//
//  KBNetworkManager.m
//  CustomKeyboard
//

#import "KBNetworkManager.h"
#import <TargetConditionals.h>
#import "AFNetworking.h"
#import "KBAuthManager.h"
#import "KBBizCode.h"
// 仅在主 App 内需要的会话管理与 HUD 组件
#import "KBUserSessionManager.h"
#import "KBHUD.h"

NSErrorDomain const KBNetworkErrorDomain = @"com.company.keyboard.network";

@interface KBNetworkManager ()
@property (nonatomic, strong) AFHTTPSessionManager *manager; // AFN 管理器（ephemeral 配置）
// 私有错误派发
- (void)fail:(KBNetworkError)code completion:(KBNetworkCompletion)completion;
@end

#if DEBUG
// 在使用到 Debug 辅助方法之前做前置声明，避免出现
// “No visible @interface declares the selector …” 的编译错误。
@interface KBNetworkManager (Debug)
- (NSString *)kb_prettyJSONStringFromObject:(id)obj;
- (NSString *)kb_textFromData:(NSData *)data;
- (NSString *)kb_trimmedString:(NSString *)s maxLength:(NSUInteger)maxLen;
@end
#endif

@implementation KBNetworkManager

+ (instancetype)shared {
    static KBNetworkManager *m; static dispatch_once_t onceToken; dispatch_once(&onceToken, ^{ m = [KBNetworkManager new]; });
    return m;
}

- (instancetype)init {
    if (self = [super init]) {
        _enabled = NO; // 键盘扩展默认无网络能力，需外部显式开启
        _timeout = 10.0;
        // 默认请求头：Accept 任意类型 + 使用项目多语言管理器设置 Accept-Language
        NSString *lang = [KBLocalizationManager shared].currentLanguageCode ?: KBLanguageCodeEnglish;
        _defaultHeaders = @{
            @"Accept": @"*/*",
            @"Accept-Language": lang,
            @"auth-token" : @""
        };
        // 设置基础域名，路径可相对该地址拼接
        _baseURL = [NSURL URLWithString:KB_BASE_URL];
    }
    return self;
}

#
#pragma mark - Public

// JSON GET：可控制业务错误是否由内部弹出
- (NSURLSessionDataTask *)GET:(NSString *)path
                    parameters:(NSDictionary *)parameters
                       headers:(NSDictionary<NSString *,NSString *> *)headers
         autoShowBusinessError:(BOOL)autoShowBusinessError
                     completion:(KBNetworkCompletion)completion {
    NSLog(@"[KBNetworkManager] GET called, enabled=%d, path=%@", self.isEnabled, path);
    if (![self ensureEnabled:completion]) return nil;
    NSString *urlString = [self buildURLStringWithPath:path];
    if (!urlString) { [self fail:KBNetworkErrorInvalidURL completion:completion]; return nil; }
    // 使用 AFHTTPRequestSerializer 生成带参数与头的请求
    AFHTTPRequestSerializer *serializer = [AFHTTPRequestSerializer serializer];
    serializer.timeoutInterval = self.timeout;
    NSError *serror = nil;
    NSMutableURLRequest *req = [serializer requestWithMethod:@"GET"
                                                   URLString:urlString
                                                  parameters:parameters
                                                       error:&serror];
    if (serror || !req) {
        if (completion) completion(nil, nil, serror ?: [NSError errorWithDomain:KBNetworkErrorDomain code:KBNetworkErrorInvalidURL userInfo:@{NSLocalizedDescriptionKey: KBLocalized(@"Invalid URL")}]);
        return nil;
    }
    [self applyHeaders:headers toMutableRequest:req contentType:nil];
#if DEBUG
    // 打印请求信息（GET）
    NSString *paramStr = [self kb_prettyJSONStringFromObject:parameters] ?: @"(null)";
    KBLOG(@"HTTP GET\nURL: %@\nHeaders: %@\n参数: %@",
          req.URL.absoluteString,
          req.allHTTPHeaderFields ?: @{},
          paramStr);
#endif
    return [self startJSONTaskWithRequest:req
                     autoShowBusinessError:autoShowBusinessError
                                completion:completion];
}

// 默认 GET：自动弹业务错误
- (NSURLSessionDataTask *)GET:(NSString *)path
                    parameters:(NSDictionary *)parameters
                       headers:(NSDictionary<NSString *,NSString *> *)headers
                     completion:(KBNetworkCompletion)completion {
    return [self GET:path
          parameters:parameters
             headers:headers
autoShowBusinessError:YES
           completion:completion];
}

// JSON POST：可控制业务错误是否由内部弹出
- (NSURLSessionDataTask *)POST:(NSString *)path
                      jsonBody:(id)jsonBody
                       headers:(NSDictionary<NSString *,NSString *> *)headers
        autoShowBusinessError:(BOOL)autoShowBusinessError
                     completion:(KBNetworkCompletion)completion {
    NSLog(@"[KBNetworkManager] POST called, enabled=%d, path=%@", self.isEnabled, path);
    if (![self ensureEnabled:completion]) return nil;
    NSString *urlString = [self buildURLStringWithPath:path];
    if (!urlString) { [self fail:KBNetworkErrorInvalidURL completion:completion]; return nil; }
    // 用 JSON 序列化器生成 JSON Body 的请求
    AFJSONRequestSerializer *serializer = [AFJSONRequestSerializer serializer];
    serializer.timeoutInterval = self.timeout;
    NSError *error = nil;
    NSMutableURLRequest *req = [serializer requestWithMethod:@"POST"
                                                   URLString:urlString
                                                  parameters:jsonBody
                                                       error:&error];
    if (error) { if (completion) completion(nil, nil, error); return nil; }
    [self applyHeaders:headers toMutableRequest:req contentType:nil];
#if DEBUG
    // 打印请求信息（POST JSON）
    NSString *bodyStr = [self kb_prettyJSONStringFromObject:jsonBody] ?: @"(null)";
    KBLOG(@"HTTP POST\nURL: %@\nHeaders: %@\nJSON: %@",
          req.URL.absoluteString,
          req.allHTTPHeaderFields ?: @{},
          bodyStr);
#endif
    return [self startJSONTaskWithRequest:req
                     autoShowBusinessError:autoShowBusinessError
                                completion:completion];
}

// 默认 POST：自动弹业务错误
- (NSURLSessionDataTask *)POST:(NSString *)path
                      jsonBody:(id)jsonBody
                       headers:(NSDictionary<NSString *,NSString *> *)headers
                     completion:(KBNetworkCompletion)completion {
    return [self POST:path
             jsonBody:jsonBody
              headers:headers
 autoShowBusinessError:YES
            completion:completion];
}

// 原始二进制 GET，用于下载 zip、图片等
- (NSURLSessionDataTask *)GETData:(NSString *)path
                       parameters:(NSDictionary *)parameters
                          headers:(NSDictionary<NSString *,NSString *> *)headers
                        completion:(KBNetworkDataCompletion)completion {
    if (!self.isEnabled) {
        NSError *e = [NSError errorWithDomain:KBNetworkErrorDomain
                                         code:KBNetworkErrorDisabled
                                     userInfo:@{NSLocalizedDescriptionKey: KBLocalized(@"Network disabled (Full Access may be off)")}];
        if (completion) completion(nil, nil, e);
        return nil;
    }
    NSString *urlString = [self buildURLStringWithPath:path];
    if (!urlString) {
        NSError *e = [NSError errorWithDomain:KBNetworkErrorDomain
                                         code:KBNetworkErrorInvalidURL
                                     userInfo:@{NSLocalizedDescriptionKey: KBLocalized(@"Invalid URL")}];
        if (completion) completion(nil, nil, e);
        return nil;
    }
    AFHTTPRequestSerializer *serializer = [AFHTTPRequestSerializer serializer];
    serializer.timeoutInterval = self.timeout;
    NSError *serror = nil;
    NSMutableURLRequest *req = [serializer requestWithMethod:@"GET"
                                                   URLString:urlString
                                                  parameters:parameters
                                                       error:&serror];
    if (serror || !req) {
        if (completion) completion(nil, nil, serror ?: [NSError errorWithDomain:KBNetworkErrorDomain code:KBNetworkErrorInvalidURL userInfo:@{NSLocalizedDescriptionKey: KBLocalized(@"Invalid URL")}]);
        return nil;
    }
    [self applyHeaders:headers toMutableRequest:req contentType:nil];
    return [self startDataTaskWithRequest:req completion:completion];
}

#pragma mark - Core

- (BOOL)ensureEnabled:(KBNetworkCompletion)completion {
    if (!self.isEnabled) {
        NSError *e = [NSError errorWithDomain:KBNetworkErrorDomain code:KBNetworkErrorDisabled userInfo:@{NSLocalizedDescriptionKey: KBLocalized(@"Network disabled (Full Access may be off)")}];
        if (completion) completion(nil, nil, e);
        return NO;
    }
    return YES;
}

- (NSString *)buildURLStringWithPath:(NSString *)path {
    if (path.length == 0) return nil;
    if ([path hasPrefix:@"http://"] || [path hasPrefix:@"https://"]) {
        return path;
    }
    if (self.baseURL) {
        // 1) 统一为目录型 base（确保以 / 结尾），否则相对路径会把最后一段当文件替换
        NSString *base = self.baseURL.absoluteString ?: @"";
        if (![base hasSuffix:@"/"]) { base = [base stringByAppendingString:@"/"]; }
        NSURL *dirBase = [NSURL URLWithString:base];
        // 2) 防呆：调用方若传了以“/”开头的 path，会导致相对路径从根覆盖，丢失 /api
        NSString *relative = ([path hasPrefix:@"/"]) ? [path substringFromIndex:1] : path;
        return [NSURL URLWithString:relative relativeToURL:dirBase].absoluteURL.absoluteString;
    }
    return path; // 当无 baseURL 且 path 不是完整 URL 时，让 AFN 处理（可能失败）
}

- (void)applyHeaders:(NSDictionary<NSString *,NSString *> *)headers toMutableRequest:(NSMutableURLRequest *)req contentType:(NSString *)contentType {
    // 合并默认头与局部头，并注入授权头（若可用）。局部覆盖优先。
    NSMutableDictionary *all = [self.defaultHeaders mutableCopy] ?: [NSMutableDictionary new];
    NSDictionary *auth = [[KBAuthManager shared] authorizationHeader];
    [auth enumerateKeysAndObjectsUsingBlock:^(NSString *key, NSString *obj, BOOL *stop) { all[key] = obj; }];
    if (contentType) all[@"Content-Type"] = contentType;
    [headers enumerateKeysAndObjectsUsingBlock:^(NSString *key, NSString *obj, BOOL *stop) { all[key] = obj; }];
    [all enumerateKeysAndObjectsUsingBlock:^(NSString *key, NSString *obj, BOOL *stop) { [req setValue:obj forHTTPHeaderField:key]; }];
}

- (NSURLSessionDataTask *)startJSONTaskWithRequest:(NSURLRequest *)req
                             autoShowBusinessError:(BOOL)autoShowBusinessError
                                        completion:(KBNetworkCompletion)completion {
    NSLog(@"[KBNetworkManager] startAFTaskWithRequest: %@", req.URL.absoluteString);
    // 响应先用原始数据返回，再按 Content-Type 解析 JSON（与原实现一致）
    self.manager.responseSerializer = [AFHTTPResponseSerializer serializer];
    NSURLSessionDataTask *task = [self.manager dataTaskWithRequest:req uploadProgress:nil downloadProgress:nil completionHandler:^(NSURLResponse *response, id responseObject, NSError *error) {
        NSLog(@"[KBNetworkManager] task finished, error = %@", error);
        // AFN 默认对非 2xx 的状态码返回 error；这里先日志，再直接回调上层
        if (error) {
#if DEBUG
            NSInteger status = [response isKindOfClass:NSHTTPURLResponse.class] ? ((NSHTTPURLResponse *)response).statusCode : 0;
            KBLOG(@"请求失败\nURL: %@\n状态: %ld\n错误: %@\nUserInfo: %@",
                  req.URL.absoluteString,
                  (long)status,
                  error.localizedDescription,
                  error.userInfo ?: @{});
#endif
            if (completion) completion(nil, response, error);
            return;
        }
        NSData *data = (NSData *)responseObject;
        if (![data isKindOfClass:[NSData class]]) {
    #if DEBUG
                KBLOG(@"无效响应\nURL: %@\n说明: %@", req.URL.absoluteString, KBLocalized(@"未获取到数据"));
    #endif
            if (completion) completion(nil, response, [NSError errorWithDomain:KBNetworkErrorDomain code:KBNetworkErrorInvalidResponse userInfo:@{NSLocalizedDescriptionKey:KBLocalized(@"No data")}]);
            return;
        }
        NSString *ct = nil;
        if ([response isKindOfClass:[NSHTTPURLResponse class]]) {
            ct = ((NSHTTPURLResponse *)response).allHeaderFields[@"Content-Type"];
        }
        // 更宽松的 JSON 判定：Content-Type 里包含 json；或首字符是 { / [
        BOOL looksJSON = (ct && [[ct lowercaseString] containsString:@"json"]);
        if (!looksJSON) {
            // 内容嗅探（不依赖服务端声明）
            const unsigned char *bytes = data.bytes;
            NSUInteger len = data.length;
            for (NSUInteger i = 0; !looksJSON && i < len; i++) {
                unsigned char c = bytes[i];
                if (c == ' ' || c == '\n' || c == '\r' || c == '\t') continue;
                looksJSON = (c == '{' || c == '[');
                break;
            }
        }
        if (looksJSON) {
            NSError *jsonErr = nil;
            id json = [NSJSONSerialization JSONObjectWithData:data options:0 error:&jsonErr];
            if (jsonErr) {
    #if DEBUG
                KBLOG(@"响应解析失败(JSON)\nURL: %@\n错误: %@",
                      req.URL.absoluteString,
                      jsonErr.localizedDescription);
    #endif
                if (completion) completion(nil, response, [NSError errorWithDomain:KBNetworkErrorDomain code:KBNetworkErrorDecodeFailed userInfo:@{NSLocalizedDescriptionKey:KBLocalized(@"Failed to parse JSON")}]);
                return;
            }

            // 必须为字典结构，否则视为无效响应
            if (![json isKindOfClass:[NSDictionary class]]) {
                if (completion) completion(nil, response, [NSError errorWithDomain:KBNetworkErrorDomain code:KBNetworkErrorInvalidResponse userInfo:@{NSLocalizedDescriptionKey:KBLocalized(@"Invalid response")}]);
                return;
            }
#if DEBUG
            NSString *pretty = [self kb_prettyJSONStringFromObject:json] ?: @"(null)";
            pretty = [self kb_trimmedString:pretty maxLength:4096];
            NSInteger status = [response isKindOfClass:NSHTTPURLResponse.class] ? ((NSHTTPURLResponse *)response).statusCode : 0;
            KBLOG(@"\n[KBNetwork] 响应成功(JSON)\nURL: %@\n状态: %ld\nContent-Type: %@\n数据: %@\n",
                  req.URL.absoluteString,
                  (long)status,
                  ct ?: @"",
                  pretty);
#endif
            NSDictionary *dict = (NSDictionary *)json;
            // 统一解析业务 code：约定后端顶层包含 { code, message, data }
            NSInteger bizCode = KBBizCodeFromJSONObject(dict);
            if (bizCode != NSNotFound && bizCode != KBBizCodeSuccess) {
                // 非成功业务 code：执行通用处理（如 token 失效）并通过 error 方式回调
                BOOL handledByAuth = [self kb_handleBizCode:bizCode json:dict response:response];
                NSString *msg = KBBizMessageFromJSONObject(dict) ?: KBLocalized(@"Server error");
                if (autoShowBusinessError && !handledByAuth) {
                    dispatch_async(dispatch_get_main_queue(), ^{
                        [KBHUD showInfo:msg];
                    });
                }
                NSError *bizErr = [NSError errorWithDomain:KBNetworkErrorDomain
                                                      code:KBNetworkErrorBusiness
                                                  userInfo:@{
                                                      NSLocalizedDescriptionKey : msg,
                                                      @"code" : @(bizCode)
                                                  }];
                if (completion) completion(dict, response, bizErr);
                return;
            }
            // code 缺失或为成功，按正常成功回调
            if (completion) completion(dict, response, nil);
        } else {
            // 预期 JSON，但未检测到 JSON 内容
            if (completion) completion(nil, response, [NSError errorWithDomain:KBNetworkErrorDomain code:KBNetworkErrorInvalidResponse userInfo:@{NSLocalizedDescriptionKey:KBLocalized(@"Invalid response")}]);
        }
    }];
    [task resume];
    return task;
}

// 原始二进制任务
- (NSURLSessionDataTask *)startDataTaskWithRequest:(NSURLRequest *)req
                                        completion:(KBNetworkDataCompletion)completion {
    NSLog(@"[KBNetworkManager] startDataTaskWithRequest: %@", req.URL.absoluteString);
    self.manager.responseSerializer = [AFHTTPResponseSerializer serializer];
    NSURLSessionDataTask *task = [self.manager dataTaskWithRequest:req uploadProgress:nil downloadProgress:nil completionHandler:^(NSURLResponse *response, id responseObject, NSError *error) {
        NSLog(@"[KBNetworkManager] data task finished, error = %@", error);
        if (error) {
            if (completion) completion(nil, response, error);
            return;
        }
        NSData *data = (NSData *)responseObject;
        if (![data isKindOfClass:[NSData class]]) {
            if (completion) completion(nil, response, [NSError errorWithDomain:KBNetworkErrorDomain code:KBNetworkErrorInvalidResponse userInfo:@{NSLocalizedDescriptionKey:KBLocalized(@"No data")}]);
            return;
        }
        if (completion) completion(data, response, nil);
    }];
    [task resume];
    return task;
}

#pragma mark - AFHTTPSessionManager

- (AFHTTPSessionManager *)manager {
    if (!_manager) {
        NSURLSessionConfiguration *cfg = [NSURLSessionConfiguration ephemeralSessionConfiguration];
        cfg.requestCachePolicy = NSURLRequestReloadIgnoringLocalCacheData;
        // 不在会话级别设置超时，避免与 per-request 的 serializer.timeoutInterval 产生不一致
        if (@available(iOS 11.0, *)) { cfg.waitsForConnectivity = YES; }
        _manager = [[AFHTTPSessionManager alloc] initWithBaseURL:nil sessionConfiguration:cfg];
        // 默认不使用 JSON 解析器，保持原生数据，再按需解析
        _manager.responseSerializer = [AFHTTPResponseSerializer serializer];
    }
    return _manager;
}

#pragma mark - Private helpers

/// 处理通用业务 code（token 失效、被踢下线等）；
/// 返回 YES 表示该 code 已在此处消费（例如已清理登录态并提示），外部无需再提示。
- (BOOL)kb_handleBizCode:(NSInteger)bizCode
                    json:(id)json
                response:(NSURLResponse *)response {
    switch (bizCode) {
        // 登录态相关：未登录 / 无权限 / 各种 token 异常、被顶号/踢下线等
        case KBBizCodeNotLogin:
        case KBBizCodeNoAuth:
        case KBBizCodeTokenNotFound:
        case KBBizCodeTokenInvalid:
        case KBBizCodeTokenTimeout:
        case KBBizCodeTokenBeReplaced:
        case KBBizCodeTokenKickOut:
        case KBBizCodeTokenFreeze:
        case KBBizCodeTokenNoPrefix:
        case KBBizCodeForbidden: {
            // 登录态异常：统一清理本地会话并提示用户重新登录
            NSString *msg = KBBizMessageFromJSONObject(json);
            if (msg.length == 0) {
                msg = KBLocalized(@"Your session has expired. Please sign in again.");
            }
            dispatch_async(dispatch_get_main_queue(), ^{
                // 清理本地用户会话（Keychain + 用户缓存）
                [[KBUserSessionManager shared] logout];
                // 友好提示
                [KBHUD showInfo:msg];
                // 广播通知，便于 UI 侧跳转登录页等
                NSDictionary *info = @{ @"code": @(bizCode),
                                         @"message": msg ?: @"" };
                [[NSNotificationCenter defaultCenter] postNotificationName:@"KBUserSessionInvalidNotification"
                                                                    object:nil
                                                                  userInfo:info];
            });
            return YES;
        } break;
        default:
            break;
    }
    return NO;
}

    - (void)fail:(KBNetworkError)code completion:(KBNetworkCompletion)completion {
        NSString *msg = KBLocalized(@"Network error");
        switch (code) {
            case KBNetworkErrorDisabled: msg = KBLocalized(@"Network disabled (Full Access may be off)"); break;
            case KBNetworkErrorInvalidURL: msg = KBLocalized(@"Invalid URL"); break;
            case KBNetworkErrorInvalidResponse: msg = KBLocalized(@"Invalid response"); break;
            case KBNetworkErrorDecodeFailed: msg = KBLocalized(@"Parse failed"); break;
            case KBNetworkErrorBusiness: msg = KBLocalized(@"Server error"); break;
            default: break;
        }
        NSError *e = [NSError errorWithDomain:KBNetworkErrorDomain
                                         code:code
                                     userInfo:@{NSLocalizedDescriptionKey: msg}];
        if (completion) completion(nil, nil, e);
    }

@end

#pragma mark - Debug helpers

#if DEBUG
@implementation KBNetworkManager (Debug)

// 将对象转为漂亮的 JSON 字符串；否则返回 description
- (NSString *)kb_prettyJSONStringFromObject:(id)obj {
    if (!obj || obj == (id)kCFNull) return nil;
    if (![NSJSONSerialization isValidJSONObject:obj]) {
        // 非标准 JSON 对象，直接 description
        return [obj description];
    }
    NSData *data = [NSJSONSerialization dataWithJSONObject:obj options:NSJSONWritingPrettyPrinted error:NULL];
    if (!data) return [obj description];
    return [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding] ?: [obj description];
}

// 尝试把二进制数据转为可读文本；失败则返回占位带长度
- (NSString *)kb_textFromData:(NSData *)data {
    if (!data) return @"(null)";
    if (data.length == 0) return @"";
    // 优先 UTF-8
    NSString *text = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
    if (text.length > 0) return text;
    // 再尝试常见编码
    NSArray *encs = @[@(NSASCIIStringEncoding), @(NSISOLatin1StringEncoding), @(NSUnicodeStringEncoding)];
    for (NSNumber *n in encs) {
        text = [[NSString alloc] initWithData:data encoding:n.unsignedIntegerValue];
        if (text.length > 0) return text;
    }
    return [NSString stringWithFormat:@"<binary %lu bytes>", (unsigned long)data.length];
}

// 过长时裁剪，避免刷屏
- (NSString *)kb_trimmedString:(NSString *)s maxLength:(NSUInteger)maxLen {
    if (!s) return @"";
    if (s.length <= maxLen) return s;
    NSString *head = [s substringToIndex:maxLen];
    return [head stringByAppendingString:@"\n...<trimmed>..."];
}

@end
#endif