//
//  MessageStatusManager.m
//  AIIM
//
//  Created by AI Assistant on 2025/10/21.
//

#import "MessageStatusManager.h"

// plist 文件名
static NSString *const kMessageStatusPlistName = @"MessageStatus.plist";

@interface MessageStatusManager ()

@property (nonatomic, strong) NSMutableDictionary<NSString *, NSNumber *> *statusCache;
@property (nonatomic, strong) dispatch_queue_t ioQueue;
@property (nonatomic, copy) NSString *plistPath;

@end

@implementation MessageStatusManager

#pragma mark - Singleton

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

- (instancetype)init {
    self = [super init];
    if (self) {
        // 创建串行队列用于文件读写,避免并发问题
        _ioQueue = dispatch_queue_create("com.aiim.messageStatus.io", DISPATCH_QUEUE_SERIAL);
        
        // 获取 plist 文件路径
        _plistPath = [self plistFilePath];
        
        // 加载缓存
        [self loadCache];
    }
    return self;
}

#pragma mark - Public Methods

- (void)saveMessageStatus:(NSInteger)status forMessageId:(NSString *)messageId {
    if (!messageId || messageId.length == 0) {
        NSLog(@"[MessageStatusManager] 保存失败: messageId 为空");
        return;
    }
    
    dispatch_async(self.ioQueue, ^{
        // 更新内存缓存
        self.statusCache[messageId] = @(status);
        
        // 保存到文件
        [self saveCacheToDisk];
        
        NSLog(@"[MessageStatusManager] 保存成功: messageId=%@, status=%ld", messageId, (long)status);
    });
}

- (NSInteger)getMessageStatusForMessageId:(NSString *)messageId {
    if (!messageId || messageId.length == 0) {
        NSLog(@"getMessageStatusForMessageId 1: 1");
        return 1; // 默认返回发送成功
    }
    
    if (![self.statusCache.allKeys containsObject:messageId]) {
        NSLog(@"getMessageStatusForMessageId 2: 1");
        return 0;
    }
    
    __block NSInteger status = 0; // 默认值
    dispatch_sync(self.ioQueue, ^{
        NSNumber *statusNumber = self.statusCache[messageId];
        if (statusNumber) {
            status = [statusNumber integerValue];
        }
    });
    NSLog(@"getMessageStatusForMessageId 3: %ld", status);
    return status;
}

- (void)batchSaveMessageStatus:(NSDictionary<NSString *, NSNumber *> *)statusDict {
    if (!statusDict || statusDict.count == 0) {
        return;
    }
    
    dispatch_async(self.ioQueue, ^{
        // 批量更新内存缓存
        [self.statusCache addEntriesFromDictionary:statusDict];
        
        // 保存到文件
        [self saveCacheToDisk];
        
        NSLog(@"[MessageStatusManager] 批量保存成功: %lu 条", (unsigned long)statusDict.count);
    });
}

- (NSDictionary<NSString *, NSNumber *> *)batchGetMessageStatusForMessageIds:(NSArray<NSString *> *)messageIds {
    if (!messageIds || messageIds.count == 0) {
        return @{};
    }
    
    __block NSMutableDictionary *result = [NSMutableDictionary dictionary];
    dispatch_sync(self.ioQueue, ^{
        for (NSString *messageId in messageIds) {
            NSNumber *status = self.statusCache[messageId];
            if (status) {
                result[messageId] = status;
            } else {
                result[messageId] = @(1); // 默认发送成功
            }
        }
    });
    
    return [result copy];
}

- (void)removeMessageStatusForMessageId:(NSString *)messageId {
    if (!messageId || messageId.length == 0) {
        return;
    }
    
    dispatch_async(self.ioQueue, ^{
        [self.statusCache removeObjectForKey:messageId];
        
        // 保存到文件
        [self saveCacheToDisk];
        
        NSLog(@"[MessageStatusManager] 删除成功: messageId=%@", messageId);
    });
}

- (void)batchRemoveMessageStatusForMessageIds:(NSArray<NSString *> *)messageIds {
    if (!messageIds || messageIds.count == 0) {
        return;
    }
    
    dispatch_async(self.ioQueue, ^{
        [self.statusCache removeObjectsForKeys:messageIds];
        
        // 保存到文件
        [self saveCacheToDisk];
        
        NSLog(@"[MessageStatusManager] 批量删除成功: %lu 条", (unsigned long)messageIds.count);
    });
}

- (void)clearAllMessageStatus {
    dispatch_async(self.ioQueue, ^{
        [self.statusCache removeAllObjects];
        
        // 删除文件
        NSFileManager *fileManager = [NSFileManager defaultManager];
        if ([fileManager fileExistsAtPath:self.plistPath]) {
            NSError *error = nil;
            [fileManager removeItemAtPath:self.plistPath error:&error];
            if (error) {
                NSLog(@"[MessageStatusManager] 清空失败: %@", error);
            } else {
                NSLog(@"[MessageStatusManager] 清空成功");
            }
        }
    });
}

- (NSInteger)getAllMessageStatusCount {
    __block NSInteger count = 0;
    dispatch_sync(self.ioQueue, ^{
        count = self.statusCache.count;
    });
    return count;
}

#pragma mark - Private Methods

/// 获取 plist 文件路径
- (NSString *)plistFilePath {
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths firstObject];
    return [documentsDirectory stringByAppendingPathComponent:kMessageStatusPlistName];
}

/// 从磁盘加载缓存
- (void)loadCache {
    dispatch_sync(self.ioQueue, ^{
        NSFileManager *fileManager = [NSFileManager defaultManager];
        if ([fileManager fileExistsAtPath:self.plistPath]) {
            NSDictionary *diskData = [NSDictionary dictionaryWithContentsOfFile:self.plistPath];
            if (diskData) {
                self.statusCache = [diskData mutableCopy];
                NSLog(@"[MessageStatusManager] 加载缓存成功: %lu 条", (unsigned long)self.statusCache.count);
            } else {
                self.statusCache = [NSMutableDictionary dictionary];
                NSLog(@"[MessageStatusManager] 缓存文件为空,创建新缓存");
            }
        } else {
            self.statusCache = [NSMutableDictionary dictionary];
            NSLog(@"[MessageStatusManager] 缓存文件不存在,创建新缓存");
        }
    });
}

/// 将缓存保存到磁盘
- (void)saveCacheToDisk {
    // 注意: 此方法必须在 ioQueue 中调用
    BOOL success = [self.statusCache writeToFile:self.plistPath atomically:YES];
    if (!success) {
        NSLog(@"[MessageStatusManager] 保存到磁盘失败");
    }
}

@end