// Copyright (c) .NET Foundation. All rights reserved.
// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.

using System;
using Xunit;

namespace Microsoft.AspNetCore.DataProtection
{
    /// <summary>
    /// Helpful ISecret-based assertions.
    /// </summary>
    public static class SecretAssert
    {
        /// <summary>
        /// Asserts that two <see cref="ISecret"/> instances contain the same material.
        /// </summary>
        public static void Equal(ISecret secret1, ISecret secret2)
        {
            Assert.Equal(SecretToBase64String(secret1), SecretToBase64String(secret2));
        }

        /// <summary>
        /// Asserts that <paramref name="secret"/> has the length specified by <paramref name="expectedLengthInBits"/>.
        /// </summary>
        public static void LengthIs(int expectedLengthInBits, ISecret secret)
        {
            Assert.Equal(expectedLengthInBits, checked(secret.Length * 8));
        }

        /// <summary>
        /// Asserts that two <see cref="ISecret"/> instances do not contain the same material.
        /// </summary>
        public static void NotEqual(ISecret secret1, ISecret secret2)
        {
            Assert.NotEqual(SecretToBase64String(secret1), SecretToBase64String(secret2));
        }

        private static string SecretToBase64String(ISecret secret)
        {
            byte[] secretBytes = new byte[secret.Length];
            secret.WriteSecretIntoBuffer(new ArraySegment<byte>(secretBytes));
            return Convert.ToBase64String(secretBytes);
        }
    }
}