package main

import (
	"fmt"
	"os"

	"fn-registry/functions/infra"
)

const usage = `set_exe_icon - embed a .ico into a Windows .exe (post-build, no deps)

Usage:
  set_exe_icon <exe> <ico>

Notes:
  Modifies the .exe in place (creates a backup at <exe>.bak first).
  Only supports PE binaries without an existing .rsrc section.
`

func main() {
	if len(os.Args) != 3 {
		fmt.Fprint(os.Stderr, usage)
		os.Exit(2)
	}
	exePath, icoPath := os.Args[1], os.Args[2]

	bak := exePath + ".bak"
	src, err := os.ReadFile(exePath)
	if err != nil {
		die("read exe: %v", err)
	}
	if err := os.WriteFile(bak, src, 0o755); err != nil {
		die("write backup: %v", err)
	}

	if err := infra.SetExeIcon(exePath, icoPath); err != nil {
		_ = os.WriteFile(exePath, src, 0o755)
		_ = os.Remove(bak)
		die("set icon: %v", err)
	}
	fmt.Printf("OK: icon embedded in %s (backup: %s)\n", exePath, bak)
}

func die(format string, a ...any) {
	fmt.Fprintf(os.Stderr, "error: "+format+"\n", a...)
	os.Exit(1)
}