import { IStoreState, ID, ISelectionType, ISelection, ICell } from '../../index.data';
import { pickPatch } from '../../utils';
import { getCell, getCellByij, getCellij } from '../selectors';

/**
 * 设置selection相关内容
 * @param state
 * @type 行 和 cell 两种选择模式
 * @id 如果是选行模式, 则指rowid, 否则指cellid
 * @return selection相关
 */
export function setSelection(
  state: IStoreState,
  type: 'cell' | 'row',
  id: ID,
  forceClear = false,
): ISelection | {} {
  const lastSelection = {
    selectionType: state.selectionType,
    selectedRowRange: state.selectedRowRange,
    selectedColumnRange: state.selectedColumnRange,
    selectedCellRange: state.selectedCellRange,
  };

  const clear = forceClear || type !== lastSelection.selectionType;

  const result = { selectionType: type } as ISelection;

  if (type === 'row') {
    if (clear) {
      result['selectedRowRange'] = [id, id];
    } else {
      result['selectedRowRange'] = [lastSelection.selectedRowRange[0], id];
    }
  } else if (type === 'cell') {
    if (clear) {
      result['selectedCellRange'] = [id, id];
    } else {
      result['selectedCellRange'] = [lastSelection.selectedCellRange[0], id];
    }
  } else if (type === 'column') {
    if (clear) {
      result['selectedColumnRange'] = [id, id];
    } else {
      result['selectedColumnRange'] = [lastSelection.selectedColumnRange[0], id];
    }
  }

  return pickPatch(state, { ...result, mode: 'view' });
}

/**
 * 反选全部
 * deprecated 直接使用状态机
 */
// export function clearSelection(state: IStoreState): ISelection {
//   return {
//     selectionType: null,
//   } as any;
// }

////////////////////////////////  光标上下移动 /////////////////////////////////////////////////////////
// 是否可以改变当前选择
function _canChangeCellSelection(state: IStoreState): boolean {
  const { selectionType, selectedCellRange } = state;
  if (selectionType !== 'cell') return false;

  // 当前未选择单元格, 或多选了单元格
  if (selectedCellRange.length < 2 || selectedCellRange[0] !== selectedCellRange[1]) return false;

  return true;
}

export function selectCellAbove(state: IStoreState) {
  if (!_canChangeCellSelection(state)) return;

  const { selectedCellRange } = state;
  const selectedCell = getCell(state, selectedCellRange[0])!;
  const { i, j } = getCellij(state, selectedCell.id);

  // 第一行
  if (i === 0) return;

  const nextCell = getCellByij(state, i - 1, j);
  return setSelection(state, 'cell', nextCell!.id, true);
}

export function selectCellBelow(state: IStoreState) {
  if (!_canChangeCellSelection(state)) return;

  const { selectedCellRange } = state;
  const selectedCell = getCell(state, selectedCellRange[0])!;
  const { i, j } = getCellij(state, selectedCell.id);

  // 最后一行
  if (i === state.rows.length - 1) return;

  const nextCell = getCellByij(state, i! + (selectedCell.rowspan || 1), j!);
  return setSelection(state, 'cell', nextCell!.id, true);
}

export function selectCellLeft(state: IStoreState) {
  if (!_canChangeCellSelection(state)) return;

  const { selectedCellRange } = state;
  const selectedCell = getCell(state, selectedCellRange[0])!;
  const { i, j } = getCellij(state, selectedCell.id);

  // 第一列
  if (j === 0) return;

  const nextCell = getCellByij(state, i, j - 1);
  return setSelection(state, 'cell', nextCell!.id, true);
}

export function selectCellRight(state: IStoreState) {
  if (!_canChangeCellSelection(state)) return;

  const { selectedCellRange } = state;
  const selectedCell = getCell(state, selectedCellRange[0])!;
  const { i, j } = getCellij(state, selectedCell.id);

  // 第一列
  if (j === state.columns.length - 1) return;

  const nextCell = getCellByij(state, i, j + (selectedCell.colspan || 1));
  return setSelection(state, 'cell', nextCell!.id, true);
}