package sample;

import java.util.ArrayList;
import java.util.HashMap;

/**
 * Created by liufengkai on 16/7/10.
 */
public class DfaBuilder {
 /**
 * NFA 状态机的起始状态
 */
 public DfaState startState = null;
 /**
 * 状态机的当前状态
 */
 public DfaState currentState = null;
 /**
 * 接受状态
 */
 public HashMap<Integer, DfaState> acceptState;

 private static final int RETURN_ID = 13;

 private static final int CHANGE_LINE_ID = 10;

 private static final int TAB_ID = 9;

 private static final int SPACE_ID = 32;

 private ArrayList<Integer> endIdList;

 private DfaCallBack dfaCallBack = null;

 public DfaBuilder() {
 // parent is null
 this(new DfaState(null, null));
 }

 public DfaBuilder(DfaState startState) {
 this.startState = startState;
 this.currentState = startState;
 initial();
 }

 /**
 * 添加接受状态
 */
 public void addAcceptState(int input, DfaState accept) {
 if (!acceptState.containsKey(input)) {
 acceptState.put(input, accept);
 }
 }

 private void initial() {
 this.acceptState = new HashMap<>();
 this.endIdList = new ArrayList<>();
 initialEndIdList();
 }


 private void initialEndIdList() {
 endIdList.add(RETURN_ID);
 endIdList.add(CHANGE_LINE_ID);
 endIdList.add(TAB_ID);
 endIdList.add(SPACE_ID);
 }

 public DfaState input(int input) {
 // parser 了所有特殊情况 对于单词的提示
 // 一个单词内是不会出现空格制表符和换行的
// System.out.println(input + "sss");
 if (endIdList.contains(input)) {
 this.currentState = startState;
 return null;
 }


 // 处理了当输入串还在起始状态的情况
 if (currentState.getStateId() == startState.getStateId()) {
 return startInput(input);
 }

 // 说明状态不在起始状态
 DfaState tempCurrent = currentState.getTransitionInput(input);
 if (tempCurrent == null) {
 tempCurrent = new DfaState(input, currentState);
 currentState.addTransition(input, tempCurrent);
 } else {
 if (dfaCallBack != null) dfaCallBack.onMultipleSetBack(tempCurrent, tempCurrent.getTransitionSet());
 }
 currentState = tempCurrent;
 return currentState;
 }

 /**
 * 处理还在输入串起始状态的情况
 *
 * @param input 输入
 * @return current状态
 */
 public DfaState startInput(int input) {
 DfaState current;
 // 转入第一个起始状态
 if (!acceptState.containsKey(input)) {
 current = new DfaState(input, currentState);
 this.addAcceptState(input, current);
 } else {
 current = acceptState.get(input);
 if (dfaCallBack != null) dfaCallBack.onMultipleSetBack(current, current.getTransitionSet());
 }
 this.currentState = current;
 return current;
 }

 public void setDfaCallBack(DfaCallBack dfaCallBack) {
 this.dfaCallBack = dfaCallBack;
 }

 public void printDfa() {
 for (Integer integer : acceptState.keySet()) {
 System.out.println("接受状态 " + acceptState.get(integer).getStateId());
 acceptState.get(integer).printState();
 }
 }

 /**
 * 重设startState
 */
 public void resetStartState() {
 this.currentState = startState;
 }
}