using IM.Commons.IntegrationEvents;

namespace ConnectorService.Dtos
{
    public record MessageHubResponse
    {
        public Guid Id { get; init; }

        /// <summary>
        /// 客户端去重/回执使用的本地 ID
        /// </summary>
        public Guid ClientId { get; init; }

        public string ChatType { get; init; } = string.Empty;
        public string MsgType { get; init; } = string.Empty;
        public Guid SenderId { get; init; }
        public Guid TargetId { get; init; }
        public string State { get; init; } = string.Empty;
        public string StreamKey { get; init; } = string.Empty;
        public long SequenceId { get; init; }

        /// <summary>
        /// 服务器推送到达时间 (毫秒级时间戳，强烈建议加上)
        /// </summary>
        public long PushTimestamp { get; init; } = DateTimeOffset.UtcNow.ToUnixTimeMilliseconds();

        public HubMsgContentDto Content { get; init; } = null!;
    }

    // 嵌套的内容对象，允许 Ext 和 Quote 为 null 以缩减 JSON 体积
    public record HubMsgContentDto(
        string Fallback,
        object Body,
        Dictionary<string, string>? Ext,
        HubQuoteInfoDto? Quote
    );

    public record HubQuoteInfoDto(
        Guid MessageId,
        Guid SenderId,
        string SenderName,
        string MessageType,
        string Preview
    );
    public static class MessageEventMapper
    {
        /// <summary>
        /// 将内部集成事件转换为对外推送的 DTO
        /// </summary>
        public static MessageHubResponse ToHubResponse(this MsgCreatedEvent @event)
        {
            if (@event == null) throw new ArgumentNullException(nameof(@event));

            return new MessageHubResponse
            {
                Id = @event.Id,
                ClientId = @event.ClientId,
                ChatType = @event.ChatType,
                MsgType = @event.MsgType,
                SenderId = @event.SenderId,
                TargetId = @event.TargetId,
                State = @event.State,
                StreamKey = @event.StreamKey,
                SequenceId = @event.SequenceId,
                // 嵌套映射
                Content = @event.Content != null ? new HubMsgContentDto(
                    @event.Content.Fallback,
                    @event.Content.Body,
                    @event.Content.Ext,
                    @event.Content.Quote != null ? new HubQuoteInfoDto(
                        @event.Content.Quote.MessageId,
                        @event.Content.Quote.SenderId,
                        @event.Content.Quote.SenderName,
                        @event.Content.Quote.MessageType,
                        @event.Content.Quote.Preview
                    ) : null
                ) : null!
            };
        }
    }
}