using FluentAssertions;
using Microsoft.Extensions.Logging.Abstractions;
using Microsoft.Extensions.Options;
using StellaOps.Policy.Persistence.Postgres;
using StellaOps.Policy.Persistence.Postgres.Models;
using StellaOps.Policy.Persistence.Postgres.Repositories;
using Xunit;

using StellaOps.TestKit;
namespace StellaOps.Policy.Persistence.Tests;

/// <summary>
/// Tests for pack versioning workflow scenarios (PG-T4.8.2).
/// Validates the complete lifecycle of pack versioning including:
/// - Creating pack versions
/// - Activating/deactivating versions
/// - Rolling back to previous versions
/// - Version history preservation
/// </summary>
[Collection(PolicyPostgresCollection.Name)]
public sealed class PackVersioningWorkflowTests : IAsyncLifetime
{
    private readonly PolicyPostgresFixture _fixture;
    private readonly PackRepository _packRepository;
    private readonly RuleRepository _ruleRepository;
    private readonly string _tenantId = Guid.NewGuid().ToString();

    public PackVersioningWorkflowTests(PolicyPostgresFixture fixture)
    {
        _fixture = fixture;

        var options = fixture.Fixture.CreateOptions();
        options.SchemaName = fixture.SchemaName;
        var dataSource = new PolicyDataSource(Options.Create(options), NullLogger<PolicyDataSource>.Instance);
        _packRepository = new PackRepository(dataSource, NullLogger<PackRepository>.Instance);
        _ruleRepository = new RuleRepository(dataSource, NullLogger<RuleRepository>.Instance);
    }

    public Task InitializeAsync() => _fixture.TruncateAllTablesAsync();
    public Task DisposeAsync() => Task.CompletedTask;

    [Trait("Category", TestCategories.Unit)]
        [Fact]
    public async Task VersionWorkflow_CreateUpdateActivate_MaintainsVersionIntegrity()
    {
        // Arrange - Create initial pack
        var pack = new PackEntity
        {
            Id = Guid.NewGuid(),
            TenantId = _tenantId,
            Name = "versioned-pack",
            DisplayName = "Versioned Policy Pack",
            Description = "Pack for version testing",
            ActiveVersion = 1,
            IsBuiltin = false
        };
        await _packRepository.CreateAsync(pack);

        // Act - Update to version 2
        await _packRepository.SetActiveVersionAsync(_tenantId, pack.Id, 2);
        var afterV2 = await _packRepository.GetByIdAsync(_tenantId, pack.Id);

        // Assert
        afterV2.Should().NotBeNull();
        afterV2!.ActiveVersion.Should().Be(2);

        // Act - Update to version 3
        await _packRepository.SetActiveVersionAsync(_tenantId, pack.Id, 3);
        var afterV3 = await _packRepository.GetByIdAsync(_tenantId, pack.Id);

        // Assert
        afterV3.Should().NotBeNull();
        afterV3!.ActiveVersion.Should().Be(3);
    }

    [Trait("Category", TestCategories.Unit)]
        [Fact]
    public async Task VersionWorkflow_RollbackVersion_RestoresPreviousVersion()
    {
        // Arrange - Create pack at version 3
        var pack = new PackEntity
        {
            Id = Guid.NewGuid(),
            TenantId = _tenantId,
            Name = "rollback-pack",
            ActiveVersion = 3,
            IsBuiltin = false
        };
        await _packRepository.CreateAsync(pack);

        // Act - Rollback to version 2
        await _packRepository.SetActiveVersionAsync(_tenantId, pack.Id, 2);
        var afterRollback = await _packRepository.GetByIdAsync(_tenantId, pack.Id);

        // Assert
        afterRollback.Should().NotBeNull();
        afterRollback!.ActiveVersion.Should().Be(2);
    }

    [Trait("Category", TestCategories.Unit)]
        [Fact]
    public async Task VersionWorkflow_MultiplePacksDifferentVersions_Isolated()
    {
        // Arrange - Create multiple packs with different versions
        var pack1 = new PackEntity
        {
            Id = Guid.NewGuid(),
            TenantId = _tenantId,
            Name = "pack-a",
            ActiveVersion = 1
        };
        var pack2 = new PackEntity
        {
            Id = Guid.NewGuid(),
            TenantId = _tenantId,
            Name = "pack-b",
            ActiveVersion = 5
        };
        await _packRepository.CreateAsync(pack1);
        await _packRepository.CreateAsync(pack2);

        // Act - Update pack1 only
        await _packRepository.SetActiveVersionAsync(_tenantId, pack1.Id, 10);

        // Assert - pack2 should be unaffected
        var fetchedPack1 = await _packRepository.GetByIdAsync(_tenantId, pack1.Id);
        var fetchedPack2 = await _packRepository.GetByIdAsync(_tenantId, pack2.Id);

        fetchedPack1!.ActiveVersion.Should().Be(10);
        fetchedPack2!.ActiveVersion.Should().Be(5);
    }

    [Trait("Category", TestCategories.Unit)]
        [Fact]
    public async Task VersionWorkflow_DeprecatedPackVersionStillReadable()
    {
        // Arrange - Create and deprecate pack
        var pack = new PackEntity
        {
            Id = Guid.NewGuid(),
            TenantId = _tenantId,
            Name = "deprecated-version-pack",
            ActiveVersion = 3,
            IsDeprecated = false
        };
        await _packRepository.CreateAsync(pack);

        // Act - Deprecate the pack
        await _packRepository.DeprecateAsync(_tenantId, pack.Id);
        var deprecated = await _packRepository.GetByIdAsync(_tenantId, pack.Id);

        // Assert - Version should still be readable
        deprecated.Should().NotBeNull();
        deprecated!.IsDeprecated.Should().BeTrue();
        deprecated.ActiveVersion.Should().Be(3);
    }

    [Trait("Category", TestCategories.Unit)]
        [Fact]
    public async Task VersionWorkflow_ConcurrentVersionUpdates_LastWriteWins()
    {
        // Arrange - Create pack
        var pack = new PackEntity
        {
            Id = Guid.NewGuid(),
            TenantId = _tenantId,
            Name = "concurrent-version-pack",
            ActiveVersion = 1
        };
        await _packRepository.CreateAsync(pack);

        // Act - Simulate concurrent updates
        var tasks = new[]
        {
            _packRepository.SetActiveVersionAsync(_tenantId, pack.Id, 2),
            _packRepository.SetActiveVersionAsync(_tenantId, pack.Id, 3),
            _packRepository.SetActiveVersionAsync(_tenantId, pack.Id, 4)
        };
        await Task.WhenAll(tasks);

        // Assert - One of the versions should win
        var final = await _packRepository.GetByIdAsync(_tenantId, pack.Id);
        final.Should().NotBeNull();
        final!.ActiveVersion.Should().BeOneOf(2, 3, 4);
    }

    [Trait("Category", TestCategories.Unit)]
        [Fact]
    public async Task VersionWorkflow_DeterministicOrdering_VersionsReturnConsistently()
    {
        // Arrange - Create multiple packs
        var packs = Enumerable.Range(1, 5).Select(i => new PackEntity
        {
            Id = Guid.NewGuid(),
            TenantId = _tenantId,
            Name = $"ordered-pack-{i}",
            ActiveVersion = i
        }).ToList();

        foreach (var pack in packs)
        {
            await _packRepository.CreateAsync(pack);
        }

        // Act - Fetch multiple times
        var results1 = await _packRepository.GetAllAsync(_tenantId);
        var results2 = await _packRepository.GetAllAsync(_tenantId);
        var results3 = await _packRepository.GetAllAsync(_tenantId);

        // Assert - Order should be deterministic
        var names1 = results1.Select(p => p.Name).ToList();
        var names2 = results2.Select(p => p.Name).ToList();
        var names3 = results3.Select(p => p.Name).ToList();

        names1.Should().Equal(names2);
        names2.Should().Equal(names3);
    }

    [Trait("Category", TestCategories.Unit)]
        [Fact]
    public async Task VersionWorkflow_UpdateTimestampProgresses_OnVersionChange()
    {
        // Arrange
        var pack = new PackEntity
        {
            Id = Guid.NewGuid(),
            TenantId = _tenantId,
            Name = "timestamp-version-pack",
            ActiveVersion = 1
        };
        await _packRepository.CreateAsync(pack);
        var created = await _packRepository.GetByIdAsync(_tenantId, pack.Id);
        var initialUpdatedAt = created!.UpdatedAt;

        // Small delay to ensure timestamp difference
        await Task.Delay(10);

        // Act - Update version
        await _packRepository.SetActiveVersionAsync(_tenantId, pack.Id, 2);
        var updated = await _packRepository.GetByIdAsync(_tenantId, pack.Id);

        // Assert - UpdatedAt should have progressed
        updated!.UpdatedAt.Should().BeOnOrAfter(initialUpdatedAt);
    }

    [Trait("Category", TestCategories.Unit)]
        [Fact]
    public async Task VersionWorkflow_ZeroVersionAllowed_AsInitialState()
    {
        // Arrange - Create pack with version 0 (no active version)
        var pack = new PackEntity
        {
            Id = Guid.NewGuid(),
            TenantId = _tenantId,
            Name = "zero-version-pack",
            ActiveVersion = 0
        };

        // Act
        await _packRepository.CreateAsync(pack);
        var fetched = await _packRepository.GetByIdAsync(_tenantId, pack.Id);

        // Assert
        fetched.Should().NotBeNull();
        fetched!.ActiveVersion.Should().Be(0);
    }

    [Trait("Category", TestCategories.Unit)]
        [Fact]
    public async Task VersionWorkflow_BuiltinPackVersioning_WorksLikeCustomPacks()
    {
        // Arrange - Create builtin pack
        var builtinPack = new PackEntity
        {
            Id = Guid.NewGuid(),
            TenantId = _tenantId,
            Name = "builtin-versioned",
            ActiveVersion = 1,
            IsBuiltin = true
        };
        await _packRepository.CreateAsync(builtinPack);

        // Act - Update version
        await _packRepository.SetActiveVersionAsync(_tenantId, builtinPack.Id, 2);
        var updated = await _packRepository.GetByIdAsync(_tenantId, builtinPack.Id);

        // Assert
        updated.Should().NotBeNull();
        updated!.ActiveVersion.Should().Be(2);
        updated.IsBuiltin.Should().BeTrue();
    }
}