/**
 * Copyright (c) 2015-present, Facebook, Inc.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 *
 * @providesModule SwipeableListViewDataSource
 */
'use strict';

import ListViewDataSource from '../ListView/ListViewDataSource';

/**
 * Data source wrapper around ListViewDataSource to allow for tracking of
 * which row is swiped open and close opened row(s) when another row is swiped
 * open.
 *
 * See https://github.com/facebook/react-native/pull/5602 for why
 * ListViewDataSource is not subclassed.
 */
class SwipeableListViewDataSource {
  _previousOpenRowID: string;
  _openRowID: string;

  _dataBlob: any;
  _dataSource: ListViewDataSource;

  rowIdentities: Array<Array<string>>;
  sectionIdentities: Array<string>;

  constructor(params: Object) {
    this._dataSource = new ListViewDataSource({
      getRowData: params.getRowData,
      getSectionHeaderData: params.getSectionHeaderData,
      rowHasChanged: (row1, row2) => {
        /**
         * Row needs to be re-rendered if its swiped open/close status is
         * changed, or its data blob changed.
         */
        return (
          (row1.id !== this._previousOpenRowID && row2.id === this._openRowID) ||
          (row1.id === this._previousOpenRowID && row2.id !== this._openRowID) ||
          params.rowHasChanged(row1, row2)
        );
      },
      sectionHeaderHasChanged: params.sectionHeaderHasChanged,
    });
  }

  cloneWithRowsAndSections(
    dataBlob: any,
    sectionIdentities: ?Array<string>,
    rowIdentities: ?Array<Array<string>>
  ): SwipeableListViewDataSource {
    this._dataSource = this._dataSource.cloneWithRowsAndSections(
      dataBlob,
      sectionIdentities,
      rowIdentities
    );

    this._dataBlob = dataBlob;
    this.rowIdentities = this._dataSource.rowIdentities;
    this.sectionIdentities = this._dataSource.sectionIdentities;

    return this;
  }

  // For the actual ListView to use
  getDataSource(): ListViewDataSource {
    return this._dataSource;
  }

  getOpenRowID(): ?string {
    return this._openRowID;
  }

  getFirstRowID(): ?string {
    /**
     * If rowIdentities is specified, find the first data row from there since
     * we don't want to attempt to bounce section headers. If unspecified, find
     * the first data row from _dataBlob.
     */
    if (this.rowIdentities) {
      return this.rowIdentities[0] && this.rowIdentities[0][0];
    }
    return Object.keys(this._dataBlob)[0];
  }

  getLastRowID(): ?string {
    if (this.rowIdentities && this.rowIdentities.length) {
      const lastSection = this.rowIdentities[this.rowIdentities.length - 1];
      if (lastSection && lastSection.length) {
       return lastSection[lastSection.length - 1];
     }
    }
   return Object.keys(this._dataBlob)[this._dataBlob.length - 1];
  }

  setOpenRowID(rowID: string): SwipeableListViewDataSource {
    this._previousOpenRowID = this._openRowID;
    this._openRowID = rowID;

    this._dataSource = this._dataSource.cloneWithRowsAndSections(
      this._dataBlob,
      this.sectionIdentities,
      this.rowIdentities
    );

    return this;
  }
}

export default SwipeableListViewDataSource;
