package example.javatpoint.com.kotlinsqlitecrud

import android.support.v7.app.AppCompatActivity
import android.os.Bundle
import android.view.View
import android.widget.EditText
import android.widget.Toast
import kotlinx.android.synthetic.main.activity_main.*
import android.content.DialogInterface
import android.support.v7.app.AlertDialog


class MainActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
    }
    //method for saving records in database
    fun saveRecord(view: View){
        val id = u_id.text.toString()
        val name = u_name.text.toString()
        val email = u_email.text.toString()
        val databaseHandler: DatabaseHandler= DatabaseHandler(this)
        if(id.trim()!="" && name.trim()!="" && email.trim()!=""){
            val status = databaseHandler.addEmployee(EmpModelClass(Integer.parseInt(id),name, email))
            if(status > -1){
                Toast.makeText(applicationContext,"record save",Toast.LENGTH_LONG).show()
                u_id.text.clear()
                u_name.text.clear()
                u_email.text.clear()
            }
        }else{
            Toast.makeText(applicationContext,"id or name or email cannot be blank",Toast.LENGTH_LONG).show()
        }

    }
    //method for read records from database in ListView
    fun viewRecord(view: View){
        //creating the instance of DatabaseHandler class
        val databaseHandler: DatabaseHandler= DatabaseHandler(this)
        //calling the viewEmployee method of DatabaseHandler class to read the records
        val emp: List = databaseHandler.viewEmployee()
        val empArrayId = Array(emp.size){"0"}
        val empArrayName = Array(emp.size){"null"}
        val empArrayEmail = Array(emp.size){"null"}
        var index = 0
        for(e in emp){
            empArrayId[index] = e.userId.toString()
            empArrayName[index] = e.userName
            empArrayEmail[index] = e.userEmail
            index++
        }
        //creating custom ArrayAdapter
        val myListAdapter = MyListAdapter(this,empArrayId,empArrayName,empArrayEmail)
        listView.adapter = myListAdapter
    }
    //method for updating records based on user id
    fun updateRecord(view: View){
        val dialogBuilder = AlertDialog.Builder(this)
        val inflater = this.layoutInflater
        val dialogView = inflater.inflate(R.layout.update_dialog, null)
        dialogBuilder.setView(dialogView)

        val edtId = dialogView.findViewById(R.id.updateId) as EditText
        val edtName = dialogView.findViewById(R.id.updateName) as EditText
        val edtEmail = dialogView.findViewById(R.id.updateEmail) as EditText

        dialogBuilder.setTitle("Update Record")
        dialogBuilder.setMessage("Enter data below")
        dialogBuilder.setPositiveButton("Update", DialogInterface.OnClickListener { _, _ ->

            val updateId = edtId.text.toString()
            val updateName = edtName.text.toString()
            val updateEmail = edtEmail.text.toString()
            //creating the instance of DatabaseHandler class
            val databaseHandler: DatabaseHandler= DatabaseHandler(this)
            if(updateId.trim()!="" && updateName.trim()!="" && updateEmail.trim()!=""){
                //calling the updateEmployee method of DatabaseHandler class to update record
                val status = databaseHandler.updateEmployee(EmpModelClass(Integer.parseInt(updateId),updateName, updateEmail))
                if(status > -1){
                    Toast.makeText(applicationContext,"record update",Toast.LENGTH_LONG).show()
                }
            }else{
                Toast.makeText(applicationContext,"id or name or email cannot be blank",Toast.LENGTH_LONG).show()
            }

        })
        dialogBuilder.setNegativeButton("Cancel", DialogInterface.OnClickListener { dialog, which ->
            //pass
        })
        val b = dialogBuilder.create()
        b.show()
    }
    //method for deleting records based on id
    fun deleteRecord(view: View){
        //creating AlertDialog for taking user id
        val dialogBuilder = AlertDialog.Builder(this)
        val inflater = this.layoutInflater
        val dialogView = inflater.inflate(R.layout.delete_dialog, null)
        dialogBuilder.setView(dialogView)

        val dltId = dialogView.findViewById(R.id.deleteId) as EditText
        dialogBuilder.setTitle("Delete Record")
        dialogBuilder.setMessage("Enter id below")
        dialogBuilder.setPositiveButton("Delete", DialogInterface.OnClickListener { _, _ ->

            val deleteId = dltId.text.toString()
            //creating the instance of DatabaseHandler class
            val databaseHandler: DatabaseHandler= DatabaseHandler(this)
            if(deleteId.trim()!=""){
                //calling the deleteEmployee method of DatabaseHandler class to delete record
                val status = databaseHandler.deleteEmployee(EmpModelClass(Integer.parseInt(deleteId),"",""))
                if(status > -1){
                    Toast.makeText(applicationContext,"record deleted",Toast.LENGTH_LONG).show()
                }
            }else{
                Toast.makeText(applicationContext,"id or name or email cannot be blank",Toast.LENGTH_LONG).show()
            }

        })
        dialogBuilder.setNegativeButton("Cancel", DialogInterface.OnClickListener { _, _ ->
            //pass
        })
        val b = dialogBuilder.create()
        b.show()
    }
}

package example.javatpoint.com.kotlinsqlitecrud
//creating a Data Model Class
class EmpModelClass (var userId: Int, val userName:String , val userEmail: String)

package example.javatpoint.com.kotlinsqlitecrud

import android.app.Activity
import android.view.View
import android.view.ViewGroup
import android.widget.ArrayAdapter
import android.widget.TextView

class MyListAdapter(private val context: Activity, private val id: Array, private val name: Array, private val email: Array)
    : ArrayAdapter(context, R.layout.custom_list, name) {

    override fun getView(position: Int, view: View?, parent: ViewGroup): View {
        val inflater = context.layoutInflater
        val rowView = inflater.inflate(R.layout.custom_list, null, true)

        val idText = rowView.findViewById(R.id.textViewId) as TextView
        val nameText = rowView.findViewById(R.id.textViewName) as TextView
        val emailText = rowView.findViewById(R.id.textViewEmail) as TextView

        idText.text = "Id: ${id[position]}"
        nameText.text = "Name: ${name[position]}"
        emailText.text = "Email: ${email[position]}"
        return rowView
    }
}

package example.javatpoint.com.kotlinsqlitecrud

import android.content.Context
import android.database.sqlite.SQLiteDatabase
import android.database.sqlite.SQLiteOpenHelper
import android.content.ContentValues
import android.database.Cursor
import android.database.sqlite.SQLiteException

//creating the database logic, extending the SQLiteOpenHelper base class
class DatabaseHandler(context: Context): SQLiteOpenHelper(context,DATABASE_NAME,null,DATABASE_VERSION) {
    companion object {
        private val DATABASE_VERSION = 1
        private val DATABASE_NAME = "EmployeeDatabase"
        private val TABLE_CONTACTS = "EmployeeTable"
        private val KEY_ID = "id"
        private val KEY_NAME = "name"
        private val KEY_EMAIL = "email"
    }
    override fun onCreate(db: SQLiteDatabase?) {
       // TODO("not implemented") //To change body of created functions use File | Settings | File Templates.
       //creating table with fields
        val CREATE_CONTACTS_TABLE = ("CREATE TABLE " + TABLE_CONTACTS + "("
                + KEY_ID + " INTEGER PRIMARY KEY," + KEY_NAME + " TEXT,"
                + KEY_EMAIL + " TEXT" + ")")
        db?.execSQL(CREATE_CONTACTS_TABLE)
    }

    override fun onUpgrade(db: SQLiteDatabase?, oldVersion: Int, newVersion: Int) {
      //  TODO("not implemented") //To change body of created functions use File | Settings | File Templates.
        db!!.execSQL("DROP TABLE IF EXISTS " + TABLE_CONTACTS)
        onCreate(db)
    }


    //method to insert data
    fun addEmployee(emp: EmpModelClass):Long{
        val db = this.writableDatabase
        val contentValues = ContentValues()
        contentValues.put(KEY_ID, emp.userId)
        contentValues.put(KEY_NAME, emp.userName) // EmpModelClass Name
        contentValues.put(KEY_EMAIL,emp.userEmail ) // EmpModelClass Phone
        // Inserting Row
        val success = db.insert(TABLE_CONTACTS, null, contentValues)
        //2nd argument is String containing nullColumnHack
        db.close() // Closing database connection
        return success
    }
    //method to read data
    fun viewEmployee():List{
        val empList:ArrayList = ArrayList()
        val selectQuery = "SELECT  * FROM $TABLE_CONTACTS"
        val db = this.readableDatabase
        var cursor: Cursor? = null
        try{
            cursor = db.rawQuery(selectQuery, null)
        }catch (e: SQLiteException) {
            db.execSQL(selectQuery)
            return ArrayList()
        }
        var userId: Int
        var userName: String
        var userEmail: String
        if (cursor.moveToFirst()) {
            do {
                userId = cursor.getInt(cursor.getColumnIndex("id"))
                userName = cursor.getString(cursor.getColumnIndex("name"))
                userEmail = cursor.getString(cursor.getColumnIndex("email"))
                val emp= EmpModelClass(userId = userId, userName = userName, userEmail = userEmail)
                empList.add(emp)
            } while (cursor.moveToNext())
        }
        return empList
    }
    //method to update data
    fun updateEmployee(emp: EmpModelClass):Int{
        val db = this.writableDatabase
        val contentValues = ContentValues()
        contentValues.put(KEY_ID, emp.userId)
        contentValues.put(KEY_NAME, emp.userName) // EmpModelClass Name
        contentValues.put(KEY_EMAIL,emp.userEmail ) // EmpModelClass Email

        // Updating Row
        val success = db.update(TABLE_CONTACTS, contentValues,"id="+emp.userId,null)
        //2nd argument is String containing nullColumnHack
        db.close() // Closing database connection
        return success
    }
    //method to delete data
    fun deleteEmployee(emp: EmpModelClass):Int{
        val db = this.writableDatabase
        val contentValues = ContentValues()
        contentValues.put(KEY_ID, emp.userId) // EmpModelClass UserId
        // Deleting Row
       val success = db.delete(TABLE_CONTACTS,"id="+emp.userId,null)
        //2nd argument is String containing nullColumnHack
        db.close() // Closing database connection
        return success
    }
}