package com.example.myapplication

import android.content.Context
import android.database.sqlite.SQLiteDatabase
import android.database.sqlite.SQLiteOpenHelper
import androidx.core.content.contentValuesOf

class DBHelper(val context: Context) : SQLiteOpenHelper(context, DATABASE_NAME, null, DATABASE_VERSION) {

    companion object {

        internal const val DATABASE_VERSION = 1
        internal const val DATABASE_NAME = "Users.db"
        internal const val TABLE_NAME = "users"
        internal const val COL_ID = "id"
        internal const val COL_NAME = "name"
        internal const val COL_SURNAME = "surname"

    }

    override fun onCreate(db: SQLiteDatabase?) {

        val sql = db!!.execSQL("CREATE TABLE IF NOT EXISTS $TABLE_NAME(" +
            "$COL_ID INTEGER PRIMARY KEY, " +
            "$COL_NAME TEXT NOT NULL, " +
            "$COL_SURNAME TEXT NOT NULL)")
    }

    override fun onUpgrade(db: SQLiteDatabase?, oldVersion: Int, newVersion: Int) {
        db!!.execSQL("DROP TABLE IF EXISTS $TABLE_NAME")
        onCreate(db!!)
    }

    val allUsers: MutableList<User>
    get(){

        val query = "SELECT * FROM $TABLE_NAME"
        val users = mutableListOf<User>()
        val db = this.writableDatabase
        val cursor = db.rawQuery(query, null)

        if(cursor.moveToFirst())
        {

            do {

                val id = cursor.getInt(cursor.getColumnIndex(COL_ID))
                val name = cursor.getString(cursor.getColumnIndex(COL_NAME))
                val surname = cursor.getString(cursor.getColumnIndex(COL_SURNAME))
                val user = User(name,surname, id)
                users.add((user))

            } while (cursor.moveToNext())

        }
        db.close()
        return users
    }
    override fun onDowngrade(db: SQLiteDatabase, oldVersion: Int, newVersion: Int) {
        onUpgrade(db, oldVersion, newVersion)
    }

    fun addUser(user: User) : Long
    {
        val db = this.writableDatabase
        val value = contentValuesOf()
        value.put(COL_NAME, user.name)
        value.put(COL_SURNAME, user.surname)

        val result = db.insert(TABLE_NAME, null, value)

        user.id = result.toInt()

        db.close()
        return result

    }

}