//-----------
// FUNCTIONS
//-----------
function getInactiveTabs(callback) {
  chrome.storage.local.get(['sleepyTabsInactiveTabs'], (result) => {
    callback(result.sleepyTabsInactiveTabs || {});
  });
}

function getOptions(callback) {
  chrome.storage.local.get(['sleepyTabsOptions'], (result) => {
    callback(result.sleepyTabsOptions || {
      suspendAfterMins: 30,
      suspendIncognito: false,
      suspendAudible: false,
      whitelistPages: [],
      whitelistDomains: [],
    });
  });
}

function inWhitelist(url, options) {
  let inWhiteList = false;
  options.whitelistPages.every((whitelistUrl, index) => {
    if(url.replace(/\?.*$/, '') == whitelistUrl) {
      inWhiteList = true;
      return false;
    }
    return true;
  });
  if(!inWhiteList) {
    options.whitelistDomains.every((whitelistUrl, index) => {
      if(url.match(whitelistUrl)) {
        inWhiteList = true;
        return false;
      }
      return true;
    });
  }
  return inWhiteList;
}

function setInactiveTabs(inactiveTabs, callback) {
  chrome.storage.local.set({
    sleepyTabsInactiveTabs: inactiveTabs
  }, callback);
}

function setOptions(options, callback) {
  chrome.storage.local.set({
    sleepyTabsOptions: options
  }, callback);
}

function suspendTab(_tab) {
  getInactiveTabs((inactiveTabs) => {
    let _params = new URLSearchParams();
    _params.append('url', _tab.url);
    _params.append('title', _tab.title);
    _params.append('favIconUrl', _tab.favIconUrl);
    chrome.tabs.update(_tab.id, {
      url: 'suspended.html?' + _params
    });
    delete inactiveTabs[_tab.id];
    setInactiveTabs(inactiveTabs);
  });
}

function unSuspendTab(_tab, _updateInactiveTabList = true) {
  getInactiveTabs((inactiveTabs) => {
    if(_tab.url.match('^chrome-extension://' + chrome.runtime.id + '/suspended.html')) { // check if currently suspended
      chrome.tabs.sendMessage(_tab.id, {type: 'UNSUSPEND'}, () => {
        if(_updateInactiveTabList) {
          inactiveTabs[_tab.id] = Date.now();
          setInactiveTabs(inactiveTabs);
        }
      });
    }
  });
}

function startAlarm() {
  stopAlarm(); // just to make sure it's not already running
  setInactiveTabs({}); // re-start timer for inactive tabs
  chrome.alarms.create('sleepyTabsAlarm', {
    when: Date.now(),
    periodInMinutes: 1
  });
}

function stopAlarm() {
  chrome.alarms.clear('sleepyTabsAlarm');
}


//-----------
// LISTENERS
//-----------

// check to suspend tabs (once per minute)
chrome.alarms.onAlarm.addListener((alarm) => {
  if(alarm.name == 'sleepyTabsAlarm') {
    const _currentTime = Date.now();
    getOptions((options) => {
      if(options.suspendAfterMins > 0) {
        getInactiveTabs((inactiveTabs) => {
          chrome.windows.getAll({populate: true}, (_windows) => {
            _windows.forEach((_window, _windowIndex) => {
              _window.tabs.forEach((_tab, _tabIndex) => {
                if(!_tab.active &&
                   !_tab.url.match(/^chrome/) &&
                   !inWhitelist(_tab.url, options) &&
                   !(options.suspendIncognito && _tab.incognito) &&
                   !(options.suspendAudible && _tab.audible)) {
                  if(!inactiveTabs[_tab.id]) {
                    inactiveTabs[_tab.id] = _currentTime;
                    setInactiveTabs(inactiveTabs);
                  } else if(_currentTime - inactiveTabs[_tab.id] >= options.suspendAfterMins * 60000) {
                    suspendTab(_tab);
                  }
                }
              });
            });
          });
        });
      }
    });
  }
});

// remove tab from inactive list when activated
chrome.tabs.onActivated.addListener((activeInfo) => {
  getInactiveTabs((inactiveTabs) => {
    delete inactiveTabs[activeInfo.tabId];
    setInactiveTabs(inactiveTabs);
  });
});

// remove tab from inactive list when removed
chrome.tabs.onRemoved.addListener((tabId, removeInfo) => {
  getInactiveTabs((inactiveTabs) => {
    delete inactiveTabs[tabId];
    setInactiveTabs(inactiveTabs);
  });
});

// listen for messages
chrome.runtime.onMessage.addListener((request, sender, sendResponse) => {
  getOptions((options) => {
    switch(request.type) {
      case 'GET_OPTIONS':
        sendResponse(options);
        break;
      case 'SET_OPTIONS':
        setOptions(request.options);
        if(options.suspendAfterMins > 0 && request.options.suspendAfterMins == 0) {
          stopAlarm();
        } else if(options.suspendAfterMins == 0 && request.options.suspendAfterMins > 0) {
          startAlarm();
        }
        sendResponse();
        break;
      case 'SUSPEND_TAB':
        suspendTab(request.tab);
        sendResponse();
        break;
      case 'UNSUSPEND_TAB':
        unSuspendTab(request.tab);
        sendResponse();
        break;
      case 'SUSPEND_OTHER_TABS':
        chrome.tabs.query({windowId: request.tab.windowId}, (_tabs) => {
          _tabs.forEach((_tab, _tabIndex) => {
            if(_tab.id != request.tab.id && !_tab.url.match(/^chrome/)) {
              suspendTab(_tab);
              sendResponse();
            }
          });
        });
        break;
      case 'UNSUSPEND_ALL_TABS':
        setInactiveTabs({});
        chrome.tabs.query({windowId: request.tab.windowId}, (_tabs) => {
          _tabs.forEach((_tab, _tabIndex) => {
            unSuspendTab(_tab, false);
            sendResponse();
          });
        });
        break;
      case 'NEVER_SUSPEND_PAGE':
        options.whitelistPages.push(request.tab.url.replace(/(^.*)\?.*$/, '$1'));
        setOptions(options);
        sendResponse();
        break;
      case 'REMOVE_NEVER_SUSPEND_PAGE':
        options.whitelistPages.splice(options.whitelistPages.indexOf(request.tab.url.replace(/(^.*)\?.*$/, '$1')));
        setOptions(options);
        sendResponse();
        break;
      case 'NEVER_SUSPEND_DOMAIN':
        options.whitelistDomains.push(request.tab.url.replace(/(^https?:\/\/[^/]+).*$/, '$1'));
        setOptions(options);
        sendResponse();
        break;
      case 'REMOVE_NEVER_SUSPEND_DOMAIN':
        options.whitelistDomains.splice(options.whitelistDomains.indexOf(request.tab.url.replace(/(^https?:\/\/[^/]+).*$/, '$1')));
        setOptions(options);
        sendResponse();
        break;
    }
  });
  return true;
});


//------
// INIT
//------
chrome.runtime.onInstalled.addListener(() => {
  getOptions((options) => {
    if(options.suspendAfterMins > 0) {
      startAlarm();
    }
  });
});