PlanTempusApp/Core/Outbox/OutboxService.cs

#nullable enable

using System.Data;
using System.Text.Json;
using Insight.Database;
using PlanTempus.Core.Database;

namespace PlanTempus.Core.Outbox;

public class OutboxService(IDatabaseOperations databaseOperations) : IOutboxService
{
	public async Task EnqueueAsync(string type, object payload, IDbConnection? connection = null, IDbTransaction? transaction = null)
	{
		var sql = @"
			INSERT INTO system.outbox (type, payload)
			VALUES (@Type, @Payload::jsonb)";

		var parameters = new
		{
			Type = type,
			Payload = JsonSerializer.Serialize(payload)
		};

		if (connection != null)
		{
			await connection.ExecuteSqlAsync(sql, parameters);
		}
		else
		{
			using var db = databaseOperations.CreateScope(nameof(OutboxService));
			await db.Connection.ExecuteSqlAsync(sql, parameters);
		}
	}

	public async Task<List<OutboxMessage>> GetPendingAsync(int batchSize = 10)
	{
		using var db = databaseOperations.CreateScope(nameof(OutboxService));

		var sql = @"
			UPDATE system.outbox
			SET status = 'processing'
			WHERE id IN (
				SELECT id FROM system.outbox
				WHERE status = 'pending'
				ORDER BY created_at
				LIMIT @BatchSize
				FOR UPDATE SKIP LOCKED
			)
			RETURNING id, type, payload, status, created_at, processed_at, retry_count, error_message";

		var results = await db.Connection.QuerySqlAsync<OutboxMessageDto>(sql, new { BatchSize = batchSize });

		return results.Select(r => new OutboxMessage
		{
			Id = r.Id,
			Type = r.Type,
			Payload = JsonSerializer.Deserialize<JsonElement>(r.Payload),
			Status = r.Status,
			CreatedAt = r.CreatedAt,
			ProcessedAt = r.ProcessedAt,
			RetryCount = r.RetryCount,
			ErrorMessage = r.ErrorMessage
		}).ToList();
	}

	public async Task MarkAsSentAsync(Guid id)
	{
		using var db = databaseOperations.CreateScope(nameof(OutboxService));

		var sql = @"
			UPDATE system.outbox
			SET status = 'sent', processed_at = NOW()
			WHERE id = @Id";

		await db.Connection.ExecuteSqlAsync(sql, new { Id = id });
	}

	public async Task MarkAsFailedAsync(Guid id, string errorMessage)
	{
		using var db = databaseOperations.CreateScope(nameof(OutboxService));

		var sql = @"
			UPDATE system.outbox
			SET status = 'failed',
				processed_at = NOW(),
				retry_count = retry_count + 1,
				error_message = @ErrorMessage
			WHERE id = @Id";

		await db.Connection.ExecuteSqlAsync(sql, new { Id = id, ErrorMessage = errorMessage });
	}

	private class OutboxMessageDto
	{
		public Guid Id { get; set; }
		public string Type { get; set; } = "";
		public string Payload { get; set; } = "";
		public string Status { get; set; } = "";
		public DateTime CreatedAt { get; set; }
		public DateTime? ProcessedAt { get; set; }
		public int RetryCount { get; set; }
		public string? ErrorMessage { get; set; }
	}
}