using System;
using System.Data;
using System.Data.SqlClient;

namespace BSHash
{
    public class Database
    {
        private readonly string _connectionString;

        public Database()
        {
            string serverstring = Properties.Settings.Default.Server;
            string databasestring = Properties.Settings.Default.Database;
            string userstring = Properties.Settings.Default.User;
            string passwordstring = Properties.Settings.Default.Password;

            // Ricompongo la stringa di connessione
            _connectionString = $"Server={serverstring};Database={databasestring};User Id={userstring};Password={passwordstring};";
        }

        public bool ClearHash()
        {
            using (SqlConnection connection = new SqlConnection(_connectionString))
            {
                connection.Open();
                using (SqlTransaction transaction = connection.BeginTransaction())
                {
                    try
                    {
                        // Delete all rows from the Hash table
                        string deleteQuery = "DELETE FROM Hash";
                        using (SqlCommand deleteCommand = new SqlCommand(deleteQuery, connection, transaction))
                        {
                            deleteCommand.ExecuteNonQuery();
                        }

                        transaction.Commit();
                        return true;
                    }
                    catch
                    {
                        transaction.Rollback();
                        return false;
                        throw;
                    }
                }
            }
        }

        public bool HashExists(string hash)
        {
            using (SqlConnection connection = new SqlConnection(_connectionString))
            {
                try
                {
                    connection.Open();

                    // Controlla se l'hash esiste già nel database
                    string checkQuery = "SELECT COUNT(*) FROM Hash WHERE Hash = (@Hash)";
                    using (SqlCommand checkCommand = new SqlCommand(checkQuery, connection))
                    {
                        checkCommand.Parameters.AddWithValue("@Hash", hash);
                        int count = (int)checkCommand.ExecuteScalar();

                        return count != 0;
                    }
                }
                catch
                {
                    return true;
                    throw;
                }
            }
        }

        public bool InsertHash(string path, string hash)
        {
            using (SqlConnection connection = new SqlConnection(_connectionString))
            {
                connection.Open();
                using (SqlTransaction transaction = connection.BeginTransaction())
                {
                    try
                    {
                        // L'hash non esiste quindi lo inserisco
                        string insertQuery = "INSERT INTO Hash (Path, Hash) VALUES (@Path, @Hash)";
                        using (SqlCommand insertCommand = new SqlCommand(insertQuery, connection, transaction))
                        {
                            insertCommand.Parameters.AddWithValue("@Path", path);
                            insertCommand.Parameters.AddWithValue("@Hash", hash);
                            insertCommand.ExecuteNonQuery();
                        }                     

                        transaction.Commit();

                        return true;
                    }
                    catch
                    {
                        transaction.Rollback();
                        return false;
                        throw;
                    }
                }
            }
        }

        public bool UpdateHash(string path, string hash)
        {
            using (SqlConnection connection = new SqlConnection(_connectionString))
            {
                connection.Open();
                using (SqlTransaction transaction = connection.BeginTransaction())
                {
                    try
                    {
                        // L'hash esiste quindi aggiorno la data di ultima scansione
                        string updateQuery = "UPDATE Hash SET Path = (@Path) WHERE Hash = (@Hash)";
                        using (SqlCommand updateCommand = new SqlCommand(updateQuery, connection, transaction))
                        {
                            updateCommand.Parameters.AddWithValue("@Path", path);
                            updateCommand.Parameters.AddWithValue("@Hash", hash);
                            updateCommand.ExecuteNonQuery();
                        }

                        transaction.Commit();

                        return true;
                    }
                    catch
                    {
                        transaction.Rollback();

                        return false;
                        throw;
                    }
                }
            }
        }

        public bool InsertHistory(string hash)
        {
            using (SqlConnection connection = new SqlConnection(_connectionString))
            {
                connection.Open();
                using (SqlTransaction transaction = connection.BeginTransaction())
                {
                    try
                    {

                        // L'hash esiste quindi aggiorno la data di ultima scansione
                        string updateQuery = "INSERT INTO History (Hash) VALUES (@Hash)";
                        using (SqlCommand updateCommand = new SqlCommand(updateQuery, connection, transaction))
                        {
                            updateCommand.Parameters.AddWithValue("@Hash", hash);
                            updateCommand.ExecuteNonQuery();
                        }

                        transaction.Commit();

                        return true;
                    }
                    catch
                    {
                        transaction.Rollback();

                        return false;
                        throw;
                    }
                }
            }
        }

        public void InsertLog(string message, LogType type = LogType.INFO)
        {
            using (SqlConnection connection = new SqlConnection(_connectionString))
            {
                connection.Open();
                using (SqlTransaction transaction = connection.BeginTransaction())
                {
                    try
                    {
                        string query = "INSERT INTO Log (Message, Type) VALUES (@Message, @Type)";
                        using (SqlCommand command = new SqlCommand(query, connection, transaction))
                        {
                            command.Parameters.AddWithValue("@Message", message);
                            command.Parameters.AddWithValue("@Type", type);
                            command.ExecuteNonQuery();
                        }
                        transaction.Commit();
                    }
                    catch
                    {
                        transaction.Rollback();
                        throw;
                    }
                }
            }
        }

        public DataTable GetHashes()
        {
            DataTable hashes = new DataTable();

            using (SqlConnection connection = new SqlConnection(_connectionString))
            {
                string query = "SELECT * FROM Hash";

                using (SqlCommand command = new SqlCommand(query, connection))
                {
                    connection.Open();
                    using (SqlDataReader reader = command.ExecuteReader())
                    {
                        hashes.Load(reader);
                    }
                }
            }

            return hashes;
        }

        public DataTable GetLogs(string query)
        {
            DataTable logs = new DataTable();

            using (SqlConnection connection = new SqlConnection(_connectionString))
            {
                using (SqlCommand command = new SqlCommand(query, connection))
                {
                    connection.Open();
                    using (SqlDataReader reader = command.ExecuteReader())
                    {
                        logs.Load(reader);
                    }
                }
            }

            return logs;
        }
    }
}