using System;
using System.Collections.Generic;
using System.Data;
using System.Data.SqlClient;
using System.Configuration;
using VNCServerList.Models;

namespace VNCServerList.Services
{
    public class DatabaseService
    {
        private readonly string _connectionString;
        private readonly SettingsService _settingsService;

        public DatabaseService(SettingsService settingsService = null)
        {
            _settingsService = settingsService ?? new SettingsService();
            _connectionString = Properties.Settings.Default.VNCServerDB;
            InitializeDatabase();
        }

        private void InitializeDatabase()
        {
            using (var connection = new SqlConnection(_connectionString))
            {
                connection.Open();
                
                // VNC_ServerList 테이블이 존재하는지 확인
                string checkTableSql = @"
                    IF NOT EXISTS (SELECT * FROM sysobjects WHERE name='VNC_ServerList' AND xtype='U')
                    CREATE TABLE [dbo].[VNC_ServerList](
                        [User] [varchar](50) NOT NULL,
                        [IP] [varchar](20) NOT NULL,
                        [Category] [varchar](20) NULL,
                        [Title] [varchar](50) NULL,
                        [Description] [varchar](100) NULL,
                        [Password] [varchar](20) NULL,
                        [Argument] [varchar](50) NULL,
                        CONSTRAINT [PK_VNC_ServerList] PRIMARY KEY CLUSTERED 
                        (
                            [User] ASC,
                            [IP] ASC
                        )
                    )";

                using (var command = new SqlCommand(checkTableSql, connection))
                {
                    command.ExecuteNonQuery();
                }
            }
        }

        public List<VNCServer> GetAllServers()
        {
            var servers = new List<VNCServer>();
            
            using (var connection = new SqlConnection(_connectionString))
            {
                connection.Open();
                string sql = "SELECT * FROM VNC_ServerList ORDER BY [User]";
                
                using (var command = new SqlCommand(sql, connection))
                using (var reader = command.ExecuteReader())
                {
                    while (reader.Read())
                    {
                        servers.Add(new VNCServer
                        {
                            User = reader["User"].ToString(),
                            IP = reader["IP"].ToString(),
                            Category = reader["Category"] == DBNull.Value ? null : reader["Category"].ToString(),
                            Title = reader["Title"] == DBNull.Value ? null : reader["Title"].ToString(),
                            Description = reader["Description"] == DBNull.Value ? null : reader["Description"].ToString(),
                            Password = reader["Password"] == DBNull.Value ? null : reader["Password"].ToString(),
                            Argument = reader["Argument"] == DBNull.Value ? null : reader["Argument"].ToString()
                        });
                    }
                }
            }
            
            return servers;
        }

        public VNCServer GetServerByUserAndIP(string user, string ip)
        {
            using (var connection = new SqlConnection(_connectionString))
            {
                connection.Open();
                string sql = "SELECT * FROM VNC_ServerList WHERE [User] = @User AND [IP] = @IP";
                
                using (var command = new SqlCommand(sql, connection))
                {
                    command.Parameters.AddWithValue("@User", user);
                    command.Parameters.AddWithValue("@IP", ip);
                    
                    using (var reader = command.ExecuteReader())
                    {
                        if (reader.Read())
                        {
                            return new VNCServer
                            {
                                User = reader["User"].ToString(),
                                IP = reader["IP"].ToString(),
                                Category = reader["Category"] == DBNull.Value ? null : reader["Category"].ToString(),
                                Title = reader["Title"] == DBNull.Value ? null : reader["Title"].ToString(),
                                Description = reader["Description"] == DBNull.Value ? null : reader["Description"].ToString(),
                                Password = reader["Password"] == DBNull.Value ? null : reader["Password"].ToString(),
                                Argument = reader["Argument"] == DBNull.Value ? null : reader["Argument"].ToString()
                            };
                        }
                    }
                }
            }
            
            return null;
        }

        public bool AddServer(VNCServer server)
        {
            using (var connection = new SqlConnection(_connectionString))
            {
                connection.Open();
                string sql = @"
                    INSERT INTO VNC_ServerList ([User], [IP], [Category], [Title],[Description], [Password], [Argument])
                    VALUES (@User, @IP, @Category, @Description, @Password, @Argument)";
                
                using (var command = new SqlCommand(sql, connection))
                {
                    command.Parameters.AddWithValue("@User", server.User);
                    command.Parameters.AddWithValue("@IP", server.IP);
                    command.Parameters.AddWithValue("@Category", (object)server.Category ?? DBNull.Value);
                    command.Parameters.AddWithValue("@Title", (object)server.Title ?? DBNull.Value);
                    command.Parameters.AddWithValue("@Description", (object)server.Description ?? DBNull.Value);
                    command.Parameters.AddWithValue("@Password", (object)server.Password ?? DBNull.Value);
                    command.Parameters.AddWithValue("@Argument", (object)server.Argument ?? DBNull.Value);
                    
                    return command.ExecuteNonQuery() > 0;
                }
            }
        }

        public bool UpdateServer(VNCServer server)
        {
            using (var connection = new SqlConnection(_connectionString))
            {
                connection.Open();
                string sql = @"
                    UPDATE VNC_ServerList 
                    SET [Category] = @Category, [Title] = @Title, [Description] = @Description, 
                        [Password] = @Password, [Argument] = @Argument
                    WHERE [User] = @User AND [IP] = @IP";
                
                using (var command = new SqlCommand(sql, connection))
                {
                    command.Parameters.AddWithValue("@User", server.User);
                    command.Parameters.AddWithValue("@IP", server.IP);
                    command.Parameters.AddWithValue("@Category", (object)server.Category ?? DBNull.Value);
                    command.Parameters.AddWithValue("@Title", (object)server.Title ?? DBNull.Value);
                    command.Parameters.AddWithValue("@Description", (object)server.Description ?? DBNull.Value);
                    command.Parameters.AddWithValue("@Password", (object)server.Password ?? DBNull.Value);
                    command.Parameters.AddWithValue("@Argument", (object)server.Argument ?? DBNull.Value);
                    
                    return command.ExecuteNonQuery() > 0;
                }
            }
        }

        public bool DeleteServer(string user, string ip)
        {
            using (var connection = new SqlConnection(_connectionString))
            {
                connection.Open();
                string sql = "DELETE FROM VNC_ServerList WHERE [User] = @User AND [IP] = @IP";
                
                using (var command = new SqlCommand(sql, connection))
                {
                    command.Parameters.AddWithValue("@User", user);
                    command.Parameters.AddWithValue("@IP", ip);
                    return command.ExecuteNonQuery() > 0;
                }
            }
        }
    }
}