package com.example.simplecalculator6088102

import android.app.AlertDialog
import android.content.Context
import android.os.Bundle
import android.view.View
import android.widget.Button
import android.widget.EditText
import android.widget.TextView
import androidx.appcompat.app.AppCompatActivity

class MainActivity : AppCompatActivity() {
    private var input1: EditText? = null
    private var input2: EditText? = null
    private var solution: EditText? = null
    private var operator: TextView? = null
    private val mContext: Context? = null

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        input1 = findViewById<View>(R.id.editText) as EditText
        input2 = findViewById<View>(R.id.editText2) as EditText
        solution = findViewById<View>(R.id.editText3) as EditText
        operator = findViewById<View>(R.id.textView) as TextView
        val plusButton = findViewById<View>(R.id.button) as Button
        val minusButton = findViewById<View>(R.id.button2) as Button
        val mulButton = findViewById<View>(R.id.button3) as Button
        val divButton = findViewById<View>(R.id.button4) as Button
        val equalButton = findViewById<View>(R.id.button5) as Button
        plusButton.setOnClickListener { operator!!.text = "+" }
        minusButton.setOnClickListener { operator!!.text = "-" }
        mulButton.setOnClickListener { operator!!.text = "*" }
        divButton.setOnClickListener { operator!!.text = "/" }
        equalButton.setOnClickListener {
            if (input1!!.text.length == 0
                || input1!!.text.toString() === ""
                || input2!!.text.length == 0
                || input2!!.text.toString() === "") {
                AlertDialog.Builder(mContext).setTitle("Error")
                    .setMessage("Some inputs are empty")
                    .setPositiveButton("OK", null).show()
            } else if (operator!!.text == "") {
                AlertDialog.Builder(mContext).setTitle("Error")
                    .setMessage("Operator is null")
                    .setPositiveButton("OK", null).show()
            } else if (operator!!.text == "+") {
                val result: Double = input1!!.text.toString().toDouble() + input2!!.text.toString().toDouble()
                solution!!.setText(java.lang.Double.toString(result))
            } else if (operator!!.text == "-") {
                val result: Double = input1!!.text.toString().toDouble() - input2!!.text.toString().toDouble()
                solution!!.setText(java.lang.Double.toString(result))
            } else if (operator!!.text == "*") {
                val result: Double = input1!!.text.toString().toDouble() * input2!!.text.toString().toDouble()
                solution!!.setText(java.lang.Double.toString(result))
            } else if (operator!!.text == "/") {
                val result: Double = input1!!.text.toString().toDouble() / input2!!.text.toString().toDouble()
                solution!!.setText(java.lang.Double.toString(result))
            }
        }
    }

}