package main

import (
	"errors"
	"os"
	"os/exec"
	"path"

	"git.gensokyo.uk/security/fortify/fst"
	"git.gensokyo.uk/security/fortify/internal/fmsg"
)

func actionActivate(args []string) {
	// simple check so activate is not attempted outside fortify
	if s, err := os.Stat(path.Join(fst.Tmp, "sbin")); err != nil {
		fmsg.Fatalf("cannot stat fortify sbin: %v", err)
	} else if !s.IsDir() {
		fmsg.Fatal("fortify sbin path is not a directory")
	}

	home := os.Getenv("HOME")
	if !path.IsAbs(home) {
		fmsg.Fatalf("path %q is not aboslute", home)
	}
	marker := path.Join(home, ".hm-activation")

	if len(args) != 1 {
		fmsg.Fatalf("invalid argument")
	}
	activate := path.Join(args[0], "activate")

	var cmd *exec.Cmd
	if l, err := os.Readlink(marker); err != nil && !errors.Is(err, os.ErrNotExist) {
		fmsg.Fatalf("cannot read activation marker %q: %v", marker, err)
	} else if err != nil || l != activate {
		cmd = exec.Command(activate)
	}

	// marker present and equals to current activation package
	if cmd == nil {
		fmsg.Exit(0)
		panic("unreachable")
	}

	cmd.Stdin, cmd.Stdout, cmd.Stderr = os.Stdin, os.Stdout, os.Stderr
	cmd.Env = os.Environ()
	if err := cmd.Run(); err != nil {
		fmsg.Fatalf("cannot activate home-manager configuration: %v", err)
	}

	if err := os.Remove(marker); err != nil && !errors.Is(err, os.ErrNotExist) {
		fmsg.Fatalf("cannot remove existing marker: %v", err)
	}
	if err := os.Symlink(activate, marker); err != nil {
		fmsg.Fatalf("cannot create activation marker: %v", err)
	}
}