yaotp/app/src/main/java/com/chameth/yaotp/viewmodel/OtpListViewModel.kt

package com.chameth.yaotp.viewmodel

import androidx.lifecycle.ViewModel
import com.chameth.yaotp.accounts.Account
import java.util.concurrent.CopyOnWriteArrayList

class OtpListViewModel : ViewModel() {

    private val observers = CopyOnWriteArrayList<AccountObserver>()
    private val accounts = ArrayList<Account>()
    private val accountViewModels = ArrayList<OtpItemViewModel>()

    val numberOfAccounts: Int
        get() = accounts.size

    fun getViewModelForAccount(accountId: Int) = accountViewModels[accountId]

    fun addAccount(account: Account) {
        accounts.add(account)
        accountViewModels.add(OtpItemViewModel().also { it.account = account })
        observers.forEach { it.accountAdded(accounts.size - 1) }
    }

    fun removeAccount(account: Account) {
        val index = accounts.indexOf(account)
        if (index >= 0) {
            accounts.removeAt(index)
            accountViewModels.removeAt(index)
            observers.forEach { it.accountRemoved(index) }
        }
    }

    fun addObserver(observer: AccountObserver) = observers.add(observer)
    fun removeObserver(observer: AccountObserver) = observers.remove(observer)

    interface AccountObserver {
        fun accountAdded(position: Int)
        fun accountRemoved(position: Int)
    }

}