using NewsBlogAbstractions.Models;
using NewsBlogAbstractions.WorkAbstractions;
using Npgsql;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace NewsBlogDatabaseImplementation.WorkImplementation
{
	public class ArticleWork : IArticleWork
	{
		public Article? Create(Article article)
		{
			using var con = SqlConnection.GetConnection();
			con.Open();
			using var cmd = new NpgsqlCommand("INSERT INTO article (title, content, publication_date, author_id, category_id) VALUES (@Title, @Content, @Publication_date, @Author_id, @Category_id)", con);
			cmd.Parameters.AddWithValue("@Title", article.Title);
			cmd.Parameters.AddWithValue("@Content", article.Content);
			cmd.Parameters.AddWithValue("@Publication_date", article.PublicationDate);
			cmd.Parameters.AddWithValue("@Author_id", article.AuthorId == 0 ? DBNull.Value : article.AuthorId);
			cmd.Parameters.AddWithValue("@Category_id", article.CategoryId == 0 ? DBNull.Value : article.CategoryId);
			cmd.ExecuteNonQuery();
			return article;
		}

		public Article? Delete(int id)
		{
			var element = Get(id);
			using var con = SqlConnection.GetConnection();
			con.Open();
			using var cmd = new NpgsqlCommand($"DELETE FROM article WHERE article_id = {id}", con);
			cmd.ExecuteNonQuery();
			return element;
		}

		public Article? Get(int id)
		{
			using var con = SqlConnection.GetConnection();
			con.Open();
			using var cmd = new NpgsqlCommand($"SELECT * FROM article WHERE article_id = {id}", con);
			using var reader = cmd.ExecuteReader();
			if (reader.Read())
			{
				return new Article
				{
					Id = reader.GetInt32(0),
					Title = reader.GetString(1),
					Content = reader.GetString(2),
					PublicationDate = reader.GetDateTime(3),
					AuthorId = !reader.IsDBNull(4) ? reader.GetInt32(4) : 0,
					CategoryId = !reader.IsDBNull(5) ? reader.GetInt32(5) : 0,
				};
			}
			return null;
		}

		public List<Article> GetAll()
		{
			var articles = new List<Article>();
			using var con = SqlConnection.GetConnection();
			con.Open();
			using var cmd = new NpgsqlCommand("SELECT * FROM article order by article_id", con);
			using var reader = cmd.ExecuteReader();
			while (reader.Read())
			{
				articles.Add(new Article
				{
					Id = reader.GetInt32(0),
					Title = reader.GetString(1),
					Content = reader.GetString(2),
					PublicationDate = reader.GetDateTime(3),
					AuthorId = !reader.IsDBNull(4) ? reader.GetInt32(4) : 0,
					CategoryId = !reader.IsDBNull(5) ? reader.GetInt32(5) : 0,
				});
			}
			return articles;
		}

		public Article? Update(Article article)
		{
			using var con = SqlConnection.GetConnection();
			con.Open();
			using var cmd = new NpgsqlCommand($"UPDATE article SET title = '{article.Title}', content = '{article.Content}', publication_date = '{article.PublicationDate}', author_id = @Author_Id, category_id = @Category_id WHERE article_id = {article.Id}", con);
			cmd.Parameters.AddWithValue("@Author_Id", article.AuthorId == 0 ? DBNull.Value : article.AuthorId);
			cmd.Parameters.AddWithValue("@Category_Id", article.CategoryId == 0 ? DBNull.Value : article.CategoryId);
			cmd.ExecuteNonQuery();
			var element = Get(article.Id);
			return element;
		}
	}
}