//
// Copyright (c) Microsoft. All rights reserved.
// Licensed under the MIT license. See LICENSE file in the project root for full license information.
//

using System;
using System.Collections.Generic;
using System.IO;
using System.Reflection;
using Microsoft.SqlTools.ServiceLayer.Connection;
using Microsoft.SqlTools.ServiceLayer.Connection.Contracts;
using Microsoft.SqlTools.ServiceLayer.Credentials;
using Microsoft.SqlTools.ServiceLayer.Hosting;
using Microsoft.SqlTools.ServiceLayer.LanguageServices;
using Microsoft.SqlTools.ServiceLayer.QueryExecution;
using Microsoft.SqlTools.ServiceLayer.QueryExecution.DataStorage;
using Microsoft.SqlTools.ServiceLayer.SqlContext;
using Microsoft.SqlTools.ServiceLayer.Workspace;
using Moq;
using Xunit;

namespace Microsoft.SqlTools.ServiceLayer.Test.Common
{
    /// <summary>
    /// Class to provide SQL tools service classes
    /// </summary>
    public class TestServiceProvider
    {
        private TestServiceProvider()
        {
            InitializeTestServices();
        }

        private static object _lockObject = new object();
        private static TestServiceProvider _instance = new TestServiceProvider();


        public static TestServiceProvider Instance
        {
            get
            {
                return _instance;
            }
        }

        public CredentialService CredentialService
        {
            get
            {
                return CredentialService.Instance;
            }
        }

        public TestConnectionProfileService ConnectionProfileService
        {
            get
            {
                return TestConnectionProfileService.Instance;
            }
        }

        public WorkspaceService<SqlToolsSettings> WorkspaceService
        {
            get
            {
                return WorkspaceService<SqlToolsSettings>.Instance;
            }
        }

        /// <summary>
        /// Runs a query by calling the services directly (not using the test driver) 
        /// </summary>
        public void RunQuery(TestServerType serverType, string databaseName, string queryText)
        {
            using (SelfCleaningTempFile queryTempFile = new SelfCleaningTempFile())
            {
                ConnectionInfo connInfo = InitLiveConnectionInfo(serverType, databaseName, queryTempFile.FilePath);
                Query query = new Query(queryText, connInfo, new QueryExecutionSettings(), GetFileStreamFactory(new Dictionary<string, byte[]>()));
                query.Execute();
                query.ExecutionTask.Wait();
            }
        }

        private ConnectionInfo InitLiveConnectionInfo(TestServerType serverType, string databaseName, string scriptFilePath)
        {
            ConnectParams connectParams = ConnectionProfileService.GetConnectionParameters(serverType, databaseName);

            string ownerUri = scriptFilePath;
            var connectionService = ConnectionService.Instance;
            var connectionResult = connectionService.Connect(new ConnectParams()
                {
                    OwnerUri = ownerUri,
                    Connection = connectParams.Connection
                });

            connectionResult.Wait();

            ConnectionInfo connInfo = null;
            connectionService.TryFindConnection(ownerUri, out connInfo);
            Assert.NotNull(connInfo);
            return connInfo;
        }

        private static IFileStreamFactory GetFileStreamFactory(Dictionary<string, byte[]> storage)
        {
            Mock<IFileStreamFactory> mock = new Mock<IFileStreamFactory>();
            mock.Setup(fsf => fsf.CreateFile())
                .Returns(() =>
                {
                    string fileName = Guid.NewGuid().ToString();
                    storage.Add(fileName, new byte[8192]);
                    return fileName;
                });
            mock.Setup(fsf => fsf.GetReader(It.IsAny<string>()))
                .Returns<string>(output => new ServiceBufferFileStreamReader(new MemoryStream(storage[output])));
            mock.Setup(fsf => fsf.GetWriter(It.IsAny<string>()))
                .Returns<string>(output => new ServiceBufferFileStreamWriter(new MemoryStream(storage[output]), 1024, 1024));

            return mock.Object;
        }

        private static bool hasInitServices = false;

        private static void InitializeTestServices()
        {
            if (TestServiceProvider.hasInitServices)
            {
                return;
            }

            lock (_lockObject)
            {
                if (TestServiceProvider.hasInitServices)
                {
                    return;
                }
                TestServiceProvider.hasInitServices = true;

                const string hostName = "SQ Tools Test Service Host";
                const string hostProfileId = "SQLToolsTestService";
                Version hostVersion = new Version(1, 0);

                // set up the host details and profile paths 
                var hostDetails = new HostDetails(hostName, hostProfileId, hostVersion);
                SqlToolsContext sqlToolsContext = new SqlToolsContext(hostDetails);

                // Grab the instance of the service host
                ServiceHost serviceHost = ServiceHost.Instance;

                // Start the service
                serviceHost.Start().Wait();

                // Initialize the services that will be hosted here
                WorkspaceService<SqlToolsSettings>.Instance.InitializeService(serviceHost);
                LanguageService.Instance.InitializeService(serviceHost, sqlToolsContext);
                ConnectionService.Instance.InitializeService(serviceHost);
                CredentialService.Instance.InitializeService(serviceHost);
                QueryExecutionService.Instance.InitializeService(serviceHost);

                serviceHost.Initialize();
            }
        }

    }
}