using System;
using System.IO;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Data;
using System.Data.SQLite;
using log4net;

namespace bsmd.Tool
{
    public static class LocodeSQliteImport
    {
        private static readonly ILog _log = LogManager.GetLogger(typeof(LocodeSQliteImport));

        /// <summary>
        /// Importer / Updater für CSV files, die im SVN unter \bsmd\nsw\Archiv abgelegt wurde
        /// (offizielle UNLOCODEs)..
        /// </summary>
        /// <param name="sqliteDBPath"></param>
        /// <param name="csvFilePath"></param>
        public static void Import(string sqliteDBPath, string csvFilePath)
        {
            if (!File.Exists(sqliteDBPath)) throw new ArgumentException($"file {sqliteDBPath} does not exits");
            if (!File.Exists(csvFilePath)) throw new ArgumentException($"file {csvFilePath} does not exist");
            List<string> currentLocodes = new List<string>();

            using (var connection = new SQLiteConnection($"Data Source={sqliteDBPath}"))
            {
                connection.Open();

                // preload countries
                Dictionary<string, int> countryDict = new Dictionary<string, int>();
                
                SQLiteCommand countryCmd = new SQLiteCommand(connection);
                countryCmd.CommandText = "SELECT id, code FROM countries";
                SQLiteDataReader reader = countryCmd.ExecuteReader();
                while (reader.Read())
                {
                    countryDict[reader.GetString(1)] = reader.GetInt32(0);
                }

                SQLiteCommand lookupCmd = new SQLiteCommand(connection);
                lookupCmd.CommandText = "SELECT locodes.id FROM locodes INNER JOIN countries ON locodes.country_id = countries.id WHERE countries.code = @CCODE AND locodes.city_code = @LCODE";
                SQLiteParameter ccode = new SQLiteParameter("@CCODE", DbType.String);
                lookupCmd.Parameters.Add(ccode);
                SQLiteParameter lcode = new SQLiteParameter("@LCODE", DbType.String);
                lookupCmd.Parameters.Add(lcode);

                SQLiteCommand insertCmd = new SQLiteCommand(connection);
                insertCmd.CommandText = "INSERT INTO locodes (country_id, city_code, name, name_wo_diacritics, sub_div, port, rail_terminal, road_terminal, airport, postal_exchange_office, inland_clearance_depot, fixed_transport_functions, border_crossing_function, status, date, iata, coordinates, remarks) VALUES " +
                    "(@P1, @P2, @P3, @P4, @P5, @P6, @P7, @P8, @P9, @P10, @P11, @P12, @P13, @P14, @P15, @P16, @P17, @P18)";


                SQLiteCommand updateCmd = new SQLiteCommand(connection);
                updateCmd.CommandText = "UPDATE locodes SET name = @P3, name_wo_diacritics = @P4, sub_div = @P5, port = @P6, rail_terminal = @P7, road_terminal = @P8, airport = @P9, postal_exchange_office = @P10, " +
                    "inland_clearance_depot = @P11, fixed_transport_functions = @P12, border_crossing_function = @P13, status = @P14, date = @P15, iata = @P16, coordinates = @P17, remarks = @P18 WHERE id = @ID";

                SQLiteParameter p1 = new SQLiteParameter("@P1", DbType.Int32);
                SQLiteParameter p2 = new SQLiteParameter("@P2", DbType.String);
                SQLiteParameter p3 = new SQLiteParameter("@P3", DbType.String);
                SQLiteParameter p4 = new SQLiteParameter("@P4", DbType.String);
                SQLiteParameter p5 = new SQLiteParameter("@P5", DbType.String);
                SQLiteParameter p6 = new SQLiteParameter("@P6", DbType.Boolean);
                SQLiteParameter p7 = new SQLiteParameter("@P7", DbType.Boolean);
                SQLiteParameter p8 = new SQLiteParameter("@P8", DbType.Boolean);
                SQLiteParameter p9 = new SQLiteParameter("@P9", DbType.Boolean);
                SQLiteParameter p10 = new SQLiteParameter("@P10", DbType.Boolean);
                SQLiteParameter p11 = new SQLiteParameter("@P11", DbType.Boolean);
                SQLiteParameter p12 = new SQLiteParameter("@P12", DbType.Boolean);
                SQLiteParameter p13 = new SQLiteParameter("@P13", DbType.Boolean);
                SQLiteParameter p14 = new SQLiteParameter("@P14", DbType.String);
                SQLiteParameter p15 = new SQLiteParameter("@P15", DbType.String);
                SQLiteParameter p16 = new SQLiteParameter("@P16", DbType.String);
                SQLiteParameter p17 = new SQLiteParameter("@P17", DbType.String);
                SQLiteParameter p18 = new SQLiteParameter("@P18", DbType.String);

                SQLiteParameter idParam = new SQLiteParameter("@ID", DbType.Int32);

                insertCmd.Parameters.AddRange(new[] { p1, p2, p3, p4, p5, p6, p7, p8, p9, p10, p11, p12, p13, p14, p15, p16, p17, p18 });
                updateCmd.Parameters.AddRange(new[] { p3, p4, p5, p6, p7, p8, p9, p10, p11, p12, p13, p14, p15, p16, p17, p18, idParam });

                string[] csvLines = File.ReadAllLines(csvFilePath);
                int updateCnt = 0, insertCnt = 0;

                for (int i = 0; i < csvLines.Length; i++)
                {
                    string line = csvLines[i];
                    string[] elems = line.Split(',');
                    if (elems.Length < 12) continue;
                    string country = elems[1].Trim().Replace("\"", "");
                    if (country.Length < 2) continue;
                    string code = elems[2].Trim().Replace("\"", "");
                    if (code.Length < 3) continue;

                    currentLocodes.Add(country + code);
                    
                    ccode.Value = country;
                    lcode.Value = code;

                    // Eingabeformat: https://service.unece.org/trade/locode/Service/LocodeColumn.htm

                    object lookupResult = lookupCmd.ExecuteScalar();
                    if ((lookupResult != null) && (lookupResult != DBNull.Value))
                    {
                        int lid = Convert.ToInt32(lookupResult);

                        p3.Value = elems[3].Trim().Replace("\"", "");
                        p4.Value = elems[4].Trim().Replace("\"", "");
                        p5.Value = elems[5].Trim().Replace("\"", "");
                        SetBoolParamsFromFunctionString(elems[6].Trim().Replace("\"", ""), p6, p7, p8, p9, p10, p11, p12, p13);
                        p14.Value = elems[7].Trim().Replace("\"", "");
                        p15.Value = elems[8].Trim().Replace("\"", "");
                        p16.Value = elems[9].Trim().Replace("\"", "");
                        p17.Value = elems[10].Trim().Replace("\"", "");
                        p18.Value = elems[11].Trim().Replace("\"", "");

                        idParam.Value = lid;
                        if (updateCmd.ExecuteNonQuery() == 0)
                        {
                            _log.WarnFormat("Update of {0} affected no rows.", lid);
                        }
                        // UPDATE entry
                        updateCnt++;
                    }
                    else
                    {
                        if(!countryDict.ContainsKey(country))
                        {
                            _log.WarnFormat("Country {0} not in dictionary!", country);
                            continue;
                        }
                        p1.Value = countryDict[country];
                        p2.Value = code;
                        p3.Value = elems[3].Trim().Replace("\"", "");
                        p4.Value = elems[4].Trim().Replace("\"", "");
                        p5.Value = elems[5].Trim().Replace("\"", "");
                        SetBoolParamsFromFunctionString(elems[6].Trim().Replace("\"", ""), p6, p7, p8, p9, p10, p11, p12, p13);
                        p14.Value = elems[7].Trim().Replace("\"", "");
                        p15.Value = elems[8].Trim().Replace("\"", "");
                        p16.Value = elems[9].Trim().Replace("\"", "");
                        p17.Value = elems[10].Trim().Replace("\"", "");
                        p18.Value = elems[11].Trim().Replace("\"", "");

                        if (insertCmd.ExecuteNonQuery() == 0)
                        {
                            _log.Warn("Insert of {0} affected no rows.");
                        }
                        // CREATE new entry
                        insertCnt++;
                    }


                    Console.Write($"\r({i}/{csvLines.Length})");
                }

                Console.Write("\n");
                Console.WriteLine($"{insertCnt} new entries, {updateCnt} updated");

                // jetzt durch alle Ids in der DB laufen und mit dem Import vergleichen
                List<int> deleteIds = new List<int>();
                SQLiteCommand cmd = new SQLiteCommand(connection);
                cmd.CommandText = "SELECT countries.code, locodes.id, locodes.city_code FROM countries INNER JOIN locodes on locodes.country_id = countries.id";
                SQLiteDataReader reader2 = cmd.ExecuteReader();
                while (reader2.Read())
                {
                    if (reader2.IsDBNull(2))
                    {
                        deleteIds.Add(reader2.GetInt32(1));
                    }
                    else
                    {
                        string locode = reader2.GetString(0) + reader2.GetString(2);
                        if (!currentLocodes.Contains(locode))
                            deleteIds.Add(reader2.GetInt32(1));
                    }
                }

                Console.WriteLine($"deleting {deleteIds.Count} obsolete entries");

                SQLiteCommand delCmd = new SQLiteCommand(connection);
                delCmd.CommandText = "DELETE FROM locodes where id = @DELID";
                //  diejenigen löschen, die nicht mehr in der Quell CSV Datei auftauchen
                foreach (int deleteId in deleteIds)
                {
                    delCmd.Parameters.AddWithValue("@DELID", deleteId);
                    if (delCmd.ExecuteNonQuery() != 1)
                        _log.WarnFormat("{0} affected no rows", deleteId);
                }
            }
        }

        private static void SetBoolParamsFromFunctionString(string func, SQLiteParameter p6, SQLiteParameter p7, SQLiteParameter p8,
            SQLiteParameter p9, SQLiteParameter p10, SQLiteParameter p11, SQLiteParameter p12, SQLiteParameter p13)
        {
            if (func.Length < 8) return;
            p6.Value = (func[0] == '1');
            p7.Value = (func[1] == '2');
            p8.Value = (func[2] == '3');
            p9.Value = (func[3] == '4');
            p10.Value = (func[4] == '5');
            p11.Value = (func[5] == '6');
            p12.Value = (func[6] == '7');
            p13.Value = (func[7] == 'B');
        }
    }
}