using MedicalDatabaseContracts;
using MedicalDatabaseContracts.Models;
using Microsoft.Extensions.Logging;
using Npgsql;
using System.Diagnostics;
using System.Text;

namespace MedicalPostgresqlDatabase
{
    public abstract class AbstractPostgresqlStorage<T> : IStorage<T> where T : AbstractModel
    {
        protected ILogger _logger;
        protected readonly string TABLE_NAME;
        protected readonly string PRIMARY_KEY_COLUMN_NAME;
        protected readonly string PRIMARY_KEY_SEQUENCE_NAME;

        protected readonly string TIME_LOG_FILENAME_SUFFIX;
        protected readonly string TIME_LOG_FOLDERNAME;

        protected AbstractPostgresqlStorage(
            ILogger<IStorage<T>> logger,
            string tableName,
            string primaryKeyColumnName,
            string primary_key_sequence_name)
        {
            _logger = logger;
            TABLE_NAME = tableName;
            PRIMARY_KEY_COLUMN_NAME = primaryKeyColumnName;
            PRIMARY_KEY_SEQUENCE_NAME = primary_key_sequence_name;

            TIME_LOG_FILENAME_SUFFIX = "sqltimelog.csv";
            TIME_LOG_FOLDERNAME = "timelogs";
        }

        protected abstract T CreateEntityFromReader(NpgsqlDataReader reader);

        protected abstract Dictionary<string, object> GetEntityAttributesDictionary(T item);

        public void DeleteAll(out double elapsedMilliseconds)
        {
            using var connection = GetConnection();
            connection.Open();
            using var cmd = new NpgsqlCommand($"DELETE FROM {TABLE_NAME}", connection);
            _logger.LogDebug(cmd.CommandText);
            Stopwatch stopwatch = new();
            stopwatch.Start();
            cmd.ExecuteNonQuery();
            stopwatch.Stop();
            elapsedMilliseconds = stopwatch.Elapsed.TotalMilliseconds;
            WriteTimeToFile(stopwatch, "DELETEALL");
        }
        public void DeleteAll()
        {
            DeleteAll(out _);
        }

        protected void WriteTimeToFile(Stopwatch stopwatch, string filenamePrefix)
        {
            if (!Directory.Exists(TIME_LOG_FOLDERNAME))
            {
                Directory.CreateDirectory(TIME_LOG_FOLDERNAME);
            }
            string filename = GetType().Name + "_" + filenamePrefix + "_" + TIME_LOG_FILENAME_SUFFIX;
            string path = Path.Combine(TIME_LOG_FOLDERNAME, filename);
            using (StreamWriter sw = new StreamWriter(path, true))
            {
                sw.WriteLine(stopwatch.Elapsed.TotalMilliseconds);
            }
        }

        public virtual void Delete(int id)
        {
            Delete(id, out _);
        }
        public virtual void Delete(int id, out double elapsedMilliseconds)
        {
            using var connection = GetConnection();
            connection.Open();
            using var cmd = new NpgsqlCommand($"DELETE FROM {TABLE_NAME} WHERE {PRIMARY_KEY_COLUMN_NAME} = @id", connection);
            cmd.Parameters.AddWithValue("@id", id);
            _logger.LogDebug(cmd.CommandText);
            Stopwatch stopwatch = new();
            stopwatch.Start();
            cmd.ExecuteNonQuery();
            stopwatch.Stop();
            elapsedMilliseconds = stopwatch.Elapsed.TotalMilliseconds;
            WriteTimeToFile(stopwatch, "DELETE");
        }
        public virtual T? Get(int id)
        {
            return Get(id, out _);
        }
        public virtual T? Get(int id, out double elapsedMilliseconds)
        {
            using var connection = GetConnection();
            connection.Open();
            using var cmd = new NpgsqlCommand($"SELECT * FROM {TABLE_NAME} WHERE {PRIMARY_KEY_COLUMN_NAME} = @id", connection);
            cmd.Parameters.AddWithValue($"@id", id);
            _logger.LogDebug(cmd.CommandText);
            Stopwatch stopwatch = new();
            stopwatch.Start();
            using var reader = cmd.ExecuteReader();
            stopwatch.Stop();
            elapsedMilliseconds = stopwatch.Elapsed.TotalMilliseconds;
            WriteTimeToFile(stopwatch, "GET");
            if (reader.Read())
            {
                return CreateEntityFromReader(reader);
            }
            return null;
        }
        public virtual List<T> GetAll()
        {
            return GetAll(out _);
        }
        public virtual List<T> GetAll(out double elapsedMilliseconds)
        {
            var items = new List<T>();
            using var connection = GetConnection();
            connection.Open();
            using var cmd = new NpgsqlCommand($"SELECT * FROM {TABLE_NAME} ORDER BY {PRIMARY_KEY_COLUMN_NAME}", connection);
            _logger.LogDebug(cmd.CommandText);
            Stopwatch stopwatch = new();
            stopwatch.Start();
            using var reader = cmd.ExecuteReader();
            stopwatch.Stop();
            elapsedMilliseconds = stopwatch.Elapsed.TotalMilliseconds;
            WriteTimeToFile(stopwatch, "GETALL");
            while (reader.Read())
            {
                items.Add(CreateEntityFromReader(reader));
            }
            return items;
        }
        public virtual void Insert(T item)
        {
            Insert(item, out _);
        }
        public virtual void Insert(T item, out double elapsedMilliseconds)
        {
            using var connection = GetConnection();
            connection.Open();
            var dict = GetEntityAttributesDictionary(item);

            string namesString = "";
            string valuesString = "";
            foreach (var key in dict.Keys)
            {
                namesString += (string.IsNullOrEmpty(namesString) ? "" : ", ") + $"{key}";
                if (key == PRIMARY_KEY_COLUMN_NAME)
                    valuesString += (string.IsNullOrEmpty(valuesString) ? "" : ", ") + $"nextval('{PRIMARY_KEY_SEQUENCE_NAME}')";
                else
                    valuesString += (string.IsNullOrEmpty(valuesString) ? "" : ", ") + $"@{key}";
            }
            namesString = $"({namesString})";
            valuesString = $"({valuesString})";


            string[] queryBuilder = {
                "INSERT INTO",
                TABLE_NAME,
                namesString,
                "VALUES",
                valuesString
            };

            using var cmd = new NpgsqlCommand(string.Join(' ', queryBuilder), connection);

            foreach (var key in dict.Keys)
            {
                cmd.Parameters.AddWithValue($"@{key}", dict[key] ?? DBNull.Value);
            }
            _logger.LogDebug(cmd.CommandText);
            Stopwatch stopwatch = new();
            stopwatch.Start();
            cmd.ExecuteNonQuery();
            stopwatch.Stop();
            elapsedMilliseconds = stopwatch.Elapsed.TotalMilliseconds;
            WriteTimeToFile(stopwatch, "INSERT");
        }
        public virtual void Update(T item)
        {
            Update(item, out _);
        }
        public virtual void Update(T item, out double elapsedMilliseconds)
        {
            using var connection = GetConnection();
            connection.Open();

            var dict = GetEntityAttributesDictionary(item);

            string setString = "";
            foreach (var key in dict.Keys)
            {
                if (key != PRIMARY_KEY_COLUMN_NAME)
                    setString += (string.IsNullOrEmpty(setString) ? "" : ", ") + $"{key} = @{key}";
            }

            string[] queryBuilder = {
                "UPDATE",
                TABLE_NAME,
                "SET",
                setString,
                "WHERE",
                $"{PRIMARY_KEY_COLUMN_NAME} = @{PRIMARY_KEY_COLUMN_NAME}"
            };

            using var cmd = new NpgsqlCommand(string.Join(' ', queryBuilder), connection);


            foreach (var key in dict.Keys)
            {
                cmd.Parameters.AddWithValue($"@{key}", dict[key] ?? DBNull.Value);
            }

            _logger.LogDebug(cmd.CommandText);

            Stopwatch stopwatch = new();
            stopwatch.Start();
            cmd.ExecuteNonQuery();
            stopwatch.Stop();
            elapsedMilliseconds = stopwatch.Elapsed.TotalMilliseconds;
            WriteTimeToFile(stopwatch, "UPDATE");
        }

        protected NpgsqlConnection GetConnection()
        {
            return new NpgsqlConnection("Host=127.0.0.1;Port=5555;Username=postgres;Database=medicalbase;Password=postgres");
        }
    }
}