package whisper

import (
	"context"
	"errors"
	"os"
	"os/exec"
	"path/filepath"
	"strings"
	"time"
)

type Config struct {
	Model     string
	Language  string
	Device    string
	ExtraArgs string
	Timeout   time.Duration
}

func Transcribe(ctx context.Context, wavPath, outDir string, cfg Config) (string, error) {
	if cfg.Timeout > 0 {
		var cancel context.CancelFunc
		ctx, cancel = context.WithTimeout(ctx, cfg.Timeout)
		defer cancel()
	}

	if err := os.MkdirAll(outDir, 0o755); err != nil {
		return "", err
	}

	args := []string{wavPath,
		"--model", cfg.Model,
		"--task", "transcribe",
		"--device", cfg.Device,
		"--output_format", "txt",
		"--output_dir", outDir,
		"--verbose", "False",
	}

	if strings.TrimSpace(cfg.Language) != "" {
		args = append(args, "--language", cfg.Language)
	}
	if strings.TrimSpace(cfg.ExtraArgs) != "" {
		extra := strings.Fields(cfg.ExtraArgs)
		args = append(args, extra...)
	}

	cmd := exec.CommandContext(ctx, "whisper", args...)
	out, err := cmd.CombinedOutput()
	if err != nil {
		if len(out) > 0 {
			return "", errors.New(string(out))
		}
		return "", err
	}

	txt := filepath.Join(outDir, strings.TrimSuffix(filepath.Base(wavPath), filepath.Ext(wavPath))+".txt")
	data, err := os.ReadFile(txt)
	if err != nil {
		return "", err
	}

	text := strings.TrimSpace(string(data))
	if text == "" {
		return "", errors.New("empty transcript")
	}
	return text, nil
}