// Command open-proxy forwards `open`/`xdg-open` requests from a remote VM to
// the host machine that actually has the browser/GUI.
//
// On the host:   open-proxy serve
// On the VM:     open-proxy open <file|url|string>...
//
// The VM reaches the host's server over an SSH reverse tunnel, e.g.
//
//	ssh -R 7777:127.0.0.1:7777 vm
//
// so the VM's 127.0.0.1:7777 maps to the host's server.
//
// As a convenience, when the binary is invoked under the name "open" (e.g. via
// a symlink early on $PATH), it behaves exactly like `open-proxy open`.
package main

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

func main() {
	// Shadowed-name mode: when symlinked to `open` or `xdg-open`, act as the
	// client and fall back to that same real opener if the host is unreachable.
	if base := filepath.Base(os.Args[0]); base == "open" || base == "xdg-open" {
		os.Exit(runClient(os.Args[1:], base))
	}

	if len(os.Args) < 2 {
		usage()
		os.Exit(2)
	}

	switch os.Args[1] {
	case "serve":
		os.Exit(runServer(os.Args[2:]))
	case "open":
		os.Exit(runClient(os.Args[2:], defaultOpenerName()))
	case "-h", "--help", "help":
		usage()
		os.Exit(0)
	default:
		fmt.Fprintf(os.Stderr, "open-proxy: unknown command %q\n\n", os.Args[1])
		usage()
		os.Exit(2)
	}
}

func usage() {
	fmt.Fprint(os.Stderr, `open-proxy - forward `+"`open`"+` from a remote VM to the host

Usage:
  open-proxy serve [-addr 127.0.0.1:7777]
  open-proxy open  <file|url|string>...

Environment:
  OPEN_PROXY_ADDR    client target / server listen address (default 127.0.0.1:7777)
  OPEN_PROXY_TOKEN      shared secret; if set on the server, clients must match
  OPEN_PROXY_TOKEN_FILE file containing the shared secret, used when OPEN_PROXY_TOKEN is unset
  OPEN_PROXY_MAXSIZE    max file transfer size in bytes (default 104857600)

Tip: symlink the binary to "open" and/or "xdg-open" early on the VM's $PATH.
     When the host is unreachable, it falls back to the real opener on $PATH.
`)
}