using NeonSprawl.Server.Game.Contracts;
using NeonSprawl.Server.Game.PositionState;
using NeonSprawl.Server.Tests.Game.PositionState;

namespace NeonSprawl.Server.Tests.Game.Contracts;

[Collection("Postgres integration")]
public sealed class ContractInstancePersistenceIntegrationTests(PostgresIntegrationHarness harness)
{
    private PostgresWebApplicationFactory Factory => harness.Factory;

    private const string PlayerId = "dev-local-1";
    private const string InstanceId = "prototype_contract_instance_pg_001";
    private const string TemplateId = "prototype_contract_clear_combat_pocket";
    private const string SeedBucket = "2026-06-22";
    private static readonly DateTimeOffset IssuedAt = new(2026, 6, 22, 10, 0, 0, TimeSpan.Zero);
    private static readonly DateTimeOffset CompletedAt = new(2026, 6, 22, 14, 0, 0, TimeSpan.Zero);

    [RequirePostgresFact]
    public async Task TryCreateActive_ShouldReturnOneTrueAndRestFalse_WhenCalledConcurrently()
    {
        // Arrange
        await ResetContractInstanceTableAsync();
        const int concurrentCalls = 8;

        // Act
        var results = await Task.WhenAll(
            Enumerable.Range(0, concurrentCalls).Select(_ => Task.Run(() =>
            {
                using var scope = Factory.Services.CreateScope();
                var store = scope.ServiceProvider.GetRequiredService<IContractInstanceStore>();
                return store.TryCreateActive(
                    PlayerId,
                    InstanceId,
                    TemplateId,
                    SeedBucket,
                    IssuedAt,
                    out ContractInstanceState _);
            })));

        // Assert
        Assert.Equal(1, results.Count(static r => r));
        Assert.Equal(concurrentCalls - 1, results.Count(static r => !r));
        Assert.True(
            Factory.Services.CreateScope().ServiceProvider
                .GetRequiredService<IContractInstanceStore>()
                .TryGet(PlayerId, InstanceId, out var snapshot));
        Assert.Equal(ContractInstanceStatus.Active, snapshot.Status);
        Assert.Equal(TemplateId, snapshot.TemplateId);
    }

    [RequirePostgresFact]
    public async Task TryCreateActive_ShouldAllowOnlyOneActive_WhenDistinctInstanceIdsRace()
    {
        // Arrange
        await ResetContractInstanceTableAsync();
        const int concurrentCalls = 8;

        // Act
        var results = await Task.WhenAll(
            Enumerable.Range(0, concurrentCalls).Select(i => Task.Run(() =>
            {
                using var scope = Factory.Services.CreateScope();
                var store = scope.ServiceProvider.GetRequiredService<IContractInstanceStore>();
                var instanceId = $"prototype_contract_instance_pg_race_{i:D3}";
                return (
                    Success: store.TryCreateActive(
                        PlayerId,
                        instanceId,
                        TemplateId,
                        SeedBucket,
                        IssuedAt,
                        out _),
                    InstanceId: instanceId);
            })));

        // Assert
        Assert.Equal(1, results.Count(static r => r.Success));
        Assert.Equal(concurrentCalls - 1, results.Count(static r => !r.Success));
        Assert.True(
            Factory.Services.CreateScope().ServiceProvider
                .GetRequiredService<IContractInstanceStore>()
                .TryGetActiveForPlayer(PlayerId, out var active));
        Assert.Equal(ContractInstanceStatus.Active, active.Status);
        Assert.Contains(results.Where(static r => r.Success).Select(static r => r.InstanceId), id => id == active.ContractInstanceId);
    }

    [RequirePostgresFact]
    public async Task TryMarkComplete_ShouldBeIdempotent_OnPostgres()
    {
        // Arrange
        await ResetContractInstanceTableAsync();
        using var scope = Factory.Services.CreateScope();
        var store = scope.ServiceProvider.GetRequiredService<IContractInstanceStore>();
        Assert.True(store.TryCreateActive(
            PlayerId,
            InstanceId,
            TemplateId,
            SeedBucket,
            IssuedAt,
            out _));
        // Act
        var first = store.TryMarkComplete(PlayerId, InstanceId, CompletedAt, out var firstSnapshot);
        var second = store.TryMarkComplete(
            PlayerId,
            InstanceId,
            CompletedAt.AddHours(1),
            out var secondSnapshot);
        // Assert
        Assert.True(first);
        Assert.False(second);
        Assert.Equal(CompletedAt, secondSnapshot.CompletedAt);
        Assert.Equal(firstSnapshot.ContractInstanceId, secondSnapshot.ContractInstanceId);
    }

    [RequirePostgresFact]
    public async Task CreateComplete_ShouldPersistAcrossNewFactory()
    {
        // Arrange
        await ResetContractInstanceTableAsync();

        // Act — write through first host
        using (var firstScope = Factory.Services.CreateScope())
        {
            var store = firstScope.ServiceProvider.GetRequiredService<IContractInstanceStore>();
            Assert.True(store.TryCreateActive(
                PlayerId,
                InstanceId,
                TemplateId,
                SeedBucket,
                IssuedAt,
                out _));
            Assert.True(store.TryMarkComplete(PlayerId, InstanceId, CompletedAt, out _));
        }

        ContractInstanceState readBack;
        await using var secondFactory = new PostgresWebApplicationFactory();
        using var secondScope = secondFactory.Services.CreateScope();
        var readStore = secondScope.ServiceProvider.GetRequiredService<IContractInstanceStore>();
        readBack = readStore.TryGet(PlayerId, InstanceId, out var snapshot)
            ? snapshot
            : null!;

        // Assert
        Assert.NotNull(readBack);
        Assert.Equal(ContractInstanceStatus.Completed, readBack.Status);
        Assert.Equal(SeedBucket, readBack.SeedBucket);
        Assert.Equal(CompletedAt, readBack.CompletedAt);
    }

    private async Task ResetContractInstanceTableAsync()
    {
        var cs = Environment.GetEnvironmentVariable("ConnectionStrings__NeonSprawl");
        if (string.IsNullOrWhiteSpace(cs))
        {
            throw new InvalidOperationException("ConnectionStrings__NeonSprawl is not set.");
        }

        _ = Factory.Services;
        var options = Factory.Services.GetRequiredService<IOptions<GamePositionOptions>>().Value;

        var positionDdlPath = Path.Combine(AppContext.BaseDirectory, "db", "migrations", "V001__player_position.sql");
        var instanceDdlPath = Path.Combine(AppContext.BaseDirectory, "db", "migrations", "V011__contract_instance.sql");
        if (!File.Exists(positionDdlPath) || !File.Exists(instanceDdlPath))
        {
            throw new FileNotFoundException("Test DDL for contract instance persistence not found.");
        }

        var positionDdl = await File.ReadAllTextAsync(positionDdlPath);
        var instanceDdl = await File.ReadAllTextAsync(instanceDdlPath);
        await using var conn = new NpgsqlConnection(cs);
        await conn.OpenAsync();
        await using var applyPosition = new NpgsqlCommand(positionDdl, conn);
        await applyPosition.ExecuteNonQueryAsync();

        await using var truncate = new NpgsqlCommand("TRUNCATE player_position CASCADE;", conn);
        await truncate.ExecuteNonQueryAsync();

        PostgresPositionBootstrap.SeedDevPlayer(conn, options);

        await using var applyInstance = new NpgsqlCommand(instanceDdl, conn);
        await applyInstance.ExecuteNonQueryAsync();
    }
}