package config

import (
	"archive/zip"
	"bytes"
	"io"
	"log"
	"os"
	"path/filepath"
	"strings"
)

// ExtractBin copies an embedded binary to the bin directory if not already present.
func (c *Config) ExtractBin(name string, embedded []byte) string {
	dest := filepath.Join(c.BinDir(), name)
	if _, err := os.Stat(dest); err == nil {
		return dest
	}
	log.Printf("[config] extracting %s ...", name)
	if err := os.WriteFile(dest, embedded, 0755); err != nil {
		log.Printf("[config] extract %s failed: %v", name, err)
		return ""
	}
	return dest
}

// ExtractZip extracts an embedded zip file to the bin directory.
// Extracts ffmpeg.exe and ffprobe.exe from the zip, skipping if already present.
func (c *Config) ExtractZip(embedded []byte) (ffmpegPath, ffprobePath string) {
	dir := c.BinDir()
	ffmpegPath = filepath.Join(dir, "ffmpeg.exe")
	ffprobePath = filepath.Join(dir, "ffprobe.exe")

	// If both exist, skip extraction
	if fileExists(ffmpegPath) && fileExists(ffprobePath) {
		return
	}

	reader, err := zip.NewReader(bytes.NewReader(embedded), int64(len(embedded)))
	if err != nil {
		log.Printf("[config] zip open failed: %v", err)
		return
	}

	for _, f := range reader.File {
		name := strings.ToLower(f.Name)
		name = filepath.Base(name)
		if name != "ffmpeg.exe" && name != "ffprobe.exe" {
			continue
		}

		dest := filepath.Join(dir, name)
		if fileExists(dest) {
			continue
		}

		log.Printf("[config] extracting %s (%d bytes)...", name, f.UncompressedSize64)
		rc, err := f.Open()
		if err != nil {
			log.Printf("[config] zip open %s: %v", name, err)
			continue
		}
		out, err := os.Create(dest)
		if err != nil {
			rc.Close()
			continue
		}
		_, err = io.Copy(out, rc)
		rc.Close()
		out.Close()
		if err != nil {
			os.Remove(dest)
			log.Printf("[config] extract %s failed: %v", name, err)
		}
	}

	return
}

func fileExists(path string) bool {
	_, err := os.Stat(path)
	return err == nil
}