/**
 * @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.
 */
import '../../shared/gr-dialog/gr-dialog.js';
import '../../../styles/shared-styles.js';
import '../../plugins/gr-endpoint-decorator/gr-endpoint-decorator.js';
import '../../shared/gr-js-api-interface/gr-js-api-interface.js';
import {GestureEventListeners} from '@polymer/polymer/lib/mixins/gesture-event-listeners.js';
import {LegacyElementMixin} from '@polymer/polymer/lib/legacy/legacy-element-mixin.js';
import {PolymerElement} from '@polymer/polymer/polymer-element.js';
import {htmlTemplate} from './gr-confirm-revert-dialog_html.js';

const ERR_COMMIT_NOT_FOUND =
    'Unable to find the commit hash of this change.';
const CHANGE_SUBJECT_LIMIT = 50;

// TODO(dhruvsri): clean up repeated definitions after moving to js modules
const REVERT_TYPES = {
  REVERT_SINGLE_CHANGE: 1,
  REVERT_SUBMISSION: 2,
};

/**
 * @extends PolymerElement
 */
class GrConfirmRevertDialog extends GestureEventListeners(
    LegacyElementMixin(PolymerElement)) {
  static get template() { return htmlTemplate; }

  static get is() { return 'gr-confirm-revert-dialog'; }
  /**
   * Fired when the confirm button is pressed.
   *
   * @event confirm
   */

  /**
   * Fired when the cancel button is pressed.
   *
   * @event cancel
   */

  static get properties() {
    return {
      /* The revert message updated by the user
      The default value is set by the dialog */
      _message: String,
      _revertType: {
        type: Number,
        value: REVERT_TYPES.REVERT_SINGLE_CHANGE,
      },
      _showRevertSubmission: {
        type: Boolean,
        value: false,
      },
      _changesCount: Number,
      _showErrorMessage: {
        type: Boolean,
        value: false,
      },
      /* store the default revert messages per revert type so that we can
      check if user has edited the revert message or not
      Set when populate() is called */
      _originalRevertMessages: {
        type: Array,
        value() { return []; },
      },
      // Store the actual messages that the user has edited
      _revertMessages: {
        type: Array,
        value() { return []; },
      },
    };
  }

  _computeIfSingleRevert(revertType) {
    return revertType === REVERT_TYPES.REVERT_SINGLE_CHANGE;
  }

  _computeIfRevertSubmission(revertType) {
    return revertType === REVERT_TYPES.REVERT_SUBMISSION;
  }

  _modifyRevertMsg(change, commitMessage, message) {
    return this.$.jsAPI.modifyRevertMsg(change,
        message, commitMessage);
  }

  populate(change, commitMessage, changes) {
    this._changesCount = changes.length;
    // The option to revert a single change is always available
    this._populateRevertSingleChangeMessage(
        change, commitMessage, change.current_revision);
    this._populateRevertSubmissionMessage(change, changes, commitMessage);
  }

  _populateRevertSingleChangeMessage(change, commitMessage, commitHash) {
    // Figure out what the revert title should be.
    const originalTitle = (commitMessage || '').split('\n')[0];
    const revertTitle = `Revert "${originalTitle}"`;
    if (!commitHash) {
      this.dispatchEvent(new CustomEvent('show-alert', {
        detail: {message: ERR_COMMIT_NOT_FOUND},
        composed: true, bubbles: true,
      }));
      return;
    }
    const revertCommitText = `This reverts commit ${commitHash}.`;

    this._message = `${revertTitle}\n\n${revertCommitText}\n\n` +
        `Reason for revert: <INSERT REASONING HERE>\n`;
    // This is to give plugins a chance to update message
    this._message = this._modifyRevertMsg(change, commitMessage,
        this._message);
    this._revertType = REVERT_TYPES.REVERT_SINGLE_CHANGE;
    this._showRevertSubmission = false;
    this._revertMessages[this._revertType] = this._message;
    this._originalRevertMessages[this._revertType] = this._message;
  }

  _getTrimmedChangeSubject(subject) {
    if (!subject) return '';
    if (subject.length < CHANGE_SUBJECT_LIMIT) return subject;
    return subject.substring(0, CHANGE_SUBJECT_LIMIT) + '...';
  }

  _modifyRevertSubmissionMsg(change, msg, commitMessage) {
    return this.$.jsAPI.modifyRevertSubmissionMsg(change, msg,
        commitMessage);
  }

  _populateRevertSubmissionMessage(change, changes, commitMessage) {
    // Follow the same convention of the revert
    const commitHash = change.current_revision;
    if (!commitHash) {
      this.dispatchEvent(new CustomEvent('show-alert', {
        detail: {message: ERR_COMMIT_NOT_FOUND},
        composed: true, bubbles: true,
      }));
      return;
    }
    if (!changes || changes.length <= 1) return;
    const submissionId = change.submission_id;
    const revertTitle = 'Revert submission ' + submissionId;
    this._message = revertTitle + '\n\n' + 'Reason for revert: <INSERT ' +
      'REASONING HERE>\n';
    this._message += 'Reverted Changes:\n';
    changes.forEach(change => {
      this._message += change.change_id.substring(0, 10) + ':'
        + this._getTrimmedChangeSubject(change.subject) + '\n';
    });
    this._message = this._modifyRevertSubmissionMsg(change, this._message,
        commitMessage);
    this._revertType = REVERT_TYPES.REVERT_SUBMISSION;
    this._revertMessages[this._revertType] = this._message;
    this._originalRevertMessages[this._revertType] = this._message;
    this._showRevertSubmission = true;
  }

  _handleRevertSingleChangeClicked() {
    this._showErrorMessage = false;
    this._revertMessages[REVERT_TYPES.REVERT_SUBMISSION] = this._message;
    this._message = this._revertMessages[REVERT_TYPES.REVERT_SINGLE_CHANGE];
    this._revertType = REVERT_TYPES.REVERT_SINGLE_CHANGE;
  }

  _handleRevertSubmissionClicked() {
    this._showErrorMessage = false;
    this._revertType = REVERT_TYPES.REVERT_SUBMISSION;
    this._revertMessages[REVERT_TYPES.REVERT_SINGLE_CHANGE] = this._message;
    this._message = this._revertMessages[REVERT_TYPES.REVERT_SUBMISSION];
  }

  _handleConfirmTap(e) {
    e.preventDefault();
    e.stopPropagation();
    if (this._message === this._originalRevertMessages[this._revertType]) {
      this._showErrorMessage = true;
      return;
    }
    this.dispatchEvent(new CustomEvent('confirm', {
      detail: {revertType: this._revertType,
        message: this._message},
      composed: true, bubbles: false,
    }));
  }

  _handleCancelTap(e) {
    e.preventDefault();
    e.stopPropagation();
    this.dispatchEvent(new CustomEvent('cancel', {
      detail: {revertType: this._revertType},
      composed: true, bubbles: false,
    }));
  }
}

customElements.define(GrConfirmRevertDialog.is, GrConfirmRevertDialog);