// 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';

  // TODO(davido): Add the rest of the change actions.
  var ChangeActions = {
    ABANDON: 'abandon',
    DELETE: '/',
    RESTORE: 'restore',
    REVERT: 'revert',
  };

  // TODO(andybons): Add the rest of the revision actions.
  var RevisionActions = {
    CHERRYPICK: 'cherrypick',
    DELETE: '/',
    PUBLISH: 'publish',
    REBASE: 'rebase',
    SUBMIT: 'submit',
  };

  var ActionLoadingLabels = {
    'abandon': 'Abandoning...',
    'cherrypick': 'Cherry-Picking...',
    'delete': 'Deleting...',
    'publish': 'Publishing...',
    'rebase': 'Rebasing...',
    'restore': 'Restoring...',
    'revert': 'Reverting...',
    'submit': 'Submitting...',
  };

  var ActionType = {
    CHANGE: 'change',
    REVISION: 'revision',
  };

  Polymer({
    is: 'gr-change-actions',

    /**
     * Fired when the change should be reloaded.
     *
     * @event reload-change
     */

    properties: {
      actions: {
        type: Object,
      },
      changeNum: String,
      patchNum: String,
      commitInfo: Object,
      _loading: {
        type: Boolean,
        value: true,
      },
      _revisionActions: Object,
    },

    behaviors: [
      Gerrit.RESTClientBehavior,
    ],

    observers: [
      '_actionsChanged(actions, _revisionActions)',
    ],

    reload: function() {
      if (!this.changeNum || !this.patchNum) {
        return Promise.resolve();
      }

      this._loading = true;
      return this._getRevisionActions().then(function(revisionActions) {
        if (!revisionActions) { return; }

        this._revisionActions = revisionActions;
        this._loading = false;
      }.bind(this)).catch(function(err) {
        alert('Couldn’t load revision actions. Check the console ' +
            'and contact the PolyGerrit team for assistance.');
        this._loading = false;
        throw err;
      }.bind(this));
    },

    _getRevisionActions: function() {
      return this.$.restAPI.getChangeRevisionActions(this.changeNum,
          this.patchNum);
    },

    _keyCount: function(obj) {
      return Object.keys(obj).length;
    },

    _actionsChanged: function(actions, revisionActions) {
      this.hidden = this._keyCount(actions) === 0 &&
          this._keyCount(revisionActions) === 0;
    },

    _getValuesFor: function(obj) {
      return Object.keys(obj).map(function(key) {
        return obj[key];
      });
    },

    _computeActionValues: function(actions, type) {
      var result = [];
      var values = this._getValuesFor(
          type === ActionType.CHANGE ? ChangeActions : RevisionActions);
      for (var a in actions) {
        if (values.indexOf(a) === -1) { continue; }
        actions[a].__key = a;
        actions[a].__type = type;
        result.push(actions[a]);
      }
      return result;
    },

    _computeLoadingLabel: function(action) {
      return ActionLoadingLabels[action] || 'Working...';
    },

    _computePrimary: function(actionKey) {
      return actionKey === RevisionActions.SUBMIT ||
          actionKey === RevisionActions.PUBLISH;
    },

    _canSubmitChange: function() {
      return this.$.jsAPI.canSubmitChange();
    },

    _handleActionTap: function(e) {
      e.preventDefault();
      var el = Polymer.dom(e).rootTarget;
      var key = el.getAttribute('data-action-key');
      var type = el.getAttribute('data-action-type');
      if (type === ActionType.REVISION) {
        this._handleRevisionAction(key);
      } else if (key === ChangeActions.REVERT) {
        this._showActionDialog(this.$.confirmRevertDialog);
      } else {
        this._fireAction(this._prependSlash(key), this.actions[key], false);
      }
    },

    _handleRevisionAction: function(key) {
      switch (key) {
        case RevisionActions.REBASE:
          this._showActionDialog(this.$.confirmRebase);
          break;
        case RevisionActions.CHERRYPICK:
          this._showActionDialog(this.$.confirmCherrypick);
          break;
        case RevisionActions.SUBMIT:
          if (!this._canSubmitChange()) {
            return;
          }
          /* falls through */ // required by JSHint
        default:
          this._fireAction(this._prependSlash(key),
              this._revisionActions[key], true);
      }
    },

    _prependSlash: function(key) {
      return key === '/' ? key : '/' + key;
    },

    _handleConfirmDialogCancel: function() {
      var dialogEls =
          Polymer.dom(this.root).querySelectorAll('.confirmDialog');
      for (var i = 0; i < dialogEls.length; i++) {
        dialogEls[i].hidden = true;
      }
      this.$.overlay.close();
    },

    _handleRebaseConfirm: function() {
      var payload = {};
      var el = this.$.confirmRebase;
      if (el.clearParent) {
        // There is a subtle but important difference between setting the base
        // to an empty string and omitting it entirely from the payload. An
        // empty string implies that the parent should be cleared and the
        // change should be rebased on top of the target branch. Leaving out
        // the base implies that it should be rebased on top of its current
        // parent.
        payload.base = '';
      } else if (el.base && el.base.length > 0) {
        payload.base = el.base;
      }
      this.$.overlay.close();
      el.hidden = false;
      this._fireAction('/rebase', this._revisionActions.rebase, true, payload);
    },

    _handleCherrypickConfirm: function() {
      var el = this.$.confirmCherrypick;
      if (!el.branch) {
        // TODO(davido): Fix error handling
        alert('The destination branch can’t be empty.');
        return;
      }
      if (!el.message) {
        alert('The commit message can’t be empty.');
        return;
      }
      this.$.overlay.close();
      el.hidden = false;
      this._fireAction(
          '/cherrypick',
          this._revisionActions.cherrypick,
          true,
          {
            destination: el.branch,
            message: el.message,
          }
      );
    },

    _handleRevertDialogConfirm: function() {
      var el = this.$.confirmRevertDialog;
      this.$.overlay.close();
      el.hidden = false;
      this._fireAction(
          '/revert',
          this.actions.revert,
          false,
          {
            message: el.message,
          }
      );
    },

    _setLoadingOnButtonWithKey: function(key) {
      var buttonEl = this.$$('[data-action-key="' + key + '"]');
      buttonEl.setAttribute('loading', true);
      buttonEl.disabled = true;
      return function() {
        buttonEl.removeAttribute('loading');
        buttonEl.disabled = false;
      };
    },

    _fireAction: function(endpoint, action, revAction, opt_payload) {
      var cleanupFn = this._setLoadingOnButtonWithKey(action.__key);

      this._send(action.method, opt_payload, endpoint, revAction, cleanupFn)
          .then(this._handleResponse.bind(this, action));
    },

    _showActionDialog: function(dialog) {
      dialog.hidden = false;
      this.$.overlay.open();
    },

    _handleResponse: function(action, response) {
      return this.$.restAPI.getResponseObject(response).then(function(obj) {
        switch (action.__key) {
          case ChangeActions.REVERT:
          case RevisionActions.CHERRYPICK:
            page.show(this.changePath(obj._number));
            break;
          case RevisionActions.DELETE:
            page.show(this.changePath(this.changeNum));
            break;
          case ChangeActions.DELETE:
            page.show('/');
            break;
          default:
            this.fire('reload-change', null, {bubbles: false});
            break;
        }
      }.bind(this));
    },

    _handleResponseError: function(response) {
      if (response.ok) { return response; }

      return response.text().then(function(errText) {
        alert('Could not perform action: ' + errText);
        throw Error(errText);
      });
    },

    _send: function(method, payload, actionEndpoint, revisionAction,
        cleanupFn) {
      var url = this.$.restAPI.getChangeActionURL(this.changeNum,
          revisionAction ? this.patchNum : null, actionEndpoint);
      return this.$.restAPI.send(method, url, payload).then(function(response) {
        cleanupFn.call(this);
        return response;
      }.bind(this)).then(this._handleResponseError.bind(this));
    },
  });
})();