package output

import (
	"fmt"
	"strings"

	"transcribe/internal/whisper"
)

// SRTFormatter formats transcription results as SRT subtitles
type SRTFormatter struct{}

// Format converts transcription result to SRT format
func (f *SRTFormatter) Format(result *whisper.TranscriptionResult) (string, error) {
	var builder strings.Builder

	for i, seg := range result.Segments {
		// Subtitle number (1-indexed)
		builder.WriteString(fmt.Sprintf("%d\n", i+1))

		// Timestamps in SRT format: HH:MM:SS,mmm --> HH:MM:SS,mmm
		startTime := formatSRTTimestamp(seg.Start)
		endTime := formatSRTTimestamp(seg.End)
		builder.WriteString(fmt.Sprintf("%s --> %s\n", startTime, endTime))

		// Text with optional speaker label
		text := strings.TrimSpace(seg.Text)
		if seg.Speaker != "" {
			text = fmt.Sprintf("[%s] %s", seg.Speaker, text)
		}
		builder.WriteString(text)
		builder.WriteString("\n\n")
	}

	return strings.TrimSuffix(builder.String(), "\n"), nil
}

// formatSRTTimestamp converts seconds to SRT timestamp format (HH:MM:SS,mmm)
func formatSRTTimestamp(seconds float64) string {
	totalMs := int64(seconds * 1000)
	ms := totalMs % 1000
	totalSeconds := totalMs / 1000
	s := totalSeconds % 60
	totalMinutes := totalSeconds / 60
	m := totalMinutes % 60
	h := totalMinutes / 60

	return fmt.Sprintf("%02d:%02d:%02d,%03d", h, m, s, ms)
}