// ==UserScript==
// @name Fanfiction.net Unwanted Result Filter
// @namespace   http://www.ficfan.org/
// @description Make up for how limited Fanfiction.net's result filtering is
//              compared to sites like Twisting the Hellmouth.
// @copyright   2014-2015, Stephan Sokolow (http://www.ssokolow.com/)
// @license     MIT; http://www.opensource.org/licenses/mit-license.php
// @version     0.1.0
//
// @require     http://ajax.aspnetcdn.com/ajax/jQuery/jquery-1.11.2.min.js
// @require     https://greasyfork.org/scripts/2855-gm-config/code/GM_config.js?version=33973
//
// @grant       GM_registerMenuCommand
// @grant       GM_getValue
// @grant       GM_setValue
// @grant       GM_log
// @noframes
//
// @match       *://www.fanfiction.net/*
// @downloadURL none
// ==/UserScript==
(function($) {

  /* NOTE TO USERS OF VERSION 0.0.1:
   * Sorry for erasing any modifications you made to the filter settings.
   *
   * I didn't put much thought into version 0.0.1 and, as a result, it was
   * impossible to release an update without erasing modifications.
   *
   * I'm now storing settings via GM_setValue, so it should never happen again
   * and there's a proper configuration GUI available at
   *   Greasemonkey > User Script Commands... > Configure Result Filter...
   */

  // ----==== Configuration ====----

  var fieldDefs = {
    'filter_slash': {
      'section': ['Slash Filter',
        'Hide stories with slash based on warnings in story descriptions'],
        'label': 'Enabled',
        'labelPos': 'right',
        'type': 'checkbox',
        'default': true,
    },
    'hide_slash': {
        'label': 'No Placeholder',
        'labelPos': 'right',
        'type': 'checkbox',
        'default': false,
    },
    'slash_pat': {
      'label': 'Slash is...',
      'title': 'A regular expression which matches slash in descriptions',
      'type': 'text',
      'size': 255,
      'default': ".*(slash|yaoi)([.,!: ]|$)"
    },
    'not_slash_pat': {
      'label': '...but not...',
      'title': 'A regular expression which matches "not slash" and so on',
      'type': 'text',
      'size': 255,
      'default': ".*(fem|not?[ ]+)(slash|yaoi)([.,!: ]|$)"
    },
    'filter_cats': {
      'section': ['Unwanted Category Filter',
        'Hide unwanted fandoms in author pages and "All Crossovers" searches'],
        'label': 'Enabled',
        'labelPos': 'right',
        'type': 'checkbox',
        'default': true,
    },
    'hide_cats': {
        'label': 'No Placeholder',
        'labelPos': 'right',
        'type': 'checkbox',
        'default': false,
    },
    'unwanted_cats': {
      'label': 'Unwanted categories (One per line, blanks lines and lines ' +
        'beginning with # will be ignored):',
        'title': 'One entry per line',
        'type': 'textarea',
        'size': 100,
        'default': [
          "# --== Never wanted ==-- ",
          "Invader Zim",
          "Supernatural",
          "Twilight",
          "",
          "# --== Not right now ==-- ",
          "Harry Potter & Avengers",
          "Naruto",
        ].join("\n"),
    },
    'unwanted_cats_escape': {
      'label': 'Lines are literal strings (uncheck for regular expressions)',
      'labelPos': 'right',
      'title': 'NOTE: Leading/trailing whitespace is always ignored and ' +
               'newlines always have OR behaviour.',
      'type': 'checkbox',
      'default': true,
    },
    'unwanted_cats_commute': {
      'label': 'Automatically generate "B & A" lines from "A & B" lines',
      'labelPos': 'right',
      'title': "WARNING: This will break regexes with & inside () or []",
      'type': 'checkbox',
      'default': true,
    }
  };

  var config_params = {
    'id': 'ffnet_result_filter',
    'title': 'Fanfiction.net Unwanted Result Filter',
    'fields': fieldDefs,
    'css': (
      // Match Fanfiction.net styling
      ".section_header { background-color: #339 !important; }\n" +
      ".section_desc { background-color: #f6f7ee !important; }\n" +
      // Form layout fixes
      "input[type=text], textarea { width: 99%; resize: vertical; }\n" +
      "input[type=checkbox] { vertical-align: middle; }\n" +
      "#ffnet_result_filter_filter_slash_var, " +
      "#ffnet_result_filter_filter_cats_var, " +
      "#ffnet_result_filter_hide_slash_var, " +
      "#ffnet_result_filter_hide_cats_var " +
      "    { display: inline-block; margin-right: 1em !important; } " +
      "#ffnet_result_filter_field_unwanted_cats { min-height: 10em; }"),
    'events': {
      'open': function(doc) {
        $(this.frame).css('border-color', '#d4d4d4');
        $("<div>", {'id': 'gm_modal_back'}).css({
          position: 'fixed',
          top: 0,
          left: 0,
          width: '100%',
          height: '100%',
          background: 'black',
          opacity: 0.15,
        }).click(function() {
          GM_config.close();
        }).appendTo('body');
      },
      'close': function() {
        $('#gm_modal_back').remove();
      }
    }
  };

  // ----==== Functions ====----

  /// Escape string for literal meaning inside a regular expression
  /// Source: http://stackoverflow.com/a/3561711/435253
  var re_escape = function(s) {
    return s.replace(/[-\/\\^$*+?.()|[\]{}]/g, '\\$&');
  };

  /// Use with Array.filter() to remove comments and blank lines
  var rows_filter = function(elem, idx, arr) {
    elem = elem.trim()
    if (elem.charAt(0) == '#' || !elem) {
      return false;
    }
    return true;
  };

  /// Parse an array from a newline-delimited string containing # comments
  var parse_lines = function(s) {
    return s.split("\n").map(function(e, i, a) {
      return e.trim();
    }).filter(rows_filter);
  };

  /// Parse a usable list of category patterns from a raw string
  var parse_cats_list = function(s, escape, commute) {
    // Parse the config
    var cats_raw = parse_lines(s);
    if (escape) { cats_raw = cats_raw.map(re_escape) }
    if (commute) {
      var cats_out = [];
      for (var i = 0, len = cats_raw.length; i < len; i++) {
        var line = cats_raw[i];
        cats_out.push(line);
        var parts = line.split(' & ');
        if (parts.length > 1) {
          cats_out.push(parts[1] + ' & ' + parts[0]);
        }
      }
    }
    return cats_out;
  }

  /// Hide a story entry in a way it can be recovered
  var hide_entry = function(node) {
    $(node).addClass('filtered').hide();
  };

  /// Hide a story entry and add a clickable placeholder
  var add_placeholder = function(node, reason) {
    var $story = $(node);
    var $placeholder = $story.clone();

    $placeholder.html("Click to Show (" + reason + ")").css({
      minHeight: 0,
      maxHeight: '1em',
      color: 'lightgray',
      textAlign: 'center',
      cursor: 'pointer',
    }).click($story, function(e) {
      $(this).slideUp();
      e.data.css('min-height', 0).slideDown();
    }).addClass('filter_placeholder').insertBefore($story);
    hide_entry($story);
  };

  /// Code which must be re-run to reapply filters after changing the config
  var initialize_filters_and_apply = function() {
    // Parse the config
    var bad_cats = parse_cats_list(
      GM_config.get('unwanted_cats'),
      GM_config.get('unwanted_cats_escape'),
      GM_config.get('unwanted_cats_commute')
    );

    // Generate RegExp objects from the parsed config
    var slash_re = new RegExp(GM_config.get('slash_pat'), 'i');
    var not_slash_re = new RegExp(GM_config.get('not_slash_pat'), 'i');
    var cats_re = new RegExp(".*(" + bad_cats.join('|') + ').*Rated:.*');


    // Clean up after any previous run
    $(".filter_placeholder").remove();
    $(".filtered").show();

    var results = $(".z-list");
    for (var i = 0, reslen = results.length; i < reslen; i++) {
      var story = results[i];
      var meta_row = $('.xgray', story).text();
      var description = $('.z-padtop', story).contents()[0].data;

      // TODO: Redesign to collapse runs of hidden entries
      var reason = null;
      if (GM_config.get('filter_slash') && slash_re.test(description)
          && !not_slash_re.test(description)) {
        if (GM_config.get('hide_slash')) {
          hide_entry(story);
        } else {
          add_placeholder(story, "Slash");
        }
      } else if (GM_config.get('filter_cats')) {
        var matches = meta_row.match(cats_re);
        if (matches && matches.length > 0) {
          if (GM_config.get('hide_cats')) {
            hide_entry(story);
          } else {
            add_placeholder(story, matches[1]);
          }
        }
      }
    }
  };

  // ----==== Begin Main Program ====----

  // Stuff which either must or need only be called once
  GM_config.init(config_params);
  GM_config.onChange = initialize_filters_and_apply;
  GM_registerMenuCommand("Configure Result Filter...",
                         function() { GM_config.open(); }, 'C');

  // Clear out ad box which misaligns "Hidden" message if it's first result
  $($('#content_wrapper_inner ins.adsbygoogle').parent()[0]).remove();

  initialize_filters_and_apply();

}).call(this, jQuery);