using Microsoft.Extensions.Logging;
using QYZH.InteractiveMagazine.Infrastructure.RabbitMQ;
using QYZH.InteractiveMagazine.IService;
using QYZH.InteractiveMagazine.Models.Common;
using QYZH.InteractiveMagazine.Models.Dto;
using QYZH.InteractiveMagazine.Models.Dto.RabbitMQ;
using QYZH.InteractiveMagazine.Models.Entity;
using QYZH.InteractiveMagazine.Models.Enum;
using QYZH.InteractiveMagazine.Repository;
using System.Text.Json;

namespace QYZH.InteractiveMagazine.Service;

/// <summary>
/// MQ消息发布服务。
/// </summary>
public class MessagePublishService(
    IRabbitMQService rabbitMQService,
    ILogger<MessagePublishService> logger) : BaseRepository<MessageOutbox>, IMessagePublishService
{
    /// <summary>
    /// 可靠发布消息，默认写入Outbox。
    /// </summary>
    public async Task<MessagePublishResult> PublishAsync<T>(MessagePublishInput<T> input, CancellationToken cancellationToken = default)
    {
        ValidateInput(input);
        var message = BuildOutboxMessage(input);
        await Context.Insertable(message).ExecuteCommandAsync(cancellationToken);
        return new MessagePublishResult
        {
            Success = true,
            OutboxIds = [message.Id],
            Message = "消息已写入Outbox"
        };
    }

    /// <summary>
    /// 批量可靠发布消息，默认写入Outbox。
    /// </summary>
    public async Task<MessagePublishResult> PublishBatchAsync<T>(IEnumerable<MessagePublishInput<T>> inputs, CancellationToken cancellationToken = default)
    {
        var inputList = inputs.ToList();
        BusinessException.ThrowIf(inputList.Count == 0, "消息发布列表不能为空", ResultCode.BAD_REQUEST);
        inputList.ForEach(ValidateInput);

        var messages = inputList.Select(BuildOutboxMessage).ToList();
        await Context.Insertable(messages).ExecuteCommandAsync(cancellationToken);
        return new MessagePublishResult
        {
            Success = true,
            OutboxIds = messages.Select(x => x.Id).ToList(),
            Message = "消息已批量写入Outbox"
        };
    }

    /// <summary>
    /// 直接发布消息，不写Outbox。
    /// </summary>
    public async Task<MessagePublishResult> PublishDirectAsync<T>(MessagePublishInput<T> input, CancellationToken cancellationToken = default)
    {
        ValidateInput(input);
        var sent = await rabbitMQService.SendAsync(new RabbitMQSendParam
        {
            Exchange = input.Exchange,
            Queue = input.Queue,
            RoutingKey = input.RoutingKey,
            Data = input.Data!
        }, cancellationToken);

        if (!sent)
        {
            logger.LogError("MQ直接发布失败，Exchange: {Exchange}, Queue: {Queue}, RoutingKey: {RoutingKey}, BusinessType: {BusinessType}, BusinessId: {BusinessId}",
                input.Exchange, input.Queue, input.RoutingKey, input.BusinessType, input.BusinessId);
            throw new BusinessException("MQ消息发送失败", ResultCode.GLOBAL_ERROR);
        }

        return new MessagePublishResult
        {
            Success = true,
            Message = "消息已直接发送"
        };
    }

    private static MessageOutbox BuildOutboxMessage<T>(MessagePublishInput<T> input)
    {
        var now = DateTime.Now;
        return new MessageOutbox
        {
            Exchange = input.Exchange,
            Queue = input.Queue,
            RoutingKey = input.RoutingKey,
            Payload = JsonSerializer.Serialize(input.Data),
            BusinessType = input.BusinessType,
            BusinessId = input.BusinessId,
            Status = (int)MessageOutboxStatusEnum.Pending,
            CreatedBy = "System",
            CreatedAt = now,
            UpdatedBy = "System",
            UpdatedAt = now
        };
    }

    private static void ValidateInput<T>(MessagePublishInput<T> input)
    {
        BusinessException.ThrowIf(string.IsNullOrWhiteSpace(input.Exchange), "MQ交换机不能为空", ResultCode.BAD_REQUEST);
        BusinessException.ThrowIf(string.IsNullOrWhiteSpace(input.Queue), "MQ队列不能为空", ResultCode.BAD_REQUEST);
        BusinessException.ThrowIf(string.IsNullOrWhiteSpace(input.RoutingKey), "MQ路由键不能为空", ResultCode.BAD_REQUEST);
        BusinessException.ThrowIf(string.IsNullOrWhiteSpace(input.BusinessType), "MQ业务类型不能为空", ResultCode.BAD_REQUEST);
        BusinessException.ThrowIf(input.BusinessId <= 0, "MQ业务ID无效", ResultCode.BAD_REQUEST);
        BusinessException.ThrowIf(input.Data == null, "MQ消息数据不能为空", ResultCode.BAD_REQUEST);
    }
}