using System.Data.Common;
using Data.SeaHavenIndustries;
using Microsoft.Data.Sqlite;
using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Diagnostics;
using SeaHaven.DataServices.Implementation;

namespace SeaHavenIndustries.Tests;

public sealed class UpliftDataServiceTransactionTests
{
    [Fact]
    public async Task ExecuteWorkOrderMutationAsync_ReleasesGate_WhenTransactionInitializationFails()
    {
        await using var connection = new SqliteConnection("DataSource=:memory:");
        await connection.OpenAsync();

        var failingOptions = new DbContextOptionsBuilder<ApplicationDbContext>()
            .UseSqlite(connection)
            .AddInterceptors(new ThrowOnceTransactionInterceptor())
            .Options;

        await using (var failedContext = new ApplicationDbContext(failingOptions))
        {
            var failedService = new UpliftDataService(failedContext);

            await Assert.ThrowsAsync<InvalidOperationException>(() =>
                failedService.ExecuteWorkOrderMutationAsync(
                    387,
                    _ => Task.FromResult(true),
                    CancellationToken.None));
        }

        var retryOptions = new DbContextOptionsBuilder<ApplicationDbContext>()
            .UseSqlite(connection)
            .Options;
        await using var retryContext = new ApplicationDbContext(retryOptions);
        var retryService = new UpliftDataService(retryContext);

        var retry = retryService.ExecuteWorkOrderMutationAsync(
            387,
            _ => Task.FromResult("entered"),
            CancellationToken.None);

        Assert.Equal("entered", await retry.WaitAsync(TimeSpan.FromSeconds(1)));
    }

    private sealed class ThrowOnceTransactionInterceptor : DbTransactionInterceptor
    {
        private int _remaining = 1;

        public override InterceptionResult<DbTransaction> TransactionStarting(
            DbConnection connection,
            TransactionStartingEventData eventData,
            InterceptionResult<DbTransaction> result)
        {
            ThrowOnce();
            return base.TransactionStarting(connection, eventData, result);
        }

        public override ValueTask<InterceptionResult<DbTransaction>> TransactionStartingAsync(
            DbConnection connection,
            TransactionStartingEventData eventData,
            InterceptionResult<DbTransaction> result,
            CancellationToken cancellationToken = default)
        {
            ThrowOnce();
            return base.TransactionStartingAsync(connection, eventData, result, cancellationToken);
        }

        private void ThrowOnce()
        {
            if (Interlocked.Exchange(ref _remaining, 0) == 1)
                throw new InvalidOperationException("Forced transaction initialization failure");
        }
    }
}