//
//  KBAIChatMessageCacheManager.m
//  keyBoard
//
//  Created by Mac on 2026/1/28.
//

#import "KBAIChatMessageCacheManager.h"
#import "KBAiChatMessage.h"
#import <UIKit/UIKit.h>

@interface KBAIChatMessageCacheManager ()
/// 消息缓存：Key = companionId，Value = messages 数组
@property (nonatomic, strong) NSCache<NSNumber *, NSMutableArray<KBAiChatMessage *> *> *messageCache;
@end

@implementation KBAIChatMessageCacheManager

#pragma mark - Singleton

+ (instancetype)shared {
    static KBAIChatMessageCacheManager *instance = nil;
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        instance = [[self alloc] init];
    });
    return instance;
}

- (instancetype)init {
    if (self = [super init]) {
        _messageCache = [[NSCache alloc] init];
        
        // 设置缓存上限，防止内存过大
        _messageCache.countLimit = 20;  // 最多缓存 20 个人设的消息
        _messageCache.totalCostLimit = 10 * 1024 * 1024;  // 最大 10MB
        
        // 监听内存警告，自动清理缓存
        [[NSNotificationCenter defaultCenter] addObserver:self
                                                 selector:@selector(handleMemoryWarning)
                                                     name:UIApplicationDidReceiveMemoryWarningNotification
                                                   object:nil];
        
        NSLog(@"[MessageCache] 缓存管理器初始化成功，限制：20个人设，最大10MB");
    }
    return self;
}

#pragma mark - Public Methods

- (void)saveMessages:(NSArray<KBAiChatMessage *> *)messages forCompanionId:(NSInteger)companionId {
    if (!messages || messages.count == 0) {
        NSLog(@"[MessageCache] 警告：尝试保存空消息数组，companionId=%ld", (long)companionId);
        return;
    }
    
    NSNumber *key = @(companionId);
    NSMutableArray *mutableMessages = [messages mutableCopy];
    [self.messageCache setObject:mutableMessages forKey:key];
    
    NSLog(@"[MessageCache] 保存成功：companionId=%ld, 消息数=%ld", (long)companionId, (long)messages.count);
}

- (NSArray<KBAiChatMessage *> *)messagesForCompanionId:(NSInteger)companionId {
    NSNumber *key = @(companionId);
    NSMutableArray *messages = [self.messageCache objectForKey:key];
    
    if (messages) {
        NSLog(@"[MessageCache] 缓存命中：companionId=%ld, 消息数=%ld", (long)companionId, (long)messages.count);
    } else {
        NSLog(@"[MessageCache] 缓存未命中：companionId=%ld", (long)companionId);
    }
    
    return messages;
}

- (void)appendMessages:(NSArray<KBAiChatMessage *> *)messages forCompanionId:(NSInteger)companionId {
    if (!messages || messages.count == 0) {
        return;
    }
    
    NSNumber *key = @(companionId);
    NSMutableArray *existingMessages = [self.messageCache objectForKey:key];
    
    if (existingMessages) {
        // 追加到现有消息数组
        [existingMessages addObjectsFromArray:messages];
        NSLog(@"[MessageCache] 追加消息：companionId=%ld, 新增=%ld, 总计=%ld",
              (long)companionId, (long)messages.count, (long)existingMessages.count);
    } else {
        // 如果缓存中没有，直接保存
        [self saveMessages:messages forCompanionId:companionId];
    }
}

- (void)clearMessagesForCompanionId:(NSInteger)companionId {
    NSNumber *key = @(companionId);
    [self.messageCache removeObjectForKey:key];
    NSLog(@"[MessageCache] 清空缓存：companionId=%ld", (long)companionId);
}

- (void)clearAllMessages {
    [self.messageCache removeAllObjects];
    NSLog(@"[MessageCache] 清空所有缓存");
}

- (BOOL)hasCacheForCompanionId:(NSInteger)companionId {
    NSNumber *key = @(companionId);
    return [self.messageCache objectForKey:key] != nil;
}

#pragma mark - Memory Warning

- (void)handleMemoryWarning {
    NSLog(@"[MessageCache] ⚠️ 收到内存警告，清空所有消息缓存");
    [self clearAllMessages];
}

- (void)dealloc {
    [[NSNotificationCenter defaultCenter] removeObserver:self];
}

@end