import { EffectAsset, Material, Sprite, Vec4 } from 'cc';

/**
 * 圆角 Sprite 材质工具。
 *
 * 基于 rounded-sprite.effect 的 SDF alpha 裁剪实现，直接作用于 Sprite 的自定义材质。
 * 每个 Sprite 都会获得独立 Material，避免 roundedParams / uvRect 互相覆盖。
 */

let cachedTemplate: Material | null = null;
let cachedEffectRef: EffectAsset | null = null;

const getOrCreateTemplate = (effectAsset: EffectAsset): Material => {
    if (cachedTemplate && cachedEffectRef === effectAsset) {
        return cachedTemplate;
    }

    const template = new Material();
    template.initialize({
        effectAsset,
        defines: { USE_TEXTURE: true },
    });

    cachedTemplate = template;
    cachedEffectRef = effectAsset;

    return template;
};

const extractUvRect = (sprite: Sprite): Vec4 => {
    const spriteFrame = sprite.spriteFrame;
    if (!spriteFrame) {
        return new Vec4(0, 0, 1, 1);
    }

    const uv = spriteFrame.uv;
    if (!uv || uv.length < 8) {
        return new Vec4(0, 0, 1, 1);
    }

    const u0 = uv[0];
    const v0 = uv[1];
    const u1 = uv[2];
    const v1 = uv[3];
    const u2 = uv[4];
    const v2 = uv[5];
    const u3 = uv[6];
    const v3 = uv[7];

    const minU = Math.min(u0, u1, u2, u3);
    const maxU = Math.max(u0, u1, u2, u3);
    const minV = Math.min(v0, v1, v2, v3);
    const maxV = Math.max(v0, v1, v2, v3);
    const rangeU = maxU - minU;
    const rangeV = maxV - minV;

    if (rangeU <= 0 || rangeV <= 0) {
        return new Vec4(0, 0, 1, 1);
    }

    return new Vec4(minU, minV, rangeU, rangeV);
};

export const applyRoundedCorner = (
    sprite: Sprite,
    effectAsset: EffectAsset,
    width: number,
    height: number,
    cornerRadius = 0.1,
    grayscale = false,
): void => {
    if (!sprite || !sprite.isValid) {
        console.warn('[roundedMaterial] Invalid sprite, skipping');
        return;
    }

    if (!effectAsset) {
        console.warn('[roundedMaterial] EffectAsset is null, skipping');
        return;
    }

    const template = getOrCreateTemplate(effectAsset);
    const materialInstance = new Material();
    const defines: Record<string, boolean> = { USE_TEXTURE: true };
    if (grayscale) {
        defines.IS_GRAY = true;
    }

    materialInstance.initialize({
        effectAsset,
        defines,
    });

    const params = new Vec4(cornerRadius, 0, width, height);
    materialInstance.setProperty('roundedParams', params);
    materialInstance.setProperty('uvRect', extractUvRect(sprite));

    sprite.customMaterial = materialInstance;
};