using System;
using System.Collections.Generic;
using System.Data;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.Data.SqlClient;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Logging;
using PartSource.Automation.Models.Configuration;
using PartSource.Automation.Models.Ftp;
using PartSource.Automation.Services;
using Ratermania.Automation.Interfaces;

namespace PartSource.Automation.Jobs
{
    public class BulkUpdateInventory : IAutomationJob
    {
        private readonly FtpService _ftpService;
        private readonly ILogger<BulkUpdateInventory> _logger;
		private readonly string _connectionString;

        public BulkUpdateInventory(IConfiguration configuration, ILogger<BulkUpdateInventory> logger)
        {
            FtpConfiguration ftpConfiguration = configuration.GetSection("FtpServers:AzureConfiguration").Get<FtpConfiguration>();
            _ftpService = new FtpService(ftpConfiguration);

            _connectionString = configuration.GetConnectionString("PartSourceDatabase");

            _logger = logger;
        }

        public async Task Run(CancellationToken token, params string[] arguments)
        {
            FtpFileInfo lastUploadedFile = _ftpService.ListFilesExtended()
                .Where(f => f.FileType == FtpFileType.File && f.Filename.IndexOf("Availability Full") > -1)
                .OrderByDescending(f => f.Modified)
                .FirstOrDefault();

            if (lastUploadedFile == null)
            {
                _logger.LogInformation($"No full inventory file available.");
                return;
            }

            string file = _ftpService.Download(lastUploadedFile.Filename);

			DataTable dataTable = GetDataTable(file);

			using SqlConnection connection = new SqlConnection(_connectionString);
			connection.Open();

			using SqlCommand command = new SqlCommand("TRUNCATE TABLE PartAvailability", connection);
			await command.ExecuteNonQueryAsync();

			using SqlBulkCopy bulk = new SqlBulkCopy(connection)
			{
				DestinationTableName = "PartAvailability",
				BulkCopyTimeout = 14400
			};

			bulk.WriteToServer(dataTable);

            _ftpService.Delete(lastUploadedFile.Filename);

            return;
        }

		private DataTable GetDataTable(string filename)
		{
			using DataTable dataTable = new DataTable();
			dataTable.Columns.Add("Store", typeof(int));
			dataTable.Columns.Add("SKU", typeof(string));
			dataTable.Columns.Add("QTY", typeof(int));

			using StreamReader reader = new StreamReader(filename);
			string line = reader.ReadLine(); // Burn the header row

			while (reader.Peek() > 0)
			{
				line = reader.ReadLine();

				string[] columns = line.Split("|");
				for (int i = 0; i < columns.Length; i++)
				{
					columns[i] = columns[i].Replace("\"", string.Empty);
				}

				string sku = columns[1].Trim();
				if (int.TryParse(columns[0], out int store)
					&& !string.IsNullOrEmpty(sku)
					&& int.TryParse(columns[2], out int quantity))
				{
					dataTable.Rows.Add(new object[] { store, sku, quantity });
				}
			}

			return dataTable;
		}
	}
}