/* global SettingsListener, SystemBanner, LazyLoader */
/* exported CrashReporter */
'use strict';

// This file calls getElementById without waiting for an onload event, so it
// must have a defer attribute or be included at the end of the <body>.
var CrashReporter = (function() {
  var _ = navigator.mozL10n.get;
  var settings = navigator.mozSettings;
  var screen = document.getElementById('screen');

  // The name of the app that just crashed. We'll have special handling for
  // when this remains null or is set to null.
  var crashedAppName = null;

  // Whether or not to show a "Report" button in the banner.
  var showReportButton = false;

  // Only show the "Report" button if the user hasn't set a preference to
  // always/never report crashes.
  SettingsListener.observe('app.reportCrashes', 'ask',
      function handleCrashSetting(value) {
    showReportButton = (value != 'always' && value != 'never');
  });

  // This function should only ever be called once.
  function showDialog(crashID, isChrome) {
    var elem = document.getElementById('crash-dialog-title');
    if (isChrome) {
      navigator.mozL10n.setAttributes(elem, 'crash-dialog2-os');
    } else {
      navigator.mozL10n.setAttributes(
        elem,
        'crash-dialog-app',
        { name: crashedAppName || _('crash-dialog-app-noname') }
      );
    }

    // "Don't Send Report" button in dialog
    var noButton = document.getElementById('dont-send-report');
    noButton.addEventListener('click', function onNoButtonClick() {
      settings.createLock().set({'app.reportCrashes': 'never'});
      removeDialog();
    });

    // "Send Report" button in dialog
    var yesButton = document.getElementById('send-report');
    yesButton.addEventListener('click', function onYesButtonClick() {
      submitCrash(crashID);
      if (checkbox.checked) {
        settings.createLock().set({'app.reportCrashes': 'always'});
      }
      removeDialog();
    });

    var checkbox = document.getElementById('always-send');
    checkbox.addEventListener('click', function onCheckboxClick() {
      // Disable the "Don't Send Report" button if the "Always send..."
      // checkbox is checked
      noButton.disabled = this.checked;
    });

    // "What's in a crash report?" link
    var crashInfoLink = document.getElementById('crash-info-link');
    crashInfoLink.addEventListener('click', function onLearnMoreClick() {
      var dialog = document.getElementById('crash-dialog');
      document.getElementById('crash-reports-header').
               addEventListener('action', function onAction() {
        this.removeEventListener('click', onAction);
        dialog.classList.remove('learn-more');
      });
      dialog.classList.add('learn-more');
    });

    screen.classList.add('crash-dialog');
  }

  // We can get rid of the dialog after it is shown once.
  function removeDialog() {
    screen.classList.remove('crash-dialog');
    var dialog = document.getElementById('crash-dialog');
    dialog.parentNode.removeChild(dialog);
  }

  function showBanner(crashID, isChrome) {
    var appName = crashedAppName || _('crash-dialog-app-noname');
    var message = isChrome ? 'crash-banner-os2' :
      {id: 'crash-banner-app', args: { name: appName }};

    var button = null;
    if (showReportButton) {
      button = {
        label: 'crash-banner-report',
        callback: function reportCrash() {
          submitCrash(crashID);
        },
        dismiss: function dismissCrash() {
          deleteCrash(crashID);
        }
      };
    }
    LazyLoader.load(['js/system_banner.js']).then(() => {
      var systemBanner = new SystemBanner();
      systemBanner.show(message, button);
    }).catch((err) => {
      console.error(err);
    });
  }

  function deleteCrash(crashID) {
    var event = document.createEvent('CustomEvent');
    event.initCustomEvent('mozContentEvent', true, true, {
      type: 'delete-crash',
      crashID: crashID
    });
    window.dispatchEvent(event);
  }

  function submitCrash(crashID) {
    var event = document.createEvent('CustomEvent');
    event.initCustomEvent('mozContentEvent', true, true, {
      type: 'submit-crash',
      crashID: crashID
    });
    window.dispatchEvent(event);
  }

  // - Show a dialog only the first time there's a crash to report.
  // - On subsequent crashes, show a banner letting the user know there was a
  //   crash.
  // - If the user hasn't set a pref, add a "Report" button to the banner.
  function handleCrash(crashID, isChrome) {
    // Check to see if we should show a dialog.
    var dialogReq = settings.createLock().get('crashReporter.dialogShown');
    dialogReq.onsuccess = function dialogShownSuccess() {
      var dialogShown = dialogReq.result['crashReporter.dialogShown'];
      if (!dialogShown) {
        settings.createLock().set({'crashReporter.dialogShown': true});
        showDialog(crashID, isChrome);
      } else {
        showBanner(crashID, isChrome);
      }
    };
  }

  // We depend on window_manager.js calling this function before
  // we get a 'handle-crash' event from shell.js
  function setAppName(name) {
    crashedAppName = name;
  }

  // We will be notified of system crashes from shell.js
  window.addEventListener('mozChromeEvent', function handleChromeEvent(e) {
    if (e.detail.type == 'handle-crash') {
      handleCrash(e.detail.crashID, e.detail.chrome);
    }
  });

  function handleAppCrash(e) {
    var app = e.detail;
    // Only show crash reporter when the crashed app is active.
    if (app.isActive()) {
      setAppName(app.name);
    }
  }

  window.addEventListener('appcrashed', handleAppCrash);
  window.addEventListener('activitycrashed', handleAppCrash);
  window.addEventListener('homescreencrashed', handleAppCrash);
  window.addEventListener('searchcrashed', handleAppCrash);

  return {
    handleCrash: handleCrash,
    handleAppCrash: handleAppCrash,
    setAppName: setAppName
  };
})();