/**
 * @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 STORAGE_DEBOUNCE_INTERVAL_MS = 400;

  const FocusTarget = {
    ANY: 'any',
    BODY: 'body',
    CCS: 'cc',
    REVIEWERS: 'reviewers',
  };

  const ReviewerTypes = {
    REVIEWER: 'REVIEWER',
    CC: 'CC',
  };

  const LatestPatchState = {
    LATEST: 'latest',
    CHECKING: 'checking',
    NOT_LATEST: 'not-latest',
  };

  const ButtonLabels = {
    START_REVIEW: 'Start review',
    SEND: 'Send',
  };

  const ButtonTooltips = {
    SAVE: 'Save but do not send notification or change review state',
    START_REVIEW: 'Mark as ready for review and send reply',
    SEND: 'Send reply',
  };

  const EMPTY_REPLY_MESSAGE = 'Cannot send an empty reply.';

  const SEND_REPLY_TIMING_LABEL = 'SendReply';

  /**
   * @appliesMixin Gerrit.BaseUrlMixin
   * @appliesMixin Gerrit.FireMixin
   * @appliesMixin Gerrit.KeyboardShortcutMixin
   * @appliesMixin Gerrit.PatchSetMixin
   * @appliesMixin Gerrit.RESTClientMixin
   * @extends Polymer.Element
   */
  class GrReplyDialog extends Polymer.mixinBehaviors( [
    Gerrit.BaseUrlBehavior,
    Gerrit.FireBehavior,
    Gerrit.KeyboardShortcutBehavior,
    Gerrit.PatchSetBehavior,
    Gerrit.RESTClientBehavior,
  ], Polymer.GestureEventListeners(
      Polymer.LegacyElementMixin(
          Polymer.Element))) {
    static get is() { return 'gr-reply-dialog'; }
    /**
     * Fired when a reply is successfully sent.
     *
     * @event send
     */

    /**
     * Fired when the user presses the cancel button.
     *
     * @event cancel
     */

    /**
     * Fired when the main textarea's value changes, which may have triggered
     * a change in size for the dialog.
     *
     * @event autogrow
     */

    /**
     * Fires to show an alert when a send is attempted on the non-latest patch.
     *
     * @event show-alert
     */

    /**
     * Fires when the reply dialog believes that the server side diff drafts
     * have been updated and need to be refreshed.
     *
     * @event comment-refresh
     */

    /**
     * Fires when the state of the send button (enabled/disabled) changes.
     *
     * @event send-disabled-changed
     */

    constructor() {
      super();
      this.FocusTarget = FocusTarget;
    }

    static get properties() {
      return {
      /**
       * @type {{ _number: number, removable_reviewers: Array }}
       */
        change: Object,
        patchNum: String,
        canBeStarted: {
          type: Boolean,
          value: false,
        },
        disabled: {
          type: Boolean,
          value: false,
          reflectToAttribute: true,
        },
        draft: {
          type: String,
          value: '',
          observer: '_draftChanged',
        },
        quote: {
          type: String,
          value: '',
        },
        /** @type {!Function} */
        filterReviewerSuggestion: {
          type: Function,
          value() {
            return this._filterReviewerSuggestionGenerator(false);
          },
        },
        /** @type {!Function} */
        filterCCSuggestion: {
          type: Function,
          value() {
            return this._filterReviewerSuggestionGenerator(true);
          },
        },
        permittedLabels: Object,
        /**
         * @type {{ commentlinks: Array }}
         */
        projectConfig: Object,
        knownLatestState: String,
        underReview: {
          type: Boolean,
          value: true,
        },

        _account: Object,
        _ccs: Array,
        /** @type {?Object} */
        _ccPendingConfirmation: {
          type: Object,
          observer: '_reviewerPendingConfirmationUpdated',
        },
        _messagePlaceholder: {
          type: String,
          computed: '_computeMessagePlaceholder(canBeStarted)',
        },
        _owner: Object,
        /** @type {?} */
        _pendingConfirmationDetails: Object,
        _includeComments: {
          type: Boolean,
          value: true,
        },
        _reviewers: Array,
        /** @type {?Object} */
        _reviewerPendingConfirmation: {
          type: Object,
          observer: '_reviewerPendingConfirmationUpdated',
        },
        _previewFormatting: {
          type: Boolean,
          value: false,
          observer: '_handleHeightChanged',
        },
        _reviewersPendingRemove: {
          type: Object,
          value: {
            CC: [],
            REVIEWER: [],
          },
        },
        _sendButtonLabel: {
          type: String,
          computed: '_computeSendButtonLabel(canBeStarted)',
        },
        _savingComments: Boolean,
        _reviewersMutated: {
          type: Boolean,
          value: false,
        },
        _labelsChanged: {
          type: Boolean,
          value: false,
        },
        _saveTooltip: {
          type: String,
          value: ButtonTooltips.SAVE,
          readOnly: true,
        },
        _pluginMessage: {
          type: String,
          value: '',
        },
        _sendDisabled: {
          type: Boolean,
          computed: '_computeSendButtonDisabled(_sendButtonLabel, ' +
            'draftCommentThreads, draft, _reviewersMutated, _labelsChanged, ' +
            '_includeComments, disabled)',
          observer: '_sendDisabledChanged',
        },
        draftCommentThreads: {
          type: Array,
          observer: '_handleHeightChanged',
        },
      };
    }

    get keyBindings() {
      return {
        'esc': '_handleEscKey',
        'ctrl+enter meta+enter': '_handleEnterKey',
      };
    }

    static get observers() {
      return [
        '_changeUpdated(change.reviewers.*, change.owner)',
        '_ccsChanged(_ccs.splices)',
        '_reviewersChanged(_reviewers.splices)',
      ];
    }

    /** @override */
    attached() {
      super.attached();
      this._getAccount().then(account => {
        this._account = account || {};
      });
    }

    /** @override */
    ready() {
      super.ready();
      this.$.jsAPI.addElement(this.$.jsAPI.Element.REPLY_DIALOG, this);
    }

    open(opt_focusTarget) {
      this.knownLatestState = LatestPatchState.CHECKING;
      this.fetchChangeUpdates(this.change, this.$.restAPI)
          .then(result => {
            this.knownLatestState = result.isLatest ?
              LatestPatchState.LATEST : LatestPatchState.NOT_LATEST;
          });

      this._focusOn(opt_focusTarget);
      if (this.quote && this.quote.length) {
        // If a reply quote has been provided, use it and clear the property.
        this.draft = this.quote;
        this.quote = '';
      } else {
        // Otherwise, check for an unsaved draft in localstorage.
        this.draft = this._loadStoredDraft();
      }
      if (this.$.restAPI.hasPendingDiffDrafts()) {
        this._savingComments = true;
        this.$.restAPI.awaitPendingDiffDrafts().then(() => {
          this.fire('comment-refresh');
          this._savingComments = false;
        });
      }
    }

    focus() {
      this._focusOn(FocusTarget.ANY);
    }

    getFocusStops() {
      const end = this._sendDisabled ? this.$.cancelButton : this.$.sendButton;
      return {
        start: this.$.reviewers.focusStart,
        end,
      };
    }

    setLabelValue(label, value) {
      const selectorEl =
          this.$.labelScores.$$(`gr-label-score-row[name="${label}"]`);
      if (!selectorEl) { return; }
      selectorEl.setSelectedValue(value);
    }

    getLabelValue(label) {
      const selectorEl =
          this.$.labelScores.$$(`gr-label-score-row[name="${label}"]`);
      if (!selectorEl) { return null; }

      return selectorEl.selectedValue;
    }

    _handleEscKey(e) {
      this.cancel();
    }

    _handleEnterKey(e) {
      this._submit();
    }

    _ccsChanged(splices) {
      this._reviewerTypeChanged(splices, ReviewerTypes.CC);
    }

    _reviewersChanged(splices) {
      this._reviewerTypeChanged(splices, ReviewerTypes.REVIEWER);
    }

    _reviewerTypeChanged(splices, reviewerType) {
      if (splices && splices.indexSplices) {
        this._reviewersMutated = true;
        this._processReviewerChange(splices.indexSplices,
            reviewerType);
        let key;
        let index;
        let account;
        // Remove any accounts that already exist as a CC for reviewer
        // or vice versa.
        const isReviewer = ReviewerTypes.REVIEWER === reviewerType;
        for (const splice of splices.indexSplices) {
          for (let i = 0; i < splice.addedCount; i++) {
            account = splice.object[splice.index + i];
            key = this._accountOrGroupKey(account);
            const array = isReviewer ? this._ccs : this._reviewers;
            index = array.findIndex(
                account => this._accountOrGroupKey(account) === key);
            if (index >= 0) {
              this.splice(isReviewer ? '_ccs' : '_reviewers', index, 1);
              const moveFrom = isReviewer ? 'CC' : 'reviewer';
              const moveTo = isReviewer ? 'reviewer' : 'CC';
              const message = (account.name || account.email || key) +
                  ` moved from ${moveFrom} to ${moveTo}.`;
              this.fire('show-alert', {message});
            }
          }
        }
      }
    }

    _processReviewerChange(indexSplices, type) {
      for (const splice of indexSplices) {
        for (const account of splice.removed) {
          if (!this._reviewersPendingRemove[type]) {
            console.err('Invalid type ' + type + ' for reviewer.');
            return;
          }
          this._reviewersPendingRemove[type].push(account);
        }
      }
    }

    /**
     * Resets the state of the _reviewersPendingRemove object, and removes
     * accounts if necessary.
     *
     * @param {boolean} isCancel true if the action is a cancel.
     * @param {Object=} opt_accountIdsTransferred map of account IDs that must
     *     not be removed, because they have been readded in another state.
     */
    _purgeReviewersPendingRemove(isCancel, opt_accountIdsTransferred) {
      let reviewerArr;
      const keep = opt_accountIdsTransferred || {};
      for (const type in this._reviewersPendingRemove) {
        if (this._reviewersPendingRemove.hasOwnProperty(type)) {
          if (!isCancel) {
            reviewerArr = this._reviewersPendingRemove[type];
            for (let i = 0; i < reviewerArr.length; i++) {
              if (!keep[reviewerArr[i]._account_id]) {
                this._removeAccount(reviewerArr[i], type);
              }
            }
          }
          this._reviewersPendingRemove[type] = [];
        }
      }
    }

    /**
     * Removes an account from the change, both on the backend and the client.
     * Does nothing if the account is a pending addition.
     *
     * @param {!Object} account
     * @param {string} type
     */
    _removeAccount(account, type) {
      if (account._pendingAdd) { return; }

      return this.$.restAPI.removeChangeReviewer(this.change._number,
          account._account_id).then(response => {
        if (!response.ok) { return response; }

        const reviewers = this.change.reviewers[type] || [];
        for (let i = 0; i < reviewers.length; i++) {
          if (reviewers[i]._account_id == account._account_id) {
            this.splice(`change.reviewers.${type}`, i, 1);
            break;
          }
        }
      });
    }

    _mapReviewer(reviewer) {
      let reviewerId;
      let confirmed;
      if (reviewer.account) {
        reviewerId = reviewer.account._account_id || reviewer.account.email;
      } else if (reviewer.group) {
        reviewerId = reviewer.group.id;
        confirmed = reviewer.group.confirmed;
      }
      return {reviewer: reviewerId, confirmed};
    }

    send(includeComments, startReview) {
      this.$.reporting.time(SEND_REPLY_TIMING_LABEL);
      const labels = this.$.labelScores.getLabelValues();

      const obj = {
        drafts: includeComments ? 'PUBLISH_ALL_REVISIONS' : 'KEEP',
        labels,
      };

      if (startReview) {
        obj.ready = true;
      }

      if (this.draft != null) {
        obj.message = this.draft;
      }

      const accountAdditions = {};
      obj.reviewers = this.$.reviewers.additions().map(reviewer => {
        if (reviewer.account) {
          accountAdditions[reviewer.account._account_id] = true;
        }
        return this._mapReviewer(reviewer);
      });
      const ccsEl = this.$.ccs;
      if (ccsEl) {
        for (let reviewer of ccsEl.additions()) {
          if (reviewer.account) {
            accountAdditions[reviewer.account._account_id] = true;
          }
          reviewer = this._mapReviewer(reviewer);
          reviewer.state = 'CC';
          obj.reviewers.push(reviewer);
        }
      }

      this.disabled = true;

      const errFn = this._handle400Error.bind(this);
      return this._saveReview(obj, errFn)
          .then(response => {
            if (!response) {
              // Null or undefined response indicates that an error handler
              // took responsibility, so just return.
              return {};
            }
            if (!response.ok) {
              this.fire('server-error', {response});
              return {};
            }

            this.draft = '';
            this._includeComments = true;
            this.fire('send', null, {bubbles: false});
            return accountAdditions;
          })
          .then(result => {
            this.disabled = false;
            return result;
          })
          .catch(err => {
            this.disabled = false;
            throw err;
          });
    }

    _focusOn(section) {
      // Safeguard- always want to focus on something.
      if (!section || section === FocusTarget.ANY) {
        section = this._chooseFocusTarget();
      }
      if (section === FocusTarget.BODY) {
        const textarea = this.$.textarea;
        textarea.async(textarea.getNativeTextarea()
            .focus.bind(textarea.getNativeTextarea()));
      } else if (section === FocusTarget.REVIEWERS) {
        const reviewerEntry = this.$.reviewers.focusStart;
        reviewerEntry.async(reviewerEntry.focus);
      } else if (section === FocusTarget.CCS) {
        const ccEntry = this.$.ccs.focusStart;
        ccEntry.async(ccEntry.focus);
      }
    }

    _chooseFocusTarget() {
      // If we are the owner and the reviewers field is empty, focus on that.
      if (this._account && this.change && this.change.owner &&
          this._account._account_id === this.change.owner._account_id &&
          (!this._reviewers || this._reviewers.length === 0)) {
        return FocusTarget.REVIEWERS;
      }

      // Default to BODY.
      return FocusTarget.BODY;
    }

    _handle400Error(response) {
      // A call to _saveReview could fail with a server error if erroneous
      // reviewers were requested. This is signalled with a 400 Bad Request
      // status. The default gr-rest-api-interface error handling would
      // result in a large JSON response body being displayed to the user in
      // the gr-error-manager toast.
      //
      // We can modify the error handling behavior by passing this function
      // through to restAPI as a custom error handling function. Since we're
      // short-circuiting restAPI we can do our own response parsing and fire
      // the server-error ourselves.
      //
      this.disabled = false;

      // Using response.clone() here, because getResponseObject() and
      // potentially the generic error handler will want to call text() on the
      // response object, which can only be done once per object.
      const jsonPromise = this.$.restAPI.getResponseObject(response.clone());
      return jsonPromise.then(result => {
        // Only perform custom error handling for 400s and a parseable
        // ReviewResult response.
        if (response.status === 400 && result) {
          const errors = [];
          for (const state of ['reviewers', 'ccs']) {
            if (!result.hasOwnProperty(state)) { continue; }
            for (const reviewer of Object.values(result[state])) {
              if (reviewer.error) {
                errors.push(reviewer.error);
              }
            }
          }
          response = {
            ok: false,
            status: response.status,
            text() { return Promise.resolve(errors.join(', ')); },
          };
        }
        this.fire('server-error', {response});
        return null; // Means that the error has been handled.
      });
    }

    _computeHideDraftList(draftCommentThreads) {
      return draftCommentThreads.length === 0;
    }

    _computeDraftsTitle(draftCommentThreads) {
      const total = draftCommentThreads.length;
      if (total == 0) { return ''; }
      if (total == 1) { return '1 Draft'; }
      if (total > 1) { return total + ' Drafts'; }
    }

    _computeMessagePlaceholder(canBeStarted) {
      return canBeStarted ?
        'Add a note for your reviewers...' :
        'Say something nice...';
    }

    _changeUpdated(changeRecord, owner) {
      // Polymer 2: check for undefined
      if ([changeRecord, owner].some(arg => arg === undefined)) {
        return;
      }

      this._rebuildReviewerArrays(changeRecord.base, owner);
    }

    _rebuildReviewerArrays(change, owner) {
      this._owner = owner;

      const reviewers = [];
      const ccs = [];

      for (const key in change) {
        if (change.hasOwnProperty(key)) {
          if (key !== 'REVIEWER' && key !== 'CC') {
            console.warn('unexpected reviewer state:', key);
            continue;
          }
          for (const entry of change[key]) {
            if (entry._account_id === owner._account_id) {
              continue;
            }
            switch (key) {
              case 'REVIEWER':
                reviewers.push(entry);
                break;
              case 'CC':
                ccs.push(entry);
                break;
            }
          }
        }
      }

      this._ccs = ccs;
      this._reviewers = reviewers;
    }

    _accountOrGroupKey(entry) {
      return entry.id || entry._account_id;
    }

    /**
     * Generates a function to filter out reviewer/CC entries. When isCCs is
     * truthy, the function filters out entries that already exist in this._ccs.
     * When falsy, the function filters entries that exist in this._reviewers.
     *
     * @param {boolean} isCCs
     * @return {!Function}
     */
    _filterReviewerSuggestionGenerator(isCCs) {
      return suggestion => {
        let entry;
        if (suggestion.account) {
          entry = suggestion.account;
        } else if (suggestion.group) {
          entry = suggestion.group;
        } else {
          console.warn(
              'received suggestion that was neither account nor group:',
              suggestion);
        }
        if (entry._account_id === this._owner._account_id) {
          return false;
        }

        const key = this._accountOrGroupKey(entry);
        const finder = entry => this._accountOrGroupKey(entry) === key;
        if (isCCs) {
          return this._ccs.find(finder) === undefined;
        }
        return this._reviewers.find(finder) === undefined;
      };
    }

    _getAccount() {
      return this.$.restAPI.getAccount();
    }

    _cancelTapHandler(e) {
      e.preventDefault();
      this.cancel();
    }

    cancel() {
      this.fire('cancel', null, {bubbles: false});
      this.$.textarea.closeDropdown();
      this._purgeReviewersPendingRemove(true);
      this._rebuildReviewerArrays(this.change.reviewers, this._owner);
    }

    _saveClickHandler(e) {
      e.preventDefault();
      if (!this.$.ccs.submitEntryText()) {
        // Do not proceed with the save if there is an invalid email entry in
        // the text field of the CC entry.
        return;
      }
      this.send(this._includeComments, false).then(keepReviewers => {
        this._purgeReviewersPendingRemove(false, keepReviewers);
      });
    }

    _sendTapHandler(e) {
      e.preventDefault();
      this._submit();
    }

    _submit() {
      if (!this.$.ccs.submitEntryText()) {
        // Do not proceed with the send if there is an invalid email entry in
        // the text field of the CC entry.
        return;
      }
      if (this._sendDisabled) {
        this.dispatchEvent(new CustomEvent('show-alert', {
          bubbles: true,
          composed: true,
          detail: {message: EMPTY_REPLY_MESSAGE},
        }));
        return;
      }
      return this.send(this._includeComments, this.canBeStarted)
          .then(keepReviewers => {
            this._purgeReviewersPendingRemove(false, keepReviewers);
          })
          .catch(err => {
            this.dispatchEvent(new CustomEvent('show-error', {
              bubbles: true,
              composed: true,
              detail: {message: `Error submitting review ${err}`},
            }));
          });
    }

    _saveReview(review, opt_errFn) {
      return this.$.restAPI.saveChangeReview(this.change._number, this.patchNum,
          review, opt_errFn);
    }

    _reviewerPendingConfirmationUpdated(reviewer) {
      if (reviewer === null) {
        this.$.reviewerConfirmationOverlay.close();
      } else {
        this._pendingConfirmationDetails =
            this._ccPendingConfirmation || this._reviewerPendingConfirmation;
        this.$.reviewerConfirmationOverlay.open();
      }
    }

    _confirmPendingReviewer() {
      if (this._ccPendingConfirmation) {
        this.$.ccs.confirmGroup(this._ccPendingConfirmation.group);
        this._focusOn(FocusTarget.CCS);
      } else {
        this.$.reviewers.confirmGroup(this._reviewerPendingConfirmation.group);
        this._focusOn(FocusTarget.REVIEWERS);
      }
    }

    _cancelPendingReviewer() {
      this._ccPendingConfirmation = null;
      this._reviewerPendingConfirmation = null;

      const target =
          this._ccPendingConfirmation ? FocusTarget.CCS : FocusTarget.REVIEWERS;
      this._focusOn(target);
    }

    _getStorageLocation() {
      // Tests trigger this method without setting change.
      if (!this.change) { return {}; }
      return {
        changeNum: this.change._number,
        patchNum: '@change',
        path: '@change',
      };
    }

    _loadStoredDraft() {
      const draft = this.$.storage.getDraftComment(this._getStorageLocation());
      return draft ? draft.message : '';
    }

    _handleAccountTextEntry() {
      // When either of the account entries has input added to the autocomplete,
      // it should trigger the save button to enable/
      //
      // Note: if the text is removed, the save button will not get disabled.
      this._reviewersMutated = true;
    }

    _draftChanged(newDraft, oldDraft) {
      this.debounce('store', () => {
        if (!newDraft.length && oldDraft) {
          // If the draft has been modified to be empty, then erase the storage
          // entry.
          this.$.storage.eraseDraftComment(this._getStorageLocation());
        } else if (newDraft.length) {
          this.$.storage.setDraftComment(this._getStorageLocation(),
              this.draft);
        }
      }, STORAGE_DEBOUNCE_INTERVAL_MS);
    }

    _handleHeightChanged(e) {
      this.fire('autogrow');
    }

    _handleLabelsChanged() {
      this._labelsChanged = Object.keys(
          this.$.labelScores.getLabelValues()).length !== 0;
    }

    _isState(knownLatestState, value) {
      return knownLatestState === value;
    }

    _reload() {
      // Load the current change without any patch range.
      Gerrit.Nav.navigateToChange(this.change);
      this.cancel();
    }

    _computeSendButtonLabel(canBeStarted) {
      return canBeStarted ? ButtonLabels.START_REVIEW : ButtonLabels.SEND;
    }

    _computeSendButtonTooltip(canBeStarted) {
      return canBeStarted ? ButtonTooltips.START_REVIEW : ButtonTooltips.SEND;
    }

    _computeSavingLabelClass(savingComments) {
      return savingComments ? 'saving' : '';
    }

    _computeSendButtonDisabled(
        buttonLabel, draftCommentThreads, text, reviewersMutated,
        labelsChanged, includeComments, disabled) {
      // Polymer 2: check for undefined
      if ([
        buttonLabel,
        draftCommentThreads,
        text,
        reviewersMutated,
        labelsChanged,
        includeComments,
        disabled,
      ].some(arg => arg === undefined)) {
        return undefined;
      }

      if (disabled) { return true; }
      if (buttonLabel === ButtonLabels.START_REVIEW) { return false; }
      const hasDrafts = includeComments && draftCommentThreads.length;
      return !hasDrafts && !text.length && !reviewersMutated && !labelsChanged;
    }

    _computePatchSetWarning(patchNum, labelsChanged) {
      let str = `Patch ${patchNum} is not latest.`;
      if (labelsChanged) {
        str += ' Voting on a non-latest patch will have no effect.';
      }
      return str;
    }

    setPluginMessage(message) {
      this._pluginMessage = message;
    }

    _sendDisabledChanged(sendDisabled) {
      this.dispatchEvent(new CustomEvent('send-disabled-changed'));
    }

    _getReviewerSuggestionsProvider(change) {
      const provider = GrReviewerSuggestionsProvider.create(this.$.restAPI,
          change._number, Gerrit.SUGGESTIONS_PROVIDERS_USERS_TYPES.REVIEWER);
      provider.init();
      return provider;
    }

    _getCcSuggestionsProvider(change) {
      const provider = GrReviewerSuggestionsProvider.create(this.$.restAPI,
          change._number, Gerrit.SUGGESTIONS_PROVIDERS_USERS_TYPES.CC);
      provider.init();
      return provider;
    }

    _onThreadListModified() {
      // TODO(taoalpha): this won't propogate the changes to the files
      // should consider replacing this with either top level events
      // or gerrit level events

      // emit the event so change-view can also get updated with latest changes
      this.fire('comment-refresh');
    }
  }

  customElements.define(GrReplyDialog.is, GrReplyDialog);
})();