using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.DependencyInjection;
using ScadaLink.Commons.Entities.Security;
using ScadaLink.Commons.Interfaces.Repositories;
using ScadaLink.Commons.Interfaces.Services;
using ScadaLink.ConfigurationDatabase;

namespace ScadaLink.IntegrationTests;

/// <summary>
/// WP-22: Audit transactional guarantee — entity change + audit log in same transaction.
/// </summary>
public class AuditTransactionTests : IClassFixture<ScadaLinkWebApplicationFactory>
{
    private readonly ScadaLinkWebApplicationFactory _factory;

    public AuditTransactionTests(ScadaLinkWebApplicationFactory factory)
    {
        _factory = factory;
    }

    [Fact]
    public async Task AuditLog_IsCommittedWithEntityChange_InSameTransaction()
    {
        using var scope = _factory.Services.CreateScope();
        var securityRepo = scope.ServiceProvider.GetRequiredService<ISecurityRepository>();
        var auditService = scope.ServiceProvider.GetRequiredService<IAuditService>();
        var dbContext = scope.ServiceProvider.GetRequiredService<ScadaLinkDbContext>();

        // Add a mapping and an audit log entry in the same unit of work
        var mapping = new LdapGroupMapping("test-group-audit", "Admin");
        await securityRepo.AddMappingAsync(mapping);

        await auditService.LogAsync(
            user: "test-user",
            action: "Create",
            entityType: "LdapGroupMapping",
            entityId: "0", // ID not yet assigned
            entityName: "test-group-audit",
            afterState: new { Group = "test-group-audit", Role = "Admin" });

        // Both should be in the change tracker before saving
        var trackedEntities = dbContext.ChangeTracker.Entries().Count(e => e.State == EntityState.Added);
        Assert.True(trackedEntities >= 2, "Both entity and audit log should be tracked before SaveChanges");

        // Single SaveChangesAsync commits both
        await securityRepo.SaveChangesAsync();

        // Verify both were persisted
        var mappings = await securityRepo.GetAllMappingsAsync();
        Assert.Contains(mappings, m => m.LdapGroupName == "test-group-audit");

        var auditEntries = await dbContext.AuditLogEntries.ToListAsync();
        Assert.Contains(auditEntries, a => a.EntityName == "test-group-audit" && a.Action == "Create");
    }

    [Fact]
    public async Task AuditLog_IsNotPersistedWhenSaveNotCalled()
    {
        // Create a separate scope so we have a fresh DbContext
        using var scope1 = _factory.Services.CreateScope();
        var securityRepo = scope1.ServiceProvider.GetRequiredService<ISecurityRepository>();
        var auditService = scope1.ServiceProvider.GetRequiredService<IAuditService>();

        // Add entity + audit but do NOT call SaveChangesAsync
        var mapping = new LdapGroupMapping("orphan-group", "Design");
        await securityRepo.AddMappingAsync(mapping);
        await auditService.LogAsync("test", "Create", "LdapGroupMapping", "0", "orphan-group", null);

        // Dispose scope without saving — simulates a failed transaction
        scope1.Dispose();

        // In a new scope, verify nothing was persisted
        using var scope2 = _factory.Services.CreateScope();
        var securityRepo2 = scope2.ServiceProvider.GetRequiredService<ISecurityRepository>();
        var dbContext2 = scope2.ServiceProvider.GetRequiredService<ScadaLinkDbContext>();

        var mappings = await securityRepo2.GetAllMappingsAsync();
        Assert.DoesNotContain(mappings, m => m.LdapGroupName == "orphan-group");

        var auditEntries = await dbContext2.AuditLogEntries.ToListAsync();
        Assert.DoesNotContain(auditEntries, a => a.EntityName == "orphan-group");
    }
}