package bookfile

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

func TestContains(t *testing.T) {
	dir := t.TempDir()
	sub := filepath.Join(dir, "sub")
	if err := os.MkdirAll(sub, 0o755); err != nil {
		t.Fatal(err)
	}
	if !Contains(dir, sub) {
		t.Fatal("sub should be inside dir")
	}
	if Contains(sub, dir) {
		t.Fatal("dir should not be inside sub")
	}
	if Contains(dir, "/completely/different") {
		t.Fatal("unrelated path should not be inside dir")
	}
	// Same path.
	if !Contains(dir, dir) {
		t.Fatal("dir should contain itself")
	}
}

func TestOpenReaderAt(t *testing.T) {
	dir := t.TempDir()
	// Create a test file.
	path := filepath.Join(dir, "test.txt")
	if err := os.WriteFile(path, []byte("hello"), 0o644); err != nil {
		t.Fatal(err)
	}
	f, size, err := OpenReaderAt(dir, "test.txt")
	if err != nil {
		t.Fatal(err)
	}
	defer f.Close()
	if size != 5 {
		t.Fatalf("size = %d, want 5", size)
	}

	// Non-existent file.
	_, _, err = OpenReaderAt(dir, "nope.txt")
	if err == nil {
		t.Fatal("expected error for non-existent file")
	}
}