import 'package:flutter/material.dart';
import 'alertz_box.dart';


class SiApp extends StatefulWidget {
  @override
  State<StatefulWidget> createState() => _SiForm();
}

class _SiForm extends State<SiApp> {
  var _currencies = ['Select Currency', 'Rupees', 'Dollar', 'Pound'];
  var _currentItemSelected = 'Select Currency';
  TextEditingController principalController = TextEditingController();
  TextEditingController roiController = TextEditingController();
  TextEditingController termController = TextEditingController();

  var displayResult = '';
  var _formKey = GlobalKey<FormState>();

  //final _minipadding = 5.0;
  @override
  Widget build(BuildContext context) {
    TextStyle textStyle = Theme.of(context).textTheme.title;

    return MaterialApp(
      debugShowCheckedModeBanner: false,
      theme: ThemeData(
          primaryColor: Colors.purple, accentColor: Colors.purpleAccent),
      home: Scaffold(
        appBar: AppBar(
          centerTitle: true,
          title: Text(
            "Simple Interest Calculator",
            style: TextStyle(
                fontFamily: 'PoiretOne',
                fontSize: 25.0,
                fontWeight: FontWeight.bold),
          ),
//          backgroundColor: Colors.teal,
        ),
        body: Form(
          key: _formKey,
          child: Padding(
            padding: const EdgeInsets.all(8.0),
            child: ListView(
              children: <Widget>[
                getImage(),

                SizedBox(
                  height: 10.0,
                ),
//              Column(
//                children: <Widget>[
                TextFormField(
                  keyboardType: TextInputType.number,
                  validator: (String value) {
                    if (value.isEmpty) {
                      return 'Please Enter Principal Amount';
                    }
                  },
//                    style: textStyle,
                  controller: principalController,
                  decoration: InputDecoration(
                    labelText: "Principal",
//                      labelStyle: textStyle,
                    hintText: "Enter principal e.g:- 12000",
//                    errorText:'Please ',
                    border: OutlineInputBorder(
                        borderRadius: BorderRadius.circular(10.0)),
                  ),
                ),
                SizedBox(
                  height: 10.0,
                ),
                TextFormField(
                  keyboardType: TextInputType.number,
                  validator: (String value) {
                  if (value.isEmpty) {
                  return 'Please Enter Interest';
                  }},
                  controller: roiController,
                  decoration: InputDecoration(
                    labelText: "Rate of interest",
                    hintText: "Enter rate of interest",
                    border: OutlineInputBorder(
                        borderRadius: BorderRadius.circular(10.0)),
                  ),
                ),
                SizedBox(height: 10.0),

                Row(
                  children: <Widget>[
                    Expanded(
                        child: TextFormField(
                      keyboardType: TextInputType.number,
                          validator: (String value) {
                            if (value.isEmpty) {
                              return 'Please Enter Term';
                            }},
                      controller: termController,
                      decoration: InputDecoration(
                        labelText: "Term",
                        hintText: "Time in years",
                        border: OutlineInputBorder(
                            borderRadius: BorderRadius.circular(10.0)),
                      ),
                    )),
                    SizedBox(width: 20.0),
                    Container(
                      height: 60.0,
                      decoration: ShapeDecoration(
                        shape: RoundedRectangleBorder(
                            side: BorderSide(color: Colors.black54),
                            borderRadius: BorderRadius.circular(10.0)),
                      ),
                      child: DropdownButtonHideUnderline(
                        child: ButtonTheme(
                          alignedDropdown: true,
                          child: DropdownButton<String>(
                            items: _currencies.map((String dropDownStringItem) {
                              return DropdownMenuItem<String>(
                                  value: dropDownStringItem,
                                  child: Text(dropDownStringItem));
                            }).toList(),
                            onChanged: (String newValueSelected) {
                              _OndropDownItemSelected(newValueSelected);
                            },
                            value: _currentItemSelected,
//                          hint: Text('Select Currency'),
                          ),
                        ),
                      ),
                    ),
                  ],
                ),
                SizedBox(
                  height: 10.0,
                ),

                Row(
                  children: <Widget>[
                    Expanded(
                        child: FlatButton(
                            child: Text(
                              "Reset",
                              style: TextStyle(
                                fontSize: 25.0,
                                fontFamily: 'PoiretOne',
                                fontWeight: FontWeight.bold,
                                color: Colors.teal,
                              ),
                            ),
//                    shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(15.0),),
                            onPressed: () {
                              setState(() {
                                reset();
                              });
                            })),
                    SizedBox(
                      width: 20.0,
                    ),
                    Expanded(
                      child: RaisedGradientButton(
                        child: Text(
                          'Calculate',
                          style: TextStyle(
                              fontSize: 20.0,
                              color: Colors.white,
                              fontFamily: 'PoiretOne',
                              fontWeight: FontWeight.bold),
                        ),
                        gradient: LinearGradient(colors: <Color>[
                          Colors.purple,
                          Colors.yellowAccent,
                        ]),
                        onPressed: () {
                          setState(() {
                            if (_formKey.currentState.validate()) {
                              this.displayResult = _calculateTotalReturns();
//                            build(BuildContext context) {
//                              showDialog();
//                            }
                            }
                          });
                        },
                      ),
                    ),
                  ],
                ),
//                SizedBox(height: 20.0),
//                Text(displayResult),
                showDialog(),
              ],
            ),
          ),
        ),
      ),
    );
  }

  void _OndropDownItemSelected(String newValueSelected) {
    setState(() {
      this._currentItemSelected = newValueSelected;
    });
  }

  void reset() {
    principalController.text = '';
    roiController.text = '';
    termController.text = '';

    displayResult = '';
    _currentItemSelected = 'Select Currency';
  }

  String _calculateTotalReturns() {
    double principal = double.parse(principalController.text);
    double roi = double.parse(roiController.text);
    double term = double.parse(termController.text);

    double totalInterest = principal + (principal * roi * term) / 100;
    String result =
        'After $term years, your investment will be worth $totalInterest $_currentItemSelected';
    return result;
  }

  Widget showDialog(){
    return AlertDialog(
      title: Text('Result'),
      content: Text(displayResult, style: TextStyle(
          fontFamily: 'PoiretOne',
          fontWeight: FontWeight.bold,
          color: Colors.black),),
      actions: <Widget>[
        // usually buttons at the bottom of the dialog
        new FlatButton(
          child: new Text("Close"),
          onPressed: () {
            Navigator.of(context).pop();
          },
        ),
      ],
    );
  }

}

Widget getImage() {
  return Container(
    height: 200.0,
    width: 400.0,
    decoration: BoxDecoration(
      image: DecorationImage(
          image: AssetImage("images/money.png"), fit: BoxFit.fitWidth),
    ),
  );
}



class RaisedGradientButton extends StatelessWidget {
  final Widget child;
  final Gradient gradient;
  final double width;
  final double height;
  final Function onPressed;

  const RaisedGradientButton({
    Key key,
    @required this.child,
    this.gradient,
    this.width = double.infinity,
    this.height = 50.0,
    this.onPressed,
  }) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Container(
      width: width,
      height: 50.0,
      decoration: BoxDecoration(
          gradient: gradient,
          borderRadius: BorderRadius.circular(30.0),
          boxShadow: [
            BoxShadow(
              color: Colors.grey[500],
              offset: Offset(0.0, 1.5),
              blurRadius: 1.5,
            ),
          ]),
      child: Material(
        color: Colors.transparent,
        child: InkWell(
            onTap: onPressed,
            child: Center(
              child: child,
            )),
      ),
    );
  }
}