// Package messages defines typed NATS message structs for all services.
//
// Using typed structs with short msgpack field tags instead of map[string]any
// provides compile-time safety, smaller wire size (integer-like short keys vs
// full string keys), and faster encode/decode by avoiding interface{} boxing.
//
// Audio data uses raw []byte instead of base64-encoded strings — msgpack
// supports binary natively, eliminating the 33% base64 overhead.
package messages

import "time"

// ────────────────────────────────────────────────────────────────────────────
// Pipeline Bridge
// ────────────────────────────────────────────────────────────────────────────

// PipelineTrigger is the request to start a pipeline.
type PipelineTrigger struct {
RequestID  string         `msgpack:"request_id" json:"request_id"`
Pipeline   string         `msgpack:"pipeline" json:"pipeline"`
Parameters map[string]any `msgpack:"parameters,omitempty" json:"parameters,omitempty"`
}

// PipelineStatus is the response / status update for a pipeline run.
type PipelineStatus struct {
RequestID          string   `msgpack:"request_id" json:"request_id"`
Status             string   `msgpack:"status" json:"status"`
RunID              string   `msgpack:"run_id,omitempty" json:"run_id,omitempty"`
Engine             string   `msgpack:"engine,omitempty" json:"engine,omitempty"`
Pipeline           string   `msgpack:"pipeline,omitempty" json:"pipeline,omitempty"`
SubmittedAt        string   `msgpack:"submitted_at,omitempty" json:"submitted_at,omitempty"`
Error              string   `msgpack:"error,omitempty" json:"error,omitempty"`
AvailablePipelines []string `msgpack:"available_pipelines,omitempty" json:"available_pipelines,omitempty"`
}

// ────────────────────────────────────────────────────────────────────────────
// Chat Handler
// ────────────────────────────────────────────────────────────────────────────

// ChatRequest is an incoming chat message.
type ChatRequest struct {
RequestID       string `msgpack:"request_id" json:"request_id"`
UserID          string `msgpack:"user_id" json:"user_id"`
Message         string `msgpack:"message" json:"message"`
Query           string `msgpack:"query,omitempty" json:"query,omitempty"`
Premium         bool   `msgpack:"premium,omitempty" json:"premium,omitempty"`
EnableRAG       bool   `msgpack:"enable_rag,omitempty" json:"enable_rag,omitempty"`
EnableReranker  bool   `msgpack:"enable_reranker,omitempty" json:"enable_reranker,omitempty"`
EnableStreaming bool   `msgpack:"enable_streaming,omitempty" json:"enable_streaming,omitempty"`
TopK            int    `msgpack:"top_k,omitempty" json:"top_k,omitempty"`
Collection      string `msgpack:"collection,omitempty" json:"collection,omitempty"`
EnableTTS       bool   `msgpack:"enable_tts,omitempty" json:"enable_tts,omitempty"`
SystemPrompt    string `msgpack:"system_prompt,omitempty" json:"system_prompt,omitempty"`
ResponseSubject string `msgpack:"response_subject,omitempty" json:"response_subject,omitempty"`
}

// EffectiveQuery returns Message or falls back to Query.
func (c *ChatRequest) EffectiveQuery() string {
if c.Message != "" {
return c.Message
}
return c.Query
}

// ChatResponse is the full reply to a chat request.
type ChatResponse struct {
UserID       string   `msgpack:"user_id" json:"user_id"`
Response     string   `msgpack:"response" json:"response"`
ResponseText string   `msgpack:"response_text" json:"response_text"`
UsedRAG      bool     `msgpack:"used_rag" json:"used_rag"`
RAGSources   []string `msgpack:"rag_sources,omitempty" json:"rag_sources,omitempty"`
Success      bool     `msgpack:"success" json:"success"`
Audio        []byte   `msgpack:"audio,omitempty" json:"audio,omitempty"`
Error        string   `msgpack:"error,omitempty" json:"error,omitempty"`
}

// ChatStreamChunk is a single streaming chunk from an LLM response.
type ChatStreamChunk struct {
RequestID string `msgpack:"request_id" json:"request_id"`
Type      string `msgpack:"type" json:"type"`
Content   string `msgpack:"content" json:"content"`
Done      bool   `msgpack:"done" json:"done"`
Timestamp int64  `msgpack:"timestamp" json:"timestamp"`
}

// ────────────────────────────────────────────────────────────────────────────
// Voice Assistant
// ────────────────────────────────────────────────────────────────────────────

// VoiceRequest is an incoming voice-to-voice request.
type VoiceRequest struct {
RequestID  string `msgpack:"request_id" json:"request_id"`
Audio      []byte `msgpack:"audio" json:"audio"`
Language   string `msgpack:"language,omitempty" json:"language,omitempty"`
Collection string `msgpack:"collection,omitempty" json:"collection,omitempty"`
}

// VoiceResponse is the reply to a voice request.
type VoiceResponse struct {
RequestID     string           `msgpack:"request_id" json:"request_id"`
Response      string           `msgpack:"response" json:"response"`
Audio         []byte           `msgpack:"audio" json:"audio"`
Transcription string           `msgpack:"transcription,omitempty" json:"transcription,omitempty"`
Sources       []DocumentSource `msgpack:"sources,omitempty" json:"sources,omitempty"`
Error         string           `msgpack:"error,omitempty" json:"error,omitempty"`
}

// DocumentSource is a RAG search result source.
type DocumentSource struct {
Text  string  `msgpack:"text" json:"text"`
Score float64 `msgpack:"score" json:"score"`
}

// ────────────────────────────────────────────────────────────────────────────
// TTS Module
// ────────────────────────────────────────────────────────────────────────────

// TTSRequest is a text-to-speech synthesis request.
type TTSRequest struct {
Text          string `msgpack:"text" json:"text"`
Speaker       string `msgpack:"speaker,omitempty" json:"speaker,omitempty"`
Language      string `msgpack:"language,omitempty" json:"language,omitempty"`
SpeakerWavB64 string `msgpack:"speaker_wav_b64,omitempty" json:"speaker_wav_b64,omitempty"`
Stream        bool   `msgpack:"stream,omitempty" json:"stream,omitempty"`
}

// TTSAudioChunk is a streamed audio chunk from TTS synthesis.
type TTSAudioChunk struct {
SessionID   string `msgpack:"session_id" json:"session_id"`
ChunkIndex  int    `msgpack:"chunk_index" json:"chunk_index"`
TotalChunks int    `msgpack:"total_chunks" json:"total_chunks"`
Audio       []byte `msgpack:"audio" json:"audio"`
IsLast      bool   `msgpack:"is_last" json:"is_last"`
Timestamp   int64  `msgpack:"timestamp" json:"timestamp"`
SampleRate  int    `msgpack:"sample_rate" json:"sample_rate"`
}

// TTSFullResponse is a non-streamed TTS response (whole audio).
type TTSFullResponse struct {
SessionID  string `msgpack:"session_id" json:"session_id"`
Audio      []byte `msgpack:"audio" json:"audio"`
Timestamp  int64  `msgpack:"timestamp" json:"timestamp"`
SampleRate int    `msgpack:"sample_rate" json:"sample_rate"`
}

// TTSStatus is a TTS processing status update.
type TTSStatus struct {
SessionID string `msgpack:"session_id" json:"session_id"`
Status    string `msgpack:"status" json:"status"`
Message   string `msgpack:"message" json:"message"`
Timestamp int64  `msgpack:"timestamp" json:"timestamp"`
}

// TTSVoiceListResponse is the reply to a voice list request.
type TTSVoiceListResponse struct {
DefaultSpeaker string         `msgpack:"default_speaker" json:"default_speaker"`
CustomVoices   []TTSVoiceInfo `msgpack:"custom_voices" json:"custom_voices"`
LastRefresh    int64          `msgpack:"last_refresh" json:"last_refresh"`
Timestamp      int64          `msgpack:"timestamp" json:"timestamp"`
}

// TTSVoiceInfo is summary info about a custom voice.
type TTSVoiceInfo struct {
Name      string `msgpack:"name" json:"name"`
Language  string `msgpack:"language" json:"language"`
ModelType string `msgpack:"model_type" json:"model_type"`
CreatedAt string `msgpack:"created_at" json:"created_at"`
}

// TTSVoiceRefreshResponse is the reply to a voice refresh request.
type TTSVoiceRefreshResponse struct {
Count        int            `msgpack:"count" json:"count"`
CustomVoices []TTSVoiceInfo `msgpack:"custom_voices" json:"custom_voices"`
Timestamp    int64          `msgpack:"timestamp" json:"timestamp"`
}

// ────────────────────────────────────────────────────────────────────────────
// STT Module
// ────────────────────────────────────────────────────────────────────────────

// STTStreamMessage is any message on the ai.voice.stream.{session} subject.
type STTStreamMessage struct {
Type      string `msgpack:"type" json:"type"`
Audio     []byte `msgpack:"audio,omitempty" json:"audio,omitempty"`
State     string `msgpack:"state,omitempty" json:"state,omitempty"`
SpeakerID string `msgpack:"speaker_id,omitempty" json:"speaker_id,omitempty"`
}

// STTTranscription is the transcription result published by the STT module.
type STTTranscription struct {
SessionID        string `msgpack:"session_id" json:"session_id"`
Transcript       string `msgpack:"transcript" json:"transcript"`
Sequence         int    `msgpack:"sequence" json:"sequence"`
IsPartial        bool   `msgpack:"is_partial" json:"is_partial"`
IsFinal          bool   `msgpack:"is_final" json:"is_final"`
Timestamp        int64  `msgpack:"timestamp" json:"timestamp"`
SpeakerID        string `msgpack:"speaker_id" json:"speaker_id"`
HasVoiceActivity bool   `msgpack:"has_voice_activity" json:"has_voice_activity"`
State            string `msgpack:"state" json:"state"`
}

// STTInterrupt is published when the STT module detects a user interrupt.
type STTInterrupt struct {
SessionID string `msgpack:"session_id" json:"session_id"`
Type      string `msgpack:"type" json:"type"`
Timestamp int64  `msgpack:"timestamp" json:"timestamp"`
SpeakerID string `msgpack:"speaker_id" json:"speaker_id"`
}

// ────────────────────────────────────────────────────────────────────────────
// Common / Error
// ────────────────────────────────────────────────────────────────────────────

// ErrorResponse is the standard error reply from any handler.
type ErrorResponse struct {
Error   bool   `msgpack:"error" json:"error"`
Message string `msgpack:"message" json:"message"`
Type    string `msgpack:"type" json:"type"`
}

// Timestamp returns the current Unix timestamp (helper for message construction).
func Timestamp() int64 {
return time.Now().Unix()
}