import UEBase from "../../frameWork/compment/UEBase";
import { GridConstant } from "./GridConstant";
import UECell from "./UECell";

const { ccclass, property } = cc._decorator;

@ccclass
export default class UEGridMap extends UEBase {
    static readonly BundleKey: string = "gridMap";
    static readonly PrefabUrl: string = "UEGridMap";
    static readonly CLS: string = "UEGridMap";
    @property(cc.Prefab)
    cellPrefab: cc.Prefab = null!;
    @property(cc.Node)
    gridCenter: cc.Node = null;
    @property(cc.Node)
    gridLayer: cc.Node = null;
    gridMap: UECell[][] = [];
    private isDragging: boolean = false;
    private dragStartPos: cc.Vec2 = cc.v2(0, 0);
    private selectedCell: UECell = null!;

    Init() {
        const startX = -(GridConstant.ROW * GridConstant.CELL_WIDTH) / 2;
        const startY = (GridConstant.COL * GridConstant.CELL_HEIGHT) / 2;
        this.gridLayer.setContentSize(GridConstant.CELL_WIDTH * GridConstant.ROW, GridConstant.CELL_HEIGHT * GridConstant.COL);
        let idx = 0;
        for (let i = 0; i < GridConstant.COL; i++) {
            let row = [];
            for (let j = 0; j < GridConstant.ROW; j++) {
                let cell = cc.instantiate(this.cellPrefab).getComponent(UECell);
                this.gridLayer.addChild(cell.node);
                cell.node.width = GridConstant.CELL_WIDTH;
                cell.node.height = GridConstant.CELL_HEIGHT;
                cell.node.setPosition(cc.v2(
                    startX + j * GridConstant.CELL_WIDTH + GridConstant.CELL_WIDTH / 2,
                    startY - i * GridConstant.CELL_HEIGHT - GridConstant.CELL_HEIGHT / 2
                ));
                row.push(cell);
                cell.Init(idx);
                idx++;
            }
            this.gridMap.push(row);
        }
        this.initEvent();
    }

    initEvent(): void {
        this.gridLayer.on(cc.Node.EventType.TOUCH_START, this.onTouchStart, this);
        this.gridLayer.on(cc.Node.EventType.TOUCH_MOVE, this.onTouchMove, this);
        this.gridLayer.on(cc.Node.EventType.TOUCH_END, this.onTouchEnd, this);
        this.gridLayer.on(cc.Node.EventType.TOUCH_CANCEL, this.onTouchEnd, this);
    }

    private onTouchStart(event: cc.Event.EventTouch): void {
        const touchPos = this.node.convertToNodeSpaceAR(event.getLocation());
        const cell = this.getCellByPos(touchPos);
        if (cell && cell.hasItem()) {
            this.isDragging = true;
            this.dragStartPos = touchPos;
            this.selectedCell = cell;
            cell.startDrag();
        }
    }

    private onTouchMove(event: cc.Event.EventTouch): void {
        if (!this.isDragging || !this.selectedCell) return;
        const touchPos = this.node.convertToNodeSpaceAR(event.getLocation());
        this.selectedCell.updateDragPosition(cc.v3(touchPos.x, touchPos.y));
    }

    private onTouchEnd(event: cc.Event.EventTouch): void {
        if (!this.isDragging || !this.selectedCell) return;
        const touchPos = this.node.convertToNodeSpaceAR(event.getLocation());
        const targetCell = this.getCellByPos(touchPos);

        if (targetCell && targetCell !== this.selectedCell) {
            this.tryMergeItems(this.selectedCell, targetCell);
        }

        this.selectedCell.endDrag();
        this.isDragging = false;
        this.selectedCell = null;
    }

    private getCellByPos(pos: cc.Vec2): UECell | null {
        const row = Math.floor(-pos.y / GridConstant.CELL_HEIGHT);
        const col = Math.floor(pos.x / GridConstant.CELL_WIDTH);

        if (row >= 0 && row < GridConstant.ROW && col >= 0 && col < GridConstant.COL) {
            return this.gridMap[row][col];
        }
        return null;
    }

    private tryMergeItems(fromCell: UECell, toCell: UECell): void {
        if (fromCell.canMergeWith(toCell)) {
            toCell.mergeFrom(fromCell);
        }
    }
}