package media

import (
	"os"
	"os/exec"
	"path/filepath"
	"runtime"
)

type Binaries struct {
	FFmpeg  string `json:"ffmpeg"`
	FFprobe string `json:"ffprobe"`
	Source  string `json:"source"` // "custom", "bundled", "path", "winget", "missing"
}

func FindBinaries(customFFmpeg, customFFprobe string) Binaries {
	exeName := func(base string) string {
		if runtime.GOOS == "windows" {
			return base + ".exe"
		}
		return base
	}

	ff := findSingle(exeName("ffmpeg"), customFFmpeg)
	fp := findSingle(exeName("ffprobe"), customFFprobe)

	source := "missing"
	if ff.path != "" && fp.path != "" {
		source = ff.source
	} else if ff.path != "" || fp.path != "" {
		if ff.path != "" {
			source = ff.source
		} else {
			source = fp.source
		}
	}

	return Binaries{
		FFmpeg:  ff.path,
		FFprobe: fp.path,
		Source:  source,
	}
}

type foundBin struct {
	path   string
	source string
}

func findSingle(exeName, custom string) foundBin {
	if custom != "" {
		if st, err := os.Stat(custom); err == nil && !st.IsDir() {
			return foundBin{path: custom, source: "custom"}
		}
	}

	if exePath, err := os.Executable(); err == nil {
		dir := filepath.Dir(exePath)
		candidates := []string{
			filepath.Join(dir, "bin", exeName),
			filepath.Join(dir, exeName),
		}
		for _, c := range candidates {
			if st, err := os.Stat(c); err == nil && !st.IsDir() {
				return foundBin{path: c, source: "bundled"}
			}
		}
	}

	if p, err := exec.LookPath(exeName); err == nil {
		return foundBin{path: p, source: "path"}
	}

	if runtime.GOOS == "windows" {
		if localAppData := os.Getenv("LOCALAPPDATA"); localAppData != "" {
			wg := filepath.Join(localAppData, "Microsoft", "WinGet", "Links", exeName)
			if st, err := os.Stat(wg); err == nil && !st.IsDir() {
				return foundBin{path: wg, source: "winget"}
			}
		}
	}

	return foundBin{}
}