//
//  SenseVoiceBridge.mm
//  康康
//
//  ObjC++ 实现。链接 sherpa-mnn 时走真实 C-API;否则编为桩(返回不可用,上层回退系统识别)。
//
//  可用性闸门:仅当能找到 sherpa-mnn 的 C-API 头时才编真实路径。这样在尚未接入 sherpa-mnn
//  的工程里本文件也能正常编过(走桩),接入后(把 sherpa-mnn.xcframework 加进 Frameworks/ 并
//  让 HEADER_SEARCH_PATHS 找到其头)自动切到真实实现。见 docs/release/sensevoice-integration.md。
//

#import "SenseVoiceBridge.h"

#if __has_include(<sherpa-mnn/c-api/c-api.h>)
#define KK_SHERPA_MNN_AVAILABLE 1
#else
#define KK_SHERPA_MNN_AVAILABLE 0
#endif

#if !KK_SHERPA_MNN_AVAILABLE

// ============ 桩:工程未链接 sherpa-mnn ============
@implementation SenseVoiceBridge
+ (BOOL)isAvailable { return NO; }
- (nullable instancetype)initWithModelPath:(NSString *)modelPath
                                tokensPath:(NSString *)tokensPath
                                  language:(NSString *)language { return nil; }
- (nullable NSString *)transcribeSamples:(const float *)samples
                                   count:(int)count
                              sampleRate:(int)sampleRate { return nil; }
@end

#else

// ============ 真实:sherpa-mnn 离线 SenseVoice ============
#include <sherpa-mnn/c-api/c-api.h>
#include <string>

@implementation SenseVoiceBridge {
    const SherpaMnnOfflineRecognizer *_recognizer;
}

+ (BOOL)isAvailable { return YES; }

- (nullable instancetype)initWithModelPath:(NSString *)modelPath
                                tokensPath:(NSString *)tokensPath
                                  language:(NSString *)language {
    self = [super init];
    if (!self) return nil;

    std::string model = modelPath.UTF8String;
    std::string tokens = tokensPath.UTF8String;
    std::string lang = language.length ? language.UTF8String : "auto";

    SherpaMnnOfflineSenseVoiceModelConfig senseVoice;
    memset(&senseVoice, 0, sizeof(senseVoice));
    senseVoice.model = model.c_str();
    senseVoice.language = lang.c_str();
    senseVoice.use_itn = 1;   // 逆文本规整:把「一百四十」之类还原成 140,数值更利于阅读/给医生看

    SherpaMnnOfflineModelConfig modelConfig;
    memset(&modelConfig, 0, sizeof(modelConfig));
    modelConfig.tokens = tokens.c_str();
    modelConfig.num_threads = 2;       // 端侧保守取 2,避免与 UI 抢核
    modelConfig.debug = 0;
    modelConfig.provider = "cpu";      // sherpa-mnn 后端即 MNN(CPU/SME2),provider 维持 "cpu"
    modelConfig.sense_voice = senseVoice;

    SherpaMnnOfflineRecognizerConfig config;
    memset(&config, 0, sizeof(config));
    config.decoding_method = "greedy_search";
    config.model_config = modelConfig;

    _recognizer = SherpaMnnCreateOfflineRecognizer(&config);
    if (_recognizer == nullptr) return nil;
    return self;
}

- (void)dealloc {
    if (_recognizer) {
        SherpaMnnDestroyOfflineRecognizer(_recognizer);
        _recognizer = nullptr;
    }
}

- (nullable NSString *)transcribeSamples:(const float *)samples
                                   count:(int)count
                              sampleRate:(int)sampleRate {
    if (_recognizer == nullptr || samples == nullptr || count <= 0) return nil;

    const SherpaMnnOfflineStream *stream = SherpaMnnCreateOfflineStream(_recognizer);
    if (stream == nullptr) return nil;

    SherpaMnnAcceptWaveformOffline(stream, sampleRate, samples, count);
    SherpaMnnDecodeOfflineStream(_recognizer, stream);

    NSString *text = nil;
    const SherpaMnnOfflineRecognizerResult *result =
        SherpaMnnGetOfflineStreamResult(stream);
    if (result) {
        if (result->text) {
            text = [NSString stringWithUTF8String:result->text];
        }
        SherpaMnnDestroyOfflineRecognizerResult(result);
    }
    SherpaMnnDestroyOfflineStream(stream);
    return text;
}

@end

#endif