//
//  Copyright (c) 2012 Stefan Bolte <portix@gmx.net>
//
//  This program is free software; you can redistribute it and/or modify
//  it under the terms of the GNU General Public License as published by
//  the Free Software Foundation; either version 3 of the License, or
//  (at your option) any later version.
//  
//  This program is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU General Public License for more details.
//  
//  You should have received a copy of the GNU General Public License along
//  with this program; if not, write to the Free Software Foundation, Inc.,
//  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
//
/*
 * Block requests from thirdparty domains
 *
 * Extension that blocks requests from thirdparty domains with whitelisting
 * support, either permanently or just for the session.
 * It is also possible to block requests from certain domains on all sites, they
 * have highest precedence and will also be blocked on sites where 
 * thirdparty requests are allowed in general. 
 *
 *
 * To use this extension load it with a userscript in
 * $HOME/.config/dwb/userscripts/, e.g. 
 *
 * ------------------------------------------------------------------------------
 * |#!javascript                                                                | 
 * |                                                                            | 
 * |extensions.load("requestpolicy");                                           | 
 * ------------------------------------------------------------------------------
 *
 *
 * Configuration options:
 *
 * shortcut       : Shortcut to block / allow requests, default "erp"
 *
 * unblockCurrent : Shortcut to unblock always blocked requests, shows only
 *                  domains from the current site, default "erC"
 *
 * unblockAll     : Shortcut to unblock always blocked requests, shows all
 *                  blocked domains, default "erA"
 *
 * whiteList      : A path to the whitelisting file, default is
 *                  $XDG_CONFIG_HOME/dwb/<profile>/requestpolicy.json
 *
 * autoreload     : Whether to automatically reload the website after the
 *                  persistentList has changed, default false
 *
 * notify         : Whether to notify about blocked request, default false
 *
 *
 * Example (loading config with extensions.load()) 
 *
 * ------------------------------------------------------------------------------
 * |extensions.load("requestpolicy", {                                          |
 * |    whiteList  : system.getEnv("HOME") + "/.dwb_request_policy",            |
 * |    autoreload      : true                                                  |
 * |});                                                                         |
 * ------------------------------------------------------------------------------
 *
 * Example extensionrc:
 *
 * ------------------------------------------------------------------------------
 * |return {                                                                    |
 * |   foo : { ... },                                                           |
 * |                                                                            |
 * |   requestpolicy : {                                                        |
 * |      autoreload    : true                                                  |
 * |      shortcut : "rp",                                                      |
 * |      notify : false                                                        |
 * |   },                                                                       |
 * |   bar : { ... }                                                            |
 * |}                                                                           |
 * ------------------------------------------------------------------------------
 *
 * */

var me = "requestpolicy";

var defaultConfig = {
//<DEFAULT_CONFIG
  // path to a whitelist 
  whiteList : data.configDir + "/" + data.profile + "/requestpolicy.json",

  // shortcut to block/allow requests
  shortcut : "erp",

  // shortcut to unblock requests from current site that are blocked on all
  // sites
  unblockCurrent : "erC",

  // shortcut to unblock requests that are blocked on all sites
  unblockAll : "erA",

  // reload current site after blocking / unblocking a request
  autoreload : false, 

  // notify about blocked requests
  notify : false

//>DEFAULT_CONFIG
};
var config = {};

var sigs = {
  resource : -1,
  navigation : -1,
  loadFinished : -1
};

var persistentList = null;
var tmpList = {};

var getPrivate = (function() {
  var priv = "_requestPolicy" + parseInt(Math.random() * 9999999999, 10);
  return function (wv) {
    var o = wv[priv];
    if (o === undefined) {
      o = { domains : [], blocked : 0 };
      Object.defineProperty(wv, priv, {
          value : o,
          writable : true
      });
    }
    return o;
  };
})();

function listAdd(o, key, value, doWrite) {
  if (!o[key])
    o[key] = [];
  if (o[key].fastIndexOf(value) == -1) 
    o[key].push(value);
  if (doWrite) 
    io.write(config.whiteList, "w", JSON.stringify(persistentList));
}
function listRemove(o, firstParty, domain, doWrite) {
  var idx;
  if (o[firstParty] && (idx = o[firstParty].fastIndexOf(domain)) != -1) {
    o[firstParty].splice(idx, 1);
    if (o[firstParty].length === 0) 
      delete o[firstParty];
    if (doWrite) 
      io.write(config.whiteList, "w", JSON.stringify(persistentList));
    return true;
  }
  return false;
}

// MENU {{{
function showMenu() {
  var tmpWhiteListed, whiteListed;
  var isWhiteListed = false;
  var dom, i, l, domains, labels, currentDomain;

  var domain = tabs.current.mainFrame.domain;
  if (domain === null)
    return;

  domains = getPrivate(tabs.current).domains;
  labels = [];
  currentDomain = tabs.current.mainFrame.domain;

  for (i=0, l=domains.length; i<l; ++i){
    (function(dom) {
        if (persistentList._alwaysBlock && persistentList._alwaysBlock.fastIndexOf(dom) != -1) 
          return;
        whiteListed = persistentList[domain] && persistentList[domain].fastIndexOf(dom) != -1;
        tmpWhiteListed = tmpList[domain] && tmpList[domain].fastIndexOf(dom) != -1;
        if (!persistentList._always || persistentList._always.fastIndexOf(dom) == -1) {
          if (!whiteListed && !tmpWhiteListed) {
            labels.push({ 
                left : "[" + dom + "] allow", 
                action : function () {
                  listAdd(persistentList, currentDomain, dom, true);
                }
            });
            labels.push({ 
                left : "[" + dom + "] allow temporarily", 
                action : function() {
                  listAdd(tmpList, currentDomain, dom, false);
                }
            });
          }

          else {
            labels.push({ 
                left : "[" +  dom + "] block",
                action : function() {
                  listRemove(persistentList, currentDomain, dom, true);
                  listRemove(tmpList, currentDomain, dom, false);
                }
            });
          }
        }
        isWhiteListed = isWhiteListed || whiteListed || tmpWhiteListed;
        if (!persistentList._always || persistentList._always.fastIndexOf(dom) == -1) {
          labels.push({
              left : "[" +  dom + "] allow on all sites", 
              action : function() {
                listAdd(persistentList, "_always", dom, true);
              }
          });
        }
        else {
          labels.push({
              left : "[" + dom + "] don't allow on all sites", 
              action : function() {
                listRemove(persistentList, "_always", dom, true);
              }
          });
        }
        labels.push({ 
            left : "[" + dom + "] block on all sites", 
            action : function () {
              listAdd(persistentList, "_alwaysBlock", dom, true);
            }
        });
    })(domains[i]);
  }
  var allAllowed = (persistentList._all && persistentList._all.fastIndexOf(domain) != -1) ||
                   (tmpList._all && tmpList._all.fastIndexOf(domain) != -1);
  if (isWhiteListed || allAllowed) {
    labels.unshift({
        left : "Block all requests on " + domain, 
        action : function () {
          delete persistentList[currentDomain];
          listRemove(persistentList, "_all", currentDomain, false);
          // necessary if persistentList.currentDomain exists
          io.write(config.whiteList, "w", JSON.stringify(persistentList));
          delete tmpList[currentDomain];
          listRemove(tmpList, "_all", currentDomain, false);
        }
    });
  }
  if (allAllowed) {
    labels.unshift({
        left : "Don't allow all requests on " + domain, 
        action : function() {
          listRemove(tmpList, "_all", currentDomain, false);
          listRemove(persistentList, "_all", currentDomain, true);
        }
    });
  }
  else {
    labels.unshift({
        left : "Temporarily allow all requests on " + domain, 
        action : function() {
          listAdd(tmpList, "_all", currentDomain, false);
        }
    });
    labels.unshift({
        left : "Allow all requests on " + domain, 
        action : function() {
          listAdd(persistentList, "_all", currentDomain, true);
        }
    });
  }

  tabComplete("Requestpolicy:", labels, function (response) {
    var i, l, len;
    for (i=0, len = labels.length; i<len; ++i) {
      l = labels[i];
      if (l.left == response) {
        l.action();
        if (config.autoreload) {
          tabs.current.reload();
        }
      }
    }
  }, true);
}//}}}
function unblockCurrent() {
  if (!persistentList._alwaysBlock) {
    io.notify("No domains to unblock");
    return;
  }
  var domains = getPrivate(tabs.current).domains;
  //var domains = persistentList._alwaysBlock;
  var labels = [], i, l;
  for (i=0, l = domains.length; i<l; i++) {
    if (persistentList._alwaysBlock.fastIndexOf(domains[i]) != -1) {
      labels.push({ left : domains[i] });
    }
  }
  if (labels.length > 0) {
    tabComplete("Unblock:", labels, function(response) {
      listRemove(persistentList, "_alwaysBlock", response, true);
      if (config.autoreload) 
        tabs.current.reload();
    }, true);
  }
  else {
    io.notify("No domains to unblock");
  }
}
function unblockAll() {
  if (!persistentList._alwaysBlock) {
    io.notify("No domains to unblock");
    return;
  }
  var i, l, labels = [];
  var domains = persistentList._alwaysBlock;
  for (i=0, l=domains.length; i<l; ++i) {
    labels.push({ left : domains[i] });
  }
  if (labels.length > 0) {
    tabComplete("Unblock:", labels, function(response) {
      listRemove(persistentList, "_alwaysBlock", response, true);
      if (config.autoreload) 
        tabs.current.reload();
    }, true);
  }
}
function blockRequest(wv, request, priv, domain) {
  request.uri = "about:blank";
  priv.blocked++;
  if (config.notify && wv == tabs.current)
    io.notify("RP: blocked " + domain);
  return true;
}
// SIGNALS {{{
var resourceCB = (function () {
  var regexEmpty = /^\s*$/;
  return function resourceCB(wv, frame, request, response) {
    var o, message, domain, firstParty;
    if (regexEmpty.test(request.uri))
      return false;
    message = request.message;
    if (!message)
      return false;
    firstParty = util.domainFromHost(message.firstParty.host);
    domain = util.domainFromHost(message.uri.host);
    if (firstParty == domain)
      return false;
    o = getPrivate(wv);
    if (o.domains.fastIndexOf(domain) == -1) {
      o.domains.push(domain);
    }

    // Check for requests that are always blocked
    if (persistentList._alwaysBlock && persistentList._alwaysBlock.fastIndexOf(domain) != -1) 
      return blockRequest(wv, request, o, domain);

    // Check if domain is always allowed
    if ((persistentList._all && persistentList._all.fastIndexOf(firstParty) != -1) || 
        (tmpList._all && tmpList._all.fastIndexOf(firstParty) != -1)) 
      return false; 

    // Check request is always allowed
    if (persistentList._always && persistentList._always.fastIndexOf(domain) != -1) 
        return false;

    // Check if request is whitelisted
    if (  (!persistentList[firstParty]    || persistentList[firstParty].fastIndexOf(domain) == -1) && 
          (!tmpList[firstParty] || tmpList[firstParty].fastIndexOf(domain) == -1)) 
      return blockRequest(wv, request, o, domain);
  };
})();
function navigationCB(wv, frame) {
  if (frame == wv.mainFrame) {
    var o = getPrivate(wv);
    o.domains = [];
    o.blocked = 0;
  }
}
function loadFinishedCB(wv) {
  if (wv != tabs.current)
    return;

  var blocked = getPrivate(wv).blocked;
  if (blocked > 0) 
    io.notify("RP: blocked " + blocked + " requests");
}

function connect() {
  sigs.resource = signals.connect("resource", resourceCB);
  sigs.navigation = signals.connect("navigation", navigationCB);
  if (config.notify) 
    sigs.loadFinished = signals.connect("loadFinished", loadFinishedCB);
}
function disconnect() {
  sigs.forEach(function (key, value) {
    if (value != -1) {
      signals.disconnect(value);
      sigs[key] = -1;
    }
  });
}//}}}
return {
  init : function(c) {
    config = extensions.getConfig(c, defaultConfig);
    if (system.fileTest(config.whiteList, FileTest.regular | FileTest.symlink)) {
      var rawWhiteList = io.read(config.whiteList);
      try {
        persistentList = JSON.parse(rawWhiteList);
      }
      catch (e) {
        extensions.debug(me, e, "Error parsing persistentList");
      }
    }
    persistentList = persistentList || {};
    connect();
    bind(config.shortcut, showMenu, "requestpolicy");
    bind(config.unblockCurrent, unblockCurrent, "requestpolicyUnblockCurrent");
    bind(config.unblockAll, unblockAll, "requestpolicyUnblockAll");
    return true;
  },
  end : function () {
    disconnect();
    unbind("requestpolicy");
    unbind("requestpolicyUnblockCurrent");
    unbind("requestpolicyUnblockAll");
  }
}
// vim: set ft=javascript: