// 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.Buffers;
using System.IO;
using System.Text;
using Microsoft.AspNetCore.SignalR.Protocol;
using Xunit;

namespace Microsoft.AspNetCore.SignalR.Common.Tests.Internal.Protocol
{
    public class HandshakeProtocolTests
    {
        [Theory]
        [InlineData("{\"protocol\":\"dummy\",\"version\":1}\u001e", "dummy", 1)]
        [InlineData("{\"protocol\":\"\",\"version\":10}\u001e", "", 10)]
        [InlineData("{\"protocol\":\"\",\"version\":10,\"unknown\":null}\u001e", "", 10)]
        public void ParsingHandshakeRequestMessageSuccessForValidMessages(string json, string protocol, int version)
        {
            var message = new ReadOnlySequence<byte>(Encoding.UTF8.GetBytes(json));

            Assert.True(HandshakeProtocol.TryParseRequestMessage(ref message, out var deserializedMessage));

            Assert.Equal(protocol, deserializedMessage.Protocol);
            Assert.Equal(version, deserializedMessage.Version);
        }

        [Theory]
        [InlineData("{\"error\":\"dummy\"}\u001e", "dummy")]
        [InlineData("{\"error\":\"\"}\u001e", "")]
        [InlineData("{}\u001e", null)]
        [InlineData("{\"unknown\":null}\u001e", null)]
        public void ParsingHandshakeResponseMessageSuccessForValidMessages(string json, string error)
        {
            var message = new ReadOnlySequence<byte>(Encoding.UTF8.GetBytes(json));

            Assert.True(HandshakeProtocol.TryParseResponseMessage(ref message, out var response));
            Assert.Equal(error, response.Error);
        }

        [Theory]
        [InlineData("{\"error\":\"\",\"minorVersion\":34}\u001e", 34)]
        [InlineData("{\"error\":\"flump flump flump\",\"minorVersion\":112}\u001e", 112)]
        public void ParsingResponseMessageGivesMinorVersion(string json, int version)
        {
            var message = new ReadOnlySequence<byte>(Encoding.UTF8.GetBytes(json));

            Assert.True(HandshakeProtocol.TryParseResponseMessage(ref message, out var response));
            Assert.Equal(version, response.MinorVersion);
        }

        [Fact]
        public void ParsingHandshakeRequestNotCompleteReturnsFalse()
        {
            var message = new ReadOnlySequence<byte>(Encoding.UTF8.GetBytes("42"));

            Assert.False(HandshakeProtocol.TryParseRequestMessage(ref message, out _));
        }

        [Theory]
        [InlineData("42\u001e", "Unexpected JSON Token Type 'Integer'. Expected a JSON Object.")]
        [InlineData("\"42\"\u001e", "Unexpected JSON Token Type 'String'. Expected a JSON Object.")]
        [InlineData("null\u001e", "Unexpected JSON Token Type 'Null'. Expected a JSON Object.")]
        [InlineData("{}\u001e", "Missing required property 'protocol'.")]
        [InlineData("[]\u001e", "Unexpected JSON Token Type 'Array'. Expected a JSON Object.")]
        [InlineData("{\"protocol\":\"json\"}\u001e", "Missing required property 'version'.")]
        [InlineData("{\"version\":1}\u001e", "Missing required property 'protocol'.")]
        [InlineData("{\"version\":\"123\"}\u001e", "Expected 'version' to be of type Integer.")]
        [InlineData("{\"protocol\":null,\"version\":123}\u001e", "Expected 'protocol' to be of type String.")]
        public void ParsingHandshakeRequestMessageThrowsForInvalidMessages(string payload, string expectedMessage)
        {
            var message = new ReadOnlySequence<byte>(Encoding.UTF8.GetBytes(payload));

            var exception = Assert.Throws<InvalidDataException>(() =>
                Assert.True(HandshakeProtocol.TryParseRequestMessage(ref message, out _)));

            Assert.Equal(expectedMessage, exception.Message);
        }

        [Theory]
        [InlineData("42\u001e", "Unexpected JSON Token Type 'Integer'. Expected a JSON Object.")]
        [InlineData("\"42\"\u001e", "Unexpected JSON Token Type 'String'. Expected a JSON Object.")]
        [InlineData("null\u001e", "Unexpected JSON Token Type 'Null'. Expected a JSON Object.")]
        [InlineData("[]\u001e", "Unexpected JSON Token Type 'Array'. Expected a JSON Object.")]
        [InlineData("{\"error\":null}\u001e", "Expected 'error' to be of type String.")]
        public void ParsingHandshakeResponseMessageThrowsForInvalidMessages(string payload, string expectedMessage)
        {
            var message = new ReadOnlySequence<byte>(Encoding.UTF8.GetBytes(payload));

            var exception = Assert.Throws<InvalidDataException>(() =>
                HandshakeProtocol.TryParseResponseMessage(ref message, out _));

            Assert.Equal(expectedMessage, exception.Message);
        }
    }
}