Parser.java

import storageManager.Field;
import storageManager.FieldType;

import java.util.ArrayList;

/**
 * Created by lsr on 2016/11/24.
 */
public class Parser {
    ArrayList<String> key_word;
    String sen;
    ArrayList<Argument> arg;
    ArrayList<String> words;
    ArrayList<String> t_names;
    ArrayList<String> values;
    TreeNode delete;
    TreeNode select;

    public Parser() {
        key_word=new ArrayList<>();
        sen=null;
        arg = new ArrayList<>();
        words = new ArrayList<>();
        t_names = new ArrayList<>();
        values = new ArrayList<>();
        delete = null;
        select = null;
    }

    private void reset(){
        key_word=new ArrayList<>();
        sen=null;
        arg = new ArrayList<>();
        words = new ArrayList<>();
        t_names = new ArrayList<>();
        values = new ArrayList<>();
        delete = null;
        select = null;
    }

    public boolean syntax(String str){
        try {
            this.reset();
            str = str.trim();
            str = str.replace("//s{1,}"," ");
            String[] res = str.split(" ");

            if(res[0].equalsIgnoreCase("create")){
                key_word.add("create");
                if(!res[1].equalsIgnoreCase("table")) {
                    System.out.print("table!!!");
                    return false;
                }

                t_names.add(res[2]);

                    StringBuilder stringBuilder = new StringBuilder();
                    for(int i = 3; i<res.length;i++){
                        stringBuilder.append(res[i]+" ");
                    }
                    String temp = stringBuilder.toString();

                    if(temp.charAt(0)=='(' && temp.indexOf(")")>0){
                        String sub=temp.substring(1,temp.indexOf(")"));
                        String[] args=sub.split(",");
                        for(int j = 0; j<args.length; j++){
                            args[j] = args[j].trim();
                            String [] field=args[j].split(" ");
                            if(field.length!=2){
                                System.out.print("Wrong Arg Format");
                                return false;
                            }

                            if(field[1].equalsIgnoreCase("str20")){
                                Argument argument=new Argument(field[1],field[0]);
                                arg.add(argument);
                            }else if(field[1].equalsIgnoreCase("int")){
                                Argument argument=new Argument(field[1],field[0]);
                                arg.add(argument);
                            }else{
                                return false;
                            }
                    }
                    }

            }else if(res[0].equalsIgnoreCase("drop")){
                key_word.add("drop");
                if(!res[1].equalsIgnoreCase("table")){
                    System.out.print("table!!");
                    return false;
                }

                t_names.add(res[2]);

                if(res.length>3){
                    return false;
                }

            }else if(res[0].equalsIgnoreCase("insert")){
                key_word.add("insert");
               if(!res[1].equalsIgnoreCase("into")){
                   return false;
               }

               t_names.add(res[2]);

                int index=-1;
                int s_index=-1;
               for(int i = 3; i<res.length; i++){
                   if(res[i].equalsIgnoreCase("values")){
                       index = i;
                   }

                   if(res[i].equalsIgnoreCase("select")){
                       s_index = i;
                   }

               }

               if(index<0 && s_index<0){
                   System.out.print("no values");
                   return false;
               }


                if(index>0) {
                    StringBuilder stringBuilder = new StringBuilder();
                    for (int i = 3; i < index; i++) {
                        stringBuilder.append(res[i] + " ");
                    }
                    String temp = stringBuilder.toString();
                    if (temp.charAt(0) == '(' && temp.indexOf(")") > 0) {
                        String sub = temp.substring(1, temp.indexOf(")"));
                        String[] args = sub.split(",");
                        for (int j = 0; j < args.length; j++) {
                            args[j] = args[j].trim();
                            String[] field = args[j].split(" ");
                            if (field.length != 1) {
                                System.out.print("Wrong Arg Format");
                                return false;
                            } else {
                                Argument argument = new Argument(null, field[0]);
                                arg.add(argument);
                            }
                        }
                    } else {
                        return false;
                    }

                    stringBuilder = new StringBuilder();
                    for (int i = index + 1; i < res.length; i++) {
                        stringBuilder.append(res[i] + " ");
                    }

                    temp = stringBuilder.toString();
                    if (temp.charAt(0) == '(' && temp.indexOf(")") > 0) {
                        String sub = temp.substring(1, temp.indexOf(")"));
                        String[] args = sub.split(",");
                        for (int j = 0; j < args.length; j++) {
                            args[j] = args[j].trim();
                            String[] field = args[j].split(" ");
                            if (field.length != 1) {
                                System.out.print("Wrong Arg Format");
                                return false;
                            } else {
                                values.add(field[0]);
                            }
                        }
                    } else {
                        return false;
                    }
                }else if(s_index>0){
                    StringBuilder stringBuilder = new StringBuilder();
                    for (int i = 3; i < s_index; i++) {
                        stringBuilder.append(res[i] + " ");
                    }
                    String temp = stringBuilder.toString();
                    if (temp.charAt(0) == '(' && temp.indexOf(")") > 0) {
                        String sub = temp.substring(1, temp.indexOf(")"));
                        String[] args = sub.split(",");
                        for (int j = 0; j < args.length; j++) {
                            args[j] = args[j].trim();
                            String[] field = args[j].split(" ");
                            if (field.length != 1) {
                                System.out.print("Wrong Arg Format");
                                return false;
                            } else {
                                Argument argument = new Argument(null, field[0]);
                                arg.add(argument);
                            }
                        }
                    } else {
                        return false;
                    }

                    stringBuilder = new StringBuilder();
                    for(int i = s_index;i<res.length;i++){
                        stringBuilder.append(res[i]+" ");
                    }

                    return selectparse(stringBuilder.toString().split(" "));
                }

            } else if(res[0].equalsIgnoreCase("delete")){
                key_word.add("delete");
                delete = new TreeNode();
                if(!res[1].equalsIgnoreCase("from")){
                    return false;
                }

                int index = -1;
                for(int i=0;i<res.length;i++){
                    if(res[i].equalsIgnoreCase("where")){
                        index = i;
                        break;
                    }
                }

                if(index<0){
                    index = res.length;
                }else{
                    delete.where = true;
                }

                StringBuilder stringBuilder1 =new StringBuilder();
                for(int i=2;i<index;i++){
                    stringBuilder1.append(res[i]+" ");
                }
                String[] tables = stringBuilder1.toString().split(",");

                for(int i=0;i<tables.length;i++){
                    delete.t_names.add(tables[i].trim());
                }

                if(delete.where==true){
                    StringBuilder stringBuilder = new StringBuilder();
                    for(int i=index+1;i<res.length;i++){
                        stringBuilder.append(res[i]+" ");
                    }
                    delete.w_clause =Builder.generate(stringBuilder.toString());
                }

            }else if(res[0].equalsIgnoreCase("select")){
                return selectparse(res);

            }else {
                return false;
            }

        } catch (Exception e) {
//            e.printStackTrace();
            System.out.print("Syntax Wrong Format!!!");
            return false;
        }

        return true;

    }

    private boolean selectparse(String[] res) {
        select = new TreeNode();
        key_word.add("select");

        int f_index=-1;
        int w_index=-1;
        int o_index=-1;
        int d_index=-1;

        for(int i=1; i<res.length;i++){
            if(res[i].equalsIgnoreCase("distinct")){
                d_index = i;
            }

            if(res[i].equalsIgnoreCase("from")){
                f_index = i;
            }

            if(res[i].equalsIgnoreCase("where")){
                w_index = i;
            }

            if(res[i].equalsIgnoreCase("order")){
                o_index = i;
            }
        }

        if( d_index == 1){
            select.distinct = true;
        }else if (d_index >=0){
            return false;
        }

        if(w_index>0) {
            if(o_index>0) {
                if (w_index > o_index) {
                    System.out.print("Order can not be front of Where!");
                    return false;
                }
            }
        }

        if(f_index<0){
            System.out.print("No from!!");
            return false;
        }
        StringBuilder stringBuilder = new StringBuilder();
        if(d_index >0){
            for(int i=2;i<f_index;i++){
                stringBuilder.append(res[i]+" ");
            }
            String []arg_s = stringBuilder.toString().split(",");

            if(arg_s[0].trim().equalsIgnoreCase("*")){
                if(arg_s.length==1) {
//                    System.out.print("select *");
                    select.arg.add("*");
                }
                else{
                    return false;
                }

            }else{
                for(int i=0;i<arg_s.length;i++){
                    arg_s[i]=arg_s[i].trim();
                    select.arg.add(arg_s[i]);
                }
//                finished argument
            }
        }else{

            for(int i=1;i<f_index;i++){
                stringBuilder.append(res[i]+" ");
            }
            String []arg_s = stringBuilder.toString().split(",");

            if(arg_s[0].trim().equalsIgnoreCase("*")){
                if(arg_s.length==1) {
//                    System.out.print("select *");
                    select.arg.add("*");
                }
                else{
                    return false;
                }

            }else{
                for(int i=0;i<arg_s.length;i++){
                    arg_s[i]=arg_s[i].trim();
                    select.arg.add(arg_s[i]);
                }
//                finished argument
            }
        }



        stringBuilder = new StringBuilder();
        if(w_index>0){
            select.where = true;
            for(int i=f_index+1;i<w_index;i++){
                stringBuilder.append(res[i]+" ");
            }
            String[] tables = stringBuilder.toString().split(",");
            for(int i=0;i<tables.length;i++){
                tables[i] = tables[i].trim();
                select.t_names.add(tables[i]);
            }

            stringBuilder = new StringBuilder();
            if(o_index>0) {
                select.order = true;
                for(int i=w_index + 1; i <o_index;i++){
                    stringBuilder.append(res[i]+" ");
                }
                select.w_clause = Builder.generate(stringBuilder.toString());

                if(!res[o_index+1].equalsIgnoreCase("by")){
                    System.out.print("order by false!!");
                    return false;
                }

                stringBuilder = new StringBuilder();
                for(int i=o_index+2;i<res.length;i++){
                    stringBuilder.append(res[i]+" ");
                }
                select.o_clause = stringBuilder.toString();
            }else{
                for(int i=w_index + 1; i <res.length;i++){
                    stringBuilder.append(res[i]+" ");
                }
                select.w_clause = Builder.generate(stringBuilder.toString());
            }
        }else{
            if(o_index>0){
                if(!res[o_index+1].equalsIgnoreCase("by")){
                    System.out.print("order by false!!");
                    return false;
                }

                select.order = true;
                for(int i=f_index+1;i<o_index;i++){
                    stringBuilder.append(res[i]+" ");
                }
                String[] tables = stringBuilder.toString().split(",");
                for(int i=0;i<tables.length;i++){
                    tables[i] = tables[i].trim();
                    select.t_names.add(tables[i]);
                }

                stringBuilder = new StringBuilder();
                for(int i=o_index+2;i<res.length;i++){
                    stringBuilder.append(res[i]+" ");
                }
                select.o_clause = stringBuilder.toString();
            }else{
                for(int i=f_index+1;i<res.length;i++){
                    stringBuilder.append(res[i]+" ");
                }
                String[] tables = stringBuilder.toString().split(",");
                for(int i=0;i<tables.length;i++){
                    tables[i] = tables[i].trim();
                    select.t_names.add(tables[i]);
                }
            }
        }
        return true;
    }
}