package asr

import (
	"context"
	"fmt"
	"io"
	"time"
)

// Service provides speech-to-text functionality
type Service interface {
	TranscribeStream(ctx context.Context, audioStream io.Reader) (<-chan TranscriptEvent, error)
	Transcribe(ctx context.Context, audioData []byte) (string, error)
}

// TranscriptEvent represents a transcription event
type TranscriptEvent struct {
	Type      string  `json:"type"` // "partial" or "final"
	Text      string  `json:"text"`
	Confidence float64 `json:"confidence,omitempty"`
	Timestamp int64   `json:"timestamp"`
	Words     []Word  `json:"words,omitempty"`
}

// Word represents a word with timing information
type Word struct {
	Word      string  `json:"word"`
	StartTime float64 `json:"start_time"`
	EndTime   float64 `json:"end_time"`
	Confidence float64 `json:"confidence,omitempty"`
}

// MockASRService is a mock implementation for development
type MockASRService struct{}

// NewMockASRService creates a new mock ASR service
func NewMockASRService() *MockASRService {
	return &MockASRService{}
}

// TranscribeStream transcribes an audio stream
func (s *MockASRService) TranscribeStream(ctx context.Context, audioStream io.Reader) (<-chan TranscriptEvent, error) {
	events := make(chan TranscriptEvent, 10)

	go func() {
		defer close(events)

		// Mock implementation - in production, integrate with Deepgram, Google STT, etc.
		// For now, just send a mock event
		select {
		case <-ctx.Done():
			return
		case events <- TranscriptEvent{
			Type:      "final",
			Text:      "Hello, how can I help you today?",
			Confidence: 0.95,
			Timestamp: time.Now().Unix(),
		}:
		}
	}()

	return events, nil
}

// Transcribe transcribes audio data
func (s *MockASRService) Transcribe(ctx context.Context, audioData []byte) (string, error) {
	// Mock implementation
	return "Hello, how can I help you today?", nil
}

// DeepgramASRService integrates with Deepgram (example - requires API key)
type DeepgramASRService struct {
	apiKey string
}

// NewDeepgramASRService creates a new Deepgram ASR service
func NewDeepgramASRService(apiKey string) *DeepgramASRService {
	return &DeepgramASRService{
		apiKey: apiKey,
	}
}

// TranscribeStream transcribes using Deepgram streaming API
func (s *DeepgramASRService) TranscribeStream(ctx context.Context, audioStream io.Reader) (<-chan TranscriptEvent, error) {
	events := make(chan TranscriptEvent, 10)

	// TODO: Implement Deepgram streaming API integration
	// This would involve:
	// 1. Establishing WebSocket connection to Deepgram
	// 2. Sending audio chunks
	// 3. Receiving partial and final transcripts
	// 4. Converting to TranscriptEvent format

	return events, fmt.Errorf("not implemented - requires Deepgram API integration")
}

// Transcribe transcribes using Deepgram REST API
func (s *DeepgramASRService) Transcribe(ctx context.Context, audioData []byte) (string, error) {
	// TODO: Implement Deepgram REST API integration
	return "", fmt.Errorf("not implemented - requires Deepgram API integration")
}