background.js

var FF_MAX_SUGGESTIONS = 5;
var FF_MAX_MATCHLENGTH = 1000;
var FF_DEBUGGING = false;
var FF_INCLUDE_HISTORY = true;
var FF_MOVE_TAB_TO_FIRST = false;
var FF_MOVE_TAB_TO_FIRST_TO_CURRENT_WINDOW = false;
var ffHistory = [];
var ffCurrentWindowId;
var ffTabsOnStart = [];

function ffEscapeRegExp(str) {
  return str.replace(/[\-\[\]\/\{\}\(\)\*\+\?\.\\\^\$\|]/g, '\\$&');
}

function ffActivateTag(tab) {
  if (tab.url) {
    chrome.tabs.create({ url: tab.url });
  }
  if (tab.tabId) {
    chrome.tabs.update(tab.tabId, { active: true });
    if (FF_MOVE_TAB_TO_FIRST) {
      chrome.tabs.move(tab.tabId, { index: 0 });
    }
  }
  if (tab.windowId) {
    chrome.windows.update(tab.windowId, { focused: true });
  }
}

function ffEscapeHtml(unsafe) {
  return unsafe.replace(/&/g, '&')
               .replace(/</g, '&lt;')
               .replace(/>/g, '&gt;')
               .replace(/"/g, '&quot;')
               .replace(/'/g, '&#039;');
}

function ffGetHostname(url) {
  var a = document.createElement('a');
  a.href = url;
  return a.hostname;
}

function ffHighlightText(text, words) {
  words
    .map(function (word) { return ffRegexpExactHl(word); })
    .forEach(function (word) {
      if (text.match(word)) {
        text = text.replace(word, '\0$1\1');
      }
    });
  
  words
    .map(function (word) { return ffRegexpFuzzy(word); })
    .forEach(function (word) {
      if (text.match(word)) {
        text = text.replace(word, function (m) {
          return '\0' + m + '\1';
        });
      }
    });
  return ffEscapeHtml(text).replace(new RegExp('\0', 'g'), '<match>')
                           .replace(new RegExp('\1', 'g'), '</match>');
}

function ffCalculateScoreWords(tab, words) {
  var score = 0;
  var hostname = ffGetHostname(tab.url);
  
  var found_words = words.map(function () { return false; });
  
  words
    .map(function (word) { return ffRegexpExact(word); })
    .forEach(function (word, i) {
      if (hostname.match(word)) {
        score += 100;
        found_words[i] = true;
      }
      if (tab.title.match(word)) {
        score += 90;
        found_words[i] = true;
      }
      if (tab.url.match(word)) {
        score += 100;
        found_words[i] = true;
      }
    });
  
  words
    .map(function (word) { return ffRegexpFuzzy(word); })
    .forEach(function (word, i) {
      if (found_words[i]) { return; }
      if (hostname.match(word)) {
        score += 20;
        found_words[i] = true;
      }
      if (tab.title.match(word)) {
        score += 20;
        found_words[i] = true;
      }
      if (tab.url.match(word)) {
        score += 30;
        found_words[i] = true;
      }
    });
  
  if (tab.visitCount) {
    score += tab.visitCount * 10;
  }
  
  if (tab.lastVisitTime) {
    score += tab.lastVisitTime / (new Date().getTime());
  }
  
  if (found_words.filter(function (x) { return x; }).length !== words.length) { score = 0; }
  
  if (FF_DEBUGGING && score > 0) { console.debug('matching tab', tab.lastVisitTime && 'History' || 'Opened', 'id:' + tab.id, 'score:' + score, hostname, tab); }
  return score;
}

function ffRegexpExact(word) {
  return new RegExp(ffEscapeRegExp(word), 'i');
}

function ffRegexpExactHl(word) {
  return new RegExp('(' + ffEscapeRegExp(word) + ')', 'ig');
}

function ffRegexpFuzzy(word) {
  return new RegExp(word.split('').map(function (ch) { return ffEscapeRegExp(ch); }).join('.{0,10}?'), 'i');
}

function ffPrepareTab(tab, words) {
  var content = tab.url + '#' + tab.windowId + '.' + tab.id;
  var desc = ' 🌐<url>' + ffHighlightText(tab.url, words) + '</url> 📄' + ffHighlightText(tab.title, words);
  
  if (tab.score || FF_DEBUGGING) {
    desc = '<url>[' + (tab.score * 0.01).toFixed(1) + ']</url>' + desc;
  }
  
  if (tab.status && tab.status !== 'complete') {
    desc = '[' + tab.status + '] ' + desc;
  }
  
  if (tab.incognito) {
    desc = '<url>[🔒]</url>' + desc;
  }
  
  if (tab.pinned) {
    desc = '<url>[📌]</url>' + desc;
  }
  
  if (tab.audible) {
    desc = '<url>[🔊]</url>' + desc;
  }
  
  if (tab.lastVisitTime) {
    content = tab.url + '#url';
    desc = '<url>[🕑]</url>' + desc;
  }
  
  return { content: content, description: desc };
}

function ffFilter(tabs, words) {
  return tabs.map(function (tab) {
               tab.score = ffCalculateScoreWords(tab, words);
               return tab;
             })
             .filter(function (tab) { return tab.score >= 10 && tab.title.length > 0; })
             .sort(function (tab1, tab2) {
               if (tab1.score < tab2.score) return 1;
               if (tab1.score > tab2.score) return -1;
               return 0;
             })
    ;
}

function ffConcat(tabs1, tabs2) {
  return tabs1.concat(ffTabsWithout(tabs2, tabs1));
}

function ffTabsWithout(whiteTabs, blackTabs) {
  return whiteTabs.filter(function (whiteTab) {
    return 0 === blackTabs.filter(function (blackTab) { return blackTab.url === whiteTab.url; }).length;
  });
}

function ffReorderTabs(tabs) {
  var windows = {};
  /*
   *  move ones for all (doesn't work correctly):
   *
   *  chrome.tabs.move(tabs.map(function(tab) { return tab.id; }), {index: 0});
   */
  
  /*
   *  move once for all tabs in each window (doesn't work correctly):
   *
   *  tabs.forEach(function(tab) {
   *    if(!windows[tab.windowId]) {
   *      windows[tab.windowId] = [];
   *    }
   *    windows[tab.windowId].push(tab);
   *  });
   *  for(var windowId in windows) {
   *    console.log("WINDOW", windowId, windows[windowId]);
   *    chrome.tabs.move(windows[windowId].map(function(tab) { return tab.id; }), {index: 0, windowId: parseInt(windowId)});
   *  }
   */
  
  if (ffTabsOnStart.length === 0) {
    ffTabsOnStart = tabs.map(function (tab) { return { id: tab.id, index: tab.index }; });
  }
  
  tabs.forEach(function (tab, i) {
    if (FF_MOVE_TAB_TO_FIRST_TO_CURRENT_WINDOW && ffCurrentWindowId) {
      // move one by one to current window
      chrome.tabs.move(tab.id, { index: i, windowId: ffCurrentWindowId });
    } else {
      // move one by one
      if (!windows[tab.windowId]) { windows[tab.windowId] = []; }
      windows[tab.windowId].push(true);
      chrome.tabs.move(tab.id, { index: windows[tab.windowId].length - 1 });
    }
  });
}

function ffParseSelected(text) {
  var matchTab = text.match(/#(\d+)\.(\d+)$/);
  
  if (matchTab) {
    return { windowId: +matchTab[1], tabId: +matchTab[2] };
  } else {
    var matchUrl = text.match(/(.*)#url$/);
    if (matchUrl) { return { url: matchUrl[1] }; }
  }
  return null;
}

function ffSearchFor(text) {
  text = text.trim();
  var words = text.split(/\s+/);
  
  var words_exact_hl = text.split(/\s+/).map(function (word) {
    return ffRegexpExactHl(word);
  });
  
  return new Promise(function (resolve, reject) {
    chrome.tabs.query({}, function (array_of_tabs) {
      var matching_tabs = ffFilter(array_of_tabs, words);
      
      if (FF_MOVE_TAB_TO_FIRST) {
        ffReorderTabs(matching_tabs.slice(0, 200));
      }
      
      matching_tabs = matching_tabs.slice(0, FF_MAX_SUGGESTIONS);
      if (FF_INCLUDE_HISTORY && matching_tabs.length < FF_MAX_SUGGESTIONS) {
        chrome.history.search({
                                text: '',
                                maxResults: 5000,
                                startTime: new Date().getTime() - 30 * 24 * 3600 * 1000
                              }, function (array_of_history_items) {
          var matching_histories = ffFilter(array_of_history_items, words);
          resolve(ffConcat(matching_tabs.slice(0, FF_MAX_SUGGESTIONS), matching_histories).map(function (tab) { return ffPrepareTab(tab, words); }));
        });
        return;
      }
      resolve(matching_tabs.map(function (tab) { return ffPrepareTab(tab, words); }));
    });
  });
}

chrome.windows.onFocusChanged.addListener(
  function (windowId) {
    ffCurrentWindowId = windowId;
  }
);

chrome.omnibox.onInputChanged.addListener(
  function (text, suggest) {
    if (FF_DEBUGGING) { console.debug('input changed:', text); }
    ffSearchFor(text).then(function (suggestions) { suggest(suggestions); });
  }
);

chrome.omnibox.onInputCancelled.addListener(
  // TODO this is called even when user presses UP/Down arrows.
  function () {
    // revert tab order (one by one)
    ffTabsOnStart.sort(function (tab1, tab2) {
      if (tab1.index < tab2.index) return 1;
      if (tab1.index > tab2.index) return -1;
      return 0;
    }).forEach(function (tab, i) {
      chrome.tabs.move(tab.id, { index: tab.index });
    });
    ffTabsOnStart = [];
  }
);

chrome.omnibox.onInputEntered.addListener(
  function (text) {
    if (FF_DEBUGGING) {
      console.debug('entered:', text);
      console.debug('history:', ffHistory);
    }
    
    var selected = {};
    
    if (text.length === 0) {
      if (ffHistory.length >= 2) {
        selected = ffHistory[ffHistory.length - 2];
      } else {
        return;
      }
    } else {
      selected = ffParseSelected(text);
      if (!selected) {
        // User probably typed something but selected the first default option,
        // i.e., "Run ff command: query"
        ffSearchFor(text).then(function (suggestions) {
          if (suggestions.length === 0) { return; }
          var selected = ffParseSelected(suggestions[0].content);
          ffHistory.push(selected);
          ffActivateTag(selected);
        });
        return;
      }
    }
    
    ffHistory.push(selected);
    ffActivateTag(selected);
  }
);