import { Node, Tween, tween, UITransform, v3, Vec3 } from 'cc';
import type { TextGrid } from './TextGrid';

/** 沿弧线飞移速度（px/s） */
const MOVE_SPEED_PX = 2000;
const MIN_TOTAL_SEC = 0.14;
const MAX_TOTAL_SEC = 0.34;
/** 弧顶抬高（世界像素量级，换算到 dragLayer 本地） */
const LIFT_HEIGHT = 42;

export interface BagToMapPlaceOptions {
    /** 动画结束后挂接的槽位/地图格节点（避免 rebuild 前停在 dragLayer 再瞬移） */
    attachParent?: Node | null;
    /** 飞行时显示字块拖尾（与背包刷新入场同一套 trail1/2/3） */
    showTrail?: boolean;
    /** 飞行起点世界坐标；缺省为 node 当前 worldPosition（拉线拖动用 ghost/跟指位置） */
    startWorld?: Readonly<Vec3> | null;
    /** 沿弧线飞移速度（px/s）；缺省 MOVE_SPEED_PX */
    moveSpeedPx?: number;
    /** 最短飞行时长（秒）；缺省 MIN_TOTAL_SEC */
    minTotalSec?: number;
    /** 最长飞行时长（秒）；缺省 MAX_TOTAL_SEC */
    maxTotalSec?: number;
}

/** 字块松手后飞入目标格（背包↔地图 / 交换 / 落空格同一套） */
export class BagToMapPlaceAnimator {
    static play(
        grid: TextGrid,
        targetWorld: Readonly<Vec3>,
        dragLayer: Node,
        onComplete?: () => void,
        opts?: BagToMapPlaceOptions,
    ): void {
        const node = grid.node;
        const finish = (): void => {
            grid.hideEntranceTrail();
            onComplete?.();
        };
        if (!node?.isValid || !dragLayer?.isValid) {
            finish();
            return;
        }

        // prefab 中 ui_fly 默认可关；挂到未激活层会导致飞行全程不可见、落地才“瞬现”
        if (!dragLayer.active) {
            dragLayer.active = true;
        }

        Tween.stopAllByTarget(node);
        grid.hideEntranceTrail();
        const startWorld = opts?.startWorld
            ? new Vec3(opts.startWorld.x, opts.startWorld.y, opts.startWorld.z)
            : node.worldPosition.clone();
        node.parent = dragLayer;
        node.setWorldPosition(startWorld);

        const ut = dragLayer.getComponent(UITransform);
        if (!ut) {
            finish();
            return;
        }

        const startLocal = ut.convertToNodeSpaceAR(startWorld);
        const endLocal = ut.convertToNodeSpaceAR(new Vec3(targetWorld.x, targetWorld.y, targetWorld.z));
        const control = v3(
            (startLocal.x + endLocal.x) * 0.5,
            Math.max(startLocal.y, endLocal.y) + LIFT_HEIGHT,
            startLocal.z,
        );

        const moveSpeedPx = opts?.moveSpeedPx ?? MOVE_SPEED_PX;
        const minTotalSec = opts?.minTotalSec ?? MIN_TOTAL_SEC;
        const maxTotalSec = opts?.maxTotalSec ?? MAX_TOTAL_SEC;
        const arcLen = Vec3.distance(startLocal, control) + Vec3.distance(control, endLocal);
        const totalSec = Math.min(
            maxTotalSec,
            Math.max(minTotalSec, arcLen / moveSpeedPx),
        );

        node.setPosition(startLocal);
        node.setScale(1, 1, 1);
        if (opts?.showTrail) {
            grid.showEntranceTrail();
        }

        const proxy = { t: 0 };
        tween(proxy)
            .to(totalSec, { t: 1 }, {
                easing: 'sineInOut',
                onUpdate: () => {
                    if (!node.isValid) return;
                    const t = proxy.t;
                    const u = 1 - t;
                    node.setPosition(
                        u * u * startLocal.x + 2 * u * t * control.x + t * t * endLocal.x,
                        u * u * startLocal.y + 2 * u * t * control.y + t * t * endLocal.y,
                        startLocal.z,
                    );
                },
            })
            .call(() => {
                if (!node.isValid) {
                    finish();
                    return;
                }
                node.setPosition(endLocal);
                this._attachToParent(node, opts?.attachParent);
                finish();
            })
            .start();
    }

    static stop(grid: TextGrid | null): void {
        if (!grid?.node?.isValid) return;
        grid.hideEntranceTrail();
        grid.resetNodeTransform();
    }

    /** 保持世界坐标挂到目标父节点，并归零本地坐标（与槽位/格心对齐） */
    private static _attachToParent(node: Node, attachParent: Node | null | undefined): void {
        if (!attachParent?.isValid) return;
        const wp = node.worldPosition.clone();
        node.parent = attachParent;
        node.setWorldPosition(wp);
        node.setPosition(0, 0, 0);
    }
}