/* ========================================================================
 * Copyright (c) 2005-2025 The OPC Foundation, Inc. All rights reserved.
 *
 * OPC Foundation MIT License 1.00
 *
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use,
 * copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following
 * conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 *
 * The complete license agreement can be found here:
 * http://opcfoundation.org/License/MIT/1.00/
 * ======================================================================*/

using System.IO;
using System.Text;
using BenchmarkDotNet.Attributes;
using BenchmarkDotNet.Diagnosers;
using NUnit.Framework;
using Opc.Ua.Bindings;

namespace Opc.Ua.Core.Encoders.Tests
{
    [TestFixture]
    [Category("JsonEncoder")]
    [SetCulture("en-us")]
    [SetUICulture("en-us")]
    [NonParallelizable]
    [MemoryDiagnoser]
    [DisassemblyDiagnoser]
    public class JsonEncoderBenchmarks : EncoderBenchmarks
    {
        [Params(128, 512, 1024, 4096, 8192, 65536)]
        public int StreamSize { get; set; } = 1024;

        /// <summary>
        /// Benchmark overhead to create StreamWriter, MemoryStream is kept open.
        /// </summary>
        [Test]
        public void StreamWriter()
        {
            using var memoryStream = new MemoryStream();
            using var test = new StreamWriter(memoryStream, Encoding.UTF8, StreamSize, true);
            test.Flush();
        }

        /// <summary>
        /// Benchmark overhead to create StreamWriter and MemoryStream.
        /// </summary>
        [Test]
        public void StreamWriterMemoryStream()
        {
            using var memoryStream = new MemoryStream();
            using var test = new StreamWriter(memoryStream, Encoding.UTF8, StreamSize);
            test.Flush();
        }

        /// <summary>
        /// Benchmark encoding with internal memory stream.
        /// </summary>
        [Test]
        public void JsonEncoderConstructor()
        {
            using var jsonEncoder = new JsonEncoder(m_context, JsonEncoderOptions.Compact);
            TestEncoding(jsonEncoder);
            _ = jsonEncoder.CloseAndReturnText();
        }

        /// <summary>
        /// Test encoding with ArrayPool memory stream.
        /// </summary>
        [Theory]
        public void JsonEncoderArraySegmentStreamTest(bool toText)
        {
            using var memoryStream = new ArraySegmentStream(
                m_bufferManager,
                StreamBufferSize,
                0,
                StreamBufferSize);
            TestStreamEncode(memoryStream, toText);
        }

        /// <summary>
        /// Test encoding with memory stream kept open.
        /// </summary>
        [Theory]
        public void JsonEncoderMemoryStreamTest(bool toText)
        {
            using var memoryStream = new MemoryStream(StreamBufferSize);
            TestStreamEncode(memoryStream, toText);
        }

        /// <summary>
        /// Benchmark encoding with memory stream kept open.
        /// </summary>
        [Benchmark]
        [Test]
        public void JsonEncoderMemoryStream()
        {
            using var memoryStream = new MemoryStream(StreamBufferSize);
            JsonEncoder_StreamLeaveOpen(memoryStream);
            // get buffer for write
            _ = memoryStream.ToArray();
        }

        /// <summary>
        /// Benchmark encoding with recyclable memory stream kept open.
        /// </summary>
        [Benchmark]
        [Test]
        public void JsonEncoderArraySegmentStream()
        {
            using var arraySegmentStream = new ArraySegmentStream(m_bufferManager);
            JsonEncoder_StreamLeaveOpen(arraySegmentStream);
            // get buffers and return them to buffer manager
            foreach (System.ArraySegment<byte> buffer in arraySegmentStream.GetBuffers("writer"))
            {
                m_bufferManager.ReturnBuffer(buffer.Array, "testreturn");
            }
        }

        /// <summary>
        /// Benchmark encoding with recyclable memory stream kept open.
        /// </summary>
        [Benchmark]
        [Test]
        public void JsonEncoderArraySegmentStreamNoSpan()
        {
#if NET6_0_OR_GREATER
            using var arraySegmentStream = new ArraySegmentStreamNoSpan(m_bufferManager);
#else
            using var arraySegmentStream = new ArraySegmentStream(m_bufferManager);
#endif
            JsonEncoder_StreamLeaveOpen(arraySegmentStream);
            // get buffers and return them to buffer manager
            foreach (System.ArraySegment<byte> buffer in arraySegmentStream.GetBuffers("writer"))
            {
                m_bufferManager.ReturnBuffer(buffer.Array, "testreturn");
            }
        }

        private void TestStreamEncode(MemoryStream memoryStream, bool toArray)
        {
            int length1 = 0;
            using (var jsonEncoder = new JsonEncoder(memoryStream, m_context, JsonEncoderOptions.Compact))
            {
                TestEncoding(jsonEncoder);
                length1 = jsonEncoder.Close();
            }
            using (var jsonEncoder = new JsonEncoder(memoryStream, m_context, JsonEncoderOptions.Compact))
            {
                TestEncoding(jsonEncoder);
                if (toArray)
                {
                    int length2 = jsonEncoder.Close();
                    Assert.That(memoryStream.Position, Is.EqualTo(length2 + length1));
                    byte[] result = memoryStream.ToArray();
                    Assert.That(result, Is.Not.Null);
                    Assert.That(result, Has.Length.EqualTo(length2 + length1));
                }
                else
                {
                    string result = jsonEncoder.CloseAndReturnText();
                    Assert.That(result, Is.Not.Null);
                }
            }
        }

        private void JsonEncoder_StreamLeaveOpen(MemoryStream stream, bool testResult = false)
        {
            int length1;
            int length2;
            stream.Position = 0;
            using (var jsonEncoder = new JsonEncoder(
                stream,
                m_context,
                JsonEncoderOptions.Compact))
            {
                TestEncoding(jsonEncoder);
                length1 = jsonEncoder.Close();
            }
            using (var jsonEncoder = new JsonEncoder(
                stream,
                m_context,
                JsonEncoderOptions.Compact))
            {
                TestEncoding(jsonEncoder);
                length2 = jsonEncoder.Close();
            }
            if (testResult)
            {
                string result = Encoding.UTF8.GetString(stream.ToArray());
                Assert.That(result, Is.Not.Null);
                Assert.That(length2, Is.EqualTo(length1 * 2));
                Assert.That(result, Has.Length.EqualTo(length2));
            }
        }

        [OneTimeSetUp]
        public override void OneTimeSetUp()
        {
            base.OneTimeSetUp();
        }

        [OneTimeTearDown]
        public override void OneTimeTearDown()
        {
            base.OneTimeTearDown();
        }

        /// <summary>
        /// Set up some variables for benchmarks.
        /// </summary>
        [GlobalSetup]
        public override void GlobalSetup()
        {
            base.GlobalSetup();
        }

        /// <summary>
        /// Tear down benchmark variables.
        /// </summary>
        [GlobalCleanup]
        public override void GlobalCleanup()
        {
            base.GlobalCleanup();
        }
    }
}