work-club-manager/backend/WorkClub.Infrastructure/Data/Interceptors/TenantDbConnectionInterceptor.cs

using System.Data.Common;
using Finbuckle.MultiTenant;
using Finbuckle.MultiTenant.Abstractions;
using Microsoft.EntityFrameworkCore.Diagnostics;
using Microsoft.Extensions.Logging;
using Npgsql;

namespace WorkClub.Infrastructure.Data.Interceptors;

public class TenantDbConnectionInterceptor : DbConnectionInterceptor
{
    private readonly IMultiTenantContextAccessor _tenantAccessor;
    private readonly ILogger<TenantDbConnectionInterceptor> _logger;

    public TenantDbConnectionInterceptor(
        IMultiTenantContextAccessor tenantAccessor,
        ILogger<TenantDbConnectionInterceptor> logger)
    {
        _tenantAccessor = tenantAccessor;
        _logger = logger;
    }

    public override async ValueTask<InterceptionResult> ConnectionOpeningAsync(
        DbConnection connection,
        ConnectionEventData eventData,
        InterceptionResult result,
        CancellationToken cancellationToken = default)
    {
        await base.ConnectionOpeningAsync(connection, eventData, result, cancellationToken);

        var tenantId = _tenantAccessor.MultiTenantContext?.TenantInfo?.Identifier;
        
        if (string.IsNullOrWhiteSpace(tenantId))
        {
            _logger.LogWarning("No tenant context available for database connection");
            return result;
        }

        if (connection is NpgsqlConnection npgsqlConnection)
        {
            await using var command = npgsqlConnection.CreateCommand();
            command.CommandText = $"SET LOCAL app.current_tenant_id = '{tenantId}'";
            
            try
            {
                await command.ExecuteNonQueryAsync(cancellationToken);
                _logger.LogDebug("Set tenant context for database connection: {TenantId}", tenantId);
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "Failed to set tenant context for connection");
                throw;
            }
        }

        return result;
    }

    public override void ConnectionOpened(DbConnection connection, ConnectionEndEventData eventData)
    {
        base.ConnectionOpened(connection, eventData);

        var tenantId = _tenantAccessor.MultiTenantContext?.TenantInfo?.Identifier;
        
        if (string.IsNullOrWhiteSpace(tenantId))
        {
            _logger.LogWarning("No tenant context available for database connection");
            return;
        }

        if (connection is NpgsqlConnection npgsqlConnection)
        {
            using var command = npgsqlConnection.CreateCommand();
            command.CommandText = $"SET LOCAL app.current_tenant_id = '{tenantId}'";
            
            try
            {
                command.ExecuteNonQuery();
                _logger.LogDebug("Set tenant context for database connection: {TenantId}", tenantId);
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "Failed to set tenant context for connection");
                throw;
            }
        }
    }
}