/**
 * @license
 * Copyright (C) 2017 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 '@polymer/iron-autogrow-textarea/iron-autogrow-textarea.js';
import '../../../styles/gr-form-styles.js';
import '../../../styles/shared-styles.js';
import '../../shared/gr-button/gr-button.js';
import '../../shared/gr-select/gr-select.js';
import '../../shared/gr-rest-api-interface/gr-rest-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-rule-editor_html.js';
import {encodeURL, getBaseUrl} from '../../../utils/url-util.js';
import {AccessPermissions} from '../../../utils/access-util.js';

/**
 * Fired when the rule has been modified or removed.
 *
 * @event access-modified
 */

/**
 * Fired when a rule that was previously added was removed.
 *
 * @event added-rule-removed
 */

const PRIORITY_OPTIONS = [
  'BATCH',
  'INTERACTIVE',
];

const Action = {
  ALLOW: 'ALLOW',
  DENY: 'DENY',
  BLOCK: 'BLOCK',
};

const DROPDOWN_OPTIONS = [Action.ALLOW, Action.DENY, Action.BLOCK];

const ForcePushOptions = {
  ALLOW: [
    {name: 'Allow pushing (but not force pushing)', value: false},
    {name: 'Allow pushing with or without force', value: true},
  ],
  BLOCK: [
    {name: 'Block pushing with or without force', value: false},
    {name: 'Block force pushing', value: true},
  ],
};

const FORCE_EDIT_OPTIONS = [
  {
    name: 'No Force Edit',
    value: false,
  },
  {
    name: 'Force Edit',
    value: true,
  },
];

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

  static get is() { return 'gr-rule-editor'; }

  static get properties() {
    return {
      hasRange: Boolean,
      /** @type {?} */
      label: Object,
      editing: {
        type: Boolean,
        value: false,
        observer: '_handleEditingChanged',
      },
      groupId: String,
      groupName: String,
      permission: String,
      /** @type {?} */
      rule: {
        type: Object,
        notify: true,
      },
      section: String,

      _deleted: {
        type: Boolean,
        value: false,
      },
      _originalRuleValues: Object,
    };
  }

  static get observers() {
    return [
      '_handleValueChange(rule.value.*)',
    ];
  }

  /** @override */
  created() {
    super.created();
    this.addEventListener('access-saved',
        () => this._handleAccessSaved());
  }

  /** @override */
  ready() {
    super.ready();
    // Called on ready rather than the observer because when new rules are
    // added, the observer is triggered prior to being ready.
    if (!this.rule) { return; } // Check needed for test purposes.
    this._setupValues(this.rule);
  }

  /** @override */
  attached() {
    super.attached();
    if (!this.rule) { return; } // Check needed for test purposes.
    if (!this._originalRuleValues) {
      // Observer _handleValueChange is called after the ready()
      // method finishes. Original values must be set later to
      // avoid set .modified flag to true
      this._setOriginalRuleValues(this.rule.value);
    }
  }

  _setupValues(rule) {
    if (!rule.value) {
      this._setDefaultRuleValues();
    }
  }

  _computeForce(permission, action) {
    if (AccessPermissions.push.id === permission &&
        action !== Action.DENY) {
      return true;
    }

    return AccessPermissions.editTopicName.id === permission;
  }

  _computeForceClass(permission, action) {
    return this._computeForce(permission, action) ? 'force' : '';
  }

  _computeGroupPath(group) {
    return `${getBaseUrl()}/admin/groups/${encodeURL(group, true)}`;
  }

  _handleAccessSaved() {
    // Set a new 'original' value to keep track of after the value has been
    // saved.
    this._setOriginalRuleValues(this.rule.value);
  }

  _handleEditingChanged(editing, editingOld) {
    // Ignore when editing gets set initially.
    if (!editingOld) { return; }
    // Restore original values if no longer editing.
    if (!editing) {
      this._handleUndoChange();
    }
  }

  _computeSectionClass(editing, deleted) {
    const classList = [];
    if (editing) {
      classList.push('editing');
    }
    if (deleted) {
      classList.push('deleted');
    }
    return classList.join(' ');
  }

  _computeForceOptions(permission, action) {
    if (permission === AccessPermissions.push.id) {
      if (action === Action.ALLOW) {
        return ForcePushOptions.ALLOW;
      } else if (action === Action.BLOCK) {
        return ForcePushOptions.BLOCK;
      } else {
        return [];
      }
    } else if (permission === AccessPermissions.editTopicName.id) {
      return FORCE_EDIT_OPTIONS;
    }
    return [];
  }

  _getDefaultRuleValues(permission, label) {
    const ruleAction = Action.ALLOW;
    const value = {};
    if (permission === 'priority') {
      value.action = PRIORITY_OPTIONS[0];
      return value;
    } else if (label) {
      value.min = label.values[0].value;
      value.max = label.values[label.values.length - 1].value;
    } else if (this._computeForce(permission, ruleAction)) {
      value.force =
          this._computeForceOptions(permission, ruleAction)[0].value;
    }
    value.action = DROPDOWN_OPTIONS[0];
    return value;
  }

  _setDefaultRuleValues() {
    this.set('rule.value', this._getDefaultRuleValues(this.permission,
        this.label));
  }

  _computeOptions(permission) {
    if (permission === 'priority') {
      return PRIORITY_OPTIONS;
    }
    return DROPDOWN_OPTIONS;
  }

  _handleRemoveRule() {
    if (this.rule.value.added) {
      this.dispatchEvent(new CustomEvent(
          'added-rule-removed', {bubbles: true, composed: true}));
    }
    this._deleted = true;
    this.rule.value.deleted = true;
    this.dispatchEvent(
        new CustomEvent('access-modified', {bubbles: true, composed: true}));
  }

  _handleUndoRemove() {
    this._deleted = false;
    delete this.rule.value.deleted;
  }

  _handleUndoChange() {
    // gr-permission will take care of removing rules that were added but
    // unsaved. We need to keep the added bit for the filter.
    if (this.rule.value.added) { return; }
    this.set('rule.value', {...this._originalRuleValues});
    this._deleted = false;
    delete this.rule.value.deleted;
    delete this.rule.value.modified;
  }

  _handleValueChange() {
    if (!this._originalRuleValues) { return; }
    this.rule.value.modified = true;
    // Allows overall access page to know a change has been made.
    this.dispatchEvent(
        new CustomEvent('access-modified', {bubbles: true, composed: true}));
  }

  _setOriginalRuleValues(value) {
    this._originalRuleValues = {...value};
  }
}

customElements.define(GrRuleEditor.is, GrRuleEditor);