// -- copyright
// OpenProject is a project management system.
// Copyright (C) 2012-2017 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 {QueryResource} from '../api/api-v3/hal-resources/query-resource.service';
import {WorkPackageTablePagination} from '../wp-fast-table/wp-table-pagination';

export class WorkPackagesListChecksumService {
  constructor(protected UrlParamsHelper:any,
              protected $state:ng.ui.IStateService) {
  }

  public id:number | null;
  public checksum:string | null;
  public visibleChecksum:string | null;

  public updateIfDifferent(query:QueryResource,
                           pagination:WorkPackageTablePagination) {

    let newQueryChecksum = this.getNewChecksum(query, pagination);

    if (this.isUninitialized()) {
      // Do nothing
    } else if (this.isIdDifferent(query.id)) {
      this.maintainUrlQueryState(query.id, null)

      this.clear();

    } else if (this.isChecksumDifferent(newQueryChecksum)) {
      this.maintainUrlQueryState(query.id, newQueryChecksum)
    }

    this.set(query.id, newQueryChecksum);
  }

  public update(query:QueryResource, pagination:WorkPackageTablePagination) {
    let newQueryChecksum = this.getNewChecksum(query, pagination);

    this.set(query.id, newQueryChecksum);

    this.maintainUrlQueryState(query.id, newQueryChecksum)
  }

  public isQueryOutdated(query:QueryResource,
                         pagination:WorkPackageTablePagination) {
    let newQueryChecksum = this.getNewChecksum(query, pagination);

    return this.isOutdated(query.id, newQueryChecksum);
  }

  public executeIfOutdated(newId:number,
                           newChecksum:string,
                           callback:Function) {
    if (this.isOutdated(newId, newChecksum)) {
      this.set(newId, newChecksum);

      callback();
    }
  }

  private set(id:number | null, checksum:string) {
    this.id = id;
    this.checksum = checksum;
  }

  public clear() {
    this.id = null;
    this.checksum = null;
    this.visibleChecksum = null;
  }

  public isUninitialized() {
    return !this.id && !this.checksum;
  }

  private isIdDifferent(otherId:number | null) {
    return this.id !== otherId;
  }

  private isChecksumDifferent(otherChecksum:string) {
    return this.checksum && otherChecksum !== this.checksum;
  }

  private isOutdated(otherId:number | null, otherChecksum:string | null) {
    const hasCurrentQueryID = !!this.id;
    const hasCurrentChecksum = !!this.checksum;
    const idChanged = (this.id !== otherId);

    const checksumChanged = (otherChecksum !== this.checksum);
    const visibleChecksumChanged = (this.checksum && !otherChecksum && this.visibleChecksum);

    return (
      // Can only be outdated if either ID or props set
      (hasCurrentQueryID || hasCurrentChecksum) &&
      (
        // Query ID changed
        idChanged ||
        // Query ID same + query props changed
        (!idChanged && checksumChanged) ||
        // No query ID set
        (!hasCurrentQueryID && visibleChecksumChanged)
      )
    );
  }

  private getNewChecksum(query:QueryResource, pagination:WorkPackageTablePagination) {
    return this.UrlParamsHelper.encodeQueryJsonParams(query, _.pick(pagination, ['page', 'perPage']));
  }

  private maintainUrlQueryState(id:string | number | null, checksum:string | null) {
    this.visibleChecksum = checksum;

    this.$state.go('.', {query_props: checksum, query_id: id}, {notify: false});
  };
}

angular
  .module('openproject.workPackages.services')
  .service('wpListChecksumService', WorkPackagesListChecksumService);