package main

// `lchat install` (versions.go): staged builds land on sibling-service binary
// paths with a .prev- backup, and the guardrails hold (unknown sibling,
// unstaged version).

import (
	"os"
	"path/filepath"
	"strings"
	"testing"
)

func TestInstallSibling(t *testing.T) {
	old := optDir
	optDir = t.TempDir()
	defer func() { optDir = old }()

	// Stage a fake build the way stage would lay it out.
	ver := "abc1234"
	if err := os.MkdirAll(filepath.Dir(versionBinPath(ver)), 0o755); err != nil {
		t.Fatal(err)
	}
	if err := os.WriteFile(versionBinPath(ver), []byte("new-build"), 0o755); err != nil {
		t.Fatal(err)
	}
	// An existing home binary to be replaced.
	target := filepath.Join(optDir, "home")
	if err := os.WriteFile(target, []byte("old-build"), 0o755); err != nil {
		t.Fatal(err)
	}

	msg, err := installSibling("home", ver)
	if err != nil {
		t.Fatal(err)
	}
	if got, _ := os.ReadFile(target); string(got) != "new-build" {
		t.Fatalf("target = %q, want the staged build", got)
	}
	// The previous binary survives as a dated .prev- sibling.
	prevs, _ := filepath.Glob(target + ".prev-*")
	if len(prevs) != 1 {
		t.Fatalf("prev backups = %v, want exactly one", prevs)
	}
	if got, _ := os.ReadFile(prevs[0]); string(got) != "old-build" {
		t.Fatalf("backup = %q, want the old build", got)
	}
	if !strings.Contains(msg, "lchat-svc restart lchat-home") {
		t.Fatalf("summary should name the restart: %q", msg)
	}

	// First install (no existing binary): no backup, no error.
	if _, err := installSibling("push", ver); err != nil {
		t.Fatal(err)
	}
	if prevs, _ := filepath.Glob(filepath.Join(optDir, "push.prev-*")); len(prevs) != 0 {
		t.Fatalf("fresh install made a backup: %v", prevs)
	}

	// Guardrails.
	if _, err := installSibling("router", ver); err == nil {
		t.Fatal("unknown sibling must refuse")
	}
	if _, err := installSibling("home", "def5678"); err == nil {
		t.Fatal("unstaged version must refuse")
	}
}