//go:build linux

package test

import (
	infraUpdate "RenewCMS/internal/infrastructure/update"
	"os"
	"path/filepath"
	"testing"
)

func TestNoFollowFilesystemOnLinux(t *testing.T) {
	files := infraUpdate.NewNoFollowFilesystem()
	directory := t.TempDir()
	outside := filepath.Join(t.TempDir(), "outside.txt")
	if err := os.WriteFile(outside, []byte("sentinel"), 0o644); err != nil {
		t.Fatal(err)
	}
	link := filepath.Join(directory, "link")
	if err := os.Symlink(outside, link); err != nil {
		t.Fatal(err)
	}

	t.Run("lstat reports a symlink without following it", func(t *testing.T) {
		info, err := files.Lstat(link)
		if err != nil || !info.IsSymlink || info.IsRegular {
			t.Errorf("info = %+v, err = %v", info, err)
		}
	})

	t.Run("it never reads, copies, writes or chmods through a symlink", func(t *testing.T) {
		if _, err := files.ReadFile(link); err == nil {
			t.Error("read followed the link")
		}
		if err := files.Copy(link, filepath.Join(directory, "copy"), 0o600); err == nil {
			t.Error("copy followed the link")
		}
		if err := files.CreateExclusive(link, []byte("x"), 0o600); err == nil {
			t.Error("create followed the link")
		}
		if err := files.Chmod(link, 0o777); err == nil {
			t.Error("chmod followed the link")
		}
		if content, _ := os.ReadFile(outside); string(content) != "sentinel" {
			t.Errorf("the target changed: %q", content)
		}
		if info, _ := os.Stat(outside); info.Mode().Perm() != 0o644 {
			t.Errorf("the target mode changed: %v", info.Mode())
		}
	})

	t.Run("create-exclusive refuses an existing file and sets the mode", func(t *testing.T) {
		path := filepath.Join(directory, "exclusive")
		if err := files.CreateExclusive(path, []byte("one"), 0o640); err != nil {
			t.Fatal(err)
		}
		if err := files.CreateExclusive(path, []byte("two"), 0o640); err == nil {
			t.Error("the second create must fail")
		}
		if info, _ := os.Stat(path); info.Mode().Perm() != 0o640 {
			t.Errorf("mode = %v", info.Mode())
		}
	})

	t.Run("copy, rename, chmod and remove work on regular files", func(t *testing.T) {
		source := filepath.Join(directory, "source")
		_ = os.WriteFile(source, []byte("payload"), 0o600)
		copied := filepath.Join(directory, "copied")

		if err := files.Copy(source, copied, 0o755); err != nil {
			t.Fatal(err)
		}
		renamed := filepath.Join(directory, "renamed")
		if err := files.Rename(copied, renamed); err != nil {
			t.Fatal(err)
		}
		if err := files.Chmod(renamed, 0o700); err != nil {
			t.Fatal(err)
		}
		content, _ := files.ReadFile(renamed)
		info, _ := os.Stat(renamed)
		if string(content) != "payload" || info.Mode().Perm() != 0o700 {
			t.Errorf("content = %q, mode = %v", content, info.Mode())
		}
		if err := files.Remove(renamed); err != nil {
			t.Error(err)
		}
	})

	t.Run("remove-all unlinks links and never descends into them", func(t *testing.T) {
		tree := filepath.Join(directory, "tree")
		_ = os.MkdirAll(filepath.Join(tree, "nested"), 0o755)
		_ = os.WriteFile(filepath.Join(tree, "nested", "file"), []byte("x"), 0o644)
		escape := t.TempDir()
		_ = os.WriteFile(filepath.Join(escape, "keep"), []byte("keep"), 0o644)
		_ = os.Symlink(escape, filepath.Join(tree, "escape"))

		if err := files.RemoveAll(tree); err != nil {
			t.Fatal(err)
		}

		if _, err := os.Stat(tree); err == nil {
			t.Error("the tree must be gone")
		}
		if content, _ := os.ReadFile(filepath.Join(escape, "keep")); string(content) != "keep" {
			t.Error("the link target must be intact")
		}
		if err := files.RemoveAll(tree); err != nil {
			t.Errorf("removing a missing path = %v", err)
		}
	})

	t.Run("the temp directory is private", func(t *testing.T) {
		temp, err := files.MakePrivateTempDir()
		if err != nil {
			t.Fatal(err)
		}
		defer os.RemoveAll(temp)
		info, _ := os.Stat(temp)
		if !info.IsDir() || info.Mode().Perm() != 0o700 {
			t.Errorf("mode = %v", info.Mode())
		}
	})
}