package jrunner;
import java.sql.*;
import java.util.*;
import java.nio.file.Files;
import java.nio.file.Path ;
import java.nio.file.Paths;
import java.time.*;

public class jrunner {
   //static final String QUERY = "SELECT * from rlarp.osm LIMIT 100";
     
    public static void main(String[] args) {

        String scu = "";
        String scn = "";
        String scp = "";
        String dcu = "";
        String dcn = "";
        String dcp = "";
        String sq =  "";
        String dt =  "";
        Boolean trim = true;
        Boolean clear = true;
        Integer r = 0;
        Integer t = 0;
        String sql = "";
        String nr = "";
        String nc = "";
        String nl = "\n";
        String msg = "";
        Connection scon = null;
        Connection dcon = null;
        Statement stmt = null;
        Statement stmtd = null;
        ResultSet rs = null;
        String[] getv = null;
        Integer cols = null;
        String[] dtn = null;
        Timestamp tsStart = null;
        Timestamp tsEnd   = null;

        msg = "jrunner version 0.41";
        msg = msg + nl + "-scu       source jdbc url";
        msg = msg + nl + "-scn       source username";
        msg = msg + nl + "-scp       source passowrd";
        msg = msg + nl + "-dcu       destination jdbc url";
        msg = msg + nl + "-dcn       destination username";
        msg = msg + nl + "-dcp       destination passowrd";
        msg = msg + nl + "-sq        path to source query";
        msg = msg + nl + "-dt        fully qualified name of destination table";
        msg = msg + nl + "-t         trim text";
        msg = msg + nl + "-c         clear target table";
        msg = msg + nl + "--help     info";

        //---------------------------------------parse args into variables-------------------------------------------------

        for (int i = 0; i < args.length; i = i +1 ){
            switch (args[i]) {
                //source connection string
                case "-scu":
                    scu = args[i+1];
                    break;
                //source username
                case "-scn":
                    scn = args[i+1];
                    break;
                //source password
                //import java.time.*;
                case "-scp":
                    scp = args[i+1];
                    break;
                //destination connection string
                case "-dcu":
                    dcu = args[i+1];
                    break;
                //destination username
                case "-dcn":
                    dcn = args[i+1];
                    break;
                //destination password
                case "-dcp":
                    dcp = args[i+1];
                    break;
                //source query path
                case "-sq":
                    try {
                        //sq = Files.readAllLines(Paths.get(args[i+1]));
                        sq = Files.readString(Paths.get(args[i+1]));
                    }
                    catch (Exception e) {
                        //System.out.println(nl + "error reasing source sql file: " + printStackTrace());
                        e.printStackTrace();
                        System.exit(0);
                        return;
                    }
                    break;
                //destination table name
                case "-dt":
                    dt = args[i+1];
                    break;
                case "-t":
                    trim = true;
                    break;
                case "-c":
                    clear = true;
                    break;
                case "-v":
                    System.out.println(msg);
                    return;
                case "--version":
                    System.out.println(msg);
                    return;
                case "--help":
                    System.out.println(msg);
                    return;
                case "-help":
                    System.out.println(msg);
                    return;
                case "-h":
                    System.out.println(msg);
                    return;
                case "\\?":
                    System.out.println(msg);
                    return;
                default:
                    break;
            }
        }

        System.out.println("------------db info---------------------------------------");
        System.out.println("source db uri:        " + scu);
        System.out.println("source db username:   " + scn);
        System.out.println("destination db uri:   " + dcu);
        System.out.println("destination username: " + dcn);
        System.out.println("------------source sql------------------------------------");
        System.out.println(sq);
        System.out.println("------------destination table-----------------------------");
        System.out.println(dt);

        //return;

        //force regstration
        try {
            Class.forName("com.ibm.as400.access.AS400JDBCDriver");
        } catch (ClassNotFoundException cnf) {
            System.out.println("The AS400 JDBC driver did not load");
            System.exit(0);
        }

        //-------------------------------------------establish connections-------------------------------------------------
        //source database
        System.out.println("------------open database connections---------------------");
        try {
            scon = DriverManager.getConnection(scu, scn, scp);
        } catch (SQLException e) {
            System.out.println("issue connecting to source:");
            e.printStackTrace();
            System.exit(0);
        } 
        System.out.println(" ✅ source database");
        //destination database
        try {
            dcon = DriverManager.getConnection(dcu, dcn, dcp);
        } catch (SQLException e) {
            System.out.println("issue connecting to destination:");
            e.printStackTrace();
            System.exit(0);
        } 
        System.out.println(" ✅ destination database");
        //----------------------------------------open resultset------------------------------------------------------------
        try {
            stmt = scon.createStatement();
            stmt.setFetchSize(10000);
            tsStart = Timestamp.from(Instant.now());
            System.out.println(tsStart);
            rs = stmt.executeQuery(sq); 
            //while (rs.next()) {
            //   System.out.println(rs.getString("x"));
            //}
        } catch (SQLException e) {
            System.out.println("issue retrieving rows from source:");
            e.printStackTrace();
            System.exit(0);
        } 

        //---------------------------------------build meta---------------------------------------------------------------
        try {
            cols = rs.getMetaData().getColumnCount();
        System.out.println("------------source metadata-------------------------------");
            System.out.println("number of cols: " + cols);
            getv = new String[cols + 1];
            dtn  = new String[cols + 1];
        } catch (SQLException e) {
            e.printStackTrace();
            System.exit(0);
        }
        try {
            for (int i = 1; i <= cols; i++){
                dtn[i] = rs.getMetaData().getColumnTypeName(i);
                System.out.println("  * " + rs.getMetaData().getColumnName(i) + ": " + dtn[i]);
            }
        } catch (SQLException e) {
            e.printStackTrace();
            System.exit(0);
        }
        //-------------------------clear the target table if requeted----------------------------------------------------
        if (clear) {
            System.out.println("------------clear target table----------------------------");
            sql = "DELETE FROM " + dt;
            try {
                stmtd = dcon.createStatement();
                System.out.println(" " + sql);
                stmtd.executeUpdate(sql);
            } catch (SQLException e) {
                e.printStackTrace();
                System.out.println(sql);
                System.exit(0);
            }
        }
        System.out.println("------------row count-------------------------------------");
        //-------------------------------build & execute sql-------------------------------------------------------------
        try {
            sql = "";
            while (rs.next()) {
                r++;
                t++;
                nr = "";
                for (int i = 1; i <= cols; i++){
                    switch (dtn[i].toUpperCase()){
                        case "VARCHAR":
                            nc = rs.getString(i);
                            if (rs.wasNull() || nc == null) {
                                nc = "NULL";
                                break;
                            }
                            nc = nc.replaceAll("'","''");
                            if (trim) { nc = nc.trim();}
                            nc = "'" + nc + "'";
                            break;
                        case "TEXT":
                            nc = rs.getString(i);
                            if (rs.wasNull() || nc == null) {
                                nc = "NULL";
                                break;
                            }
                            nc = nc.replaceAll("'","''");
                            if (trim) { nc = nc.trim();}
                            nc = "'" + nc + "'";
                            break;
                        case "CHAR":
                            nc = rs.getString(i);
                            if (rs.wasNull() || nc == null) {
                                nc = "NULL";
                                break;
                            }
                            nc = nc.replaceAll("'","''");
                            if (trim) { nc = nc.trim();}
                            nc = "'" + nc + "'";
                            break;
                        case "CLOB":
                            nc = rs.getString(i);
                            if (rs.wasNull() || nc == null) {
                                nc = "NULL";
                                break;
                            }
                            nc = nc.replaceAll("'","''");
                            if (trim) { nc = nc.trim();}
                            nc = "'" + nc + "'";
                            break;
                        case "DATE":
                            nc = rs.getString(i);
                            if (rs.wasNull() || nc == null) {
                                nc = "NULL";
                                break;
                            }
                            nc = "'" + nc + "'";
                            if (nc == "'1/1/0001 12:00:00 AM'") {  
                                nc = "NULL";
                            }
                            break;
                        case "TIME":
                            nc = rs.getString(i);
                            if (rs.wasNull() || nc == null) {
                                nc = "NULL";
                                break;
                            }
                            nc.replaceAll("'","''");
                            nc = "'" + nc + "'";
                            break;
                        case "TIMESTAMP":
                            nc = rs.getString(i);
                            if (rs.wasNull() || nc == null) {
                                nc = "NULL";
                                break;
                            }
                            nc.replaceAll("'","''");
                            nc = "'" + nc + "'";
                            break;
                        case "BIGINT":
                            nc = rs.getString(i);
                            if (rs.wasNull() || nc == null) {
                                nc = "NULL";
                                break;
                            }
                        default:
                            nc = rs.getString(i);
                            if (rs.wasNull() || nc == null) {
                                nc = "NULL";
                                break;
                            }
                            break;
                    }
                    if (i != 1){
                        nr = nr + ",";
                    }
                    nr = nr + nc;
                }
                //add a comma to the end of the VALUES block to accomodate a new row
                if (sql!="") {
                    sql = sql + ",";
                }
                //add the new row to the VALUES block
                sql = sql + "(" + nr + ")";
                if (r == 250){
                    r = 0;
                    sql = "INSERT INTO " + dt + " VALUES " + "\n" + sql;
                    //System.out.println(sql);
                    try {
                        stmtd = dcon.createStatement();
                        stmtd.executeUpdate(sql);
                        System.out.print("\r" + t);
                    } catch (SQLException e) {
                        e.printStackTrace();
                        System.out.println(sql);
                        System.exit(0);
                    }
                    sql = "";
                }
            }
            //if the sql is not empty, execute
            if (sql != "") {
                sql = "INSERT INTO " + dt + " VALUES " + "\n" + sql;
                try {
                    stmtd = dcon.createStatement();
                    stmtd.executeUpdate(sql);
                    System.out.print("\r" + t);
                } catch (SQLException e) {
                    e.printStackTrace();
                    System.out.println(sql);
                    System.exit(0);
                }
            }
        } catch (SQLException e) {
            e.printStackTrace();
            System.exit(0);
        }
        //System.out.println(sql);

        //---------------------------------------close connections--------------------------------------------------------
        try {
            scon.close();
            dcon.close();
        } catch (SQLException e) {
            System.out.println("issue closing connections");
            e.printStackTrace();
        }
        System.out.println(" rows written");
        tsEnd = Timestamp.from(Instant.now());
        System.out.println(tsStart);
        System.out.println(tsEnd);
        //long time = Duration.between(tsStart, tsEnd).toMillis();
        //System.out.println("time elapsed: " + time);
        System.out.println();
    }
}