package mx.trackermap.TrackerMap.controllers

import android.content.Context
import android.net.ConnectivityManager
import android.net.Network
import android.net.NetworkCapabilities
import android.net.NetworkRequest
import android.os.Build
import kotlinx.coroutines.flow.MutableStateFlow
import kotlinx.coroutines.flow.asStateFlow
import mx.trackermap.TrackerMap.Injectable

actual class NetworkController(context: Context): Injectable {
    private val networkRequest = NetworkRequest.Builder().build()
    private val connectivityManager: ConnectivityManager
    private val _networkAvailable = MutableStateFlow<Boolean?>(null)
    actual val networkAvailable = _networkAvailable.asStateFlow()

    private val networkCallback = object: ConnectivityManager.NetworkCallback() {
        override fun onCapabilitiesChanged(
            network: Network,
            networkCapabilities: NetworkCapabilities
        ) {
            super.onCapabilitiesChanged(network, networkCapabilities)
            _networkAvailable.value = checkNetworkAccess(networkCapabilities)
        }

        override fun onLost(network: Network) {
            super.onLost(network)
            _networkAvailable.value = false
        }
    }

    init {
        connectivityManager = context.getSystemService(Context.CONNECTIVITY_SERVICE) as ConnectivityManager
        _networkAvailable.value = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            checkNetworkAccess(connectivityManager.getNetworkCapabilities(connectivityManager.activeNetwork))
        } else {
            connectivityManager.activeNetworkInfo?.isConnected == true
        }

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
            connectivityManager.registerDefaultNetworkCallback(networkCallback)
        } else {
            connectivityManager.registerNetworkCallback(networkRequest, networkCallback)
        }
    }

    private fun checkNetworkAccess(capabilities: NetworkCapabilities?) =
        capabilities != null
                && capabilities.hasCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET)
                && if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            capabilities.hasCapability(NetworkCapabilities.NET_CAPABILITY_VALIDATED)
        } else true
}