books/backend/Books.Api.Tests/Integration/ReadModelRepopulationTests.cs

using Books.Api.EventFlow.Infrastructure;
using Books.Api.EventFlow.ReadModels;
using Books.Api.EventFlow.Repositories;
using Books.Api.Tests.Helpers;
using Books.Api.Tests.Infrastructure;
using Dapper;
using AwesomeAssertions;
using Microsoft.Extensions.DependencyInjection;
using Npgsql;

namespace Books.Api.Tests.Integration;

/// <summary>
/// Integration tests for the read model auto-repair/repopulation system.
/// Tests verify that corrupt or out-of-sync read models can be repaired
/// by replaying events from the event store.
/// </summary>
[Trait("Category", "Integration")]
public class ReadModelRepopulationTests(TestWebApplicationFactory factory)
    : IntegrationTestBase(factory)
{
    [Fact]
    public async Task RepopulateReadModel_FixesCorruptedStatus()
    {
        // Arrange: Create a draft through normal flow
        var graphqlClient = new GraphQLTestClient(Client);
        var companyId = await CreateCompanyAsync(graphqlClient, "Repopulation Test Company");
        var draftId = await CreateDraftAsync(graphqlClient, companyId, "Test Draft for Repopulation");

        // Wait for read model to be created
        var originalDraft = await Eventually.GetAsync(async () =>
        {
            var repo = GetService<IJournalEntryDraftRepository>();
            return await repo.GetByIdAsync(draftId);
        });

        originalDraft.Should().NotBeNull();
        originalDraft!.Status.Should().Be("active");

        // Corrupt the read model: Set status to something wrong
        await CorruptReadModelStatusAsync(draftId, "posted");

        // Verify corruption
        var corruptedDraft = await GetService<IJournalEntryDraftRepository>().GetByIdAsync(draftId);
        corruptedDraft!.Status.Should().Be("posted"); // Corrupted!

        // Act: Repopulate the read model
        var response = await graphqlClient.MutateAsync<RepopulateResponse>("""
            mutation Repopulate($aggregateId: String!, $readModelType: String!) {
                repopulateReadModel(aggregateId: $aggregateId, readModelType: $readModelType)
            }
            """,
            new
            {
                aggregateId = draftId,
                readModelType = "JournalEntryDraftReadModel"
            });

        // Assert: Repopulation succeeded
        response.EnsureNoErrors();
        response.Data!.RepopulateReadModel.Should().BeTrue();

        // Verify read model is now fixed
        var fixedDraft = await GetService<IJournalEntryDraftRepository>().GetByIdAsync(draftId);
        fixedDraft!.Status.Should().Be("active"); // Fixed!
    }

    [Fact]
    public async Task RepopulateReadModel_FixesMissingName()
    {
        // Arrange
        var graphqlClient = new GraphQLTestClient(Client);
        var companyId = await CreateCompanyAsync(graphqlClient, "Missing Name Test Company");
        var draftId = await CreateDraftAsync(graphqlClient, companyId, "Original Draft Name");

        await Eventually.GetAsync(async () =>
        {
            var repo = GetService<IJournalEntryDraftRepository>();
            return await repo.GetByIdAsync(draftId);
        });

        // Corrupt: Clear the name
        await CorruptReadModelNameAsync(draftId, "");

        var corruptedDraft = await GetService<IJournalEntryDraftRepository>().GetByIdAsync(draftId);
        corruptedDraft!.Name.Should().BeEmpty();

        // Act
        var response = await graphqlClient.MutateAsync<RepopulateResponse>("""
            mutation Repopulate($aggregateId: String!, $readModelType: String!) {
                repopulateReadModel(aggregateId: $aggregateId, readModelType: $readModelType)
            }
            """,
            new
            {
                aggregateId = draftId,
                readModelType = "JournalEntryDraftReadModel"
            });

        // Assert
        response.EnsureNoErrors();
        var fixedDraft = await GetService<IJournalEntryDraftRepository>().GetByIdAsync(draftId);
        fixedDraft!.Name.Should().Be("Original Draft Name");
    }

    [Fact]
    public async Task RepopulateReadModel_RestoresUpdatedData()
    {
        // Arrange: Create and update a draft
        var graphqlClient = new GraphQLTestClient(Client);
        var companyId = await CreateCompanyAsync(graphqlClient, "Updated Data Test Company");
        var draftId = await CreateDraftAsync(graphqlClient, companyId, "Initial Name");

        await Eventually.GetAsync(async () =>
        {
            var repo = GetService<IJournalEntryDraftRepository>();
            return await repo.GetByIdAsync(draftId);
        });

        // Update the draft with new data
        await graphqlClient.MutateAsync<UpdateDraftResponse>("""
            mutation UpdateDraft($input: UpdateJournalEntryDraftInput!) {
                updateJournalEntryDraft(input: $input) { id name description }
            }
            """,
            new
            {
                input = new
                {
                    id = draftId,
                    name = "Updated Name",
                    description = "Test Description",
                    documentDate = "2025-01-15",
                    lines = Array.Empty<object>()
                }
            });

        // Wait for update
        await Eventually.GetAsync(async () =>
        {
            var repo = GetService<IJournalEntryDraftRepository>();
            var draft = await repo.GetByIdAsync(draftId);
            return draft?.Name == "Updated Name" ? draft : null;
        });

        // Corrupt: Revert to old data
        await CorruptReadModelNameAsync(draftId, "Wrong Name");
        await CorruptReadModelDescriptionAsync(draftId, "Wrong Description");

        var corruptedDraft = await GetService<IJournalEntryDraftRepository>().GetByIdAsync(draftId);
        corruptedDraft!.Name.Should().Be("Wrong Name");

        // Act
        var response = await graphqlClient.MutateAsync<RepopulateResponse>("""
            mutation Repopulate($aggregateId: String!, $readModelType: String!) {
                repopulateReadModel(aggregateId: $aggregateId, readModelType: $readModelType)
            }
            """,
            new
            {
                aggregateId = draftId,
                readModelType = "JournalEntryDraftReadModel"
            });

        // Assert
        response.EnsureNoErrors();
        var fixedDraft = await GetService<IJournalEntryDraftRepository>().GetByIdAsync(draftId);
        fixedDraft!.Name.Should().Be("Updated Name");
        fixedDraft.Description.Should().Be("Test Description");
    }

    [Fact]
    public async Task RepopulateReadModel_FixesOutOfSyncSequenceNumber()
    {
        // Arrange
        var graphqlClient = new GraphQLTestClient(Client);
        var companyId = await CreateCompanyAsync(graphqlClient, "Sequence Number Test Company");
        var draftId = await CreateDraftAsync(graphqlClient, companyId, "Sequence Test Draft");

        await Eventually.GetAsync(async () =>
        {
            var repo = GetService<IJournalEntryDraftRepository>();
            return await repo.GetByIdAsync(draftId);
        });

        // Update draft multiple times to increase sequence number
        for (int i = 0; i < 3; i++)
        {
            await graphqlClient.MutateAsync<UpdateDraftResponse>("""
                mutation UpdateDraft($input: UpdateJournalEntryDraftInput!) {
                    updateJournalEntryDraft(input: $input) { id }
                }
                """,
                new
                {
                    input = new
                    {
                        id = draftId,
                        name = $"Update {i + 1}",
                        lines = Array.Empty<object>()
                    }
                });
            await Task.Delay(100);
        }

        await Eventually.GetAsync(async () =>
        {
            var repo = GetService<IJournalEntryDraftRepository>();
            var draft = await repo.GetByIdAsync(draftId);
            return draft?.Name == "Update 3" ? draft : null;
        });

        // Corrupt: Set sequence number to 1 (old)
        await CorruptReadModelSequenceNumberAsync(draftId, 1);
        await CorruptReadModelNameAsync(draftId, "Old Name");

        // Act
        var response = await graphqlClient.MutateAsync<RepopulateResponse>("""
            mutation Repopulate($aggregateId: String!, $readModelType: String!) {
                repopulateReadModel(aggregateId: $aggregateId, readModelType: $readModelType)
            }
            """,
            new
            {
                aggregateId = draftId,
                readModelType = "JournalEntryDraftReadModel"
            });

        // Assert
        response.EnsureNoErrors();
        var fixedDraft = await GetService<IJournalEntryDraftRepository>().GetByIdAsync(draftId);
        fixedDraft!.Name.Should().Be("Update 3"); // Latest name from events
    }

    [Fact]
    public async Task RepopulateReadModel_FailsForNonExistentAggregate()
    {
        // Arrange
        var graphqlClient = new GraphQLTestClient(Client);
        var companyId = await CreateCompanyAsync(graphqlClient, "Non-existent Aggregate Company");
        var nonExistentId = $"journalentrydraft-{Guid.NewGuid():D}";

        // Act
        var response = await graphqlClient.MutateAsync<RepopulateResponse>("""
            mutation Repopulate($aggregateId: String!, $readModelType: String!) {
                repopulateReadModel(aggregateId: $aggregateId, readModelType: $readModelType)
            }
            """,
            new
            {
                aggregateId = nonExistentId,
                readModelType = "JournalEntryDraftReadModel"
            });

        // Assert: Should fail or succeed without effect (no events to replay)
        // The behavior depends on implementation - either error or silent success
        // Since there are no events, it should complete but read model won't exist
        if (!response.HasErrors)
        {
            var draft = await GetService<IJournalEntryDraftRepository>().GetByIdAsync(nonExistentId);
            draft.Should().BeNull();
        }
    }

    [Fact]
    public async Task RepopulateReadModel_FailsForInvalidReadModelType()
    {
        // Arrange
        var graphqlClient = new GraphQLTestClient(Client);
        var companyId = await CreateCompanyAsync(graphqlClient, "Invalid Type Company");
        var draftId = await CreateDraftAsync(graphqlClient, companyId, "Invalid Type Test");

        await Eventually.GetAsync(async () =>
        {
            var repo = GetService<IJournalEntryDraftRepository>();
            return await repo.GetByIdAsync(draftId);
        });

        // Act
        var response = await graphqlClient.MutateAsync<RepopulateNullableResponse>("""
            mutation Repopulate($aggregateId: String!, $readModelType: String!) {
                repopulateReadModel(aggregateId: $aggregateId, readModelType: $readModelType)
            }
            """,
            new
            {
                aggregateId = draftId,
                readModelType = "NonExistentReadModel"
            });

        // Assert
        response.HasErrors.Should().BeTrue();
        var errorDetails = response.Errors!
            .SelectMany(e => new[] { e.Message, e.Extensions?.GetValueOrDefault("details")?.ToString() ?? "" });
        var errorInfo = string.Join(" ", errorDetails);
        errorInfo.Should().Contain("Unknown read model type");
    }

    [Fact]
    public async Task ListReadModelTypes_ReturnsAvailableTypes()
    {
        // Arrange
        var graphqlClient = new GraphQLTestClient(Client);
        var companyId = await CreateCompanyAsync(graphqlClient, "List Types Company");

        // Act - listReadModelTypes is a mutation field (admin endpoint)
        var response = await graphqlClient.MutateAsync<ListTypesResponse>("""
            mutation {
                listReadModelTypes
            }
            """);

        // Assert
        response.EnsureNoErrors();
        response.Data!.ListReadModelTypes.Should().Contain("JournalEntryDraftReadModel");
        response.Data.ListReadModelTypes.Should().Contain("AccountReadModel");
        response.Data.ListReadModelTypes.Should().Contain("FiscalYearReadModel");
        response.Data.ListReadModelTypes.Should().Contain("CompanyReadModel");
    }

    #region Database Corruption Helpers

    private async Task CorruptReadModelStatusAsync(string aggregateId, string newStatus)
    {
        var dataSource = GetService<NpgsqlDataSource>();
        await using var conn = await dataSource.OpenConnectionAsync();
        await conn.ExecuteAsync(
            "UPDATE journal_entry_draft_read_models SET status = @status WHERE aggregate_id = @id",
            new { status = newStatus, id = aggregateId });
    }

    private async Task CorruptReadModelNameAsync(string aggregateId, string newName)
    {
        var dataSource = GetService<NpgsqlDataSource>();
        await using var conn = await dataSource.OpenConnectionAsync();
        await conn.ExecuteAsync(
            "UPDATE journal_entry_draft_read_models SET name = @name WHERE aggregate_id = @id",
            new { name = newName, id = aggregateId });
    }

    private async Task CorruptReadModelDescriptionAsync(string aggregateId, string newDescription)
    {
        var dataSource = GetService<NpgsqlDataSource>();
        await using var conn = await dataSource.OpenConnectionAsync();
        await conn.ExecuteAsync(
            "UPDATE journal_entry_draft_read_models SET description = @description WHERE aggregate_id = @id",
            new { description = newDescription, id = aggregateId });
    }

    private async Task CorruptReadModelSequenceNumberAsync(string aggregateId, int newSequenceNumber)
    {
        var dataSource = GetService<NpgsqlDataSource>();
        await using var conn = await dataSource.OpenConnectionAsync();
        await conn.ExecuteAsync(
            "UPDATE journal_entry_draft_read_models SET last_aggregate_sequence_number = @seq WHERE aggregate_id = @id",
            new { seq = newSequenceNumber, id = aggregateId });
    }

    #endregion

    #region Helper Methods

    private async Task<string> CreateCompanyAsync(GraphQLTestClient client, string name)
    {
        var response = await client.MutateAsync<CreateCompanyResponse>("""
            mutation CreateCompany($input: CreateCompanyInput!) {
                createCompany(input: $input) { id }
            }
            """,
            new { input = new { name } });

        response.EnsureNoErrors();
        var companyId = response.Data!.CreateCompany!.Id;
        client.SetCompanyId(companyId);
        return companyId;
    }

    private async Task<string> CreateDraftAsync(GraphQLTestClient client, string companyId, string name)
    {
        var response = await client.MutateAsync<CreateDraftResponse>("""
            mutation CreateDraft($input: CreateJournalEntryDraftInput!) {
                createJournalEntryDraft(input: $input) { id }
            }
            """,
            new
            {
                input = new
                {
                    companyId,
                    name
                }
            });

        response.EnsureNoErrors();
        return response.Data!.CreateJournalEntryDraft!.Id;
    }

    #endregion

    #region Response DTOs

    private class RepopulateResponse { public bool RepopulateReadModel { get; set; } }
    private class RepopulateNullableResponse { public bool? RepopulateReadModel { get; set; } }
    private class ListTypesResponse { public List<string> ListReadModelTypes { get; set; } = []; }
    private class CreateCompanyResponse { public CompanyDto? CreateCompany { get; set; } }
    private class CreateDraftResponse { public DraftDto? CreateJournalEntryDraft { get; set; } }
    private class UpdateDraftResponse { public DraftDto? UpdateJournalEntryDraft { get; set; } }

    private class CompanyDto { public string Id { get; set; } = string.Empty; }
    private class DraftDto
    {
        public string Id { get; set; } = string.Empty;
        public string Name { get; set; } = string.Empty;
        public string? Description { get; set; }
        public string Status { get; set; } = string.Empty;
    }

    #endregion
}