/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

var EXPORTED_SYMBOLS = ["SafeBrowsing"];

ChromeUtils.import("resource://gre/modules/Services.jsm");

const PREF_DEBUG_ENABLED = "browser.safebrowsing.debug";
let loggingEnabled = false;

// Log only if browser.safebrowsing.debug is true
function log(...stuff) {
  if (!loggingEnabled) {
    return;
  }

  var d = new Date();
  let msg = "SafeBrowsing: " + d.toTimeString() + ": " + stuff.join(" ");
  dump(Services.urlFormatter.trimSensitiveURLs(msg) + "\n");
}

function getLists(prefName) {
  log("getLists: " + prefName);
  let pref = Services.prefs.getCharPref(prefName, "");

  // Splitting an empty string returns [''], we really want an empty array.
  if (!pref) {
    return [];
  }

  return pref.split(",").map(value => value.trim());
}

const tablePreferences = [
  "urlclassifier.phishTable",
  "urlclassifier.malwareTable",
  "urlclassifier.downloadBlockTable",
  "urlclassifier.downloadAllowTable",
  "urlclassifier.passwordAllowTable",
  "urlclassifier.trackingAnnotationTable",
  "urlclassifier.trackingAnnotationWhitelistTable",
  "urlclassifier.trackingTable",
  "urlclassifier.trackingWhitelistTable",
  "urlclassifier.blockedTable",
  "urlclassifier.flashAllowTable",
  "urlclassifier.flashAllowExceptTable",
  "urlclassifier.flashTable",
  "urlclassifier.flashExceptTable",
  "urlclassifier.flashSubDocTable",
  "urlclassifier.flashSubDocExceptTable",
  "urlclassifier.flashInfobarTable"
];

var SafeBrowsing = {

  init() {
    if (this.initialized) {
      log("Already initialized");
      return;
    }

    Services.prefs.addObserver("browser.contentblocking.enabled", this);
    Services.prefs.addObserver("browser.safebrowsing", this);
    Services.prefs.addObserver("privacy.trackingprotection", this);
    Services.prefs.addObserver("urlclassifier", this);
    Services.prefs.addObserver("plugins.flashBlock.enabled", this);
    Services.prefs.addObserver("plugins.show_infobar", this);

    this.readPrefs();
    this.addMozEntries();

    this.controlUpdateChecking();
    this.initialized = true;

    log("init() finished");
  },

  registerTableWithURLs(listname) {
    let listManager = Cc["@mozilla.org/url-classifier/listmanager;1"].
      getService(Ci.nsIUrlListManager);

    let providerName = this.listToProvider[listname];
    let provider = this.providers[providerName];

    if (!providerName || !provider) {
      log("No provider info found for " + listname);
      log("Check browser.safebrowsing.provider.[google/mozilla].lists");
      return;
    }

    if (!provider.updateURL) {
      log("Invalid update url " + listname);
      return;
    }

    listManager.registerTable(listname, providerName, provider.updateURL, provider.gethashURL);
  },

  registerTables() {
    for (let i = 0; i < this.phishingLists.length; ++i) {
      this.registerTableWithURLs(this.phishingLists[i]);
    }
    for (let i = 0; i < this.malwareLists.length; ++i) {
      this.registerTableWithURLs(this.malwareLists[i]);
    }
    for (let i = 0; i < this.downloadBlockLists.length; ++i) {
      this.registerTableWithURLs(this.downloadBlockLists[i]);
    }
    for (let i = 0; i < this.downloadAllowLists.length; ++i) {
      this.registerTableWithURLs(this.downloadAllowLists[i]);
    }
    for (let i = 0; i < this.passwordAllowLists.length; ++i) {
      this.registerTableWithURLs(this.passwordAllowLists[i]);
    }
    for (let i = 0; i < this.trackingAnnotationLists.length; ++i) {
      this.registerTableWithURLs(this.trackingAnnotationLists[i]);
    }
    for (let i = 0; i < this.trackingAnnotationWhitelists.length; ++i) {
      this.registerTableWithURLs(this.trackingAnnotationWhitelists[i]);
    }
    for (let i = 0; i < this.trackingProtectionLists.length; ++i) {
      this.registerTableWithURLs(this.trackingProtectionLists[i]);
    }
    for (let i = 0; i < this.trackingProtectionWhitelists.length; ++i) {
      this.registerTableWithURLs(this.trackingProtectionWhitelists[i]);
    }
    for (let i = 0; i < this.blockedLists.length; ++i) {
      this.registerTableWithURLs(this.blockedLists[i]);
    }
    for (let i = 0; i < this.flashLists.length; ++i) {
      this.registerTableWithURLs(this.flashLists[i]);
    }
    for (let i = 0; i < this.flashInfobarLists.length; ++i) {
      this.registerTableWithURLs(this.flashInfobarLists[i]);
    }
  },

  unregisterTables(obsoleteLists) {
    let listManager = Cc["@mozilla.org/url-classifier/listmanager;1"].
      getService(Ci.nsIUrlListManager);

    for (let i = 0; i < obsoleteLists.length; ++i) {
      for (let j = 0; j < obsoleteLists[i].length; ++j) {
        listManager.unregisterTable(obsoleteLists[i][j]);
      }
    }
  },


  initialized:          false,
  phishingEnabled:      false,
  malwareEnabled:       false,
  downloadsEnabled:     false,
  passwordsEnabled:     false,
  trackingEnabled:      false,
  blockedEnabled:       false,
  trackingAnnotations:  false,
  flashBlockEnabled:    false,
  flashInfobarListEnabled: false,

  phishingLists:                [],
  malwareLists:                 [],
  downloadBlockLists:           [],
  downloadAllowLists:           [],
  passwordAllowLists:           [],
  trackingAnnotationLists:      [],
  trackingAnnotationWhiteLists: [],
  trackingProtectionLists:      [],
  trackingProtectionWhitelists: [],
  blockedLists:                 [],
  flashLists:                   [],
  flashInfobarLists:            [],

  updateURL:             null,
  gethashURL:            null,

  reportURL:             null,

  getReportURL(kind, info) {
    let pref;
    switch (kind) {
      case "Phish":
        pref = "browser.safebrowsing.reportPhishURL";
        break;

      case "PhishMistake":
      case "MalwareMistake":
        pref = "browser.safebrowsing.provider." + info.provider + ".report" + kind + "URL";
        break;

      default:
        let err = "SafeBrowsing getReportURL() called with unknown kind: " + kind;
        Cu.reportError(err);
        throw err;
    }

    // The "Phish" reports are about submitting new phishing URLs to Google so
    // they don't have an associated list URL
    if (kind != "Phish" && (!info.list || !info.uri)) {
      return null;
    }

    let reportUrl = Services.urlFormatter.formatURLPref(pref);
    // formatURLPref might return "about:blank" if getting the pref fails
    if (reportUrl == "about:blank") {
      reportUrl = null;
    }

    if (reportUrl) {
      reportUrl += encodeURIComponent(info.uri);
    }
    return reportUrl;
  },

  observe(aSubject, aTopic, aData) {
    // skip nextupdatetime and lastupdatetime
    if (aData.includes("lastupdatetime") || aData.includes("nextupdatetime")) {
      return;
    }

    if (aData == PREF_DEBUG_ENABLED) {
      loggingEnabled = Services.prefs.getBoolPref(PREF_DEBUG_ENABLED);
      return;
    }

    this.readPrefs();
  },

  readPrefs() {
    loggingEnabled = Services.prefs.getBoolPref(PREF_DEBUG_ENABLED);
    log("reading prefs");

    let contentBlockingEnabled = Services.prefs.getBoolPref("browser.contentblocking.enabled", true);

    this.phishingEnabled = Services.prefs.getBoolPref("browser.safebrowsing.phishing.enabled");
    this.malwareEnabled = Services.prefs.getBoolPref("browser.safebrowsing.malware.enabled");
    this.downloadsEnabled = Services.prefs.getBoolPref("browser.safebrowsing.downloads.enabled");
    this.passwordsEnabled = Services.prefs.getBoolPref("browser.safebrowsing.passwords.enabled");
    this.trackingEnabled = contentBlockingEnabled && (Services.prefs.getBoolPref("privacy.trackingprotection.enabled") || Services.prefs.getBoolPref("privacy.trackingprotection.pbmode.enabled"));
    this.blockedEnabled = Services.prefs.getBoolPref("browser.safebrowsing.blockedURIs.enabled");
    this.trackingAnnotations = Services.prefs.getBoolPref("privacy.trackingprotection.annotate_channels");
    this.flashBlockEnabled = Services.prefs.getBoolPref("plugins.flashBlock.enabled");
    this.flashInfobarListEnabled = Services.prefs.getBoolPref("plugins.show_infobar", false);

    let flashAllowTable, flashAllowExceptTable, flashTable,
        flashExceptTable, flashSubDocTable,
        flashSubDocExceptTable;

    let obsoleteLists;
    // Make a copy of the original lists before we re-read the prefs.
    if (this.initialized) {
      obsoleteLists = [this.phishingLists,
                       this.malwareLists,
                       this.downloadBlockLists,
                       this.downloadAllowLists,
                       this.passwordAllowLists,
                       this.trackingAnnotationLists,
                       this.trackingAnnotationWhitelists,
                       this.trackingProtectionLists,
                       this.trackingProtectionWhitelists,
                       this.blockedLists,
                       this.flashLists,
                       this.flashInfobarLists];
    }

    [this.phishingLists,
     this.malwareLists,
     this.downloadBlockLists,
     this.downloadAllowLists,
     this.passwordAllowLists,
     this.trackingAnnotationLists,
     this.trackingAnnotationWhitelists,
     this.trackingProtectionLists,
     this.trackingProtectionWhitelists,
     this.blockedLists,
     flashAllowTable,
     flashAllowExceptTable,
     flashTable,
     flashExceptTable,
     flashSubDocTable,
     flashSubDocExceptTable,
     this.flashInfobarLists] = tablePreferences.map(getLists);

    this.flashLists = flashAllowTable.concat(flashAllowExceptTable,
                                             flashTable,
                                             flashExceptTable,
                                             flashSubDocTable,
                                             flashSubDocExceptTable);

    if (obsoleteLists) {
      let newLists = [this.phishingLists,
                      this.malwareLists,
                      this.downloadBlockLists,
                      this.downloadAllowLists,
                      this.passwordAllowLists,
                      this.trackingAnnotationLists,
                      this.trackingAnnotationWhitelists,
                      this.trackingProtectionLists,
                      this.trackingProtectionWhitelists,
                      this.blockedLists,
                      this.flashLists,
                      this.flashInfobarLists];

      for (let i = 0; i < obsoleteLists.length; ++i) {
        obsoleteLists[i] = obsoleteLists[i]
          .filter(list => !newLists[i].includes(list));
      }
    }

    this.updateProviderURLs();
    this.registerTables();
    if (obsoleteLists) {
      this.unregisterTables(obsoleteLists);
    }

    // XXX The listManager backend gets confused if this is called before the
    // lists are registered. So only call it here when a pref changes, and not
    // when doing initialization. I expect to refactor this later, so pardon the hack.
    if (this.initialized) {
      this.controlUpdateChecking();
    }
  },


  updateProviderURLs() {
    try {
      var clientID = Services.prefs.getCharPref("browser.safebrowsing.id");
    } catch (e) {
      clientID = Services.appinfo.name;
    }

    log("initializing safe browsing URLs, client id", clientID);

    // Get the different providers
    let branch = Services.prefs.getBranch("browser.safebrowsing.provider.");
    let children = branch.getChildList("", {});
    this.providers = {};
    this.listToProvider = {};

    for (let child of children) {
      log("Child: " + child);
      let prefComponents =  child.split(".");
      let providerName = prefComponents[0];
      this.providers[providerName] = {};
    }

    if (loggingEnabled) {
      let providerStr = "";
      Object.keys(this.providers).forEach(function(provider) {
        if (providerStr === "") {
          providerStr = provider;
        } else {
          providerStr += ", " + provider;
        }
      });
      log("Providers: " + providerStr);
    }

    Object.keys(this.providers).forEach(function(provider) {
      if (provider == "test") {
        return; // skip
      }
      let updateURL = Services.urlFormatter.formatURLPref(
        "browser.safebrowsing.provider." + provider + ".updateURL");
      let gethashURL = Services.urlFormatter.formatURLPref(
        "browser.safebrowsing.provider." + provider + ".gethashURL");
      updateURL = updateURL.replace("SAFEBROWSING_ID", clientID);
      gethashURL = gethashURL.replace("SAFEBROWSING_ID", clientID);

      // Disable updates and gethash if the Google API key is missing.
      let googleKey = Services.urlFormatter.formatURL("%GOOGLE_API_KEY%").trim();
      if ((provider == "google" || provider == "google4") &&
          (!googleKey || googleKey == "no-google-api-key")) {
        log("Missing Google API key, clearing updateURL and gethashURL.");
        updateURL = "";
        gethashURL = "";
      }

      log("Provider: " + provider + " updateURL=" + updateURL);
      log("Provider: " + provider + " gethashURL=" + gethashURL);

      // Urls used to update DB
      this.providers[provider].updateURL  = updateURL;
      this.providers[provider].gethashURL = gethashURL;

      // Get lists this provider manages
      let lists = getLists("browser.safebrowsing.provider." + provider + ".lists");
      if (lists) {
        lists.forEach(function(list) {
          this.listToProvider[list] = provider;
        }, this);
      } else {
        log("Update URL given but no lists managed for provider: " + provider);
      }
    }, this);
  },

  controlUpdateChecking() {
    log("phishingEnabled:", this.phishingEnabled,
        "malwareEnabled:", this.malwareEnabled,
        "downloadsEnabled:", this.downloadsEnabled,
        "passwordsEnabled:", this.passwordsEnabled,
        "trackingEnabled:", this.trackingEnabled,
        "blockedEnabled:", this.blockedEnabled,
        "trackingAnnotations", this.trackingAnnotations,
        "flashBlockEnabled", this.flashBlockEnabled,
        "flashInfobarListEnabled:", this.flashInfobarListEnabled);

    let listManager = Cc["@mozilla.org/url-classifier/listmanager;1"].
                      getService(Ci.nsIUrlListManager);

    listManager.disableAllUpdates();

    for (let i = 0; i < this.phishingLists.length; ++i) {
      if (this.phishingEnabled) {
        listManager.enableUpdate(this.phishingLists[i]);
      }
    }
    for (let i = 0; i < this.malwareLists.length; ++i) {
      if (this.malwareEnabled) {
        listManager.enableUpdate(this.malwareLists[i]);
      }
    }
    for (let i = 0; i < this.downloadBlockLists.length; ++i) {
      if (this.malwareEnabled && this.downloadsEnabled) {
        listManager.enableUpdate(this.downloadBlockLists[i]);
      }
    }
    for (let i = 0; i < this.downloadAllowLists.length; ++i) {
      if (this.malwareEnabled && this.downloadsEnabled) {
        listManager.enableUpdate(this.downloadAllowLists[i]);
      }
    }
    for (let i = 0; i < this.passwordAllowLists.length; ++i) {
      if (this.passwordsEnabled) {
        listManager.enableUpdate(this.passwordAllowLists[i]);
      }
    }
    for (let i = 0; i < this.trackingAnnotationLists.length; ++i) {
      if (this.trackingAnnotations) {
        listManager.enableUpdate(this.trackingAnnotationLists[i]);
      }
    }
    for (let i = 0; i < this.trackingAnnotationWhitelists.length; ++i) {
      if (this.trackingAnnotations) {
        listManager.enableUpdate(this.trackingAnnotationWhitelists[i]);
      }
    }
    for (let i = 0; i < this.trackingProtectionLists.length; ++i) {
      if (this.trackingEnabled) {
        listManager.enableUpdate(this.trackingProtectionLists[i]);
      }
    }
    for (let i = 0; i < this.trackingProtectionWhitelists.length; ++i) {
      if (this.trackingEnabled) {
        listManager.enableUpdate(this.trackingProtectionWhitelists[i]);
      }
    }
    for (let i = 0; i < this.blockedLists.length; ++i) {
      if (this.blockedEnabled) {
        listManager.enableUpdate(this.blockedLists[i]);
      }
    }
    for (let i = 0; i < this.flashLists.length; ++i) {
      if (this.flashBlockEnabled) {
        listManager.enableUpdate(this.flashLists[i]);
      }
    }
    for (let i = 0; i < this.flashInfobarLists.length; ++i) {
      if (this.flashInfobarListEnabled) {
        listManager.enableUpdate(this.flashInfobarLists[i]);
      }
    }
    listManager.maybeToggleUpdateChecking();
  },


  addMozEntries() {
    // Add test entries to the DB.
    // XXX bug 779008 - this could be done by DB itself?
    const phishURL    = "itisatrap.org/firefox/its-a-trap.html";
    const malwareURL  = "itisatrap.org/firefox/its-an-attack.html";
    const unwantedURL = "itisatrap.org/firefox/unwanted.html";
    const harmfulURL  = "itisatrap.org/firefox/harmful.html";
    const trackerURLs = [
      "trackertest.org/",
      "itisatracker.org/",
    ];
    const whitelistURL  = "itisatrap.org/?resource=itisatracker.org";
    const blockedURL    = "itisatrap.org/firefox/blocked.html";

    let update = "n:1000\ni:test-malware-simple\nad:1\n" +
                 "a:1:32:" + malwareURL.length + "\n" +
                 malwareURL + "\n";
    update += "n:1000\ni:test-phish-simple\nad:1\n" +
              "a:1:32:" + phishURL.length + "\n" +
              phishURL + "\n";
    update += "n:1000\ni:test-unwanted-simple\nad:1\n" +
              "a:1:32:" + unwantedURL.length + "\n" +
              unwantedURL + "\n";
    update += "n:1000\ni:test-harmful-simple\nad:1\n" +
              "a:1:32:" + harmfulURL.length + "\n" +
              harmfulURL + "\n";
    update += "n:1000\ni:test-track-simple\n" +
              "ad:" + trackerURLs.length + "\n";
    trackerURLs.forEach((trackerURL, i) => {
      update += "a:" + (i + 1) + ":32:" + trackerURL.length + "\n" +
                trackerURL + "\n";
    });
    update += "n:1000\ni:test-trackwhite-simple\nad:1\n" +
              "a:1:32:" + whitelistURL.length + "\n" +
              whitelistURL;
    update += "n:1000\ni:test-block-simple\nad:1\n" +
              "a:1:32:" + blockedURL.length + "\n" +
              blockedURL;
    log("addMozEntries:", update);

    let db = Cc["@mozilla.org/url-classifier/dbservice;1"].
             getService(Ci.nsIUrlClassifierDBService);

    // nsIUrlClassifierUpdateObserver
    let dummyListener = {
      updateUrlRequested() { },
      streamFinished() { },
      // We notify observers when we're done in order to be able to make perf
      // test results more consistent
      updateError() {
        Services.obs.notifyObservers(db, "mozentries-update-finished", "error");
      },
      updateSuccess() {
        Services.obs.notifyObservers(db, "mozentries-update-finished", "success");
      }
    };

    try {
      let tables = "test-malware-simple,test-phish-simple,test-unwanted-simple,test-harmful-simple,test-track-simple,test-trackwhite-simple,test-block-simple";
      db.beginUpdate(dummyListener, tables, "");
      db.beginStream("", "");
      db.updateStream(update);
      db.finishStream();
      db.finishUpdate();
    } catch (ex) {
      // beginUpdate will throw harmlessly if there's an existing update in progress, ignore failures.
      log("addMozEntries failed!", ex);
      Services.obs.notifyObservers(db, "mozentries-update-finished", "exception");
    }
  },

  addMozEntriesFinishedPromise: new Promise(resolve => {
    let finished = (subject, topic, data) => {
      Services.obs.removeObserver(finished, "mozentries-update-finished");
      if (data == "error") {
        Cu.reportError("addMozEntries failed to update the db!");
      }
      resolve();
    };
    Services.obs.addObserver(finished, "mozentries-update-finished");
  }),
};