//
//  BannerScheduler.m
//  YuMi
//
//  Created by AI Assistant on 2025/1/13.
//

#import "BannerScheduler.h"

@interface BannerScheduler ()

@property (nonatomic, strong) NSMutableArray *bannerQueue;
@property (nonatomic, assign) BOOL isPlaying;
@property (nonatomic, assign) BOOL isPaused;

@end

@implementation BannerScheduler

#pragma mark - Initialization

- (instancetype)initWithDelegate:(id<BannerSchedulerDelegate>)delegate {
    if (self = [super init]) {
        _delegate = delegate;
        _bannerQueue = [NSMutableArray array];
        _isPlaying = NO;
        _isPaused = NO;
    }
    return self;
}

#pragma mark - Public Methods

- (void)enqueueBanner:(id)banner {
    if (!banner) {
        NSLog(@"⚠️ BannerScheduler: 尝试添加空的 Banner");
        return;
    }
    
    NSLog(@"🔄 BannerScheduler: 添加 Banner 到队列 - 类型: %@, 队列长度: %ld", 
          [banner class], (long)self.bannerQueue.count);
    
    [self.bannerQueue addObject:banner];
    
    // 如果当前没有在播放且未暂停，则开始处理
    if (!self.isPlaying && !self.isPaused) {
        [self processNextBanner];
    }
}

- (void)processNextBanner {
    if (self.isPaused) {
         NSLog(@"⏸️ BannerScheduler: 调度器已暂停，跳过处理");
         return;
     }
     
     // 🔧 新增：检查 delegate 是否有效
     if (!self.delegate) {
         NSLog(@"⚠️ BannerScheduler: delegate 已失效，停止处理");
         [self clearQueue];
         self.isPlaying = NO;
         return;
     }
    
    if (self.isPaused) {
        NSLog(@"⏸️ BannerScheduler: 调度器已暂停，跳过处理");
        return;
    }
    
    if (self.bannerQueue.count == 0) {
        NSLog(@"🔄 BannerScheduler: 队列为空，停止播放");
        self.isPlaying = NO;
        return;
    }
    
    if (self.isPlaying) {
        NSLog(@"🔄 BannerScheduler: 已有 Banner 正在播放，跳过处理");
        return;
    }
    
    // 对队列进行优先级排序
    [self sortQueueByPriority];
    
    // 取出队列中的第一个 Banner
    id nextBanner = [self.bannerQueue firstObject];
    [self.bannerQueue removeObjectAtIndex:0];
    
    NSLog(@"🔄 BannerScheduler: 开始播放 Banner - 类型: %@, 剩余队列: %ld", 
          [nextBanner class], (long)self.bannerQueue.count);
    
    self.isPlaying = YES;
    
    // 通知代理开始播放
    if ([self.delegate respondsToSelector:@selector(bannerScheduler:didStartPlayingBanner:)]) {
        [self.delegate bannerScheduler:self didStartPlayingBanner:nextBanner];
    }
    
    // 通知代理播放 Banner
    if ([self.delegate respondsToSelector:@selector(bannerScheduler:shouldPlayBanner:)]) {
        [self.delegate bannerScheduler:self shouldPlayBanner:nextBanner];
    }
}

- (void)clearQueue {
    NSLog(@"🗑️ BannerScheduler: 清空 Banner 队列 - 原有数量: %ld", (long)self.bannerQueue.count);
    [self.bannerQueue removeAllObjects];
}

- (void)sortQueueByPriority {
    // 保持先进先出（FIFO）策略，不需要排序
    // 队列顺序就是添加顺序，确保公平性
    NSLog(@"🔄 BannerScheduler: 使用先进先出策略，保持队列原有顺序");
}

- (void)pause {
    if (self.isPaused) {
        NSLog(@"⏸️ BannerScheduler: 调度器已经处于暂停状态");
        return;
    }
    
    NSLog(@"⏸️ BannerScheduler: 暂停调度器");
    self.isPaused = YES;
}

- (void)resume {
    NSLog(@"▶️ BannerScheduler: 恢复调度器");
    self.isPaused = NO;
    
    // 如果当前没有在播放，则开始处理队列
    if (!self.isPlaying) {
        [self processNextBanner];
    }
}

- (BOOL)isQueueEmpty {
    return self.bannerQueue.count == 0;
}

- (nullable id)bannerAtIndex:(NSInteger)index {
    if (index < 0 || index >= self.bannerQueue.count) {
        return nil;
    }
    return [self.bannerQueue objectAtIndex:index];
}

- (BOOL)removeBannerAtIndex:(NSInteger)index {
    if (index < 0 || index >= self.bannerQueue.count) {
        return NO;
    }
    
    id removedBanner = [self.bannerQueue objectAtIndex:index];
    [self.bannerQueue removeObjectAtIndex:index];
    
    NSLog(@"🗑️ BannerScheduler: 从队列中移除 Banner - 索引: %ld, 类型: %@", 
          (long)index, [removedBanner class]);
    
    return YES;
}

- (NSString *)queueStatusDescription {
    NSMutableString *description = [NSMutableString string];
    [description appendFormat:@"BannerScheduler 状态:\n"];
    [description appendFormat:@"- 播放状态: %@\n", self.isPlaying ? @"播放中" : @"空闲"];
    [description appendFormat:@"- 暂停状态: %@\n", self.isPaused ? @"已暂停" : @"运行中"];
    [description appendFormat:@"- 队列长度: %ld\n", (long)self.bannerQueue.count];
    
    if (self.bannerQueue.count > 0) {
        [description appendString:@"- 队列内容:\n"];
        for (NSInteger i = 0; i < self.bannerQueue.count; i++) {
            id banner = self.bannerQueue[i];
            [description appendFormat:@"  [%ld] 类型: %@\n", (long)i, [banner class]];
        }
    }
    
    return description;
}

#pragma mark - Public Properties

- (NSInteger)queueCount {
    return self.bannerQueue.count;
}

#pragma mark - Internal Methods

/**
 * 标记 Banner 播放完成
 * 这个方法应该由代理在 Banner 播放完成后调用
 */
- (void)markBannerFinished {
    if (!self.isPlaying) {
        NSLog(@"⚠️ BannerScheduler: 尝试标记未播放的 Banner 为完成");
        return;
    }
    
    // 防止过快标记完成，确保 banner 有足够的显示时间
    static NSTimeInterval lastFinishTime = 0;
    NSTimeInterval currentTime = [[NSDate date] timeIntervalSince1970];
    
    // 如果距离上次完成时间太短，延迟处理
    if (currentTime - lastFinishTime < 0.3) {
        NSLog(@"⏳ BannerScheduler: Banner 完成间隔过短，延迟处理 (间隔: %.2f秒)", currentTime - lastFinishTime);
        dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0.3 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
            [self markBannerFinished];
        });
        return;
    }
    lastFinishTime = currentTime;
    
    NSLog(@"✅ BannerScheduler: Banner 播放完成");
    self.isPlaying = NO;
    
    // 通知代理播放完成
    if ([self.delegate respondsToSelector:@selector(bannerSchedulerDidFinishPlaying:)]) {
        [self.delegate bannerSchedulerDidFinishPlaying:self];
    }
    
    // 处理队列中的下一个 Banner
    [self processNextBanner];
}

/**
 * 调试方法：检查调度器状态
 * @return 调试信息字符串
 */
- (NSString *)debugStatus {
    NSMutableString *debugInfo = [NSMutableString string];
    [debugInfo appendFormat:@"BannerScheduler Debug Status:\n"];
    [debugInfo appendFormat:@"- 播放状态: %@\n", self.isPlaying ? @"播放中" : @"空闲"];
    [debugInfo appendFormat:@"- 暂停状态: %@\n", self.isPaused ? @"已暂停" : @"运行中"];
    [debugInfo appendFormat:@"- 队列长度: %ld\n", (long)self.bannerQueue.count];
    
    if (self.bannerQueue.count > 0) {
        [debugInfo appendString:@"- 队列内容:\n"];
        for (NSInteger i = 0; i < self.bannerQueue.count; i++) {
            id banner = self.bannerQueue[i];
            [debugInfo appendFormat:@"  [%ld] 类型: %@\n", (long)i, [banner class]];
        }
    }
    return debugInfo;
}

@end