package main

import (
	"os"
	"regexp"
	"strings"
	"testing"
)

func TestWaitPidArg(t *testing.T) {
	for _, tc := range []struct {
		name string
		args []string
		want int
	}{
		{"after the flag", []string{"--post-update", "--wait-pid", "4321"}, 4321},
		{"joined with =", []string{"--wait-pid=4321"}, 4321},
		{"absent", []string{"--post-update"}, 0},
		{"flag with nothing after it", []string{"--wait-pid"}, 0},
		{"not a number", []string{"--wait-pid", "later"}, 0},
	} {
		if got := waitPidArg(tc.args); got != tc.want {
			t.Errorf("%s: got %d, wanted %d", tc.name, got, tc.want)
		}
	}
}

// A relaunch started from INSIDE this process has to tell the new one which
// process to wait for.
//
// The update path no longer does that from inside: its PowerShell helper waits
// for the pid and starts the exe once we are gone, which is what two rewrites
// failed to reproduce. RestartApp still spawns directly, and if a relaunch is
// ever added the same way without --wait-pid, it is the old bug again.
func TestEveryRelaunchPassesItsPid(t *testing.T) {
	// Both spellings: a relaunch built inline with exec.Command, and one built
	// through relaunchCmd. The pattern used to name only the first, and when the
	// update path moved to a PowerShell helper and RestartApp to relaunchCmd it
	// quietly matched nothing at all — a guard that passes because it looks
	// nowhere.
	spawn := regexp.MustCompile(`(exec\.Command|relaunchCmd)\(exe, "--(post-update|relaunch)"[^)]*\)`)
	for _, file := range []string{"update.go", "app.go"} {
		src, err := os.ReadFile(file)
		if err != nil {
			t.Fatalf("read %s: %v", file, err)
		}
		for _, call := range spawn.FindAllString(string(src), -1) {
			if !strings.Contains(call, "--wait-pid") {
				t.Errorf("%s: %s does not tell the new instance which process to wait for", file, call)
			}
		}
	}
}