//-- 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";

var $q;
var apiWorkPackages;
var wpCacheService;
var NotificationsService;

export class WorkPackageResource extends HalResource {
  private form;
  public schema;
  public id;
  public $pristine: { [attribute: string]: any } = {};

  public static fromCreateForm(projectIdentifier?:string):ng.IPromise<WorkPackageResource> {
    var deferred = $q.defer();

    apiWorkPackages.emptyCreateForm(projectIdentifier)
      .then(resource => {
        var wp = new WorkPackageResource(resource.payload.$source, true);

        // Copy resources from form response
        wp.schema = resource.schema;
        wp.form = $q.when(resource);
        wp.id = 'new-' + Date.now();

        // Set update link to form
        wp.$links.update = resource.$links.self;

        deferred.resolve(wp);
      })
      .catch(deferred.reject);

    return deferred.promise;
  }

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

  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 (fieldSchema === undefined) {
      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:any) => (entry.href === href));
    });
  }

  public getForm() {
    if (!this.form) {
      this.updateForm(this.$source).catch(error => {
        NotificationsService.addError(error.data.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;
        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) => {
        if (this[name] && field && field.writable && field.$isHal
          && (Array.isArray(field.allowedValues) && field.allowedValues.length > 0)) {

          this[name] = _.where(field.allowedValues, {name: this[name].name})[0];
        }
      });

      return schema;
    });
  }

  public save() {
    var deferred = $q.defer();

    this.updateForm(this.$source)
      .then(form => {

        // Merge attributes from form with resource
        var payload = this.mergeWithForm(form);

        this.saveResource(payload)
          .then(workPackage => {
            angular.extend(this, workPackage);

            // Clear shadow copy
            this.$pristine = {};

            deferred.resolve(this);
          }).catch((error) => {
            deferred.reject(error);
          }).finally(() => {
            // Update cache
            wpCacheService.updateWorkPackage(this);
        });
      })
      .catch(deferred.reject);

    return deferred.promise;
  }

  public storePristine(attribute) {
    if (this.$pristine[attribute] !== undefined) {
      return;
    }

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

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

  /**
   * 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 equal;

      if (this[key] instanceof HalResource) {
        equal = _.isEqual(this[key].$source, value.$source);
      } else {
        equal = _.isEqual(this[key], value);
      }

      if (!equal) {
        modified.push(key);
      }
    });

    return modified;
  }

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

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

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

  protected saveResource(payload):ng.IPromise<any> {
    if (this.isNew) {
      return apiWorkPackages.wpApiPath().post(payload);
    }

    return this.$links.updateImmediately(payload);
  }

  private mergeWithForm(form) {
    var plainPayload = form.payload.$source;
    var schema = form.$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.
    angular.forEach(plainPayload, (_value, key) => {
      if (typeof(schema[key]) === 'object' && schema[key]['writable'] === true) {
        plainPayload[key] = this[key];
      }
    });

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

    return plainPayload;
  }
}

function wpResource(_$q_:ng.IQService,
                    _apiWorkPackages_,
                    _wpCacheService_:WorkPackageCacheService,
                    _NotificationsService_:any) {
  $q = _$q_;
  apiWorkPackages = _apiWorkPackages_;
  wpCacheService = _wpCacheService_;
  NotificationsService = _NotificationsService_;

  return WorkPackageResource;
}

opApiModule.factory('WorkPackageResource', [
  '$q',
  'apiWorkPackages',
  'wpCacheService',
  'NotificationsService',
  wpResource
]);