'use strict';

/**
 * Copyright 2009 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS-IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */


var async = require('async');
var Changeset = require('ep_etherpad-lite/static/js/Changeset');
var padManager = require('../db/PadManager');
var eRR = require('async-stacktrace');
var _ = require('underscore');
var Security = require('ep_etherpad-lite/static/js/security');
var hooks = require('ep_etherpad-lite/static/js/pluginfw/hooks');
var eejs = require('ep_etherpad-lite/node/eejs');
var _analyzeLine = require('./ExportHelper')._analyzeLine;
var _encodeWhitespace = require('./ExportHelper')._encodeWhitespace;
// copied from ACE
var _REGEX_WORDCHAR = /[\u0030-\u0039\u0041-\u005A\u0061-\u007A\u00C0-\u00D6\u00D8-\u00F6\u00F8-\u00FF\u0100-\u1FFF\u3040-\u9FFF\uF900-\uFDFF\uFE70-\uFEFE\uFF10-\uFF19\uFF21-\uFF3A\uFF41-\uFF5A\uFF66-\uFFDC]/;
var _REGEX_URLCHAR = new RegExp('(' + (/[-:@a-zA-Z0-9_.,~%+/\\?=&#;()$]/).source + '|' + _REGEX_WORDCHAR.source + ')');
var _REGEX_URL = new RegExp(/(?:(?:https?|s?ftp|ftps|file|smb|afp|nfs|(x-)?man|gopher|txmt):\/\/|mailto:)/.source + _REGEX_URLCHAR.source + '*(?![:.,;])' + _REGEX_URLCHAR.source, 'g');

// returns null if no URLs, or [[startIndex1, url1], [startIndex2, url2], ...]
// copied from ACE
function _processSpaces (s) {
    var doesWrap = true;
    if (s.indexOf('<') < 0 && !doesWrap) {
        // short-cut
        return s.replace(/ /g, '&nbsp;');
    }
    var parts = [];
    s.replace(/<[^>]*>?| |[^ <]+/g, function (m) {
        parts.push(m);
    });
    if (doesWrap) {
        var endOfLine = true;
        var beforeSpace = false;
        // last space in a run is normal, others are nbsp,
        // end of line is nbsp
        for (var i = parts.length - 1; i >= 0; i--) {
            var p = parts[i];
            if (p === ' ') {
                if (endOfLine || beforeSpace) parts[i] = '&nbsp;';
                endOfLine = false;
                beforeSpace = true;
            } else if (p.charAt(0) !== '<') {
                endOfLine = false;
                beforeSpace = false;
            }
        }
        // beginning of line is nbsp
        for (i = 0; i < parts.length; i++) {
            p = parts[i];
            if (p === ' ') {
                parts[i] = '&nbsp;';
                break;
            } else if (p.charAt(0) !== '<') {
                break;
            }
        }
    } else {
        for (i = 0; i < parts.length; i++) {
            p = parts[i];
            if (p === ' ') {
                parts[i] = '&nbsp;';
            }
        }
    }

    return parts.join('');
}

function _findURLs (text) {
    _REGEX_URL.lastIndex = 0;
    var urls = null;
    var execResult;
    while (execResult = _REGEX_URL.exec(text)) {
        urls = urls || [];
        var startIndex = execResult.index;
        var url = execResult[0];
        urls.push([startIndex, url]);
    }

    return urls;
}

/**
     * Return docx from input html
     *
     * @param {text} [pad] text
     * @param {text} [atext] text
     * @param {text} [authorColors] text
     *
     * @returns {html} html
     *
     * @public
     */
function getHTMLFromAtext (pad, atext, authorColors) {
    var apool = pad.apool();
    var textLines = atext.text.slice(0, -1).split('\n');
    var attribLines = Changeset.splitAttributionLines(atext.attribs, atext.text);

    var tags = ['h1', 'h2', 'strong', 'em', 'u', 's'];
    var props = ['heading1', 'heading2', 'bold', 'italic', 'underline', 'strikethrough'];

    // prepare tags stored as ['tag', true] to be exported
    hooks.aCallAll('exportHtmlAdditionalTags', pad, function (err, newProps) {
        if (err) {
            return err;
        }
        newProps.forEach(function (propName) {
            tags.push(propName);
            props.push(propName);
        });
    });
    // prepare tags stored as ['tag', 'value'] to be exported. This will generate HTML
    // with tags like <span data-tag='value'>
    hooks.aCallAll('exportHtmlAdditionalTagsWithData', pad, function (err, newProps) {
        if (err) {
            return err;
        }
        newProps.forEach(function (propName) {
            tags.push('span data-' + propName[0] + '="' + propName[1] + '"');
            props.push(propName);
        });
    });

    // holds a map of used styling attributes (*1, *2, etc) in the apool
    // and maps them to an index in props
    // *3:2 -> the attribute *3 means strong
    // *2:5 -> the attribute *2 means s(trikethrough)
    var anumMap = {};
    var css = '';

    var stripDotFromAuthorID = function (id) {
        return id.replace(/\./g, '_');
    };

    if (authorColors) {
        css += '<style>\n';

        for (var a in apool.numToAttrib) {
            if (apool.numToAttrib.hasOwnProperty.call(a)) {
                var attr = apool.numToAttrib[a];
                var newLength = null;
                var propName = null;
                //skip non author attributes
                if (attr[0] === 'author' && attr[1] !== '') {
                    //add to props array
                    propName = 'author' + stripDotFromAuthorID(attr[1]);
                    newLength = props.push(propName);
                    anumMap[a] = newLength - 1;
    
                    css += '.' + propName + ' {background-color: ' + authorColors[attr[1]] + '}\n';
                } else if (attr[0] === 'removed') {
                    propName = 'removed';
    
                    newLength = props.push(propName);
                    anumMap[a] = newLength - 1;
    
                    css += '.removed {text-decoration: line-through; ' +
                      '-ms-filter:\'progid:DXImageTransform.Microsoft.Alpha(Opacity=80)\'; ' +
                      'filter: alpha(opacity=80); ' +
                      'opacity: 0.8; ' +
                      '}\n';
                }
            }
        }

        css += '</style>';
    }

    // iterates over all props(h1,h2,strong,...), checks if it is used in
    // this pad, and if yes puts its attrib id->props value into anumMap
    props.forEach(function (propName, i) {
        var attrib = [propName, true];
        if (_.isArray(propName)) {
            // propName can be in the form of ['color', 'red'],
            // see hook exportHtmlAdditionalTagsWithData
            attrib = propName;
        }
        var propTrueNum = apool.putAttrib(attrib, true);
        if (propTrueNum >= 0) {
            anumMap[propTrueNum] = i;
        }
    });

    function getLineHTML (text, attribs) {
    // Use order of tags (b/i/u) as order of nesting, for simplicity
    // and decent nesting.  For example,
    // <b>Just bold<b> <b><i>Bold and italics</i></b> <i>Just italics</i>
    // becomes
    // <b>Just bold <i>Bold and italics</i></b> <i>Just italics</i>
        var taker = Changeset.stringIterator(text);
        var assem = Changeset.stringAssembler();
        var openTags = [];

        function getSpanClassFor (i) {
            //return if author colors are disabled
            if (!authorColors) return false;

            var property = props[i];

            // we are not insterested on properties in the form of ['color', 'red'],
            // see hook exportHtmlAdditionalTagsWithData
            if (_.isArray(property)) {
                return false;
            }

            if (property.substr(0, 6) === 'author') {
                return stripDotFromAuthorID(property);
            }

            if (property === 'removed') {
                return 'removed';
            }

            return false;
        }

        // tags added by exportHtmlAdditionalTagsWithData will be exported as <span> with
        // data attributes
        function isSpanWithData (i) {
            var property = props[i];

            return _.isArray(property);
        }

        function emitOpenTag (i) {
            openTags.unshift(i);
            var spanClass = getSpanClassFor(i);

            if (spanClass) {
                assem.append('<span class="');
                assem.append(spanClass);
                assem.append('">');
            } else {
                assem.append('<');
                assem.append(tags[i]);
                assem.append('>');
            }
        }

        // this closes an open tag and removes its reference from openTags
        function emitCloseTag (i) {
            openTags.shift();
            var spanClass = getSpanClassFor(i);
            var spanWithData = isSpanWithData(i);

            if (spanClass || spanWithData) {
                assem.append('</span>');
            } else {
                assem.append('</');
                assem.append(tags[i]);
                assem.append('>');
            }
        }

        var urls = _findURLs(text);

        var idx = 0;

        function processNextChars (numChars) {
            if (numChars <= 0) {
                return;
            }

            var iter = Changeset.opIterator(Changeset.subattribution(attribs, idx, idx + numChars));
            idx += numChars;

            // this iterates over every op string and decides which tags to open or to close
            // based on the attribs used
            while (iter.hasNext()) {
                var o = iter.next();
                var usedAttribs = [];

                // mark all attribs as used
                Changeset.eachAttribNumber(o.attribs, function (a) {
                    if (a in anumMap) {
                        usedAttribs.push(anumMap[a]); // i = 0 => bold, etc.
                    }
                });
                var outermostTag = -1;
                // find the outer most open tag that is no longer used
                for (var i = openTags.length - 1; i >= 0; i--) {
                    if (usedAttribs.indexOf(openTags[i]) === -1) {
                        outermostTag = i;
                        break;
                    }
                }

                // close all tags upto the outer most
                if (outermostTag !== -1) {
                    while (outermostTag >= 0) {
                        emitCloseTag(openTags[0]);
                        outermostTag--;
                    }
                }

                // open all tags that are used but not open
                for (i = 0; i < usedAttribs.length; i++) {
                    if (openTags.indexOf(usedAttribs[i]) === -1) {
                        emitOpenTag(usedAttribs[i]);
                    }
                }

                var chars = o.chars;
                if (o.lines) {
                    chars--; // exclude newline at end of line, if present
                }

                var s = taker.take(chars);

                //removes the characters with the code 12. Don't know where they come
                //from but they break the abiword parser and are completly useless
                s = s.replace(String.fromCharCode(12), '');

                assem.append(_encodeWhitespace(Security.escapeHTML(s)));
            } // end iteration over spans in line

            // close all the tags that are open after the last op
            while (openTags.length > 0) {
                emitCloseTag(openTags[0]);
            }
        } // end processNextChars

        if (urls) {
            urls.forEach(function (urlData) {
                var startIndex = urlData[0];
                var url = urlData[1];
                var urlLength = url.length;
                processNextChars(startIndex - idx);
                assem.append('<a href="' + Security.escapeHTMLAttribute(url) + '">');
                processNextChars(urlLength);
                assem.append('</a>');
            });
        }

        processNextChars(text.length - idx);

        return _processSpaces(assem.toString());
    } // end getLineHTML

    var pieces = [css];

    // Need to deal with constraints imposed on HTML lists; can
    // only gain one level of nesting at once, can't change type
    // mid-list, etc.
    // People might use weird indenting, e.g. skip a level,
    // so we want to do something reasonable there.  We also
    // want to deal gracefully with blank lines.
    // => keeps track of the parents level of indentation
    var openLists = [];
    for (var i = 0; i < textLines.length; i++) {
        var context;
        var line = _analyzeLine(textLines[i], attribLines[i], apool);
        var lineContent = getLineHTML(line.text, line.aline);

        if (line.listLevel) { //If we are inside a list

            context = {
                line: line,
                lineContent: lineContent,
                apool: apool,
                attribLine: attribLines[i],
                text: textLines[i],
                padId: pad.id
            };
            var prevLine = null;
            var nextLine = null;
            if (i > 0) {
                prevLine = _analyzeLine(textLines[i - 1], attribLines[i - 1], apool);
            }
            if (i < textLines.length) {
                nextLine = _analyzeLine(textLines[i + 1], attribLines[i + 1], apool);
            }
            hooks.callAll('getLineHTMLForExport', context);
            //To create list parent elements 
            if ((!prevLine || prevLine.listLevel !== line.listLevel) || (prevLine && line.listTypeName !== prevLine.listTypeName)) {
                //pieces.push('<ul class="' + line.listTypeName + '">');
                var exists = _.find(openLists, function (item) {
                    return (item.level === line.listLevel && item.type === line.listTypeName); 
                });
                if (!exists) {
                    var prevLevel = prevLine.listLevel || 0;
                    if (prevLine && line.listTypeName !== prevLine.listTypeName) {
                        prevLevel = 0;
                    }

                    for (var diff = prevLevel; diff < line.listLevel; diff++) {
                        openLists.push({level: diff, type: line.listTypeName});
                        var prevPiece = pieces[pieces.length - 1];
                        
                        if (prevPiece.indexOf('<ul') === 0 || prevPiece.indexOf('<ol') === 0 || prevPiece.indexOf('</li>') === 0) {
                            pieces.push('<li>');
                        }
                        
                        if (line.listTypeName === 'number') {
                            pieces.push('<ol class="' + line.listTypeName + '">');
                        } else {
                            pieces.push('<ul class="' + line.listTypeName + '">');
                        }
                    } 
                }
                
            }

            pieces.push('<li>', context.lineContent);

            // To close list elements
            if (nextLine && nextLine.listLevel === line.listLevel && line.listTypeName === nextLine.listTypeName) {
                pieces.push('</li>');
            }
            if ((!nextLine || !nextLine.listLevel || nextLine.listLevel < line.listLevel) || (nextLine && line.listTypeName !== nextLine.listTypeName)) {
                var nextLevel = nextLine.listLevel || 0;
                if (nextLine && line.listTypeName !== nextLine.listTypeName) {
                    nextLevel = 0;
                }

                for (var diff = nextLevel; diff < line.listLevel; diff++) {
                    openLists = openLists.filter(function(el) {
                        return el.level !== diff && el.type !== line.listTypeName;
                    });

                    if (pieces[pieces.length - 1].indexOf('</ul') === 0 || pieces[pieces.length - 1].indexOf('</ol') === 0) {
                        pieces.push('</li>');
                    } 
                    
                    if (line.listTypeName === 'number') {
                        pieces.push('</ol>');
                    } else {
                        pieces.push('</ul>');
                    }
                } 
            }
        } else { //outside any list, need to close line.listLevel of lists
            context = {
                line: line,
                lineContent: lineContent,
                apool: apool,
                attribLine: attribLines[i],
                text: textLines[i],
                padId: pad.id
            };

            hooks.callAll('getLineHTMLForExport', context);
            pieces.push(context.lineContent, '<br>');
        }
    }

    return pieces.join('');
}

function getPadHTML (pad, revNum, callback) {
    var atext = pad.atext;
    var html;
    async.waterfall(
        [
        // fetch revision atext
            function (callback) {
                if (revNum !== undefined) {
                    pad.getInternalRevisionAText(revNum, function (err, revisionAtext) {
                        if (eRR(err, callback)) return;
                        atext = revisionAtext;

                        return callback();
                    });
                } else {
                    return callback(null);
                }
            },

            // convert atext to html
            function (callback) {
                html = getHTMLFromAtext(pad, atext);
                callback(null);
            }
        ],
        // run final callback


        function (err) {
            if (eRR(err, callback)) return;
            callback(null, html);
        }
    );
}

exports.getPadHTML = getPadHTML;
exports.getHTMLFromAtext = getHTMLFromAtext;
exports.getPadHTMLDocument = function (padId, revNum, callback) {
    padManager.getPad(padId, function (err, pad) {
        if (eRR(err, callback)) return;

        var stylesForExportCSS = '';
        // Include some Styles into the Head for Export
        hooks.aCallAll('stylesForExport', padId, function (err, stylesForExport) {
            if (eRR(err, callback)) return;
            stylesForExport.forEach(function (css) {
                stylesForExportCSS += css;
            });

            getPadHTML(pad, revNum, function (err, html) {
                if (eRR(err, callback)) return;
                var exportedDoc = eejs.require('ep_etherpad-lite/templates/export_html.html', {
                    body: html,
                    padId: Security.escapeHTML(padId),
                    extraCSS: stylesForExportCSS
                });
                callback(null, exportedDoc);
            });
        });
    });
};