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

namespace NeonSprawl.Server.Tests.Game.Contracts;

public sealed class InMemoryContractOutcomeStoreTests
{
    private const string PlayerId = "dev-local-1";
    private const string InstanceId = "prototype_contract_instance_001";
    private const string OutcomeRowId = "outcome-row-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 RecordedAt = new(2026, 6, 22, 12, 0, 0, TimeSpan.Zero);

    [Fact]
    public void TryAppend_ShouldPersistAndQueryByInstanceAndIdempotencyKey()
    {
        // Arrange
        var (instanceStore, store) = CreateStores();
        SeedActiveInstance(instanceStore);
        var row = CreatePrototypeOutcome();
        // Act
        var appended = store.TryAppend(row);
        var foundByKey = store.TryGetByIdempotencyKey(row.IdempotencyKey, out var byKey);
        var listed = store.GetOutcomesForInstance(InstanceId);
        // Assert
        Assert.True(appended);
        Assert.True(foundByKey);
        Assert.Equal(row.Id, byKey.Id);
        Assert.Single(listed);
        Assert.Equal("scrap_metal_bulk", listed[0].GrantedItems[0].ItemId);
        Assert.Equal(5, listed[0].GrantedItems[0].Quantity);
        Assert.Equal("salvage", listed[0].GrantedSkillXp[0].SkillId);
        Assert.Equal(15, listed[0].GrantedSkillXp[0].Amount);
    }

    [Fact]
    public void TryAppend_ShouldDenyDuplicateRowId()
    {
        // Arrange
        var (instanceStore, store) = CreateStores();
        SeedActiveInstance(instanceStore);
        var row = CreatePrototypeOutcome();
        Assert.True(store.TryAppend(row));
        // Act
        var duplicateId = store.TryAppend(row with { IdempotencyKey = "other-key" });
        // Assert
        Assert.False(duplicateId);
    }

    [Fact]
    public void TryAppend_ShouldDenyDuplicateIdempotencyKey()
    {
        // Arrange
        var (instanceStore, store) = CreateStores();
        SeedActiveInstance(instanceStore);
        var row = CreatePrototypeOutcome();
        Assert.True(store.TryAppend(row));
        // Act
        var duplicateKey = store.TryAppend(row with { Id = "outcome-row-002" });
        // Assert
        Assert.False(duplicateKey);
    }

    [Fact]
    public void TryAppend_ShouldFailClosed_WhenRequiredFieldsEmpty()
    {
        // Arrange
        var (instanceStore, store) = CreateStores();
        SeedActiveInstance(instanceStore);
        var invalidRow = CreatePrototypeOutcome() with { PlayerId = "   " };
        // Act
        var appended = store.TryAppend(invalidRow);
        // Assert
        Assert.False(appended);
        Assert.Empty(store.GetOutcomesForInstance(InstanceId));
    }

    [Fact]
    public void TryAppend_ShouldReturnFalse_WhenContractInstanceMissing()
    {
        // Arrange
        var (_, store) = CreateStores();
        var row = CreatePrototypeOutcome();
        // Act
        var appended = store.TryAppend(row);
        // Assert
        Assert.False(appended);
        Assert.Empty(store.GetOutcomesForInstance(InstanceId));
    }

    [Fact]
    public void TryAppend_ShouldReturnFalse_WhenPlayerIdDoesNotMatchInstanceOwner()
    {
        // Arrange
        var (instanceStore, store) = CreateStores();
        SeedActiveInstance(instanceStore);
        var row = CreatePrototypeOutcome() with { PlayerId = "other-player-xyz" };
        // Act
        var appended = store.TryAppend(row);
        // Assert
        Assert.False(appended);
        Assert.Empty(store.GetOutcomesForInstance(InstanceId));
    }

    [Fact]
    public async Task TryAppend_ShouldAllowOnlyOneSuccess_WhenConcurrentDuplicateIdempotencyKeysRace()
    {
        // Arrange
        var (instanceStore, store) = CreateStores();
        SeedActiveInstance(instanceStore);
        var idempotencyKey = ContractOutcomeIds.MakeIdempotencyKey(PlayerId, InstanceId);
        var baseRow = CreatePrototypeOutcome();
        // Act
        var results = await Task.WhenAll(
            Enumerable.Range(0, 8).Select(i => Task.Run(() =>
            {
                var row = baseRow with { Id = $"outcome-row-race-{i:D3}" };
                Assert.Equal(idempotencyKey, row.IdempotencyKey);
                return store.TryAppend(row);
            })));

        // Assert
        Assert.Equal(1, results.Count(static r => r));
        Assert.Equal(7, results.Count(static r => !r));
        Assert.Single(store.GetOutcomesForInstance(InstanceId));
    }

    private static (InMemoryContractInstanceStore InstanceStore, InMemoryContractOutcomeStore OutcomeStore) CreateStores()
    {
        var options = Options.Create(new GamePositionOptions { DevPlayerId = PlayerId });
        var instanceStore = new InMemoryContractInstanceStore(options);
        return (instanceStore, new InMemoryContractOutcomeStore(instanceStore));
    }

    private static void SeedActiveInstance(InMemoryContractInstanceStore instanceStore)
    {
        Assert.True(instanceStore.TryCreateActive(
            PlayerId,
            InstanceId,
            TemplateId,
            SeedBucket,
            IssuedAt,
            out _));
    }

    private static ContractOutcomeRow CreatePrototypeOutcome()
    {
        var idempotencyKey = ContractOutcomeIds.MakeIdempotencyKey(PlayerId, InstanceId);
        return new ContractOutcomeRow(
            OutcomeRowId,
            InstanceId,
            PlayerId,
            idempotencyKey,
            [new RewardItemGrantApplied("scrap_metal_bulk", 5)],
            [new RewardSkillXpGrantApplied("salvage", 15)],
            [],
            RecordedAt);
    }
}