// StudentsDb2 Example
// Source code file: MainActivity.java

package it372.smiths.studentsdb2;
import androidx.appcompat.app.AppCompatActivity;
import android.content.ContentValues;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteException;
import android.database.sqlite.SQLiteOpenHelper;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {
    private SQLiteDatabase db;
    private EditText edtxtName, edtxtGender, edtxtGrade;
    private TextView txtName, txtGrade, txtGender;
    private Cursor cursor;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        SQLiteOpenHelper dbh = new StudentsDBHelper(this);
        try {
            db = dbh.getWritableDatabase();
        }
        catch(SQLiteException e) {
            Toast toast = Toast.makeText(this,
                    "Database not created.", Toast.LENGTH_LONG);
        }

        edtxtName = findViewById(R.id.edtxt_name);
        edtxtGrade = findViewById(R.id.edtxt_grade);
        edtxtGender = findViewById(R.id.edtxt_gender);
        txtName = findViewById(R.id.txt_name);
        txtGrade = findViewById(R.id.txt_grade);
        txtGender = findViewById(R.id.txt_gender);

        cursor = db.query("students",
                new String[ ] {"name", "grade", "gender"},
                null, null, null,
                null, null);
    }

    public void onClickEnterData(View view) {
        String name = edtxtName.getText( ).toString( );
        int grade = Integer.parseInt(edtxtGrade.getText( ).toString( ));
        String gender = edtxtGender.getText( ).toString( );

        ContentValues studentValues = new ContentValues( );
        studentValues.put("name", name);
        studentValues.put("grade", grade);
        studentValues.put("gender", gender);
        db.insert("students", null, studentValues);

        edtxtName.setText("");
        edtxtGrade.setText("");
        edtxtGender.setText("");

        cursor = db.query("students",
                new String[ ] {"name", "grade", "gender"},
                null, null, null,
                null, null);
    }

    public void onClickFirst(View view) {
        if (cursor.moveToFirst()) {
            String name = cursor.getString(0);
            int grade = cursor.getInt(1);
            String gender = cursor.getString(2);
            txtName.setText(name);
            txtGrade.setText(String.valueOf(grade));
            txtGender.setText(gender);
        }
        else {
            txtName.setText("");
            txtGrade.setText("");
            txtGender.setText("");
        }
    }

    public void onClickPrev(View view) {
        if (!cursor.isFirst( )) {
            cursor.moveToPrevious( );
            String name = cursor.getString(0);
            int grade = cursor.getInt(1);
            String gender = cursor.getString(2);
            txtName.setText(name);
            txtGrade.setText(String.valueOf(grade));
            txtGender.setText(gender);
        }
        else {
            txtName.setText("");
            txtGrade.setText("");
            txtGender.setText("");
        }
    }

    public void onClickNext(View view) {
        System.out.println(cursor.isLast( ));
        if (!cursor.isLast( )) {
            cursor.moveToNext( );
            String name = cursor.getString(0);
            int grade = cursor.getInt(1);
            String gender = cursor.getString(2);
            txtName.setText(name);
            txtGrade.setText(String.valueOf(grade));
            txtGender.setText(gender);
        }
        else {
            System.out.println("In else statement.");
            txtName.setText("");
            txtGrade.setText("");
            txtGender.setText("");
        }
    }

    public void onClickLast(View view) {
        if (cursor.moveToLast()) {
            String name = cursor.getString(0);
            int grade = cursor.getInt(1);
            String gender = cursor.getString(2);
            txtName.setText(name);
            txtGrade.setText(String.valueOf(grade));
            txtGender.setText(gender);
        }
        else {
            txtName.setText("");
            txtGrade.setText("");
            txtGender.setText("");
        }
    }
}