package transcode

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

const (
    FormatWAV = "wav"
    FormatPCM = "pcm"
)

type FormatSpec struct {
    ID        string
    Extension string
    Codec     string
}

var formats = map[string]FormatSpec{
    FormatWAV: {ID: FormatWAV, Extension: ".wav", Codec: "pcm_s16le"},
    FormatPCM: {ID: FormatPCM, Extension: ".wav", Codec: "pcm_s16le"},
}

func ResolveFormat(name string) (FormatSpec, error) {
    name = strings.ToLower(strings.TrimSpace(name))
    if name == "" {
        name = FormatWAV
    }
    spec, ok := formats[name]
    if !ok {
        return FormatSpec{}, fmt.Errorf("unsupported format %q (supported: wav)", name)
    }
    return spec, nil
}

func OutputPath(dst, format string) (string, error) {
    spec, err := ResolveFormat(format)
    if err != nil {
        return "", err
    }
    ext := filepath.Ext(dst)
    if ext == "" {
        return dst + spec.Extension, nil
    }
    return dst, nil
}