using Datamodels.DatabaseModels;
using System;
using System.Collections.Generic;
using System.Threading.Tasks;
using Microsoft.Extensions.Logging;
using Repositories.Interfaces;
using Datamodels.BusinessModels;
using Datamodels.SearchModels;
using Newtonsoft.Json;
using System.Linq;
using System.Linq.Expressions;
using SearchApi.Exceptions;

namespace SearchApi.SearchLogic
{
    public class SearchLogic : ISearchLogic
    {
        private readonly ILogger<SearchLogic> _logger;
        private readonly IFwMariaSearchRepo _searchRepo;

        private List<string> _tableNames;
        private List<string> _joinConditions;
        private List<string> _fieldNames;
        private List<string> _whereConditions;
        private List<string> _sortFields;
        
        public SearchLogic(ILogger<SearchLogic> logger, IFwMariaSearchRepo searchRepo)
        {
            _logger = logger;
            _searchRepo = searchRepo;
        }

        public async Task<DataResult<List<Address>>> GetAllAddresses()
        {
            var result = await _searchRepo.GetAllAddresses();
            return result;
        }

        public async Task<DataResult<ResultModel>> GetFilteredData(FilterModel filter, long skip = 0, long take = -1)
        {
            var result = new DataResult<ResultModel>();
            result.Data = new ResultModel();
            result.Data.SearchModel = filter;

            return result;
        }

        // Extract Table
        private void GetTables(FilterModel filter)
        {
            bool hasTableList = filter.TableDescriptions.Count > 0;
            _tableNames = new List<string>();
            foreach(var table in filter.TableDescriptions)
            {
                if (hasTableList && string.IsNullOrEmpty(table.TableAlias))
                {
                    throw new TableAliasMissingException($"No Alias defined for Table {table.TableName}");
                }
                _tableNames.Add($"{table.TableName} {(string.IsNullOrEmpty(table.TableAlias) ? string.Empty : table.TableAlias)}");
            }
        }

        // Extract Fieldlist
        private void GetFields(FilterModel filter)
        {
            var tables = filter.TableDescriptions;
            foreach (var table in tables)
            {
                bool hasMultipleFields = table.Fields.Count > 0;
                foreach (var field in table.Fields) {
                    if (hasMultipleFields && string.IsNullOrEmpty(field.FieldAlias))
                    {
                        throw new FieldAliasMissingException($"No Alias defined for Field {field.FieldName} in Table {table.TableName}");
                    }
                    _fieldNames.Add($"{table.TableAlias}.{field.FieldName} {field.FieldAlias}");
                }
            }
        }

        // Extract Join Path if more than one table
        private void GetTableJoinConditions(FilterModel filter)
        {

        }

        // Extract Where Conditions
        private void GetWhereConditions(FilterModel filter)
        {

        }

        // Extract Sort Items
        private void GetSortFields(FilterModel filter)
        {

        }

        // Assemble SQL Query
        private string AssembleSqlQuery()
        {
            return null;
        }
    }
}