// 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 System.Globalization;
using System.Text;
using Moq;
using Xunit;

namespace Microsoft.AspNetCore.DataProtection
{
    public class DataProtectionAdvancedExtensionsTests
    {
        private const string SampleEncodedString = "AQI"; // = WebEncoders.Base64UrlEncode({ 0x01, 0x02 })

        [Fact]
        public void Protect_PayloadAsString_WithExplicitExpiration()
        {
            // Arrange
            var plaintextAsBytes = Encoding.UTF8.GetBytes("this is plaintext");
            var expiration = StringToDateTime("2015-01-01 00:00:00Z");
            var mockDataProtector = new Mock<ITimeLimitedDataProtector>();
            mockDataProtector.Setup(o => o.Protect(plaintextAsBytes, expiration)).Returns(new byte[] { 0x01, 0x02 });

            // Act
            string protectedPayload = mockDataProtector.Object.Protect("this is plaintext", expiration);

            // Assert
            Assert.Equal(SampleEncodedString, protectedPayload);
        }

        [Fact]
        public void Protect_PayloadAsString_WithLifetimeAsTimeSpan()
        {
            // Arrange
            var plaintextAsBytes = Encoding.UTF8.GetBytes("this is plaintext");
            DateTimeOffset actualExpiration = default(DateTimeOffset);
            var mockDataProtector = new Mock<ITimeLimitedDataProtector>();
            mockDataProtector.Setup(o => o.Protect(plaintextAsBytes, It.IsAny<DateTimeOffset>()))
                .Returns<byte[], DateTimeOffset>((_, exp) =>
                {
                    actualExpiration = exp;
                    return new byte[] { 0x01, 0x02 };
                });

            // Act
            DateTimeOffset lowerBound = DateTimeOffset.UtcNow.AddHours(48);
            string protectedPayload = mockDataProtector.Object.Protect("this is plaintext", TimeSpan.FromHours(48));
            DateTimeOffset upperBound = DateTimeOffset.UtcNow.AddHours(48);

            // Assert
            Assert.Equal(SampleEncodedString, protectedPayload);
            Assert.InRange(actualExpiration, lowerBound, upperBound);
        }

        [Fact]
        public void Protect_PayloadAsBytes_WithLifetimeAsTimeSpan()
        {
            // Arrange
            DateTimeOffset actualExpiration = default(DateTimeOffset);
            var mockDataProtector = new Mock<ITimeLimitedDataProtector>();
            mockDataProtector.Setup(o => o.Protect(new byte[] { 0x11, 0x22, 0x33 }, It.IsAny<DateTimeOffset>()))
                .Returns<byte[], DateTimeOffset>((_, exp) =>
                {
                    actualExpiration = exp;
                    return new byte[] { 0x01, 0x02 };
                });

            // Act
            DateTimeOffset lowerBound = DateTimeOffset.UtcNow.AddHours(48);
            byte[] protectedPayload = mockDataProtector.Object.Protect(new byte[] { 0x11, 0x22, 0x33 }, TimeSpan.FromHours(48));
            DateTimeOffset upperBound = DateTimeOffset.UtcNow.AddHours(48);

            // Assert
            Assert.Equal(new byte[] { 0x01, 0x02 }, protectedPayload);
            Assert.InRange(actualExpiration, lowerBound, upperBound);
        }

        [Fact]
        public void Unprotect_PayloadAsString()
        {
            // Arrange
            var futureDate = DateTimeOffset.UtcNow.AddYears(1);
            var controlExpiration = futureDate;
            var mockDataProtector = new Mock<ITimeLimitedDataProtector>();
            mockDataProtector.Setup(o => o.Unprotect(new byte[] { 0x01, 0x02 }, out controlExpiration)).Returns(Encoding.UTF8.GetBytes("this is plaintext"));

            // Act
            DateTimeOffset testExpiration;
            string unprotectedPayload = mockDataProtector.Object.Unprotect(SampleEncodedString, out testExpiration);

            // Assert
            Assert.Equal("this is plaintext", unprotectedPayload);
            Assert.Equal(futureDate, testExpiration);
        }

        private static DateTime StringToDateTime(string input)
        {
            return DateTimeOffset.ParseExact(input, "u", CultureInfo.InvariantCulture).UtcDateTime;
        }
    }
}