/* search-redirect.js
   Redirect functionality. Test if the given query is of the form "name: terms"
   or "search name for terms" where name is one of a list of search engines.
   If this is the case, redirect to a search using this engine.

   External objects:
            RedirectQuery - Class to redirect queries to other engines.
                   RedirectQuery.handle(query) - Test if the query string has the form
		   "name: terms"
	           where name is one of the names specified in redirect_searhches. If so 
	           search with this search engine.

   Semi-external objects:
         RedirectQuery.searches - associative array mapping search engine names to a pair
	 [URL, separator] used to redirect.
	 The URL has the form "...#{keywords}...". Where #{keywords}
	 is replaced with a <separator>-separated list of keywords.

   All objects prefixed with redirect_.
*/


var RedirectQuery = 
{
searches : {
    "ask" : ["http://ask.com/web?q=#{keywords}", "+"],
    "ask images": ["http://ask.com/pictures?q=#{keywords}", "+"],
    "ask news": ["http://ask.com/news?q=#{keywords}", "+"],
    "ask images": ["http://uk.ask.com/pictures?q=#{keywords}", "+"],
    "ebay" : ["http://search.ebay.com/search/search.dll?satitle=#{keywords}", "+"],
    "freedictionary": ["http://www.thefreedictionary.com/#{keywords}", "+"],
    "google": ["http://www.google.com/search?q=#{keywords}", "+"],
    "google code": ["http://code.google.com/#q=#{keywords}", "+"],
    "google images": ["http://images.google.com/images?q=#{keywords}", "+"],
    "google news": ["http://news.google.com/news?q=#{keywords}", "+"],
    "google patents": ["http://www.google.com/patents?q=#{keywords}", "+"],
    "google scholar": ["http://scholar.google.com/scholar?q=#{keywords}", "+"],
    "google shopping": ["http://www.google.com/products?q=#{keywords}", "+"],
    "google maps": ["http://maps.google.com/maps?q=#{keywords}", "+"],
    "google video": ["http://video.google.com/videosearch?q=#{keywords}", "+"],
    "slashdot": ["http://slashdot.org/search.pl?query=#{keywords}", "+"],
    "delicious": ["http://del.icio.us/search/?p=#{keywords}", "+"],
    "wiktionary": ["http://en.wiktionary.org/wiki/cats", "_"],
    "wikiquote" : ["http://en.wikiquote.org/wiki/", "_"],
    "wikipedia": ["http://en.wikipedia.org/wiki/#{keywords}", '_'],
    "yahoo": ["http://search.yahoo.com/search?p=#{keywords}", "+"],
    "youtube": ["http://www.youtube.com/results?search_query=#{keywords}&search=Search", "+"]
},

/* See if the query is meant to be diverted to a different search engine. If so redirect. */
handle : function (query)
{
    for (name in this.searches)
    {
	var URL_template = this.searches[name][0];
	var separator = this.searches[name][1];
	var re_str1 = '^\\s*search\\s+#{name}\\s+for\\s+(.*)';
	var re_str2 = '^\\s*#{name}:\\s*(.*)';
	var re_str3 = '^\\s*using\\s+#{name}\\s+find\\s+(.*)';
	var re_str4 = '\\s*find\\s+(.*)\\s+on\\s+#{name}';
        var re_str5 = '\\s*look\\s+for\\s+(.*)\\s+on\\s+#{name}';
	this._search_verify(name, URL_template, query, separator, re_str1);
	this._search_verify(name, URL_template, query, separator, re_str2);
	this._search_verify(name, URL_template, query, separator, re_str3);
	this._search_verify(name, URL_template, query, separator, re_str4);
	this._search_verify(name, URL_template, query, separator, re_str5);
	// This should become a loop if you add any more regexps.
    }
},

/* Verifies if the search term tells search wikia to search with a different search engine
   and redirect.

   If the search term is of the form <name>: other terms, then the function redirects
   to the URL specified by search_template - obtained by replacing any instance of 
   #{keywods} with a concatenated list of search terms.

   name : The name of the optional seach engine.
   search_template : The URL template for searching with this search engine. A URL
       with #{keywords} in place of the list of keywords.
   newq: The search term as a string.
   sep (optional): The seperator used when created the list of keywords for
       search_template. The default value is '+'
*/

_search_verify: function(name, search_template, newq, sep, re_str)
{
  if (!sep)
  {
    sep = '+';
  }

  expr = new RegExp(re_str.interpolate({name: name}));
  if ((groups = expr.exec(newq)))
  {
      var terms = groups[1].split(/\s+/);
      var term_str = terms.join(sep);
      window.location.assign(search_template.interpolate({'keywords':  term_str}));
  }  
}
};