using MedicalDatabaseContracts;
using MedicalDatabaseContracts.Models;
using Npgsql;
using System.Diagnostics;

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

        protected AbstractPostgresqlStorage(string tableName, string primaryKeyColumnName)
        {
            TABLE_NAME = tableName;
            PRIMARY_KEY_COLUMN_NAME = primaryKeyColumnName;
        }

        protected abstract T CreateEntityFromReader(NpgsqlDataReader reader);

        public virtual void Delete(int id)
        {
            long elapsedMilliseconds;
            Delete(id, out elapsedMilliseconds);
        }
        public virtual void Delete(int id, out long elapsedMilliseconds)
        {
            using var connection = GetConnection();
            connection.Open();
            using var cmd = new NpgsqlCommand($"DELETE FROM {TABLE_NAME} WHERE {PRIMARY_KEY_COLUMN_NAME} = @id", connection);
            cmd.Parameters.AddWithValue("@id", id);
            Stopwatch stopwatch = new();
            stopwatch.Start();
            cmd.ExecuteNonQuery();
            stopwatch.Stop();
            elapsedMilliseconds = stopwatch.ElapsedMilliseconds;
        }
        public virtual T? Get(int id)
        {
            long elapsedMilliseconds;
            return Get(id, out elapsedMilliseconds);
        }
        public virtual T? Get(int id, out long elapsedMilliseconds)
        {
            using var connection = GetConnection();
            connection.Open();
            using var cmd = new NpgsqlCommand($"SELECT * FROM {TABLE_NAME} WHERE {PRIMARY_KEY_COLUMN_NAME} = @id", connection);
            cmd.Parameters.AddWithValue("@id", id);
            Stopwatch stopwatch = new();
            stopwatch.Start();
            using var reader = cmd.ExecuteReader();
            stopwatch.Stop();
            elapsedMilliseconds = stopwatch.ElapsedMilliseconds;
            if (reader.Read())
            {
                return CreateEntityFromReader(reader);
            }
            return null;
        }
        public virtual List<T> GetAll()
        {
            long elapsedMilliseconds;
            return GetAll(out elapsedMilliseconds);
        }
        public virtual List<T> GetAll(out long 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);
            Stopwatch stopwatch = new();
            stopwatch.Start();
            using var reader = cmd.ExecuteReader();
            stopwatch.Stop();
            elapsedMilliseconds = stopwatch.ElapsedMilliseconds;
            while (reader.Read())
            {
                items.Add(CreateEntityFromReader(reader));
            }
            return items;
        }
        public virtual void Insert(T item)
        {
            long elapsedMilliseconds;
            Insert(item, out elapsedMilliseconds);
        }
        public abstract void Insert(T item, out long elapsedMilliseconds);
        public virtual void Update(T item)
        {
            long elapsedMilliseconds;
            Update(item, out elapsedMilliseconds);
        }
        public abstract void Update(T item, out long elapsedMilliseconds);

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