using System.Collections;
using System.Collections.Concurrent;
using System.Data;
using Docker.DotNet;
using Docker.DotNet.Models;
using LCU.API.Internal.DocumentIngestorLib.Persistence;
using Microsoft.Data.SqlClient;
using Microsoft.EntityFrameworkCore;

namespace LCU.API.Internal.DocumentIngestorLibTests;

public class SqlServerDbContextFactory : IAsyncDisposable
{
	private const int port = 1434;
	private const string password = "yourStrong(!)Password";

	private readonly IList<AppDbContext> _contexts = new List<AppDbContext>();

	private static readonly SemaphoreSlim ContainerUse = new(1);
	private static CreateContainerResponse? Container;
	private static readonly IDictionary<AppDbContext, bool> _activeContexts = new ConcurrentDictionary<AppDbContext, bool>();

	public async Task<AppDbContext> CreateContext()
	{
		await ContainerUse.WaitAsync();
		Container ??= await DatabaseContainerFactory();
		ContainerUse.Release();

		var connectionString =
			$"Data Source=localhost,{port};User Id=sa;Password={password};Database={Guid.NewGuid()};MultipleActiveResultSets=True;App=EntityFramework;Trust Server Certificate=true";

		var options = new DbContextOptionsBuilder<AppDbContext>()
			.UseSqlServer(connectionString)
			.EnableSensitiveDataLogging()
			.Options;

		var context = new AppDbContext(options);
		await DatabaseConnectionReady(connectionString);
		await context.Database.EnsureCreatedAsync();

		_contexts.Add(context);
		_activeContexts[context] = true;
		return context;
	}

	private static async Task<CreateContainerResponse> DatabaseContainerFactory()
	{
		const string ImageName = "mcr.microsoft.com/mssql/server:2019-CU18-ubuntu-20.04";
		const int containerPort = 1433;

		using var docker = new DockerClientConfiguration().CreateClient();

		await docker.Images.CreateImageAsync
		(
			new ImagesCreateParameters
			{
				FromImage = ImageName
			},
			null,
			new Progress<JSONMessage>()
		);
		var container = await docker.Containers.CreateContainerAsync
		(
			new CreateContainerParameters
			{
				Image = ImageName,
				Name = "LCU.API.Internal.DocumentIngestor.IntegrationTestDatabase",
				Env = new List<string>
				{
					"ACCEPT_EULA=Y",
					$"MSSQL_SA_PASSWORD={password}"
				},
				ExposedPorts = new Dictionary<string, EmptyStruct>
				{
					{$"{containerPort}", default}
				},
				HostConfig = new HostConfig
				{
					PortBindings = new Dictionary<string, IList<PortBinding>>
					{
						{ $"{containerPort}", new List<PortBinding> { new() { HostPort = $"{port}" } } }
					}
				}
			}
		);
		await docker.Containers.StartContainerAsync(container.ID, new ContainerStartParameters());

		return container;
	}

	private static async Task DatabaseConnectionReady(string connectionString)
	{
		await using var connection = new SqlConnection(connectionString);

		var ready = false;
		var triesRemaining = 20;
		while (!ready && triesRemaining > 0)
		{
			triesRemaining--;

			try
			{
				await connection.OpenAsync();
			}
			catch
			{
				await Task.Delay(TimeSpan.FromMilliseconds(200));
			}

			ready = connection.State == ConnectionState.Open;
		}
	}

	public async ValueTask DisposeAsync()
	{
		foreach (var context in _contexts)
		{
			await context.DisposeAsync();
			_activeContexts[context] = false;
		}

		await ContainerUse.WaitAsync();
		if (_activeContexts.Values.All(a => a == false))
		{
			await DisposeContainer(Container);
			Container = null;
		}
		ContainerUse.Release();
	}

	private static async Task DisposeContainer(CreateContainerResponse container)
	{
		using var docker = new DockerClientConfiguration().CreateClient();

		await docker.Containers.StopContainerAsync(container.ID, new ContainerStopParameters());
		await docker.Containers.RemoveContainerAsync(container.ID, new ContainerRemoveParameters());
	}
}