// -----------------------------------------------------------------------------
// ScanResultIdempotencyTests.cs
// Sprint: SPRINT_5100_0009_0001_scanner_tests
// Task: SCANNER-5100-014
// Description: Model S1 idempotency tests for Scanner scan results storage
// -----------------------------------------------------------------------------

using Dapper;
using FluentAssertions;
using Microsoft.Extensions.Logging.Abstractions;
using Microsoft.Extensions.Options;
using StellaOps.Infrastructure.Postgres.Options;
using StellaOps.Scanner.Storage;
using StellaOps.Scanner.Storage.Entities;
using StellaOps.Scanner.Storage.Postgres;
using StellaOps.TestKit;
using Xunit;

namespace StellaOps.Scanner.Storage.Tests;

/// <summary>
/// Idempotency tests for scan result storage operations.
/// Implements Model S1 (Storage/Postgres) test requirements:
/// - Insert same entity twice → no duplicates
/// - Same manifest hash → same record returned
/// - Update operations are idempotent
/// </summary>
[Collection("scanner-postgres")]
[Trait("Category", TestCategories.Integration)]
[Trait("Category", TestCategories.StorageIdempotency)]
public sealed class ScanResultIdempotencyTests : IAsyncLifetime
{
    private readonly ScannerPostgresFixture _fixture;
    private PostgresScanManifestRepository _manifestRepository = null!;
    private ScannerDataSource _dataSource = null!;

    public ScanResultIdempotencyTests(ScannerPostgresFixture fixture)
    {
        _fixture = fixture;
    }

    public async ValueTask InitializeAsync()
    {
        await _fixture.TruncateAllTablesAsync();

        var options = new ScannerStorageOptions
        {
            Postgres = new PostgresOptions
            {
                ConnectionString = _fixture.ConnectionString,
                SchemaName = _fixture.SchemaName
            }
        };

        _dataSource = new ScannerDataSource(Options.Create(options), NullLogger<ScannerDataSource>.Instance);
        _manifestRepository = new PostgresScanManifestRepository(_dataSource);
    }

    public ValueTask DisposeAsync() => ValueTask.CompletedTask;

    [Trait("Category", TestCategories.Unit)]
        [Fact]
    public async Task SaveAsync_SameManifestHash_Twice_CanRetrieveByHash()
    {
        // Arrange
        var manifest1 = CreateManifest("sha256:manifest1");
        var manifest2 = CreateManifest("sha256:manifest1"); // Same hash
        await EnsureScanAsync(manifest1.ScanId);
        await EnsureScanAsync(manifest2.ScanId);

        // Act
        var saved1 = await _manifestRepository.SaveAsync(manifest1);

        // Try to save second with same hash - depending on DB constraint
        // this might fail or create a new record
        try
        {
            var saved2 = await _manifestRepository.SaveAsync(manifest2);

            // If it succeeds, verify we can get by hash
            var retrieved = await _manifestRepository.GetByHashAsync("sha256:manifest1");
            retrieved.Should().NotBeNull();
        }
        catch (Npgsql.PostgresException)
        {
            // Expected if manifest_hash has unique constraint
            // Verify the first one still exists
            var retrieved = await _manifestRepository.GetByHashAsync("sha256:manifest1");
            retrieved.Should().NotBeNull();
            retrieved!.ManifestId.Should().Be(saved1.ManifestId);
        }
    }

    [Trait("Category", TestCategories.Unit)]
        [Fact]
    public async Task GetByHashAsync_SameHash_ReturnsConsistentResult()
    {
        // Arrange
        var manifest = CreateManifest("sha256:consistent");
        await EnsureScanAsync(manifest.ScanId);
        await _manifestRepository.SaveAsync(manifest);

        // Act - Query same hash multiple times
        var results = new List<ScanManifestRow?>();
        for (int i = 0; i < 10; i++)
        {
            results.Add(await _manifestRepository.GetByHashAsync("sha256:consistent"));
        }

        // Assert - All should return same record
        results.Should().AllSatisfy(r =>
        {
            r.Should().NotBeNull();
            r!.ManifestHash.Should().Be("sha256:consistent");
        });

        var distinctIds = results.Where(r => r != null).Select(r => r!.ManifestId).Distinct().ToList();
        distinctIds.Should().HaveCount(1, "same hash should always return same manifest");
    }

    [Trait("Category", TestCategories.Unit)]
        [Fact]
    public async Task GetByScanIdAsync_SameId_ReturnsConsistentResult()
    {
        // Arrange
        var scanId = Guid.NewGuid();
        var manifest = CreateManifest("sha256:byscan", scanId);
        await EnsureScanAsync(scanId);
        await _manifestRepository.SaveAsync(manifest);

        // Act - Query same scan ID multiple times
        var results = new List<ScanManifestRow?>();
        for (int i = 0; i < 10; i++)
        {
            results.Add(await _manifestRepository.GetByScanIdAsync(scanId));
        }

        // Assert - All should return same record
        results.Should().AllSatisfy(r =>
        {
            r.Should().NotBeNull();
            r!.ScanId.Should().Be(scanId);
        });
    }

    [Trait("Category", TestCategories.Unit)]
        [Fact]
    public async Task MarkCompletedAsync_Twice_IsIdempotent()
    {
        // Arrange
        var manifest = CreateManifest("sha256:complete");
        await EnsureScanAsync(manifest.ScanId);
        var saved = await _manifestRepository.SaveAsync(manifest);

        var completedAt1 = DateTimeOffset.UtcNow;
        var completedAt2 = DateTimeOffset.UtcNow.AddMinutes(1);

        // Act - Mark completed twice
        await _manifestRepository.MarkCompletedAsync(saved.ManifestId, completedAt1);
        var after1 = await _manifestRepository.GetByHashAsync("sha256:complete");

        await _manifestRepository.MarkCompletedAsync(saved.ManifestId, completedAt2);
        var after2 = await _manifestRepository.GetByHashAsync("sha256:complete");

        // Assert - Both should succeed, second updates the timestamp
        after1.Should().NotBeNull();
        after1!.ScanCompletedAt.Should().NotBeNull();

        after2.Should().NotBeNull();
        after2!.ScanCompletedAt.Should().NotBeNull();
    }

    [Trait("Category", TestCategories.Unit)]
        [Fact]
    public async Task MarkCompletedAsync_NonExistent_DoesNotThrow()
    {
        // Arrange
        var nonExistentId = Guid.NewGuid();

        // Act
        var action = async () =>
            await _manifestRepository.MarkCompletedAsync(nonExistentId, DateTimeOffset.UtcNow);

        // Assert - Should not throw (0 rows affected is OK)
        await action.Should().NotThrowAsync();
    }

    [Trait("Category", TestCategories.Unit)]
        [Fact]
    public async Task SaveAsync_MultipleDifferentScans_AllPersisted()
    {
        // Arrange
        var manifests = Enumerable.Range(0, 5)
            .Select(i => CreateManifest($"sha256:multi{i}"))
            .ToList();

        // Act
        foreach (var manifest in manifests)
        {
            await EnsureScanAsync(manifest.ScanId);
            await _manifestRepository.SaveAsync(manifest);
        }

        // Assert - All should be retrievable
        for (int i = 0; i < 5; i++)
        {
            var retrieved = await _manifestRepository.GetByHashAsync($"sha256:multi{i}");
            retrieved.Should().NotBeNull();
        }
    }

    [Trait("Category", TestCategories.Unit)]
        [Fact]
    public async Task SaveAsync_MultipleManifstsForSameScan_AllRetrievable()
    {
        // Arrange - Same scan ID, different manifests (e.g., scan retry)
        var scanId = Guid.NewGuid();
        var manifest1 = CreateManifest("sha256:retry1", scanId);
        var manifest2 = CreateManifest("sha256:retry2", scanId);
        await EnsureScanAsync(scanId);

        // Act
        await _manifestRepository.SaveAsync(manifest1);
        await _manifestRepository.SaveAsync(manifest2);

        // Assert - GetByScanId returns most recent
        var retrieved = await _manifestRepository.GetByScanIdAsync(scanId);
        retrieved.Should().NotBeNull();
        // Should return one of them (most recent by created_at)
    }

    private static ScanManifestRow CreateManifest(string hash, Guid? scanId = null) => new()
    {
        ScanId = scanId ?? Guid.NewGuid(),
        ManifestHash = hash,
        SbomHash = "sha256:sbom" + Guid.NewGuid().ToString("N")[..8],
        RulesHash = "sha256:rules" + Guid.NewGuid().ToString("N")[..8],
        FeedHash = "sha256:feed" + Guid.NewGuid().ToString("N")[..8],
        PolicyHash = "sha256:policy" + Guid.NewGuid().ToString("N")[..8],
        ScanStartedAt = DateTimeOffset.UtcNow,
        ManifestContent = """{"version": "1.0", "scanner": "stellaops"}""",
        ScannerVersion = "1.0.0"
    };

    private async Task EnsureScanAsync(Guid scanId)
    {
        var schemaName = _dataSource.SchemaName ?? ScannerDataSource.DefaultSchema;
        var sql = $"""
            INSERT INTO {schemaName}.scans (scan_id)
            VALUES (@ScanId)
            ON CONFLICT DO NOTHING
            """;

        await using var connection = await _dataSource.OpenSystemConnectionAsync();
        await connection.ExecuteAsync(sql, new { ScanId = scanId });
    }
}