//go:build linux

package client

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

func handleCameraAction(action, device string) (handled bool, success bool, message string) {
	switch action {
	case "camera_snapshot":
		raw, err := captureLinuxCameraJPEG(strings.TrimSpace(device))
		if err != nil {
			return true, false, err.Error()
		}
		b64, err := encodeCameraSnapshotJPEG(raw)
		if err != nil {
			return true, false, err.Error()
		}
		return true, true, b64
	case "camera_list":
		devs, err := listLinuxCameraDevices()
		if err != nil {
			return true, false, err.Error()
		}
		if len(devs) == 0 {
			return true, false, "no V4L2 devices found under /dev/video*"
		}
		return true, true, strings.Join(devs, "\n")
	default:
		return false, false, ""
	}
}

func listLinuxCameraDevices() ([]string, error) {
	matches, err := filepath.Glob("/dev/video*")
	if err != nil {
		return nil, err
	}
	var devs []string
	for _, p := range matches {
		if fi, err := os.Stat(p); err == nil && (fi.Mode()&os.ModeCharDevice) != 0 {
			devs = append(devs, p)
		}
	}
	return devs, nil
}

func captureLinuxCameraJPEG(preferred string) ([]byte, error) {
	devs, err := listLinuxCameraDevices()
	if err != nil {
		return nil, err
	}
	if len(devs) == 0 {
		return nil, fmt.Errorf("no /dev/video* devices — connect a USB camera or install v4l2 drivers")
	}
	device := devs[0]
	if preferred != "" {
		for _, d := range devs {
			if d == preferred {
				device = d
				break
			}
		}
	}

	if ff, err := exec.LookPath("ffmpeg"); err == nil {
		out, runErr := exec.Command(ff,
			"-hide_banner", "-loglevel", "error",
			"-f", "v4l2",
			"-i", device,
			"-frames:v", "1",
			"-q:v", "2",
			"-f", "image2",
			"pipe:1",
		).CombinedOutput()
		if runErr == nil && len(out) >= 100 {
			return out, nil
		}
		if runErr != nil {
			hint := strings.TrimSpace(string(out))
			if hint != "" {
				return nil, fmt.Errorf("ffmpeg v4l2 capture failed: %v (%s)", runErr, hint)
			}
		}
	}

	if fw, err := exec.LookPath("fswebcam"); err == nil {
		tmp, err := os.CreateTemp("", "af-cam-*.jpg")
		if err != nil {
			return nil, err
		}
		tmpPath := tmp.Name()
		_ = tmp.Close()
		defer os.Remove(tmpPath)

		out, runErr := exec.Command(fw, "-q", "-d", device, "-r", "1280x720", "--no-banner", tmpPath).CombinedOutput()
		if runErr != nil {
			return nil, fmt.Errorf("fswebcam failed: %v (%s)", runErr, strings.TrimSpace(string(out)))
		}
		raw, err := os.ReadFile(tmpPath)
		if err != nil {
			return nil, err
		}
		return raw, nil
	}

	return nil, fmt.Errorf("camera capture unsupported: install ffmpeg or fswebcam on the agent host")
}