package mysql_connector;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.sql.Statement;
import java.sql.Types;

import com.google.gson.JsonArray;
import com.google.gson.JsonElement;
import com.google.gson.JsonParser;
import com.google.gson.JsonPrimitive;

public class MySQL {
    private Connection connection;

    public MySQL(String host, String port, String database, String user, String password) throws SQLException {
        // constructor
        this.connection = DriverManager.getConnection("jdbc:mysql://" + host + ":" + port + "/" + database, user, password);
    }

    public ResultSet execute(String sql, String parameters) throws SQLException {
        ResultSet rs;
        if (parameters != null && !parameters.isEmpty())
        {
            // PreparedStatement
            PreparedStatement ps = this.getConnection().prepareStatement(sql);
            JsonArray jo = new JsonParser().parse(parameters).getAsJsonArray();
            int parameterIndex = 0;
            for (final JsonElement je : jo)
            {
                if (je.isJsonPrimitive())
                {
                    JsonPrimitive jp = je.getAsJsonPrimitive();
                    if (jp.isBoolean())
                    {
                        // Boolean
                        ps.setBoolean(parameterIndex, jp.getAsBoolean());
                    }
                    else if (jp.isJsonNull())
                    {
                        // Null
                        ps.setNull(parameterIndex, Types.NULL);
                    }
                    else if (jp.isNumber())
                    {
                        // Number
                        // ... jp.getAsNumber();
                    }
                    else
                    {
                        // String
                        ps.setString(parameterIndex, jp.getAsString());
                    }
                }
                parameterIndex++;
            }
            rs = ps.executeQuery();
        }
        else
        {
            // Statement
            Statement st = this.getConnection().createStatement();
            rs = st.executeQuery(sql);
        }
        return rs;
    }

    private enum ColumnTypes { NUMBER, BOOLEAN, STRING }

    public String fetch(ResultSet rs) throws SQLException, ClassNotFoundException {
        ResultSetMetaData md = rs.getMetaData();

        ColumnTypes[] types = null;

        int l = md.getColumnCount();

        for (int i = 0; i < l; i++)
        {
            Class<?> ColumnClass = Class.forName(md.getColumnClassName(i));

            if (Number.class.isAssignableFrom(ColumnClass))
            {
                // Number
                types[i] = ColumnTypes.NUMBER;
            }
            else if (Boolean.class.isAssignableFrom(ColumnClass))
            {
                // Boolean
                types[i] = ColumnTypes.BOOLEAN;
            }
            else
            {
                // String
                types[i] = ColumnTypes.STRING;
            }
        }

        // Collection ...?

        return null;
    }

    public void close() throws SQLException {
        // destructor
        this.connection.close();
    }

    public Connection getConnection() {
        return connection;
    }

    public void setConnection(Connection connection) {
        this.connection = connection;
    }
}