PI_Assync_PLD/Data/PostgresRepository.cs

using System;
using System.Collections.Generic;
using Npgsql;
using PI_Assync_PLD.Models;

    public class PostgresRepository : IDataRepository
    {
        private readonly string _connectionString;

        public PostgresRepository(string environment)
        {
            _connectionString = environment == "dev"
                ? "Server=smart-energia-dev-pgsql.cykff7tj7mik.us-east-1.rds.amazonaws.com; Port=5432; Database=smartimptest; User Id=postgres; Password=VfHml#Z78!%kvvNM;"
                : "Server=smart-energia-dev-pgsql.cykff7tj7mik.us-east-1.rds.amazonaws.com; Port=5432; Database=smartenergiaprod; User Id=postgres; Password=VfHml#Z78!%kvvNM;";
        }

        public DateTime ObterDataInicial()
        {
            using var conn = new NpgsqlConnection(_connectionString);
            conn.Open();

            string query = "SELECT TO_DATE('1899-12-30', 'YYYY-MM-DD') + INTERVAL '1' DAY * MAX(dia_num) AS ultimo_dia FROM pld";
            using var cmd = new NpgsqlCommand(query, conn);
            using var reader = cmd.ExecuteReader();

            return reader.Read() && DateTime.TryParse(reader["ultimo_dia"]?.ToString(), out var data)
                ? data.AddDays(1)
                : DateTime.Now.AddYears(-2);
        }

        public void SalvarPLDs(List<PLDModel> plds, DateTime ultimaData)
        {
            using var conn = new NpgsqlConnection(_connectionString);
            conn.Open();

            // Filtrar apenas os PLDs mais recentes
            var novosPLDs = plds.FindAll(pld => pld.Dia >= ultimaData);
            if (novosPLDs.Count == 0) return; // Nenhum dado novo, então sair da função

            using var transaction = conn.BeginTransaction();

            string query = "INSERT INTO pld (dia_num, hora, submercado, valor, mes_ref, dia_da_semana) " +
                           "VALUES (@Dia, @Hora, @Submercado, @Valor, @MesRef, @DiaSemana)";

            using var cmd = new NpgsqlCommand(query, conn, transaction);

            foreach (var pld in novosPLDs)
            {
                cmd.Parameters.Clear();
                cmd.Parameters.AddWithValue("@Dia", pld.Dia.ToOADate());
                cmd.Parameters.AddWithValue("@Hora", pld.Hora);
                cmd.Parameters.AddWithValue("@Submercado", pld.Submercado);
                cmd.Parameters.AddWithValue("@Valor", pld.Valor);
                cmd.Parameters.AddWithValue("@MesRef", pld.Mes);
                cmd.Parameters.AddWithValue("@DiaSemana", pld.DiaSemana);
                cmd.ExecuteNonQuery();
            }

            transaction.Commit();
        }
    }