import java.sql.*;
import java.util.Scanner;
import java.io.*;

public class Database {

    public static Connection connectToDatabase(String user, String port, String database) {
        System.out.println("-------- PostgreSQL " + "JDBC Connection Testing ------------");
        try {
            Class.forName("org.postgresql.Driver");
        } catch (ClassNotFoundException e) {

            System.out.println("Where is your PostgreSQL JDBC Driver? " + "Include in your library path!");
            e.printStackTrace();
        }
        System.out.println("PostgreSQL JDBC Driver Registered!");

        Connection connection = null;
        try {
            connection = DriverManager.getConnection("jdbc:postgresql://localhost:" + port + "/" + database, user,
                    "doesn't matter!");
        } catch (SQLException e) {
            System.out.println("Connection Failed! Check output console");
            e.printStackTrace();
        }
        return connection;
    }

    public static ResultSet executeSelect(Connection connection, String query) {
        Statement st = null;
        try {
            st = connection.createStatement();
        } catch (SQLException e) {
            e.printStackTrace();
            return null;
        }

        ResultSet rs = null;
        try {
            rs = st.executeQuery(query);
            st.close();
        } catch (SQLException e) {
            e.printStackTrace();
            return null;
        }

        return rs;
    }

    public static void dropTable(Connection connection, String table) {
        Statement st = null;
        try {
            st = connection.createStatement();
            st.execute("DROP TABLE " + table);
            st.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    public static void createTable(Connection connection, String tableDescription) {
        Statement st = null;
        try {
            st = connection.createStatement();
            st.execute("CREATE TABLE " + tableDescription);
            st.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    public static int insertIntoTableFromFile(Connection connection, String table, String file) {

        BufferedReader br = null;
        int numRows = 0;
        try {
            Statement st = connection.createStatement();
            String sCurrentLine, brokenLine[], composedLine = "";
            br = new BufferedReader(new FileReader(file));

            while ((sCurrentLine = br.readLine()) != null) {
                // Insert each line to the DB
                brokenLine = sCurrentLine.split("t");
                composedLine = "INSERT INTO dotcom VALUES (";
                int i;
                for (i = 0; i < brokenLine.length - 1; i++) {
                    composedLine += "'" + brokenLine[i] + "',";
                }
                composedLine += "'" + brokenLine[i] + "')";
                numRows = st.executeUpdate(composedLine);
            }
        } catch (IOException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            try {
                if (br != null)
                    br.close();
            } catch (IOException ex) {
                ex.printStackTrace();
            }
        }
        return numRows;
    }

    public static void main(String[] argv) throws SQLException, FileNotFoundException {

        @SuppressWarnings("resource")
        Scanner input = new Scanner(System.in);
        System.out.println("Please enter your Username:");
        String user = input.next();
        System.out.println("Please enter your Port ID:");
        String port = input.next();
        String database = "test";

        Connection connection = connectToDatabase(user, port, database);

        Statement st = connection.createStatement();

        if (connection != null) {
            System.out.println("You made it, take control your database now!");
        } else {
            System.out.println("Failed to make connection!");
            return;
        }
        // Now we're ready to work on the DB

        // read TopURLs file
        try {
            BufferedReader fileReader = new BufferedReader(new FileReader("TopURLs"));

            while (fileReader.readLine() != null) {

                st.execute("DROP TABLE IF EXISTS dotcom;");
                st.execute("CREATE TABLE dotcom (rank integer PRIMARY KEY, domainName varchar(128), domainType varchar(128));");
                st.execute("INSERT INTO dotcom VALUES(1, 'google', 'com');");
                //st.execute("INSERT INTO dotcom VALUES(2, 'facebook', 'com');");
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
        }

        /*
        try {
            BufferedReader fileReader = new BufferedReader(new FileReader("TopURLs"));

            while (fileReader.readLine() != null) {

                st.execute("DROP TABLE IF EXISTS dotcom;");
                st.execute("CREATE TABLE dotcom (rank integer PRIMARY KEY, domainName varchar(128), domainType varchar(128));");
                st.execute("INSERT INTO dotcom SELECT com, domainType FROM dotcom WHERE domainType = 'com'");
            }

        } catch (IOException e) {
            e.printStackTrace();
        } finally {
        }
        */

        /*
        Statement createStatement = null;
        PreparedStatement insertStatement = null;
        try {
            BufferedReader fileReader = new BufferedReader(new FileReader("TopURLs"));
            String line = null;
            createStatement = connection.createStatement();
            createStatement.executeUpdate("DROP TABLE IF EXISTS dotcom");
            createStatement.executeUpdate("CREATE TABLE dotcom (rank integer PRIMARY KEY, domainName varchar(128), domainType varchar(128))");

            connection.setAutoCommit(false);//commit whole batch at the end
            insertStatement = connection.prepareStatement("INSERT INTO dotcom VALUES (?, ?, ?)");

            while ( (line = fileReader.readLine()) != null) {
                line = fileReader.readLine();
                String[] urls = line.split("t");//space or any other delimiter that you're using
                insertStatement.setInt(1, Integer.parseInt(urls[0]));
                insertStatement.setString(2, urls[1]);
                insertStatement.setString(3, urls[2]);
                //insertStatement.setString(4, urls[3]);

                insertStatement.addBatch();
            }
            insertStatement.executeBatch();
            connection.commit();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if(connection != null) {
                connection.setAutoCommit(true);
            }
            if(createStatement != null) {
                createStatement.close();
            }
            if(insertStatement != null) {
                insertStatement.close();
            }
        }
        */

        // connection is of type Connection (in JDBC)
        DatabaseMetaData dbm = connection.getMetaData();

        // check if table is there
        ResultSet tables = dbm.getTables(null, null, "table name", null);
        if (tables.next()) {
            System.out.println("Table exists");
        } else {
            System.out.println("Table does not exist");
        }

        // check if view is there?
        //"create view foo as select * from table;"
        //"select * from foo;"
        ResultSet views = dbm.getTables("catalog name", null, null, null);
        if (views.next()) {
            System.out.println("View exists");
        } else {
            System.out.println("View does not exist");
        }

        String query = "SELECT * FROM internet";
        ResultSet rs = executeSelect(connection, query);
        try {
            while (rs.next()) {
                System.out.print("Column 1 returned ");
                System.out.println(rs.getString(1));
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
        rs.close();

        dropTable(connection, "dotcom");
        createTable(connection,
                "dotcom (id int primary key, name varchar(15), type varchar(15));");
        int rows = insertIntoTableFromFile(connection, "dotcom", "TopURLs");
        System.out.println(rows + " rows inserted.");
    }
}