import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:get/get.dart';
import 'package:video_player/video_player.dart';

/// 全屏播放页业务逻辑：横竖屏切换 + 后台自动暂停
/// 注：[playCtr] 由外部页面持有并释放，本类只借用，绝不能 dispose
class VideoFullLogic extends GetxController with WidgetsBindingObserver {
  VideoFullLogic({required this.playCtr, this.isAutoV = true});

  final VideoPlayerController playCtr;
  final bool isAutoV; // true:按视频比例决定是否转横屏；false:强制转横屏

  double get aspectRatio => playCtr.value.aspectRatio;

  @override
  void onInit() {
    super.onInit();
    WidgetsBinding.instance.addObserver(this);
    // 横向视频(或调用方强制)才转横屏，竖屏视频保持竖屏全屏
    if (aspectRatio > 1 || !isAutoV) {
      SystemChrome.setEnabledSystemUIMode(SystemUiMode.manual, overlays: [SystemUiOverlay.bottom]);
      SystemChrome.setPreferredOrientations([
        DeviceOrientation.landscapeLeft,
        DeviceOrientation.landscapeRight,
      ]);
    }
    // 转屏后 Get.width/height 才是新值，下一帧刷一次让画面按新尺寸铺满
    WidgetsBinding.instance.addPostFrameCallback((_) => update());
  }

  /// 切后台暂停，防止息屏/切走后声音还在外放
  @override
  void didChangeAppLifecycleState(AppLifecycleState state) {
    super.didChangeAppLifecycleState(state);
    if (state == AppLifecycleState.paused) playCtr.pause();
  }

  /// 退出全屏：恢复竖屏 + 状态栏，再退页
  void exitFullScreen() {
    SystemChrome.setEnabledSystemUIMode(SystemUiMode.manual, overlays: [SystemUiOverlay.bottom, SystemUiOverlay.top]);
    SystemChrome.setPreferredOrientations([DeviceOrientation.portraitUp]);
    Get.back();
  }

  @override
  void onClose() {
    WidgetsBinding.instance.removeObserver(this);
    super.onClose(); // playCtr 属于调用方，这里不释放
  }
}