package com.alta189.sqllitelib;

import java.io.File;
import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class DatabaseHandler {
    /*
     * @author: alta189
     *
     */

    private sqlCore core;
    private Connection connection;
    private File SQLFile;

    public DatabaseHandler(sqlCore core, File SQLFile) {
        this.core = core;
        this.SQLFile = SQLFile;
    }

    public Connection getConnection() {
        if (connection == null) {
              initialize();
        }
        return connection;
    }

    public void closeConnection() {
        if (this.connection != null)
          try {
            this.connection.close();
          } catch (SQLException ex) {
            this.core.writeError("Error on Connection close: " + ex, true);
          }
      }

    public Boolean initialize() {
        try {
          Class.forName("org.sqlite.JDBC");
          connection = DriverManager.getConnection("jdbc:sqlite:" + SQLFile.getAbsolutePath());
          return true;
        } catch (SQLException ex) {
          core.writeError("SQLite exception on initialize " + ex, true);
        } catch (ClassNotFoundException ex) {
          core.writeError("You need the SQLite library " + ex, true);
        }
        return false;
    }

    public Connection getNewConnection() {
        try {
              Class.forName("org.sqlite.JDBC");
              return DriverManager.getConnection("jdbc:sqlite:" + SQLFile.getAbsolutePath());
            } catch (SQLException ex) {
              core.writeError("SQLite exception on initialize " + ex, true);
            } catch (ClassNotFoundException ex) {
              core.writeError("You need the SQLite library " + ex, true);
            }
            return null;
    }

    public Boolean createTable(String query) {
        try {
            if (query == null) { core.writeError("SQL Create Table query empty.", true); return false; }
            Connection con = this.getNewConnection();
            Statement statement = con.createStatement();
            statement.execute(query);
            con.close();
            return true;
        } catch (SQLException ex){
            core.writeError(ex.getMessage(), true);
            return false;
        }
    }

    public ResultSet sqlQuery(String query) {
        try {
            Connection con = getNewConnection();
            Statement statement = con.createStatement();

            ResultSet result = statement.executeQuery(query);
            con.close();
            return result;
        } catch (SQLException ex) {
            core.writeError("Error at SQL Query: " + ex.getMessage(), false);
        }
        return null;
    }

    public void insertQuery(String query) {
        try {
            Connection con = getNewConnection();
            Statement statement = con.createStatement();
            statement.executeQuery(query);
            con.close();

        } catch (SQLException ex) {
            if (!ex.toString().contains("not return ResultSet")) core.writeError("Error at SQL INSERT Query: " + ex, false);

        }
    }

    public void updateQuery(String query) {
        try {
            Connection con = getNewConnection();
            Statement statement = con.createStatement();
            statement.executeQuery(query);
            con.close();

        } catch (SQLException ex) {
            if (!ex.toString().contains("not return ResultSet")) core.writeError("Error at SQL UPDATE Query: " + ex.getMessage(), false);
        }
    }

    public void deleteQuery(String query) {
        try {
            Connection con = getNewConnection();
            Statement statement = con.createStatement();

            statement.executeQuery(query);
            con.close();

        } catch (SQLException ex) {
            if (!ex.toString().contains("not return ResultSet")) core.writeError("Error at SQL DELETE Query: " + ex.getMessage(), false);
        }
    }

    public Boolean wipeTable(String table) {
        try {
            if (!core.checkTable(table)) {
                core.writeError("Error at Wipe Table: table, " + table + ", does not exist", true);
                return false;
            }
            Connection con = getNewConnection();
            Statement statement = con.createStatement();
            String query = "DELETE FROM " + table + ";";
            statement.executeQuery(query);
            con.close();
            return true;
        } catch (SQLException ex) {
            if (!ex.toString().contains("not return ResultSet")) core.writeError("Error at SQL UPDATE Query: " + ex.getMessage(), false);
            return false;
        }
    }


    public Boolean checkTable(String table) {
        DatabaseMetaData dbm;
        try {
            Connection con = getNewConnection();
            dbm = con.getMetaData();
            ResultSet tables = dbm.getTables(null, null, table, null);
            con.close();
            if (tables.next()) {
              return true;
            }
            else {
              return false;
            }
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            core.writeError("Failed to check if table \"" + table + "\" exists: " + e.getMessage(), true);
            return false;
        }

    }
}