import {
  DataGridProvider,
  FetchByOffsetGridParameters,
  FetchByOffsetGridResults,
  GridItem,
  GridBodyItem,
  GridHeaderItem
} from 'ojs/ojdatagridprovider';
import { EventTargetMixin } from 'ojs/ojeventtarget';

interface DataParams {
  dataArray?: Array<Object>,
}

export class SampleDataGridProvider<D> implements DataGridProvider<D> {
  addEventListener: () => void;
  removeEventListener: () => void;

  constructor(protected dataParams?: DataParams) { }

  public fetchByOffset(
    parameters: FetchByOffsetGridParameters
  ): Promise<FetchByOffsetGridResults<D>> {
    return null;
  }

  public getCapability(capabilityName: string): any {
    return null;
  }

  public isEmpty(): 'yes' | 'no' | 'unknown' {
    return (this.dataParams.dataArray.length <= 0) ? 'yes' : 'no'; // Returns 'yes' if not given any data, returns 'no' otherwise
  }

  private FetchByOffsetGridResults = class <D> implements FetchByOffsetGridResults<D> {
    constructor(
      public readonly fetchParameters: FetchByOffsetGridParameters,
      public readonly rowDone: boolean,
      public readonly columnDone: boolean,
      public readonly rowOffset: number,
      public readonly columnOffset: number,
      public readonly rowCount: number,
      public readonly columnCount: number,
      public readonly totalRowCount: number,
      public readonly totalColumnCount: number,
      public readonly results: {
        readonly databody?: Array<GridBodyItem<D>>,
      },
      public readonly version: number,
      public next?: Promise<FetchByOffsetGridResults<D>>
    ) { }
  };

  private GridBodyItem = class <D> implements GridBodyItem<D> {
    constructor(
      public readonly rowExtent: number,
      public readonly columnExtent: number,
      public readonly rowIndex: number,
      public readonly columnIndex: number,
      public readonly metadata: Object,
      public readonly data: D
    ) { }
  };

  private GridHeaderItem = class <D> implements GridHeaderItem<D> {
    constructor(
      public readonly index: number,
      public readonly extent: number,
      public readonly level: number,
      public readonly depth: number,
      public readonly metadata: Object,
      public readonly data: D
    ) { }
  };

  private GridItem = class <D> implements GridItem<D> {
    constructor(public readonly metadata: Object, public readonly data: D) { }
  };

  private GridHeaderMetadata = class {
    constructor(public readonly sortDirection?: 'ascending' | 'descending', public readonly sortable?: boolean) { }
  };
}

// This is a convenience for registering addEventListener/removeEventListener
EventTargetMixin.applyMixin(SampleDataGridProvider);