// Package video prepares uploaded video for browser playback using the external
// ffmpeg/ffprobe toolchain. Availability is detected at startup; when the tools
// are absent the rest of the application keeps working and video upload is
// disabled.
package video

import (
	"os/exec"

	"galo/internal/config"
)

// Toolchain locates the external video tools and reports whether they are
// usable. A nil Toolchain is treated as unavailable.
type Toolchain struct {
	ffmpegPath  string
	ffprobePath string
	tempDir     string
	available   bool
}

// Detect resolves the configured tool paths and records whether both binaries
// are present. Missing tools are not an error: video is simply unavailable.
func Detect(cfg config.Video) *Toolchain {
	t := &Toolchain{tempDir: cfg.TempDir}
	if p, err := exec.LookPath(cfg.FFmpegPath); err == nil {
		t.ffmpegPath = p
	} else {
		t.ffmpegPath = cfg.FFmpegPath
	}
	if p, err := exec.LookPath(cfg.FFprobePath); err == nil {
		t.ffprobePath = p
	} else {
		t.ffprobePath = cfg.FFprobePath
	}
	t.available = t.ffmpegPath != "" && t.ffprobePath != "" &&
		isExecutable(t.ffmpegPath) && isExecutable(t.ffprobePath)
	return t
}

func isExecutable(path string) bool {
	if path == "" {
		return false
	}
	if _, err := exec.LookPath(path); err == nil {
		return true
	}
	return false
}

// Available reports whether both ffmpeg and ffprobe are usable.
func (t *Toolchain) Available() bool { return t != nil && t.available }

// FFmpegPath returns the resolved ffmpeg binary path.
func (t *Toolchain) FFmpegPath() string {
	if t == nil {
		return ""
	}
	return t.ffmpegPath
}

// FFprobePath returns the resolved ffprobe binary path.
func (t *Toolchain) FFprobePath() string {
	if t == nil {
		return ""
	}
	return t.ffprobePath
}

// TempDir returns the configured temporary directory (empty means the system
// default).
func (t *Toolchain) TempDir() string {
	if t == nil {
		return ""
	}
	return t.tempDir
}