import {
  _decorator,
  Component,
  Sprite,
  UITransform,
  Size,
  isValid,
  Node,
} from "cc";

const { ccclass } = _decorator;

/**
 * 父物体自适应调整组件
 * 功能：使精灵保持原始宽高比并覆盖整个父物体区域
 * 触发时机：GameObject 激活时、父物体尺寸变化时
 */
@ccclass("ParentResize")
export class ParentResize extends Component {
  private sprite: Sprite = null;
  private uiTransform: UITransform = null;
  private parentTransform: UITransform = null;
  private lastParentSize: Size = new Size();

  onLoad() {
    // 获取必要组件
    this.sprite = this.getComponent(Sprite);
    this.uiTransform = this.getComponent(UITransform);

    if (!this.sprite) {
      console.warn("ParentResize: 未找到 Sprite 组件");
      return;
    }

    if (!this.uiTransform) {
      console.warn("ParentResize: 未找到 UITransform 组件");
      return;
    }

    // 获取父物体的 UITransform
    if (this.node.parent) {
      this.parentTransform = this.node.parent.getComponent(UITransform);
      if (!this.parentTransform) {
        console.warn("ParentResize: 父物体未找到 UITransform 组件");
        return;
      }
    } else {
      console.warn("ParentResize: 未找到父物体");
      return;
    }
  }

  onEnable() {
    // 激活时立即调整尺寸
    this.adjustToParent();
  }

  /**
   * 调整精灵尺寸以覆盖整个父物体区域
   * 保持原始宽高比，使用 cover 策略
   */
  private adjustToParent() {
    if (
      !isValid(this.sprite) ||
      !isValid(this.uiTransform) ||
      !isValid(this.parentTransform)
    ) {
      return;
    }

    const spriteFrame = this.sprite.spriteFrame;
    if (!spriteFrame) {
      return;
    }

    // 获取父物体尺寸
    const parentSize = this.parentTransform.contentSize;

    // 获取精灵原始尺寸
    const originalSize = spriteFrame.originalSize;
    if (!originalSize || originalSize.width <= 0 || originalSize.height <= 0) {
      return;
    }

    // 如果父物体尺寸无效，则不进行调整
    if (parentSize.width <= 0 || parentSize.height <= 0) {
      return;
    }

    // 计算缩放比例（使用较大值以确保覆盖整个父物体区域）
    const scaleX = parentSize.width / originalSize.width;
    const scaleY = parentSize.height / originalSize.height;
    const scale = Math.max(scaleX, scaleY);

    // 计算新的尺寸
    const newWidth = originalSize.width * scale;
    const newHeight = originalSize.height * scale;

    // 应用新尺寸
    this.uiTransform.setContentSize(newWidth, newHeight);
  }

  /**
   * 手动触发尺寸调整
   * 可在外部调用，例如当 SpriteFrame 改变时或父物体尺寸手动改变时
   */
  public forceResize() {
    this.adjustToParent();
  }

  /**
   * 设置新的父物体
   * 当需要动态改变参考父物体时调用
   */
  public setParent(parentNode: Node) {
    if (parentNode) {
      this.parentTransform = parentNode.getComponent(UITransform);
      if (this.parentTransform) {
        this.lastParentSize.set(0, 0); // 重置上次记录的尺寸
        this.adjustToParent();
      } else {
        console.warn("ParentResize: 新父物体未找到 UITransform 组件");
      }
    }
  }
}