import { MutableSignal, mutableSignal, computed, ReadonlySignal } from 'boardgame-core';
import {getAvailableMoves, OnitamaState} from "boardgame-core/samples/onitama";

export interface ValidMove {
  card: string;
  fromX: number;
  fromY: number;
  toX: number;
  toY: number;
}

// 先选择牌，然后选择棋子，最后选择移动
export interface OnitamaUIState {
  selectedPiece: { x: number; y: number } | null;
  selectedCard: string | null;
}

export function createUIState(): MutableSignal<OnitamaUIState> {
  return mutableSignal<OnitamaUIState>({
    selectedPiece: null,
    selectedCard: null,
  });
}

export function createValidMoves(state: ReadonlySignal<OnitamaState>, ui: ReadonlySignal<OnitamaUIState>){
  return computed(() => {
    return getAvailableMoves(state.value, state.value.currentPlayer)
        .filter(move => {
          const {selectedCard, selectedPiece} = ui.value;
          return selectedPiece?.x === move.fromX && selectedPiece?.y === move.fromY && selectedCard === move.card;
        })
  });
}

export function clearSelection(uiState: MutableSignal<OnitamaUIState>): void {
  uiState.produce(state => {
    state.selectedPiece = null;
    state.selectedCard = null;
  });
}

export function selectPiece(
  uiState: MutableSignal<OnitamaUIState>,
  x: number,
  y: number
): void {
  uiState.produce(state => {
    // 如果点击已选中的棋子，取消选择
    if(state.selectedPiece?.x === x && state.selectedPiece?.y === y){
      state.selectedPiece = null;
    }else{
      state.selectedPiece = { x, y };
    }
  });
}

export function selectCard(
  uiState: MutableSignal<OnitamaUIState>,
  card: string
): void {
  uiState.produce(state => {
    // 如果点击已选中的卡牌，取消选择
    if (state.selectedCard === card) {
      state.selectedCard = null;
    } else {
      // 选择新卡牌，清除棋子选择
      state.selectedCard = card;
    }
  });
}