using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Logging;
using Strata.ApiLib.Standard.Models;
using Strata.RxNorm.Biz.DbContexts;
using Strata.RxNorm.Biz.Jazz;
using Strata.RxNorm.Biz.Pagination;
using Strata.RxNorm.Biz.RxNorm;
using Strata.RxNorm.Biz.Utilities;
using Strata.SqlTools.Configuration.Common.AsyncFactory;
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Linq.Expressions;
using System.Threading;
using System.Threading.Tasks;

namespace Strata.RxNorm.Biz.Ndc
{
    public class NdcDbService(
        RxNormDbContext rxNormDbContext,
        IAsyncDbContextFactory<JazzDbContext> dbContextFactory,
        ILogger<NdcDbService> logger) : INdcDbService
    {
        private readonly RxNormDbContext _rxNormDbContext = rxNormDbContext;
        protected readonly IAsyncDbContextFactory<JazzDbContext> _dbContextFactory = dbContextFactory;
        private readonly ILogger<NdcDbService> _logger = logger;

        public async Task<JazzDbContext> GetDbContext(CancellationToken cancellationToken)
        {
            return await _dbContextFactory.CreateDbContextAsync(cancellationToken);
        }

        public async Task<PagedApiResponse<DimNdc>> GetNdcsAsync(PagingOptions pagingOptions, IBaseFilterOptions filterOptions, CancellationToken cancellationToken)
        {
            var jazzDbContext = await GetDbContext(cancellationToken);
            try
            {
                var query = jazzDbContext.DimNdcs.AsQueryable().AsNoTracking();
                var filters = GetNdcFilters(filterOptions);
                var result = await query.Where(filters).ToPagedAsync(pagingOptions, cancellationToken);
                return result;
            }
            catch (Exception ex)
            {
                _logger.LogServiceError(ex, jazzDbContext);
                throw;
            }
        }

        private static List<Expression<Func<DimNdc, bool>>> GetNdcFilters(IBaseFilterOptions filterOptions)
        {
            return filterOptions.Search.CreateEntityFilters<DimNdc>(
                m => m.NdcCode,
                m => m.Description,
                m => m.BrandCode,
                m => m.BrandDescription,
                m => m.DoseFormCode,
                m => m.DoseFormDescription,
                m => m.BrandedClinicalDrugCode,
                m => m.BrandedClinicalDrugDescription,
                m => m.SemanticClinicalDrugCode,
                m => m.SemanticClinicalDrugDescription
            );
        }

        internal Dictionary<string, JazzNdcUpdate> JazzNdcUpdates = new List<JazzNdcUpdate>{
                new ("",
                (ndc, ndcDetail) =>
                    ndc.BrandCode != ndcDetail.BrandCode
                    || ndc.BrandDescription != ndcDetail.BrandDescription
                    || ndc.BrandedClinicalDrugCode != ndcDetail.BrandedClinicalDrugCode
                    || ndc.BrandedClinicalDrugDescription != ndcDetail.BrandedClinicalDrugDescription
                    || ndc.SemanticClinicalDrugCode != ndcDetail.SemanticClinicalDrugCode
                    || ndc.SemanticClinicalDrugDescription != ndcDetail.SemanticClinicalDrugDescription
                    || ndc.DoseFormCode != ndcDetail.DoseFormCode
                    || ndc.DoseFormDescription != ndcDetail.DoseFormDescription,
                (ndc, ndcDetail) =>
                {
                    ndc.BrandCode = ndcDetail.BrandCode;
                    ndc.BrandDescription = ndcDetail.BrandDescription;
                    ndc.BrandedClinicalDrugCode = ndcDetail.BrandedClinicalDrugCode;
                    ndc.BrandedClinicalDrugDescription = ndcDetail.BrandedClinicalDrugDescription;
                    ndc.SemanticClinicalDrugCode = ndcDetail.SemanticClinicalDrugCode;
                    ndc.SemanticClinicalDrugDescription = ndcDetail.SemanticClinicalDrugDescription;
                    ndc.DoseFormCode = ndcDetail.DoseFormCode;
                    ndc.DoseFormDescription = ndcDetail.DoseFormDescription;
                }),
                new ("DF",
                (ndc, ndcDetail) => ndc.DoseFormCode != ndcDetail.DoseFormCode
                    || ndc.DoseFormDescription != ndcDetail.DoseFormDescription,
                (ndc, ndcDetail) =>
                {
                    ndc.DoseFormCode = ndcDetail.DoseFormCode;
                    ndc.DoseFormDescription = ndcDetail.DoseFormDescription;
                }),
                new ("BN",
                (ndc, ndcDetail) =>
                    ndc.BrandCode != ndcDetail.BrandCode
                    || ndc.BrandDescription != ndcDetail.BrandDescription,
                (ndc, ndcDetail) =>
                {
                    ndc.BrandCode = ndcDetail.BrandCode;
                    ndc.BrandDescription = ndcDetail.BrandDescription;
                }),
                new ("SCD",
                (ndc, ndcDetail) => ndc.SemanticClinicalDrugCode != ndcDetail.SemanticClinicalDrugCode
                    || ndc.SemanticClinicalDrugDescription != ndcDetail.SemanticClinicalDrugDescription,
                (ndc, ndcDetail) =>
                {
                    ndc.SemanticClinicalDrugCode = ndcDetail.SemanticClinicalDrugCode;
                    ndc.SemanticClinicalDrugDescription = ndcDetail.SemanticClinicalDrugDescription;
                }),
                new("SBD",
                (ndc, ndcDetail) => ndc.BrandedClinicalDrugCode != ndcDetail.BrandedClinicalDrugCode
                    || ndc.BrandedClinicalDrugDescription != ndcDetail.BrandedClinicalDrugDescription,
                (ndc, ndcDetail) =>
                {
                    ndc.BrandedClinicalDrugCode = ndcDetail.BrandedClinicalDrugCode;
                    ndc.BrandedClinicalDrugDescription = ndcDetail.BrandedClinicalDrugDescription;
                })
            }.ToDictionary(k => k.Tty, v => v);

        public async Task UpdateJazzNdc(bool withNormalization, CancellationToken cancellationToken)
        {
            var hasDetails = await _rxNormDbContext.FactNdcDetails.AnyAsync(cancellationToken);
            if (!hasDetails) { return; }

            var jazzDbContext = await GetDbContext(cancellationToken);
            await jazzDbContext.DropNdcDetailTable(cancellationToken);
            await jazzDbContext.CreateNdcDetailTable(cancellationToken);

            await UpdateJazzNdc(JazzNdcUpdates.TryGetValue("", out var result) ? result : null, withNormalization, cancellationToken);

            await jazzDbContext.UpdateDimNdcTable(cancellationToken);
        }

        public async Task UpdateJazzNdcBrands(bool withNormalization, CancellationToken cancellationToken)
        {
            var hasDetails = await _rxNormDbContext.FactNdcDetails.AnyAsync(cancellationToken);
            if (!hasDetails) { return; }

            await UpdateJazzNdc(JazzNdcUpdates.TryGetValue("BN", out var result) ? result : null, withNormalization, cancellationToken);
        }

        public async Task UpdateJazzNdcDoseForms(bool withNormalization, CancellationToken cancellationToken)
        {
            var hasDetails = await _rxNormDbContext.FactNdcDetails.AnyAsync(cancellationToken);
            if (!hasDetails) { return; }

            await UpdateJazzNdc(JazzNdcUpdates.TryGetValue("DF", out var result) ? result : null, withNormalization, cancellationToken);
        }

        public async Task UpdateJazzNdcSemanticClinicalDrugs(bool withNormalization, CancellationToken cancellationToken)
        {
            var hasDetails = await _rxNormDbContext.FactNdcDetails.AnyAsync(cancellationToken);
            if (!hasDetails) { return; }

            await UpdateJazzNdc(JazzNdcUpdates.TryGetValue("SCD", out var result) ? result : null, withNormalization, cancellationToken);
        }

        public async Task UpdateJazzNdcBrandedClinicalDrugs(bool withNormalization, CancellationToken cancellationToken)
        {
            var hasDetails = await _rxNormDbContext.FactNdcDetails.AnyAsync(cancellationToken);
            if (!hasDetails) { return; }

            await UpdateJazzNdc(JazzNdcUpdates.TryGetValue("SBD", out var result) ? result : null, withNormalization, cancellationToken);
        }

        public async Task ClearDimNdcData(CancellationToken cancellationToken)
        {
            var jazzDbContext = await GetDbContext(cancellationToken);
            await jazzDbContext.ClearDimNdc(cancellationToken);
        }

        /// <summary>
        /// 
        /// </summary>
        /// <param name="jazzNdcUpdate"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        private async Task UpdateJazzNdc(JazzNdcUpdate jazzNdcUpdate, bool withNormalization, CancellationToken cancellationToken)
        {
            await UpdateJazzNdc([jazzNdcUpdate], withNormalization, cancellationToken);
        }

        /// <summary>
        /// 
        /// </summary>
        /// <param name="jazzNdcUpdates"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        private async Task UpdateJazzNdc(IEnumerable<JazzNdcUpdate> jazzNdcUpdates, bool withNormalization, CancellationToken cancellationToken)
        {
            var jazzDbContext = await GetDbContext(cancellationToken);
            foreach (var jazzNdcUpdate in jazzNdcUpdates)
            {
                await UpdateJazzNdc(jazzDbContext, jazzNdcUpdate, withNormalization, cancellationToken);
            }
        }

        /// <summary>
        /// 
        /// </summary>
        /// <param name="jazzNdcUpdate"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        private async Task UpdateJazzNdc(JazzDbContext jazzDbContext, JazzNdcUpdate jazzNdcUpdate,
            bool withNormalization,
            CancellationToken cancellationToken)
        {
            var start = Stopwatch.StartNew();
            var skip = 0;
            var take = 10000;
            var totalUpdates = 0;

            var query = jazzDbContext.DimNdcs.AsQueryable();
            while (true)
            {
                var batch = await query.Skip(skip).Take(take).ToListAsync(cancellationToken);
                if (batch.Count == 0) { break; }
                var batchNdcs = batch.Select(ndc => withNormalization ? ndc.NdcCode.NormalizeNdc() : ndc.NdcCode).Distinct().ToList();
                var ndcDetails = await _rxNormDbContext.FactNdcDetails
                    .Where(r => batchNdcs.Contains(r.NdcCode)).ToListAsync(cancellationToken);
                totalUpdates += await UpdateDetails(jazzDbContext, jazzNdcUpdate,
                    withNormalization,
                    batch, ndcDetails, cancellationToken);
                skip += take;
            }

            var elapsed = start.Elapsed.TotalSeconds;
            _logger.LogServiceInfo(jazzDbContext, nameof(UpdateJazzNdc),
                new Dictionary<string, object> {
                    { nameof(elapsed), elapsed },
                    { nameof(totalUpdates), totalUpdates }
                });
        }

        private async Task<int> UpdateDetails(JazzDbContext jazzDbContext, JazzNdcUpdate jazzNdcUpdate,
            bool withNormalization,
            List<DimNdc> batch, List<FactNdcDetail> ndcDetails,
            CancellationToken cancellationToken)
        {
            if (ndcDetails.Count == 0) { return 0; }
            var updates =
                (from ndc in batch
                 join ndcDetail in ndcDetails on withNormalization ? ndc.NdcCode.NormalizeNdc() : ndc.NdcCode equals ndcDetail.NdcCode
                 where jazzNdcUpdate.IsUpdateNdc(ndc, ndcDetail)
                 select new { ndc, ndcDetail }).ToList();
            if (updates.Count == 0) { return 0; }
            if (string.IsNullOrEmpty(jazzNdcUpdate.Tty))
            {
                var ndcDetailInserts = updates.Select(update => new NdcDetail(update.ndc, update.ndcDetail));
                await jazzDbContext.NdcDetails.AddRangeAsync(ndcDetailInserts, cancellationToken);
                return await jazzDbContext.SaveChangesAsync(cancellationToken);
            }
            try
            {
                updates.ForEach(update => jazzNdcUpdate.UpdateData(update.ndc, update.ndcDetail));
                return await jazzDbContext.SaveChangesAsync(cancellationToken);
            }
            catch (Exception ex)
            {
                _logger.LogServiceError(ex);
                throw;
            }
        }
    }
}