using AsbCloudApp;
using AsbCloudApp.Services;
using AsbCloudDb.Model;
using AsbCloudInfrastructure.Services.Cache;
using Mapster;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;

namespace AsbCloudInfrastructure.Services
{
    public class CrudCacheServiceBase<TDto, TModel> : ICrudService<TDto>
        where TDto : AsbCloudApp.Data.IId
        where TModel : class, AsbCloudDb.Model.IId
    {
        private CacheTable<TModel> cache = null;
        private readonly IAsbCloudDbContext db;
        private readonly CacheDb cacheDb;

        public ISet<string> Includes { get; } = new SortedSet<string>();

        protected CacheTable<TModel> Cache { 
            get {
                if(cache is null)
                    cache = cacheDb.GetCachedTable<TModel>((AsbCloudDbContext)db, Includes);
                return cache;
            }
        }

        public CrudCacheServiceBase(IAsbCloudDbContext db, CacheDb cacheDb)
        {            
            this.db = db;
            this.cacheDb = cacheDb;
        }

        public virtual async Task<int> InsertAsync(TDto newItem, CancellationToken token = default)
        {
            var entity = Convert(newItem);
            var insertedEntity = await Cache.InsertAsync(entity, token)
                .ConfigureAwait(false);
            return insertedEntity?.Id??-1;
        }

        public virtual async Task<int> InsertRangeAsync(IEnumerable<TDto> dtos, CancellationToken token)
        {
            var entities = dtos.Select(Convert);            
            var insertedEntities = await Cache.InsertAsync(entities, token)
                .ConfigureAwait(false);
            return insertedEntities?.Count()??0;
        }

        public virtual async Task<IEnumerable<TDto>> GetAllAsync(CancellationToken token)
        {
            var entities = await Cache.WhereAsync(token)
                .ConfigureAwait(false);
            var dtos = entities?.Select(Convert);
            return dtos;
        }

        public virtual async Task<TDto> GetAsync(int id, CancellationToken token)
        {
            var entity = await Cache
                .FirstOrDefaultAsync(p => p.Id == id, token)
                .ConfigureAwait(false);
            if (entity is null)
                return default;
            var dto = Convert(entity);
            return dto;
        }

        public virtual async Task<int> UpdateAsync(int id, TDto dto, CancellationToken token)
        {
            if (dto.Id != id)
            {
                var exist = await Cache.ContainsAsync(i=>i.Id == dto.Id, token)
                    .ConfigureAwait(false);
                
                if (exist)
                    return -1;
                
                await Cache.RemoveAsync(i => i.Id == id, token)
                    .ConfigureAwait(false);
            }

            var entity = Convert(dto);
            await Cache.UpsertAsync(entity, token)
                .ConfigureAwait(false);
            return 1;
        }

        public virtual async Task<int> DeleteAsync(int id, CancellationToken token)
        {
            var affected = await Cache.RemoveAsync(p => p.Id == id, token)
                .ConfigureAwait(false);
            return affected;
        }

        public virtual async Task<int> DeleteAsync(IEnumerable<int> ids, CancellationToken token = default)
        {
            var affected = await Cache.RemoveAsync(p => ids.Contains(p.Id), token)
                .ConfigureAwait(false);
            return affected;
        }

        protected virtual TModel Convert(TDto src)
        {
            var entity = src.Adapt<TModel>();
            return entity;
        }

        protected virtual TDto Convert(TModel src)
        {
            var dto = src.Adapt<TDto>();
            return dto;
        }
    }
}