1]) + '-' + String(pos[1][0]) + ':' +
                                String(pos[1][1])]);
                }
            }



            cr();
            out(tag(tagname, attrs, selfClosing));
            if (container) {
                indentLevel += 1;
            } else if (!container && !selfClosing) {
                if (node.literal) {
                    out(unescapedContents ? node.literal : esc(node.literal));
                }
                out(tag('/' + tagname));
            }
        } else {
            indentLevel -= 1;
            cr();
            out(tag('/' + tagname));
        }


    }
    if (options.time) { console.timeEnd("rendering"); }
    buffer += '\n';
    return buffer;
};

var replaceUnsafeChar = function(s) {
    switch (s) {
    case '&':
        return '&amp;';
    case '<':
        return '&lt;';
    case '>':
        return '&gt;';
    case '"':
        return '&quot;';
    default:
        return s;
    }
};

var reNeedsEscaping = /[&<>"]/;

// The XmlRenderer object.
function XmlRenderer(options){
    return {
        // default options:
        softbreak: '\n', // by default, soft breaks are rendered as newlines in HTML
        // set to "<br />" to make them hard breaks
        // set to " " if you want to ignore line wrapping in source
        escape: function(s, preserve_entities) {
            if (reNeedsEscaping.test(s)) {
                if (preserve_entities) {
                    return s.replace(/[&](?:[#](x[a-f0-9]{1,8}|[0-9]{1,8});|[a-z][a-z0-9]{1,31};)|[&<>"]/gi, replaceUnsafeChar);
                } else {
                    return s.replace(/[&<>"]/g, replaceUnsafeChar);
                }
            } else {
                return s;
            }
        },
        options: options || {},
        render: renderNodes
    };
}

module.exports = XmlRenderer;