// -- 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 {opWorkPackagesModule} from "../../angular-modules";
import {State} from "reactivestates";
import {Observable, Subject} from "rxjs";
import {WorkPackageResource} from "../api/api-v3/hal-resources/work-package-resource.service";
import {ApiWorkPackagesService} from "../api/api-work-packages/api-work-packages.service";
import {States} from "../states.service";
import { WorkPackageNotificationService } from "./../wp-edit/wp-notification.service";
import { SchemaResource } from "../api/api-v3/hal-resources/schema-resource.service";
import IScope = angular.IScope;
import IPromise = angular.IPromise;

export class SchemaCacheService {

  /*@ngInject*/
  constructor(private states:States, private $q:ng.IQService) {
  }

  /**
   * Ensure the given schema identified by its href is currently loaded.
   * @param href The schema's href.
   * @return A promise with the loaded schema.
   */
  ensureLoaded(workPackage:WorkPackageResource):PromiseLike<any> {
    if (workPackage.hasOverriddenSchema) {
      return this.$q.resolve();
    }

    const state = this.state(workPackage);

    if (!state.hasValue()) {
      this.load(workPackage);
    }

    return state.valuesPromise();
  }

  /**
   * Get the associated schema state of the work package
   *  without initializing a new resource.
  */
  state(workPackage:WorkPackageResource) {
    const schema = workPackage.$links.schema;
    return this.states.schemas.get(schema.href!);
  }

  /**
   * Load the associated schema for the given work package, if needed.
   */
  load(workPackage:WorkPackageResource, forceUpdate = false):State<SchemaResource> {
    const state = this.state(workPackage);

    if (forceUpdate) {
      state.clear();
    }

    state.putFromPromiseIfPristine(() => {
      const resource = workPackage.createLinkedResource('schema', workPackage.$links.schema.$link);
      return resource.$load();
    });

    return state;
  }
}

opWorkPackagesModule.service('schemaCacheService', SchemaCacheService);