//
//  TokenGenerator.m
//  SellyCloudSDK_Example
//
//  Created by Caleb on 20/11/25.
//  Copyright © 2025 Caleb. All rights reserved.
//

#import "TokenGenerator.h"

#define KSecret @"CHANGE_ME"
#define CALL_APP_ID @"demo-app"

@implementation TokenGenerator

+ (NSString *)generateRTCCallTokenWithUserId:(NSString *)userId
                              callId:(NSString *)callId
{
    // 当前时间戳（秒）
    long signTime = (long)[[NSDate date] timeIntervalSince1970];
    long exprTime = signTime + 600;   // 10 分钟后过期

    // payload 拼接
    NSString *payload = [NSString stringWithFormat:@"%@%@%@%ld%ld",
                         CALL_APP_ID, userId, callId, signTime, exprTime];

    // HMAC-SHA256 计算
    const char *cKey  = [KSecret cStringUsingEncoding:NSUTF8StringEncoding];
    const char *cData = [payload cStringUsingEncoding:NSUTF8StringEncoding];

    unsigned char cHMAC[CC_SHA256_DIGEST_LENGTH];
    CCHmac(kCCHmacAlgSHA256, cKey, strlen(cKey), cData, strlen(cData), cHMAC);

    // 转 hex 字符串
    NSMutableString *sign = [NSMutableString stringWithCapacity:CC_SHA256_DIGEST_LENGTH * 2];
    for (int i = 0; i < CC_SHA256_DIGEST_LENGTH; i++) {
        [sign appendFormat:@"%02x", cHMAC[i]];
    }

    // 拼接最终 Token
    NSString *token = [NSString stringWithFormat:
                       @"appid=%@&userid=%@&callid=%@&signtime=%ld&exprtime=%ld&sign=%@",
                       CALL_APP_ID, userId, callId, signTime, exprTime, sign];

    return token;
}

+ (NSString *)generateStreamSignatureWithVhost:(NSString *)vhost
                                         appId:(NSString *)appId
                                     channelId:(NSString *)channelId
                                          type:(NSString *)type
                                           key:(NSString *)key
{
    // 当前时间戳（秒）
    long signTm = (long)[[NSDate date] timeIntervalSince1970];
    long expireTm = signTm + 600;  // 10 分钟后过期
    
    // 拼接签名字符串: vhost|app_id|channel_id|sign_tm|expire_tm|type
    NSString *payload = [NSString stringWithFormat:@"%@|%@|%@|%ld|%ld|%@",
                         vhost, appId, channelId, signTm, expireTm, type];
    
    // 使用 key 生成签名
    NSString *sign = [self generateSign:payload withKey:key];
    
    // 拼接完整 payload: vhost|app_id|channel_id|sign_tm|expire_tm|type|sign
    NSString *fullPayload = [NSString stringWithFormat:@"%@|%@", payload, sign];
    NSLog(@"###fullPayload == %@",fullPayload);
    
    // Base64 编码
    NSData *data = [fullPayload dataUsingEncoding:NSUTF8StringEncoding];
    NSString *base64String = [data base64EncodedStringWithOptions:0];
    
    return base64String;
}

+ (NSString *)generateSign:(NSString *)payload withKey:(NSString *)key {
    // HMAC-SHA256 计算
    const char *cKey  = [key cStringUsingEncoding:NSUTF8StringEncoding];
    const char *cData = [payload cStringUsingEncoding:NSUTF8StringEncoding];
    
    unsigned char cHMAC[CC_SHA256_DIGEST_LENGTH];
    CCHmac(kCCHmacAlgSHA256, cKey, strlen(cKey), cData, strlen(cData), cHMAC);
    
    // 转 hex 字符串
    NSMutableString *sign = [NSMutableString stringWithCapacity:CC_SHA256_DIGEST_LENGTH * 2];
    for (int i = 0; i < CC_SHA256_DIGEST_LENGTH; i++) {
        [sign appendFormat:@"%02x", cHMAC[i]];
    }
    
    return sign;
}

@end