using MongoDB.Bson;
using MongoDB.Driver;
using MongoDB.Driver.Core.Configuration;
using Npgsql;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace SushiBarMongoDB
{
    public static class PostgresToMongo
    {
        public static void Convert()
        {
            string postgresConnection = "Host=localhost;Username=postgres;Password=shotboll200412;Database=SUBDLab8";
            using var psqlConn = new NpgsqlConnection(postgresConnection);
            psqlConn.Open();

            var client = new MongoClient("mongodb://localhost:27017");
            var database = client.GetDatabase("lab8SUBD");

            var buyers = database.GetCollection<BsonDocument>("Buyers");
            var cooks = database.GetCollection<BsonDocument>("Cooks");
            var menus = database.GetCollection<BsonDocument>("Menus");
            var places = database.GetCollection<BsonDocument>("Places");
            var tasks = database.GetCollection<BsonDocument>("Tasks");

            //Конвертация покупателей

            using var psqlBuyers = new NpgsqlCommand("SELECT * FROM \"Buyers\"", psqlConn);
            using var readBuyers = psqlBuyers.ExecuteReader();

            while(readBuyers.Read())
            {
                var document = new BsonDocument();
                for(int i = 0;i<readBuyers.FieldCount;i++)
                {
                    document.Add(readBuyers.GetName(i), BsonValue.Create(readBuyers.GetValue(i)));
                }
                buyers.InsertOne(document);
            }
            readBuyers.Close();
            psqlBuyers.Cancel();

            //Конвертация поваров

            using var psqlCooks = new NpgsqlCommand("SELECT * FROM \"Cooks\"", psqlConn);
            using var readCooks = psqlCooks.ExecuteReader();

            while (readCooks.Read())
            {
                var document = new BsonDocument();
                for (int i = 0; i < readCooks.FieldCount; i++)
                {
                    document.Add(readCooks.GetName(i), BsonValue.Create(readCooks.GetValue(i)));
                }
                cooks.InsertOne(document);
            }
            readCooks.Close();
            psqlCooks.Cancel();

            //Конвертация меню

            using var psqlMenus = new NpgsqlCommand("SELECT * FROM \"Menus\"", psqlConn);
            using var readMenus = psqlMenus.ExecuteReader();

            while (readMenus.Read())
            {
                var document = new BsonDocument();
                for (int i = 0; i < readMenus.FieldCount; i++)
                {
                    document.Add(readMenus.GetName(i), BsonValue.Create(readMenus.GetValue(i)));
                }
                menus.InsertOne(document);
            }
            readMenus.Close();
            psqlMenus.Cancel();

            //Конвертация столиков

            using var psqlPlaces = new NpgsqlCommand("SELECT * FROM \"Places\"", psqlConn);
            using var readPlaces = psqlPlaces.ExecuteReader();

            while (readPlaces.Read())
            {
                var document = new BsonDocument();
                for (int i = 0; i < readPlaces.FieldCount; i++)
                {
                    document.Add(readPlaces.GetName(i), BsonValue.Create(readPlaces.GetValue(i)));
                }
                places.InsertOne(document);
            }
            readPlaces.Close();
            psqlPlaces.Cancel();

            //Конфертация заказов

            using var psqlTasks = new NpgsqlCommand("SELECT * FROM \"Tasks\"", psqlConn);
            using var readTasks = psqlTasks.ExecuteReader();

            while (readTasks.Read())
            {
                var document = new BsonDocument();
                for (int i = 0; i < readTasks.FieldCount; i++)
                {
                    string fieldName = readTasks.GetName(i);
                    if (fieldName == "PlaceId") fieldName = "place_id";
                    if (fieldName == "CookId") fieldName = "cook_id";
                    if (fieldName == "BuyerId") fieldName = "buyer_id";
                    if (fieldName == "MenuIds") fieldName = "menu_ids";
                    document.Add(readTasks.GetName(i), BsonValue.Create(readTasks.GetValue(i)));
                }
                tasks.InsertOne(document);
            }
            readTasks.Close();
            psqlTasks.Cancel();
            psqlConn.Close();
        }
    }
}