package safeio

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

	"github.com/aritmolab/thothii/tools/thothctl/internal/testsupport"
)

func TestReadCanonicalRegularRejectsFinalAndParentSymlinks(t *testing.T) {
	temporaryRoot, err := filepath.EvalSymlinks(os.TempDir())
	if err != nil {
		t.Fatal(err)
	}
	root, err := os.MkdirTemp(temporaryRoot, "thothctl-safeio-")
	if err != nil {
		t.Fatal(err)
	}
	t.Cleanup(func() { _ = os.RemoveAll(root) })

	realDirectory := filepath.Join(root, "real")
	if err := os.Mkdir(realDirectory, 0o700); err != nil {
		t.Fatal(err)
	}
	realFile := filepath.Join(realDirectory, "secret")
	if err := os.WriteFile(realFile, []byte("secret"), 0o600); err != nil {
		t.Fatal(err)
	}

	parentLink := filepath.Join(root, "parent-link")
	testsupport.SymlinkOrSkip(t, realDirectory, parentLink)
	if _, err := ReadCanonicalRegular(filepath.Join(parentLink, "secret"), 1024); !errors.Is(err, ErrUnsafeFile) {
		t.Fatalf("parent symlink error = %v, want ErrUnsafeFile", err)
	}

	finalLink := filepath.Join(root, "final-link")
	testsupport.SymlinkOrSkip(t, realFile, finalLink)
	if _, err := ReadCanonicalRegular(finalLink, 1024); !errors.Is(err, ErrUnsafeFile) {
		t.Fatalf("final symlink error = %v, want ErrUnsafeFile", err)
	}
}

func TestReadCanonicalUTF8RejectsNonUTF8AndBounds(t *testing.T) {
	path := filepath.Join(t.TempDir(), "input.sql")
	if err := os.WriteFile(path, []byte("\xff"), 0o600); err != nil {
		t.Fatal(err)
	}
	if _, err := ReadCanonicalUTF8(path, 1024); !errors.Is(err, ErrUnsafeFile) {
		t.Fatalf("ReadCanonicalUTF8 invalid UTF-8 = %v", err)
	}
	if err := os.WriteFile(path, []byte("12345"), 0o600); err != nil {
		t.Fatal(err)
	}
	if _, err := ReadCanonicalUTF8(path, 4); !errors.Is(err, ErrUnsafeFile) {
		t.Fatalf("ReadCanonicalUTF8 oversized = %v", err)
	}
}

func TestWriteCanonicalExclusiveRejectsExistingAndCreatesPrivateFile(t *testing.T) {
	root, err := filepath.EvalSymlinks(t.TempDir())
	if err != nil {
		t.Fatal(err)
	}
	path := filepath.Join(root, "candidate.yaml")
	if err := WriteCanonicalExclusive(path, []byte("ok"), 0o600); err != nil {
		t.Fatal(err)
	}
	contents, err := os.ReadFile(path)
	if err != nil || string(contents) != "ok" {
		t.Fatalf("output = %q, %v", contents, err)
	}
	if err := WriteCanonicalExclusive(path, []byte("replace"), 0o600); !errors.Is(err, ErrUnsafeFile) {
		t.Fatalf("replacement = %v", err)
	}
}

func TestReadCanonicalRegularRejectsHardlinkAndDirectory(t *testing.T) {
	root, err := filepath.EvalSymlinks(t.TempDir())
	if err != nil {
		t.Fatal(err)
	}
	original := filepath.Join(root, "original.sql")
	if err := os.WriteFile(original, []byte("select 1"), 0o600); err != nil {
		t.Fatal(err)
	}
	hardlink := filepath.Join(root, "hardlink.sql")
	if err := os.Link(original, hardlink); err != nil {
		t.Fatal(err)
	}
	if _, err := ReadCanonicalRegular(hardlink, 1024); !errors.Is(err, ErrUnsafeFile) {
		t.Fatalf("hardlink error = %v, want ErrUnsafeFile", err)
	}
	directory := filepath.Join(root, "directory.sql")
	if err := os.Mkdir(directory, 0o700); err != nil {
		t.Fatal(err)
	}
	if _, err := ReadCanonicalRegular(directory, 1024); !errors.Is(err, ErrUnsafeFile) {
		t.Fatalf("directory error = %v, want ErrUnsafeFile", err)
	}
}

func TestValidateCanonicalOutputPathRejectsExistingDirectoryAndSymlink(t *testing.T) {
	root, err := filepath.EvalSymlinks(t.TempDir())
	if err != nil {
		t.Fatal(err)
	}
	directory := filepath.Join(root, "existing.yaml")
	if err := os.Mkdir(directory, 0o700); err != nil {
		t.Fatal(err)
	}
	if err := ValidateCanonicalOutputPath(directory); !errors.Is(err, ErrUnsafeFile) {
		t.Fatalf("existing directory error = %v, want ErrUnsafeFile", err)
	}
	target := filepath.Join(root, "target.yaml")
	if err := os.WriteFile(target, []byte("target"), 0o600); err != nil {
		t.Fatal(err)
	}
	link := filepath.Join(root, "link.yaml")
	testsupport.SymlinkOrSkip(t, target, link)
	if err := ValidateCanonicalOutputPath(link); !errors.Is(err, ErrUnsafeFile) {
		t.Fatalf("output symlink error = %v, want ErrUnsafeFile", err)
	}
}