using System;
using System.Xml.Linq;
using Npgsql;

namespace _2chSQL
{
    public class DBLinks
    {
        // Obtain connection string information from the portal
        //
        private static string Host = "postgres.vdk2ch.ru";
        private static string User = "postgres";
        private static string DBname = "postgres";
        private static string Password = "postgres";
        private static string Port = "5432";

        public static void DbList()
        {
            // Build connection string using parameters from portal
            //
            string connString =
                String.Format(
                    "Server={0}; User Id={1}; Database={2}; Port={3}; Password={4};SSLMode=Prefer",
                    Host,
                    User,
                    DBname,
                    Port,
                    Password);

            using (var conn = new NpgsqlConnection(connString))
            {

                //Console.Out.WriteLine("Opening connection");
                conn.Open();


                using (var command = new NpgsqlCommand("SELECT * FROM (SELECT post_id, substring(post,1,200) FROM dvach ORDER BY post_id DESC limit 10) subquery ORDER BY  post_id ASC", conn))
                {

                    var reader = command.ExecuteReader();
                    while (reader.Read())
                    {
                        Console.WriteLine(
                            string.Format(
                                "#{0}: {1}",
                                reader.GetInt32(0).ToString(),
                                reader.GetString(1)
                                //reader.GetString(2)
                                )
                            );
                    }
                    reader.Close();
                }
            }

            //Console.WriteLine("На этом вся таблица!");
        }

        public static void DbUpdate(string id, string text)
        {
            // Build connection string using parameters from portal
            //
            string connString =
                String.Format(
                    "Server={0}; User Id={1}; Database={2}; Port={3}; Password={4};SSLMode=Prefer",
                    Host,
                    User,
                    DBname,
                    Port,
                    Password);

            using (var conn = new NpgsqlConnection(connString))
            {

                //Console.Out.WriteLine("Opening connection");
                conn.Open();

                using (var command = new NpgsqlCommand("UPDATE dvach " +
                    "SET post = @postText WHERE post_id = @ID", conn))
                {
                    command.Parameters.AddWithValue("ID", int.Parse(id));
                    command.Parameters.AddWithValue("postText", text);
                    
                    int nRows = command.ExecuteNonQuery();
                    Console.Out.WriteLine(String.Format("Number of rows updated={0}", nRows));
                }
            }

            Console.WriteLine("Данные обновлены!");
            Console.ReadLine();
        }
        public static void DbAdd(string text)
        {
            // Build connection string using parameters from portal
            //
            string connString =
                String.Format(
                    "Server={0}; User Id={1}; Database={2}; Port={3}; Password={4};SSLMode=Prefer",
                    Host,
                    User,
                    DBname,
                    Port,
                    Password);

            using (var conn = new NpgsqlConnection(connString))
            {

                Console.Out.WriteLine("Opening connection");
                conn.Open();

                using (var command = new NpgsqlCommand("INSERT INTO dvach " +
                    "(post_id, post) VALUES (DEFAULT, @postText)", conn))
                {
                    command.Parameters.AddWithValue("postText", text);

                    int nRows = command.ExecuteNonQuery();
                    Console.Out.WriteLine(String.Format("Number of rows updated={0}", nRows));
                }
            }

            Console.WriteLine("С добавлением закончено");
        }
    }
}