//go:build windows

package safeio

import (
	"errors"
	"os"
	"path/filepath"
	"runtime"
	"testing"

	"golang.org/x/sys/windows"
)

func TestPrivateWindowsDACLRejectsPermissiveDirectoryAndRegularFile(t *testing.T) {
	directory := filepath.Join(t.TempDir(), "auth")
	if err := os.Mkdir(directory, 0o700); err != nil {
		t.Fatal(err)
	}
	if err := ProtectPrivateDirectory(directory); err != nil {
		t.Fatal(err)
	}
	if err := ValidatePrivateDirectory(directory); err != nil {
		t.Fatalf("ValidatePrivateDirectory() protected directory error = %v", err)
	}

	path := filepath.Join(directory, "users.yaml")
	if err := os.WriteFile(path, []byte("private"), 0o600); err != nil {
		t.Fatal(err)
	}
	if err := ProtectPrivateRegular(path); err != nil {
		t.Fatal(err)
	}
	if err := ValidatePrivateRegular(path); err != nil {
		t.Fatalf("ValidatePrivateRegular() protected file error = %v", err)
	}

	for name, path := range map[string]string{"directory": directory, "regular file": path} {
		t.Run(name, func(t *testing.T) {
			if err := setPermissiveDACL(path); err != nil {
				t.Fatal(err)
			}
			var err error
			if name == "directory" {
				err = ValidatePrivateDirectory(path)
			} else {
				err = ValidatePrivateRegular(path)
			}
			if !errors.Is(err, ErrUnsafeFile) {
				t.Fatalf("private validation error = %v, want ErrUnsafeFile", err)
			}
		})
	}
}

func TestReplaceCanonicalRegularCreatesPrivateTemporaryAndReplacement(t *testing.T) {
	directory := filepath.Join(t.TempDir(), "auth")
	if err := os.Mkdir(directory, 0o700); err != nil {
		t.Fatal(err)
	}
	if err := ProtectPrivateDirectory(directory); err != nil {
		t.Fatal(err)
	}
	path := filepath.Join(directory, "users.yaml")
	if err := os.WriteFile(path, []byte("old"), 0o600); err != nil {
		t.Fatal(err)
	}
	if err := ProtectPrivateRegular(path); err != nil {
		t.Fatal(err)
	}

	temporary, err := writePrivateTemporary(directory, []byte("temporary"))
	if err != nil {
		t.Fatal(err)
	}
	t.Cleanup(func() { _ = os.Remove(temporary) })
	if err := ValidatePrivateRegular(temporary); err != nil {
		t.Fatalf("temporary DACL error = %v", err)
	}

	if err := ReplaceCanonicalRegular(path, []byte("replacement"), 0o600); err != nil {
		t.Fatal(err)
	}
	if err := ValidatePrivateRegular(path); err != nil {
		t.Fatalf("replacement DACL error = %v", err)
	}
}

func TestReplaceCanonicalRegularRejectsReparseParent(t *testing.T) {
	root := t.TempDir()
	realDirectory := filepath.Join(root, "real")
	if err := os.Mkdir(realDirectory, 0o700); err != nil {
		t.Fatal(err)
	}
	if err := ProtectPrivateDirectory(realDirectory); err != nil {
		t.Fatal(err)
	}
	target := filepath.Join(realDirectory, "users.yaml")
	if err := os.WriteFile(target, []byte("old"), 0o600); err != nil {
		t.Fatal(err)
	}
	if err := ProtectPrivateRegular(target); err != nil {
		t.Fatal(err)
	}

	parentLink := filepath.Join(root, "reparse-parent")
	if err := os.Symlink(realDirectory, parentLink); err != nil {
		t.Skipf("Windows host does not permit test symlink creation: %v", err)
	}
	if err := ReplaceCanonicalRegular(filepath.Join(parentLink, "users.yaml"), []byte("new"), 0o600); !errors.Is(err, ErrUnsafeFile) {
		t.Fatalf("reparse-parent replacement error = %v, want ErrUnsafeFile", err)
	}
}

func TestOpenCanonicalWindowsParentBlocksParentRename(t *testing.T) {
	root := t.TempDir()
	realDirectory := filepath.Join(root, "real")
	if err := os.Mkdir(realDirectory, 0o700); err != nil {
		t.Fatal(err)
	}
	if err := ProtectPrivateDirectory(realDirectory); err != nil {
		t.Fatal(err)
	}
	target := filepath.Join(realDirectory, "users.yaml")
	if err := os.WriteFile(target, []byte("old"), 0o600); err != nil {
		t.Fatal(err)
	}
	if err := ProtectPrivateRegular(target); err != nil {
		t.Fatal(err)
	}
	parents, _, err := openCanonicalWindowsParent(target)
	if err != nil {
		t.Fatal(err)
	}
	renamed := realDirectory + "-renamed"
	if err := os.Rename(realDirectory, renamed); err == nil {
		parents.Close()
		t.Fatal("parent rename succeeded while canonical replacement handles were retained")
	}
	parents.Close()
	if err := os.Rename(realDirectory, renamed); err != nil {
		t.Fatalf("parent rename after closing canonical replacement handles: %v", err)
	}
}

func setPermissiveDACL(path string) error {
	world, err := windows.StringToSid("S-1-1-0")
	if err != nil {
		return err
	}
	var pinner runtime.Pinner
	pinner.Pin(world)
	defer pinner.Unpin()
	acl, err := windows.ACLFromEntries([]windows.EXPLICIT_ACCESS{{
		AccessPermissions: windows.GENERIC_READ | windows.GENERIC_WRITE,
		AccessMode:        windows.GRANT_ACCESS,
		Trustee: windows.TRUSTEE{
			TrusteeForm:  windows.TRUSTEE_IS_SID,
			TrusteeType:  windows.TRUSTEE_IS_GROUP,
			TrusteeValue: windows.TrusteeValueFromSID(world),
		},
	}}, nil)
	if err != nil {
		return err
	}
	return windows.SetNamedSecurityInfo(path, windows.SE_FILE_OBJECT,
		windows.DACL_SECURITY_INFORMATION|windows.PROTECTED_DACL_SECURITY_INFORMATION,
		nil, nil, acl, nil)
}