/**
 * @license
 * Copyright (C) 2016 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
(function() {
  'use strict';

  const PROJECT_PLACEHOLDER_PATTERN = /\$\{project\}/g;

  Polymer({
    is: 'gr-dashboard-view',

    /**
     * Fired when the title of the page should change.
     *
     * @event title-change
     */

    properties: {
      account: {
        type: Object,
        value: null,
      },
      preferences: Object,
      /** @type {{ selectedChangeIndex: number }} */
      viewState: Object,

      /** @type {{ user: string }} */
      params: {
        type: Object,
      },

      createChangeTap: {
        type: Function,
        value() {
          return this._createChangeTap.bind(this);
        },
      },

      _results: Array,

      /**
       * For showing a "loading..." string during ajax requests.
       */
      _loading: {
        type: Boolean,
        value: true,
      },

      _showDraftsBanner: {
        type: Boolean,
        value: false,
      },

      _showNewUserHelp: {
        type: Boolean,
        value: false,
      },
    },

    observers: [
      '_paramsChanged(params.*)',
    ],

    behaviors: [
      Gerrit.RESTClientBehavior,
    ],

    get options() {
      return this.listChangesOptionsToHex(
          this.ListChangesOption.LABELS,
          this.ListChangesOption.DETAILED_ACCOUNTS,
          this.ListChangesOption.REVIEWED
      );
    },

    attached() {
      this._loadPreferences();
    },

    _loadPreferences() {
      return this.$.restAPI.getLoggedIn().then(loggedIn => {
        if (loggedIn) {
          this.$.restAPI.getPreferences().then(preferences => {
            this.preferences = preferences;
          });
        } else {
          this.preferences = {};
        }
      });
    },

    _getProjectDashboard(project, dashboard) {
      const errFn = response => {
        this.fire('page-error', {response});
      };
      return this.$.restAPI.getDashboard(
          project, dashboard, errFn).then(response => {
            if (!response) {
              return;
            }
            return {
              title: response.title,
              sections: response.sections.map(section => {
                const suffix = response.foreach ? ' ' + response.foreach : '';
                return {
                  name: section.name,
                  query:
                      section.query.replace(
                          PROJECT_PLACEHOLDER_PATTERN, project) + suffix,
                };
              }),
            };
          });
    },

    _computeTitle(user) {
      if (!user || user === 'self') {
        return 'My Reviews';
      }
      return 'Dashboard for ' + user;
    },

    _isViewActive(params) {
      return params.view === Gerrit.Nav.View.DASHBOARD;
    },

    _paramsChanged(paramsChangeRecord) {
      const params = paramsChangeRecord.base;

      if (!this._isViewActive(params)) {
        return Promise.resolve();
      }

      const user = params.user || 'self';

      // NOTE: This method may be called before attachment. Fire title-change
      // in an async so that attachment to the DOM can take place first.
      const title = params.title || this._computeTitle(user);
      this.async(() => this.fire('title-change', {title}));
      return this._reload();
    },

    /**
     * Reloads the element.
     *
     * @return {Promise<!Object>}
     */
    _reload() {
      this._loading = true;
      const {project, dashboard, title, user, sections} = this.params;
      const dashboardPromise = project ?
          this._getProjectDashboard(project, dashboard) :
          Promise.resolve(Gerrit.Nav.getUserDashboard(
              user,
              sections,
              title || this._computeTitle(user)));

      const checkForNewUser = !project && user === 'self';
      return dashboardPromise
          .then(res => this._fetchDashboardChanges(res, checkForNewUser))
          .then(() => {
            this._maybeShowDraftsBanner();
            this.$.reporting.dashboardDisplayed();
          }).catch(err => {
            console.warn(err);
          }).then(() => { this._loading = false; });
    },

    /**
     * Fetches the changes for each dashboard section and sets this._results
     * with the response.
     *
     * @param {!Object} res
     * @param {boolean} checkForNewUser
     * @return {Promise}
     */
    _fetchDashboardChanges(res, checkForNewUser) {
      if (!res) { return Promise.resolve(); }

      const queries = res.sections
          .map(section => section.suffixForDashboard ?
              section.query + ' ' + section.suffixForDashboard :
              section.query);

      if (checkForNewUser) {
        queries.push('owner:self');
      }

      return this.$.restAPI.getChanges(null, queries, null, this.options)
          .then(changes => {
            if (checkForNewUser) {
              // Last set of results is not meant for dashboard display.
              const lastResultSet = changes.pop();
              this._showNewUserHelp = lastResultSet.length == 0;
            }
            this._results = changes.map((results, i) => ({
              sectionName: res.sections[i].name,
              query: res.sections[i].query,
              results,
              isOutgoing: res.sections[i].isOutgoing,
            })).filter((section, i) => i < res.sections.length && (
                !res.sections[i].hideIfEmpty ||
                section.results.length));
          });
    },

    _computeUserHeaderClass(userParam) {
      return userParam === 'self' ? 'hide' : '';
    },

    _handleToggleStar(e) {
      this.$.restAPI.saveChangeStarred(e.detail.change._number,
          e.detail.starred);
    },

    _handleToggleReviewed(e) {
      this.$.restAPI.saveChangeReviewed(e.detail.change._number,
          e.detail.reviewed);
    },

    /**
     * Banner is shown if a user is on their own dashboard and they have draft
     * comments on closed changes.
     */
    _maybeShowDraftsBanner() {
      this._showDraftsBanner = false;
      if (!(this.params.user === 'self')) { return; }

      const draftSection = this._results
          .find(section => section.query === 'has:draft');
      if (!draftSection || !draftSection.results.length) { return; }

      const closedChanges = draftSection.results
          .filter(change => !this.changeIsOpen(change.status));
      if (!closedChanges.length) { return; }

      this._showDraftsBanner = true;
    },

    _computeBannerClass(show) {
      return show ? '' : 'hide';
    },

    _handleOpenDeleteDialog() {
      this.$.confirmDeleteOverlay.open();
    },

    _handleConfirmDelete() {
      this.$.confirmDeleteDialog.disabled = true;
      return this.$.restAPI.deleteDraftComments('-is:open').then(() => {
        this._closeConfirmDeleteOverlay();
        this._reload();
      });
    },

    _closeConfirmDeleteOverlay() {
      this.$.confirmDeleteOverlay.close();
    },

    _computeDraftsLink() {
      return Gerrit.Nav.getUrlForSearchQuery('has:draft -is:open');
    },

    _createChangeTap(e) {
      this.$.destinationDialog.open();
    },

    _handleDestinationConfirm(e) {
      this.$.commandsDialog.branch = e.detail.branch;
      this.$.commandsDialog.open();
    },
  });
})();