using System;
using System.Collections.Generic;
using System.Threading;
using System.Threading.Tasks;
using xAiModels.Interfaces.Enrichers;
using xAiModels.Models.Dtos;
using xCommons.Extensions;
using xIdentityService.Interfaces;
using xIdentityService.Extensions;
using xModels.Dtos;
using System.Linq;
using xAiModels.Interfaces.Dtos;

namespace xAiModels.Providers.Enrichers
{
    public class XAiMessageEnricher : IXAiMessageEnricher
    {
        private readonly IXIdentityProvider identityProvider;
        private readonly IXAiConversationRepositoryService conversationRepositoryService;

        public XAiMessageEnricher(
            IXIdentityProvider identityProvider,
            IXAiConversationRepositoryService conversationRepositoryService
        )
        {
            this.identityProvider = identityProvider;
            this.conversationRepositoryService = conversationRepositoryService;
        }

        public async Task EnrichAsync(
            XAiMessageDto source,
            XAiMessageDto destination,
            CancellationToken cancellationToken = default
        )
        {
            //
            // Run independent async operations concurrently
            var ownerTask = ResolveOwnerAsync(source.OwnerId, cancellationToken);
            var conversationTask = ResolveConversationAsync(source.ConversationId, cancellationToken);
            
            //
            // wait until All Tasks Resolved ... 
            await Task.WhenAll(ownerTask, conversationTask);

            //
            // Attached Resolved Info to Destination ...
            destination.Owner = ownerTask.Result;
            if (!conversationTask.Result.IsNullOrDefault())
            {
                //
                destination.ConversationTitle = conversationTask.Result.Title;
                destination.ConversationTitleResouce = conversationTask.Result.TitleResource;
            }
        }

        public async Task EnrichRangeAsync(
            IEnumerable<XAiMessageDto> sources,
            IEnumerable<XAiMessageDto> destinations,
            CancellationToken cancellationToken = default
        )
        {
            //
            // Make Tasks Ready ...
            var tasks = sources.Zip(destinations, (src, dst) =>
                EnrichAsync(src, dst, cancellationToken)
            );

            //
            await Task.WhenAll(tasks);
        }

        //
        #region Private ...
        /// <summary>
        /// Reading Owner User Info ...
        /// </summary>
        /// <param name="ownerId"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        private async Task<XPersonDto> ResolveOwnerAsync(
            string ownerId,
            CancellationToken cancellationToken = default
        )
        {
            //
            XPersonDto result = null;

            //
            // Validate ...
            if (ownerId.IsNullOrEmpty())
            {
                return result;
            }

            //
            // Try to Retrieve User Info ...
            var device = identityProvider.GetDevice();
            var userInfo = await identityProvider.GetUserInfo(
                device: device,
                userSelectByParam: ownerId
            );
            result = userInfo.ToXPersonDto();

            //
            return result;
        }

        /// <summary>
        /// Reading Conversation ...
        /// </summary>
        /// <param name="conversationId"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        private async Task<XAiConversationDto> ResolveConversationAsync(
            Guid conversationId,
            CancellationToken cancellationToken = default
        )
        {
            //
            XAiConversationDto result = null;

            //
            // Validate ...
            if (conversationId.IsNull() ||
                conversationId.IsDefaultGuid()
            )
            {
                return result;
            }

            //
            result = await conversationRepositoryService.GetAsync(
                id: conversationId,
                includeBuilder: null,
                ignoreSoftDeleteds: true,
                cancellationToken: cancellationToken
            );

            //
            return result;
        }
        #endregion
    }
}