//-- copyright
// OpenProject is a project management system.
// Copyright (C) 2012-2015 the OpenProject Foundation (OPF)
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License version 3.
//
// OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
// Copyright (C) 2006-2013 Jean-Philippe Lang
// Copyright (C) 2010-2013 the ChiliProject Team
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
//
// See doc/COPYRIGHT.rdoc for more details.
//++

import {HalResource} from './hal-resource.service';
import {opApiModule} from '../../../../angular-modules';
import {WorkPackageCacheService} from '../../../work-packages/work-package-cache.service';
import {ApiWorkPackagesService} from '../../api-work-packages/api-work-packages.service';
import {CollectionResourceInterface} from './collection-resource.service';
import {AttachmentCollectionResourceInterface} from './attachment-collection-resource.service';
import {UploadFile} from '../../op-file-upload/op-file-upload.service';
import IQService = angular.IQService;
import IPromise = angular.IPromise;
import ITimeoutService = angular.ITimeoutService;

interface WorkPackageResourceEmbedded {
  activities: CollectionResourceInterface;
  assignee: HalResource|any;
  attachments: AttachmentCollectionResourceInterface;
  author: HalResource|any;
  availableWatchers: HalResource|any;
  category: HalResource|any;
  children: WorkPackageResourceInterface[];
  parent: HalResource|any;
  priority: HalResource|any;
  project: HalResource|any;
  relations: CollectionResourceInterface;
  responsible: HalResource|any;
  schema: HalResource|any;
  status: HalResource|any;
  timeEntries: HalResource[]|any[];
  type: HalResource|any;
  version: HalResource|any;
  watchers: CollectionResourceInterface;
}

interface WorkPackageResourceLinks extends WorkPackageResourceEmbedded {
  addAttachment(attachment: HalResource): ng.IPromise<any>;
  addChild(child: HalResource): ng.IPromise<any>;
  addComment(comment: HalResource): ng.IPromise<any>;
  addRelation(relation: any): ng.IPromise<any>;
  addWatcher(watcher: HalResource): ng.IPromise<any>;
  changeParent(params: any): ng.IPromise<any>;
  copy(): ng.IPromise<WorkPackageResource>;
  delete(): ng.IPromise<any>;
  logTime(): ng.IPromise<any>;
  move(): ng.IPromise<any>;
  removeWatcher(): ng.IPromise<any>;
  self(): ng.IPromise<any>;
  update(payload: any): ng.IPromise<any>;
  updateImmediately(payload: any): ng.IPromise<any>;
  watch(): ng.IPromise<any>;
}

var $q: IQService;
var $stateParams: any;
var $timeout: ITimeoutService;
var I18n: op.I18n;
var apiWorkPackages: ApiWorkPackagesService;
var wpCacheService: WorkPackageCacheService;
var NotificationsService: any;
var wpNotificationsService: any;
var AttachmentCollectionResource;

export class WorkPackageResource extends HalResource {
  public static fromCreateForm(form) {
    var wp = new WorkPackageResource(form.payload.$plain(), true);

    wp.initializeNewResource(form);
    return wp;
  }

  /**
   * Create a copy resource from other and the new work package form
   * @param otherForm The work package form of another work package
   * @param form Work Package create form
   */
  public static copyFrom(otherForm, form) {
    var wp = new WorkPackageResource(otherForm.payload.$plain(), true);

    // Override values from form payload
    wp.lockVersion = form.payload.lockVersion;

    wp.initializeNewResource(form);

    return wp;
  }

  public $embedded: WorkPackageResourceEmbedded;
  public $links: WorkPackageResourceLinks;
  public id: number|string;
  public schema;
  public $pristine: { [attribute: string]: any } = {};
  public parentId: number;
  public subject: string;
  public updatedAt: Date;
  public lockVersion: number;
  public description: any;
  public inFlight: boolean;
  public activities: CollectionResourceInterface;
  public attachments: AttachmentCollectionResourceInterface;

  public pendingAttachments: UploadFile[] = [];

  private form;

  public get isNew(): boolean {
    return isNaN(Number(this.id));
  }

  public get isMilestone(): boolean {
    /**
     * it would be better if this was not deduced but rather taken from the type
     */
    return this.hasOwnProperty('date');
  }

  /**
   * Returns true if any field is in edition in this resource.
   */
  public get dirty(): boolean {
    return this.modifiedFields.length > 0;
  }

  public get modifiedFields(): string[] {
    var modified = [];

    angular.forEach(this.$pristine, (value, key) => {
      var args = [this[key], value];

      if (this[key] instanceof HalResource) {
        args = args.map(arg => (arg ? arg.$source : arg));
      }

      if (!_.isEqual(args[0], args[1])) {
        modified.push(key);
      }
    });

    return modified;
  }

  public get isLeaf(): boolean {
    var children = this.$links.children;
    return !(children && children.length > 0);
  }

  public get isEditable(): boolean {
    return !!this.$links.update || this.isNew;
  }

  /**
   * Return whether the user is able to upload an attachment.
   *
   * If either the `addAttachment` link is provided or the resource is being created,
   * adding attachments is allowed.
   */
  public get canAddAttachments(): boolean {
    return !!this.$links.addAttachment || this.isNew;
  }

  /**
   * Initialise the work package resource.
   *
   * Make the attachments an `AttachmentCollectionResource`. This should actually
   * be done automatically, but the backend does not provide typed collections yet.
   */
  protected $initialize(source) {
    const oldSchema = this.schema;
    super.$initialize(source);

    // Take over previously loaded schema resource
    this.setExistingSchema(oldSchema);

    var attachments = this.attachments || {$source: void 0, $loaded: void 0};
    this.attachments = new AttachmentCollectionResource(
      attachments.$source,
      attachments.$loaded
    );
  }

  /**
   * Remove the given attachment either from the pending attachments or from
   * the attachment collection, if it is a resource.
   *
   * Removing it from the elements array assures that the view gets updated immediately.
   * If an error occurs, the user gets notified and the attachment is pushed to the elements.
   */
  public removeAttachment(attachment) {
    if (attachment.$isHal) {
      attachment.delete()
        .then(() => {
          this.updateAttachments();
        })
        .catch(error => {
          wpNotificationsService.handleErrorResponse(error, this);
          this.attachments.elements.push(attachment);
        });
    }

    _.pull(this.attachments.elements, attachment);
    _.pull(this.pendingAttachments, attachment);
  }

  /**
   * Upload the pending attachments if the work package exists.
   * Do nothing, if the work package is being created.
   */
  public uploadPendingAttachments() {
   if (!this.pendingAttachments.length) {
     return;
   }

   const attachments = this.pendingAttachments;
   this.pendingAttachments = [];
   return this.uploadAttachments(attachments);
  }

  /**
   * Upload the given attachments, update the resource and notify the user.
   * Return an updated AttachmentCollectionResource.
   */
  public uploadAttachments(files: UploadFile[]): IPromise<any> {
    const {uploads, finished} = this.attachments.upload(files);
    const message = I18n.t('js.label_upload_notification', this);
    const notification = NotificationsService.addWorkPackageUpload(message, uploads);

    return finished
      .then(() => {
        $timeout(() => NotificationsService.remove(notification), 700);
        return this.updateAttachments();
      })
      .catch(error => {
        wpNotificationsService.handleRawError(error, this);
      });
  }

  public requiredValueFor(fieldName): boolean {
    var fieldSchema = this.schema[fieldName];

    // The field schema may be undefined if a custom field
    // is used as a column, but not available for this type.
    if (angular.isUndefined(fieldSchema)) {
      return false;
    }

    return !this[fieldName] && fieldSchema.writable && fieldSchema.required;
  }

  public allowedValuesFor(field): ng.IPromise<HalResource[]> {
    var deferred = $q.defer();

    this.getForm().then(form => {
      const allowedValues = form.$embedded.schema[field].allowedValues;

      if (Array.isArray(allowedValues)) {
        deferred.resolve(allowedValues);
      }
      else {
        return allowedValues.$load().then(loadedValues => {
          deferred.resolve(loadedValues.elements);
        });
      }
    });

    return deferred.promise;
  }

  public setAllowedValueFor(field, href) {
    this.allowedValuesFor(field).then(allowedValues => {
      this[field] = _.find(allowedValues, entry => entry.href === href);
      wpCacheService.updateWorkPackage(this);
    });
  }

  public getForm() {
    if (!this.form) {
      this.updateForm(this.$source).catch(error => {
        NotificationsService.addError(error.message);
      });
    }

    return this.form;
  }

  public updateForm(payload) {
    // Always resolve form to the latest form
    // This way, we won't have to actively reset it.
    // But store the existing form in case of an error.
    // Because if we get an error, the object returned is not a form
    // and thus lacks the links the implementation depends upon.
    var oldForm = this.form;
    this.form = this.$links.update(payload);
    var deferred = $q.defer();

    this.form
      .then(form => {
        // Override the current schema with
        // the changes from API
        this.schema = form.$embedded.schema;

        // Take over new values from the form
        // this resource doesn't know yet.
        this.assignNewValues(form.$embedded.payload);

        deferred.resolve(form);
      })
      .catch(error => {
        this.form = oldForm;
        deferred.reject(error);
      });

    return deferred.promise;
  }

  public getSchema() {
    return this.getForm().then(form => {
      const schema = form.$embedded.schema;

      angular.forEach(schema, (field, name) => {
        // Assign only links from schema when an href is set
        // and field is writable.
        // (exclude plain properties and null values)
        const isHalField = field.writable && this[name] && this[name].href;

        // Assign only values from embedded schema that have an expanded
        // allowedValues set (type, status, custom field lists, etc.)
        const hasAllowedValues = Array.isArray(field.allowedValues) && field.allowedValues.length > 0;

        if (isHalField && hasAllowedValues) {
          this[name] = _.find(field.allowedValues, {href: this[name].href});
        }
      });

      return schema;
    });
  }

  public save() {
    var deferred = $q.defer();
    this.inFlight = true;
    const wasNew = this.isNew;
    this.updateForm(this.$source)
      .then(form => {
        const payload = this.mergeWithForm(form);
        const sentValues = Object.keys(this.$pristine);

        this.saveResource(payload)
          .then(workPackage => {
            // Initialize any potentially new HAL values
            this.$initialize(workPackage);
            this.updateActivities();

            if (wasNew) {
              this.uploadPendingAttachments();
              wpCacheService.newWorkPackageCreated(this);
            }

            // Remove only those pristine values that were submitted
            angular.forEach(sentValues, (key) => {
              delete this.$pristine[key];
            });

            // Remove the current form, otherwise old form data
            // might still be used for the next edit field in #getSchema()
            this.form = null;

            deferred.resolve(this);
          })
          .catch(error => {
            deferred.reject(error);
            wpCacheService.updateWorkPackage(this);
          })
          .finally(() => {
            this.inFlight = false;
          });
      })
      .catch(() => {
        this.inFlight = false;
        deferred.reject();
      });

    return deferred.promise;
  }

  public storePristine(attribute: string) {
    if (this.$pristine.hasOwnProperty(attribute)) {
      return;
    }

    this.$pristine[attribute] = angular.copy(this[attribute]);
  }

  public restoreFromPristine(attribute: string) {
    if (this.$pristine[attribute]) {
      this[attribute] = this.$pristine[attribute];
    }
  }

  public isParentOf(otherWorkPackage) {
    return otherWorkPackage.parent.$links.self.$link.href === this.$links.self.$link.href;
  }

  protected saveResource(payload): ng.IPromise<any> {
    if (this.isNew) {
      return apiWorkPackages.createWorkPackage(payload);
    }
    return this.$links.updateImmediately(payload);
  }

  private mergeWithForm(form) {
    var plainPayload = form.payload.$plain();
    var schema = form.$embedded.schema;

    // Merge embedded properties from form payload
    // Do not use properties on this, since they may be incomplete
    // e.g., when switching to a type that requires a custom field.
    Object.keys(plainPayload).forEach(key => {
      if (typeof(schema[key]) === 'object' && schema[key].writable === true) {
        plainPayload[key] = this[key];
      }
    });

    // Merged linked properties from form payload
    Object.keys(plainPayload._links).forEach(key => {
      if (typeof(schema[key]) === 'object' && schema[key].writable === true) {
        var value = this[key] ? this[key].href : null;
        plainPayload._links[key] = {href: value};
      }
    });

    return plainPayload;
  }

  private assignNewValues(formPayload) {
    Object.keys(formPayload.$source).forEach(key => {
      if (angular.isUndefined(this[key])) {
        this[key] = formPayload[key];
      }
    });
  }

  private setExistingSchema(previous) {
    // Only when existing schema was loaded
    if (!(previous && previous.$loaded)) {
      return;
    }

    // If old schema was a regular schema and both href match
    // assume they are matching
    if (previous.href === this.schema.href) {
      this.schema = previous;
    }

    // If old schema was embedded into the WP form, decide
    // based on its baseSchema href.
    if (previous.baseSchema && previous.baseSchema.href === this.schema.href) {
      this.schema = previous;
    }
  }

  /**
   * Invalidate a set of linked resources of this work package.
   * And inform the cache service about the work package update.
   *
   * Return a promise that returns the linked resources as properties.
   * Return a rejected promise, if the resource is not a property of the work package.
   */
  public updateLinkedResources(...resourceNames): ng.IPromise<any> {
    const resources: {[id: string]: IPromise<HalResource>} = {};

    resourceNames.forEach(name => {
      const linked = this[name];
      resources[name] = linked ? linked.$update() : $q.reject();
    });

    const promise = $q.all(resources)
    promise.then(() => {
      wpCacheService.updateWorkPackage(this);
    });

    return promise;
  }

  /**
   * Get updated activities from the server and inform the cache service about the work
   * package update.
   *
   * Return a promise that returns the activities. Reject, if the work package has
   * no activities.
   */
  public updateActivities(): IPromise<HalResource> {
    return this
      .updateLinkedResources('activities')
      .then((resources: any) => resources.activities);
  }

  /**
   * Get updated attachments and activities from the server and inform the cache service
   * about the update.
   *
   * Return a promise that returns the attachments. Reject, if the work package has
   * no attachments.
   */
  public updateAttachments(): IPromise<HalResource> {
    return this
      .updateLinkedResources('activities', 'attachments')
      .then((resources: any) => resources.attachments);
  }

  /**
   * Assign values from the form for a newly created work package resource.
   * @param form
   */
  public initializeNewResource(form) {
    this.schema = form.schema;
    this.form = $q.when(form);
    this.id = 'new';

    // Set update link to form
    this['update'] = this.$links.update = form.$links.self;

    this.parentId = this.parentId || $stateParams.parent_id;
  }
}

export interface WorkPackageResourceInterface extends WorkPackageResourceLinks, WorkPackageResourceEmbedded, WorkPackageResource {
}

function wpResource(...args) {
  [
    $q,
    $stateParams,
    $timeout,
    I18n,
    apiWorkPackages,
    wpCacheService,
    NotificationsService,
    wpNotificationsService,
    AttachmentCollectionResource] = args;
  return WorkPackageResource;
}

wpResource.$inject = [
  '$q',
  '$stateParams',
  '$timeout',
  'I18n',
  'apiWorkPackages',
  'wpCacheService',
  'NotificationsService',
  'wpNotificationsService',
  'AttachmentCollectionResource'
];

opApiModule.factory('WorkPackageResource', wpResource);