package gateway

import (
	"encoding/json"
	"net/http"
	"strconv"
	"strings"

	apperr "git.yeij.top/AskaEth/Cyrene_v2/internal/errors"
	"git.yeij.top/AskaEth/Cyrene_v2/internal/runtime/multimodal/voice"
)

// maxAudioRequestBytes 限定 /api/v1/audio/* 请求可携带的 JSON 体大小，
// 使巨大的 base64 音频载荷无法耗尽内存。
const maxAudioRequestBytes = 32 << 20

// transcribeRequest 是 POST /api/v1/audio/transcribe 的请求体。Audio 是 base64
// （或 data: URI）数据块；Format 是其编码（"wav"/"mp3"/"ogg"）。
type transcribeRequest struct {
	Audio    string `json:"audio"`
	Format   string `json:"format"`
	DeviceID string `json:"deviceId,omitempty"`
}

// speechRequest 是 POST /api/v1/audio/speech 的请求体。Voice/format 为前向
// 兼容而被接受；合成目前遵循服务端的
// VOICE_TTS_VOICE_ID / VOICE_TTS_FORMAT 配置。Instruction 是可选的
// 每请求情绪/语气覆盖，用于克隆音色（声音复刻）；系统音色
// （longxiaochun_v3）忽略它，绝不接收自由形式的指令。
type speechRequest struct {
	Text        string `json:"text"`
	Voice       string `json:"voice,omitempty"`
	Format      string `json:"format,omitempty"`
	Instruction string `json:"instruction,omitempty"`
}

// handleTranscribe 对上传的音频执行 STT 并返回识别出的
// 文本。它是原生客户端的 REST 来源，绕过 4KB WebSocket
// 帧上限（该上限会截断 base64 音频块）。
func (s *Server) handleTranscribe(w http.ResponseWriter, r *http.Request) {
	r.Body = http.MaxBytesReader(w, r.Body, maxAudioRequestBytes)
	var req transcribeRequest
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		s.auditClaims(r, "audio.transcribe", "error")
		writeError(w, apperr.Wrap(apperr.ErrBadRequest, "bad_request", "invalid request body"))
		return
	}
	if s.voice == nil {
		s.auditClaims(r, "audio.transcribe", "error")
		writeError(w, apperr.Wrap(apperr.ErrInternal, "voice_unavailable", "voice service is not configured"))
		return
	}
	audio, err := decodeVoiceAudio(req.Audio, req.Format)
	if err != nil {
		s.auditClaims(r, "audio.transcribe", "error")
		writeError(w, apperr.Wrap(apperr.ErrBadRequest, "bad_request", "audio could not be decoded"))
		return
	}
	if len(audio.Data) == 0 {
		s.auditClaims(r, "audio.transcribe", "error")
		writeError(w, apperr.Wrap(apperr.ErrBadRequest, "bad_request", "audio is required"))
		return
	}
	text, rung, err := sttWithProvider(r.Context(), s.voice, audio)
	if err != nil {
		s.auditClaims(r, "audio.transcribe", "error")
		s.log.Warn("voice transcribe", "err", err)
		writeError(w, apperr.Wrap(apperr.ErrInternal, "stt_failed", "speech transcription failed"))
		return
	}
	s.auditClaims(r, "audio.transcribe", "ok")
	out := map[string]any{"text": text}
	if sig := providerSignal(rung, strings.TrimSpace(text) == ""); sig != "" {
		out["provider"] = sig
	}
	writeJSON(w, http.StatusOK, out)
}

// handleSpeech 为给定文本合成语音并写回原始音频
// 字节（audio/<format>）—— 二进制响应，不是 JSON 信封。
func (s *Server) handleSpeech(w http.ResponseWriter, r *http.Request) {
	r.Body = http.MaxBytesReader(w, r.Body, maxAudioRequestBytes)
	var req speechRequest
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		s.auditClaims(r, "audio.speech", "error")
		writeError(w, apperr.Wrap(apperr.ErrBadRequest, "bad_request", "invalid request body"))
		return
	}
	if strings.TrimSpace(req.Text) == "" {
		s.auditClaims(r, "audio.speech", "error")
		writeError(w, apperr.Wrap(apperr.ErrBadRequest, "bad_request", "text is required"))
		return
	}
	if s.voice == nil {
		s.auditClaims(r, "audio.speech", "error")
		writeError(w, apperr.Wrap(apperr.ErrInternal, "voice_unavailable", "voice service is not configured"))
		return
	}
	ctx := r.Context()
	if req.Instruction != "" {
		ctx = voice.WithTTSInstruction(ctx, req.Instruction)
	}
	audi, rung, err := ttsWithProvider(ctx, s.voice, req.Text)
	if err != nil {
		s.auditClaims(r, "audio.speech", "error")
		s.log.Warn("voice speech", "err", err)
		writeError(w, apperr.Wrap(apperr.ErrInternal, "tts_failed", "speech synthesis failed"))
		return
	}
	if len(audi.Data) == 0 {
		s.auditClaims(r, "audio.speech", "error")
		w.Header().Set(voiceProviderHeader, providerSignal(rung, true))
		writeError(w, apperr.Wrap(apperr.ErrInternal, "tts_empty", "no audio synthesized"))
		return
	}
	s.auditClaims(r, "audio.speech", "ok")
	w.Header().Set("Content-Type", audioMime(audi.Format))
	w.Header().Set("Content-Length", strconv.Itoa(len(audi.Data)))
	w.WriteHeader(http.StatusOK)
	_, _ = w.Write(audi.Data)
}

// voiceCloneRequest 是 POST /api/v1/audio/voice-clone 的请求体。URL 是公开的
// 参考音频 URL；prefix 是可选音色名前缀（≤10 个字母数字字符）。
// 二者都不记日志，URL 也不持久化（仅 owner + 审计，红线）。
type voiceCloneRequest struct {
	URL    string `json:"url"`
	Prefix string `json:"prefix,omitempty"`
}

// handleVoiceClone 经百炼声音注册 API（声音复刻 create_voice）从公开
// 参考音频 URL 创建自定义 TTS 音色，并返回新的
// voice_id。仅 owner + 带审计；参考 URL 绝不写入审计
// 记录或日志（红线）。
func (s *Server) handleVoiceClone(w http.ResponseWriter, r *http.Request) {
	r.Body = http.MaxBytesReader(w, r.Body, maxAudioRequestBytes)
	var req voiceCloneRequest
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		s.auditClaims(r, "audio.voice-clone", "error")
		writeError(w, apperr.Wrap(apperr.ErrBadRequest, "bad_request", "invalid request body"))
		return
	}
	if strings.TrimSpace(req.URL) == "" {
		s.auditClaims(r, "audio.voice-clone", "error")
		writeError(w, apperr.Wrap(apperr.ErrBadRequest, "bad_request", "url is required"))
		return
	}
	if s.voice == nil {
		s.auditClaims(r, "audio.voice-clone", "error")
		writeError(w, apperr.Wrap(apperr.ErrInternal, "voice_unavailable", "voice service is not configured"))
		return
	}
	voiceID, err := s.voice.CloneVoice(r.Context(), req.URL, req.Prefix)
	if err != nil {
		s.auditClaims(r, "audio.voice-clone", "error")
		// 不要记录原因：provider 的错误体可能回显参考 URL。
		s.log.Warn("voice clone failed")
		writeError(w, apperr.Wrap(apperr.ErrInternal, "voice_clone_failed", "voice clone failed"))
		return
	}
	s.auditClaims(r, "audio.voice-clone", "ok")
	writeJSON(w, http.StatusOK, map[string]any{"voiceId": voiceID})
}

// audioMime 把音频格式映射为其用于语音响应的 Content-Type。
func audioMime(format string) string {
	switch strings.ToLower(format) {
	case "mp3", "mpeg":
		return "audio/mpeg"
	case "ogg", "oga":
		return "audio/ogg"
	case "webm":
		return "audio/webm"
	default:
		return "audio/wav"
	}
}