package ok;

import java.awt.BorderLayout;

import java.awt.Color;

import java.awt.GridLayout;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import javax.swing.JButton;

import javax.swing.JFrame;

import javax.swing.JPanel;

import javax.swing.JTextField;

/**

 * @author Jifahu 自制小白计算器，目前不支持键盘输入，（键盘太麻烦了有木有……） 但是良心支持了多个输入，自动判定优先级 里面有一些小彩蛋哦~

 */

public class Calc extends JFrame implements ActionListener {

    private String[] MainKey = { "7", "8", "9", "4", "5", "6", "1", "2", "3",

            "0", ".", " " };

    private String[] Cmd1 = { "+", "-", "*", "/" };

    private String[] Cmd2 = { "←", "C", " ", "=" };

    private JButton[] MK = new JButton[MainKey.length];

    private JButton[] C1 = new JButton[Cmd1.length];

    private JButton[] C2 = new JButton[Cmd2.length];

    private JTextField ans = new JTextField("");

    boolean judge = false;

    public Calc() {

        setTitle("小白计算器");

        SetLayout();

        setResizable(false);

        setVisible(true);

        pack();

    }

    void SetLayout() {

        JPanel J_ans = new JPanel();

        J_ans.setLayout(new GridLayout());

        ans.setHorizontalAlignment(ans.RIGHT);

        ans.setEditable(false);

        ans.setBackground(Color.white);

        J_ans.add(ans);

        JPanel J_MK = new JPanel();

        J_MK.setLayout(new GridLayout(4, 3, 2, 2));

        for (int i = 0; i < MainKey.length; i++) {

            MK[i] = new JButton(MainKey[i]);

            MK[i].addActionListener(this);

            J_MK.add(MK[i]);

        }

        JPanel J_C1 = new JPanel();

        J_C1.setLayout(new GridLayout(4, 1, 2, 2));

        for (int i = 0; i < Cmd1.length; i++) {

            C1[i] = new JButton(Cmd1[i]);

            C1[i].addActionListener(this);

            J_C1.add(C1[i]);

        }

        JPanel J_C2 = new JPanel();

        J_C2.setLayout(new GridLayout(4, 1, 2, 2));

        for (int i = 0; i < Cmd2.length; i++) {

            C2[i] = new JButton(Cmd2[i]);

            C2[i].addActionListener(this);

            J_C2.add(C2[i]);

        }

        getContentPane().setLayout(new BorderLayout(2, 2));

        getContentPane().add("West", J_MK);

        getContentPane().add("Center", J_C1);

        getContentPane().add("East", J_C2);

        getContentPane().add("North", J_ans);

        setLocation(600, 300);

    }

    public String Get_ans(String now) {

        int len = now.length();

        int pos = 0, point, k = 0, Dtot = 0;

        String tmp;

        double[] Dnum = new double[30];

        String op = "";

        for (int i = 0; i <= len; i++) {

            tmp = "";

            point = 0;

            if (i == len || "+-*/".indexOf(now.charAt(i)) >= 0) {

                if (i != len) {

                    k++;

                    op += now.charAt(i);

                }

                for (int j = i - 1; j >= pos; j--) {

                    if (now.charAt(j) == '.')

                        point++;

                }

                tmp = now.substring(pos, i);

                if (point >= 2)

                    return tmp + " 是什么鬼";

                Dnum[Dtot++] = Double.valueOf(tmp);

                pos = i + 1;

            }

        }

        if (k == 0)

            return "就一个数，你还让我算，你有多笨";

        for (int i = 0; i < k; i++) {

            if (op.charAt(i) == '*') {

                Dnum[i + 1] *= Dnum[i];

                Dnum[i] = 0;

            } else if (op.charAt(i) == '/') {

                if (Dnum[i + 1] == 0)

                    return "除数不能为0，你肯定是故意的";

                Dnum[i + 1] = Dnum[i] / Dnum[i + 1];

                Dnum[i] = 0;

            }

        }

        String nop = "";

        char Lop = '+';

        for(int i = 0;i < k;i++){

            if(op.charAt(i)=='+') Lop = '+';

            else if(op.charAt(i)=='-') Lop = '-';

            if(op.charAt(i)=='*'||op.charAt(i)=='/') nop += Lop;

            else nop += op.charAt(i);

        }

        double res = Dnum[0];

        for (int i = 0; i < k; i++) {

            if(nop.charAt(i)=='-') res -= Dnum[i+1];

            else res += Dnum[i+1];

        }

        return String.valueOf(res);

    }

    public void actionPerformed(ActionEvent ae) {

        String now = ans.getText();

        String s = ae.getActionCommand();

        int len = now.length();

        if(judge == true){

                judge = false;

                ans.setText("");

        }

        else if (s.equals("C")){

            ans.setText("");

            judge = false;

        }

        else if (s.equals("←")) {

            if (len > 0) {

                now = now.substring(0, len - 1);

                ans.setText(now);

            }

        } else if (s.equals(" ") || len >= 30) {

        } else if ("+-*/".indexOf(s) >= 0) {

            if (len != 0 && "+-*/.".indexOf(now.charAt(len - 1)) < 0) {

                ans.setText(now + s);

            }

        } else if (s.equals("=")) {

            if (len != 0 && "+-*/.".indexOf(now.charAt(len - 1)) < 0) {

                ans.setText(Get_ans(now));

                judge = true;

            }

        } else if (s.equals(".")) {

            if (len != 0 && "1234567890".indexOf(now.charAt(len - 1)) >= 0)

                ans.setText(now + s);

        } else

            ans.setText(now + s);

    }

    public static void main(String args[]) {

        Calc c = new Calc();

    }

}