package srt

import (
	"fmt"
	"os"
	"path/filepath"
	"strings"
)

// formatDuration formats a duration as SRT timestamp (HH:MM:SS,mmm)
func formatDuration(d int64) string {
	ms := d % 1000
	d /= 1000
	s := d % 60
	d /= 60
	m := d % 60
	h := d / 60

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

// Save writes the transcript to an SRT file
func (t *Transcript) Save() error {
	return t.SaveTo(t.FilePath)
}

// SaveTo writes the transcript to the specified path
func (t *Transcript) SaveTo(path string) error {
	var sb strings.Builder

	for i, cue := range t.Cues {
		if i > 0 {
			sb.WriteString("\n")
		}
		sb.WriteString(fmt.Sprintf("%d\n", cue.Index))
		sb.WriteString(fmt.Sprintf("%s --> %s\n",
			formatDuration(cue.Start.Milliseconds()),
			formatDuration(cue.End.Milliseconds())))
		sb.WriteString(cue.Text)
		sb.WriteString("\n")
	}

	// Ensure directory exists
	dir := filepath.Dir(path)
	if err := os.MkdirAll(dir, 0755); err != nil {
		return fmt.Errorf("failed to create directory: %w", err)
	}

	if err := os.WriteFile(path, []byte(sb.String()), 0644); err != nil {
		return fmt.Errorf("failed to write file: %w", err)
	}

	return nil
}

// PromoteTempFile saves the transcript to a permanent location
func (t *Transcript) PromoteTempFile(audioPath string) (string, error) {
	if !t.IsTemp {
		return t.FilePath, nil
	}

	// Create permanent path next to audio file
	ext := filepath.Ext(audioPath)
	permanentPath := strings.TrimSuffix(audioPath, ext) + ".srt"

	if err := t.SaveTo(permanentPath); err != nil {
		return "", err
	}

	// Update transcript state
	t.FilePath = permanentPath
	t.IsTemp = false

	// Remove temp file
	tempPath := filepath.Join(os.TempDir(), filepath.Base(audioPath))
	os.Remove(strings.TrimSuffix(tempPath, filepath.Ext(tempPath)) + ".srt.tmp")

	return permanentPath, nil
}