/*!
 * HTML Parser By John Resig (ejohn.org)
 * Modified by Juriy "kangax" Zaytsev
 * Original code by Erik Arvidsson, Mozilla Public License
 * http://erik.eae.net/simplehtmlparser/simplehtmlparser.js
 */

/*
 * // Use like so:
 * HTMLParser(htmlString, {
 *     start: function(tag, attrs, unary) {},
 *     end: function(tag) {},
 *     chars: function(text) {},
 *     comment: function(text) {}
 * });
 *
 * // or to get an XML string:
 * HTMLtoXML(htmlString);
 *
 * // or to get an XML DOM Document
 * HTMLtoDOM(htmlString);
 *
 * // or to inject into an existing document/DOM node
 * HTMLtoDOM(htmlString, document);
 * HTMLtoDOM(htmlString, document.body);
 *
 */

/* global ActiveXObject, DOMDocument */

'use strict';

var createMapFromString = require('./utils').createMapFromString;

function makeMap(values) {
  return createMapFromString(values, true);
}

// Regular Expressions for parsing tags and attributes
var singleAttrIdentifier = /([^\s"'<>/=]+)/,
    singleAttrAssigns = [/=/],
    singleAttrValues = [
      // attr value double quotes
      /"([^"]*)"+/.source,
      // attr value, single quotes
      /'([^']*)'+/.source,
      // attr value, no quotes
      /([^ \t\n\f\r"'`=<>]+)/.source
    ],
    // https://www.w3.org/TR/1999/REC-xml-names-19990114/#NT-QName
    qnameCapture = (function() {
      var ncname = require('ncname').source.slice(1, -1);
      return '((?:' + ncname + '\\:)?' + ncname + ')';
    })(),
    startTagOpen = new RegExp('^<' + qnameCapture),
    startTagClose = /^\s*(\/?)>/,
    endTag = new RegExp('^<\\/' + qnameCapture + '[^>]*>'),
    doctype = /^<!DOCTYPE [^>]+>/i;

var IS_REGEX_CAPTURING_BROKEN = false;
'x'.replace(/x(.)?/g, function(m, g) {
  IS_REGEX_CAPTURING_BROKEN = g === '';
});

// Empty Elements
var empty = makeMap('area,base,basefont,br,col,embed,frame,hr,img,input,isindex,keygen,link,meta,param,source,track,wbr');

// Inline Elements
var inline = makeMap('a,abbr,acronym,applet,b,basefont,bdo,big,br,button,cite,code,del,dfn,em,font,i,iframe,img,input,ins,kbd,label,map,noscript,object,q,s,samp,script,select,small,span,strike,strong,sub,sup,svg,textarea,tt,u,var');

// Elements that you can, intentionally, leave open
// (and which close themselves)
var closeSelf = makeMap('colgroup,dd,dt,li,options,p,td,tfoot,th,thead,tr,source');

// Attributes that have their values filled in disabled='disabled'
var fillAttrs = makeMap('checked,compact,declare,defer,disabled,ismap,multiple,nohref,noresize,noshade,nowrap,readonly,selected');

// Special Elements (can contain anything)
var special = makeMap('script,style');

// HTML5 tags https://html.spec.whatwg.org/multipage/indices.html#elements-3
// Phrasing Content https://html.spec.whatwg.org/multipage/dom.html#phrasing-content
var nonPhrasing = makeMap('address,article,aside,base,blockquote,body,caption,col,colgroup,dd,details,dialog,div,dl,dt,fieldset,figcaption,figure,footer,form,h1,h2,h3,h4,h5,h6,head,header,hgroup,hr,html,legend,li,menuitem,meta,optgroup,option,param,rp,rt,source,style,summary,tbody,td,tfoot,th,thead,title,tr,track');

var reCache = {};

function attrForHandler(handler) {
  var pattern = singleAttrIdentifier.source +
                '(?:\\s*(' + joinSingleAttrAssigns(handler) + ')' +
                '[ \\t\\n\\f\\r]*(?:' + singleAttrValues.join('|') + '))?';
  if (handler.customAttrSurround) {
    var attrClauses = [];
    for (var i = handler.customAttrSurround.length - 1; i >= 0; i--) {
      attrClauses[i] = '(?:' +
                       '(' + handler.customAttrSurround[i][0].source + ')\\s*' +
                       pattern +
                       '\\s*(' + handler.customAttrSurround[i][1].source + ')' +
                       ')';
    }
    attrClauses.push('(?:' + pattern + ')');
    pattern = '(?:' + attrClauses.join('|') + ')';
  }
  return new RegExp('^\\s*' + pattern);
}

function joinSingleAttrAssigns(handler) {
  return singleAttrAssigns.concat(
    handler.customAttrAssign || []
  ).map(function(assign) {
    return '(?:' + assign.source + ')';
  }).join('|');
}

function HTMLParser(html, handler) {
  var stack = [], lastTag;
  var attribute = attrForHandler(handler);
  var last, prevTag, nextTag;
  while (html) {
    last = html;
    // Make sure we're not in a script or style element
    if (!lastTag || !special(lastTag)) {
      var textEnd = html.indexOf('<');
      if (textEnd === 0) {
        // Comment:
        if (/^<!--/.test(html)) {
          var commentEnd = html.indexOf('-->');

          if (commentEnd >= 0) {
            if (handler.comment) {
              handler.comment(html.substring(4, commentEnd));
            }
            html = html.substring(commentEnd + 3);
            prevTag = '';
            continue;
          }
        }

        // http://en.wikipedia.org/wiki/Conditional_comment#Downlevel-revealed_conditional_comment
        if (/^<!\[/.test(html)) {
          var conditionalEnd = html.indexOf(']>');

          if (conditionalEnd >= 0) {
            if (handler.comment) {
              handler.comment(html.substring(2, conditionalEnd + 1), true /* non-standard */);
            }
            html = html.substring(conditionalEnd + 2);
            prevTag = '';
            continue;
          }
        }

        // Doctype:
        var doctypeMatch = html.match(doctype);
        if (doctypeMatch) {
          if (handler.doctype) {
            handler.doctype(doctypeMatch[0]);
          }
          html = html.substring(doctypeMatch[0].length);
          prevTag = '';
          continue;
        }

        // End tag:
        var endTagMatch = html.match(endTag);
        if (endTagMatch) {
          html = html.substring(endTagMatch[0].length);
          endTagMatch[0].replace(endTag, parseEndTag);
          prevTag = '/' + endTagMatch[1].toLowerCase();
          continue;
        }

        // Start tag:
        var startTagMatch = parseStartTag(html);
        if (startTagMatch) {
          html = startTagMatch.rest;
          handleStartTag(startTagMatch);
          prevTag = startTagMatch.tagName.toLowerCase();
          continue;
        }
      }

      var text;
      if (textEnd >= 0) {
        text = html.substring(0, textEnd);
        html = html.substring(textEnd);
      }
      else {
        text = html;
        html = '';
      }

      // next tag
      var nextTagMatch = parseStartTag(html);
      if (nextTagMatch) {
        nextTag = nextTagMatch.tagName;
      }
      else {
        nextTagMatch = html.match(endTag);
        if (nextTagMatch) {
          nextTag = '/' + nextTagMatch[1];
        }
        else {
          nextTag = '';
        }
      }

      if (handler.chars) {
        handler.chars(text, prevTag, nextTag);
      }
      prevTag = '';

    }
    else {
      var stackedTag = lastTag.toLowerCase();
      var reStackedTag = reCache[stackedTag] || (reCache[stackedTag] = new RegExp('([\\s\\S]*?)</' + stackedTag + '[^>]*>', 'i'));

      html = html.replace(reStackedTag, function(all, text) {
        if (stackedTag !== 'script' && stackedTag !== 'style' && stackedTag !== 'noscript') {
          text = text
            .replace(/<!--([\s\S]*?)-->/g, '$1')
            .replace(/<!\[CDATA\[([\s\S]*?)]]>/g, '$1');
        }

        if (handler.chars) {
          handler.chars(text);
        }

        return '';
      });

      parseEndTag('</' + stackedTag + '>', stackedTag);
    }

    if (html === last) {
      throw new Error('Parse Error: ' + html);
    }
  }

  if (!handler.partialMarkup) {
    // Clean up any remaining tags
    parseEndTag();
  }

  function parseStartTag(input) {
    var start = input.match(startTagOpen);
    if (start) {
      var match = {
        tagName: start[1],
        attrs: []
      };
      input = input.slice(start[0].length);
      var end, attr;
      while (!(end = input.match(startTagClose)) && (attr = input.match(attribute))) {
        input = input.slice(attr[0].length);
        match.attrs.push(attr);
      }
      if (end) {
        match.unarySlash = end[1];
        match.rest = input.slice(end[0].length);
        return match;
      }
    }
  }

  function handleStartTag(match) {
    var tagName = match.tagName;
    var unarySlash = match.unarySlash;

    if (handler.html5 && lastTag === 'p' && nonPhrasing(tagName)) {
      parseEndTag('', lastTag);
    }

    if (!handler.html5) {
      while (lastTag && inline(lastTag)) {
        parseEndTag('', lastTag);
      }
    }

    if (closeSelf(tagName) && lastTag === tagName) {
      parseEndTag('', tagName);
    }

    var unary = empty(tagName) || tagName === 'html' && lastTag === 'head' || !!unarySlash;

    var attrs = match.attrs.map(function(args) {
      var name, value, customOpen, customClose, customAssign, quote;
      var ncp = 7; // number of captured parts, scalar

      // hackish work around FF bug https://bugzilla.mozilla.org/show_bug.cgi?id=369778
      if (IS_REGEX_CAPTURING_BROKEN && args[0].indexOf('""') === -1) {
        if (args[3] === '') { delete args[3]; }
        if (args[4] === '') { delete args[4]; }
        if (args[5] === '') { delete args[5]; }
      }

      function populate(index) {
        customAssign = args[index];
        value = args[index + 1];
        if (typeof value !== 'undefined') {
          return '"';
        }
        value = args[index + 2];
        if (typeof value !== 'undefined') {
          return '\'';
        }
        value = args[index + 3];
        if (typeof value === 'undefined' && fillAttrs(name)) {
          value = name;
        }
        return '';
      }

      var j = 1;
      if (handler.customAttrSurround) {
        for (var i = 0, l = handler.customAttrSurround.length; i < l; i++, j += ncp) {
          name = args[j + 1];
          if (name) {
            quote = populate(j + 2);
            customOpen = args[j];
            customClose = args[j + 6];
            break;
          }
        }
      }

      if (!name && (name = args[j])) {
        quote = populate(j + 1);
      }

      return {
        name: name,
        value: value,
        customAssign: customAssign || '=',
        customOpen: customOpen || '',
        customClose: customClose || '',
        quote: quote || ''
      };
    });

    if (!unary) {
      stack.push({ tag: tagName, attrs: attrs });
      lastTag = tagName;
      unarySlash = '';
    }

    if (handler.start) {
      handler.start(tagName, attrs, unary, unarySlash);
    }
  }

  function parseEndTag(tag, tagName) {
    var pos;

    // Find the closest opened tag of the same type
    if (tagName) {
      var needle = tagName.toLowerCase();
      for (pos = stack.length - 1; pos >= 0; pos--) {
        if (stack[pos].tag.toLowerCase() === needle) {
          break;
        }
      }
    }
    // If no tag name is provided, clean shop
    else {
      pos = 0;
    }

    if (pos >= 0) {
      // Close all the open elements, up the stack
      for (var i = stack.length - 1; i >= pos; i--) {
        if (handler.end) {
          handler.end(stack[i].tag, stack[i].attrs, i > pos || !tag);
        }
      }

      // Remove the open elements from the stack
      stack.length = pos;
      lastTag = pos && stack[pos - 1].tag;
    }
    else if (tagName.toLowerCase() === 'br') {
      if (handler.start) {
        handler.start(tagName, [], true, '');
      }
    }
    else if (tagName.toLowerCase() === 'p') {
      if (handler.start) {
        handler.start(tagName, [], false, '', true);
      }
      if (handler.end) {
        handler.end(tagName, []);
      }
    }
  }
}

exports.HTMLParser = HTMLParser;
exports.HTMLtoXML = function(html) {
  var results = '';

  new HTMLParser(html, {
    start: function(tag, attrs, unary) {
      results += '<' + tag;

      for (var i = 0, len = attrs.length; i < len; i++) {
        results += ' ' + attrs[i].name + '="' + (attrs[i].value || '').replace(/"/g, '&#34;') + '"';
      }

      results += (unary ? '/' : '') + '>';
    },
    end: function(tag) {
      results += '</' + tag + '>';
    },
    chars: function(text) {
      results += text;
    },
    comment: function(text) {
      results += '<!--' + text + '-->';
    },
    ignore: function(text) {
      results += text;
    }
  });

  return results;
};

exports.HTMLtoDOM = function(html, doc) {
  // There can be only one of these elements
  var one = {
    html: true,
    head: true,
    body: true,
    title: true
  };

  // Enforce a structure for the document
  var structure = {
    link: 'head',
    base: 'head'
  };

  if (doc) {
    doc = doc.ownerDocument || doc.getOwnerDocument && doc.getOwnerDocument() || doc;
  }
  else if (typeof DOMDocument !== 'undefined') {
    doc = new DOMDocument();
  }
  else if (typeof document !== 'undefined' && document.implementation && document.implementation.createDocument) {
    doc = document.implementation.createDocument('', '', null);
  }
  else if (typeof ActiveX !== 'undefined') {
    doc = new ActiveXObject('Msxml.DOMDocument');
  }

  var elems = [],
      documentElement = doc.documentElement ||
        doc.getDocumentElement && doc.getDocumentElement();

  // If we're dealing with an empty document then we
  // need to pre-populate it with the HTML document structure
  if (!documentElement && doc.createElement) {
    (function() {
      var html = doc.createElement('html');
      var head = doc.createElement('head');
      head.appendChild(doc.createElement('title'));
      html.appendChild(head);
      html.appendChild(doc.createElement('body'));
      doc.appendChild(html);
    })();
  }

  // Find all the unique elements
  if (doc.getElementsByTagName) {
    for (var i in one) {
      one[i] = doc.getElementsByTagName(i)[0];
    }
  }

  // If we're working with a document, inject contents into
  // the body element
  var curParentNode = one.body;

  new HTMLParser(html, {
    start: function(tagName, attrs, unary) {
      // If it's a pre-built element, then we can ignore
      // its construction
      if (one[tagName]) {
        curParentNode = one[tagName];
        return;
      }

      var elem = doc.createElement(tagName);

      for (var attr in attrs) {
        elem.setAttribute(attrs[attr].name, attrs[attr].value);
      }

      if (structure[tagName] && typeof one[structure[tagName]] !== 'boolean') {
        one[structure[tagName]].appendChild(elem);
      }
      else if (curParentNode && curParentNode.appendChild) {
        curParentNode.appendChild(elem);
      }

      if (!unary) {
        elems.push(elem);
        curParentNode = elem;
      }
    },
    end: function(/* tag */) {
      elems.length -= 1;

      // Init the new parentNode
      curParentNode = elems[elems.length - 1];
    },
    chars: function(text) {
      curParentNode.appendChild(doc.createTextNode(text));
    },
    comment: function(/* text */) {
      // create comment node
    },
    ignore: function(/* text */) {
      // What to do here?
    }
  });

  return doc;
};