/*
 * Copyright (C) 2022-2023 MURENA SAS
 * Copyright (C) 2021 E FOUNDATION
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */

package foundation.e.advancedprivacy.features.trackers

import android.net.Uri
import androidx.lifecycle.ViewModel
import androidx.lifecycle.viewModelScope
import androidx.navigation.NavDirections
import foundation.e.advancedprivacy.domain.entities.ApplicationDescription
import foundation.e.advancedprivacy.domain.usecases.TrackersAndAppsListsUseCase
import foundation.e.advancedprivacy.domain.usecases.TrackersStatisticsUseCase
import foundation.e.advancedprivacy.trackers.domain.entities.Tracker
import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.flow.MutableSharedFlow
import kotlinx.coroutines.flow.MutableStateFlow
import kotlinx.coroutines.flow.asSharedFlow
import kotlinx.coroutines.flow.asStateFlow
import kotlinx.coroutines.flow.update
import kotlinx.coroutines.launch
import kotlinx.coroutines.withContext

class TrackersViewModel(
    private val trackersStatisticsUseCase: TrackersStatisticsUseCase,
    private val trackersAndAppsListsUseCase: TrackersAndAppsListsUseCase
) : ViewModel() {

    private val _state = MutableStateFlow(TrackersState())
    val state = _state.asStateFlow()

    private val _singleEvents = MutableSharedFlow<SingleEvent>()
    val singleEvents = _singleEvents.asSharedFlow()

    private val _navigate = MutableSharedFlow<NavDirections>()
    val navigate = _navigate.asSharedFlow()

    suspend fun doOnStartedState() = withContext(Dispatchers.IO) {
        trackersStatisticsUseCase.listenUpdates().collect {
            trackersStatisticsUseCase.getDayMonthYearStatistics()
                .let { (day, month, year) ->
                    _state.update { s ->
                        s.copy(
                            dayStatistics = day,
                            monthStatistics = month,
                            yearStatistics = year
                        )
                    }
                }

            trackersAndAppsListsUseCase.getAppsAndTrackersCounts().let { (appList, trackerList) ->
                _state.update {
                    it.copy(apps = appList, trackers = trackerList)
                }
            }
        }
    }

    fun onClickTracker(tracker: Tracker) = viewModelScope.launch {
        _navigate.emit(TrackersFragmentDirections.gotoTrackerDetailsFragment(trackerId = tracker.id))
    }

    fun onClickApp(app: ApplicationDescription) = viewModelScope.launch {
        _navigate.emit(TrackersFragmentDirections.gotoAppTrackersFragment(appUid = app.uid))
    }

    fun onClickLearnMore() = viewModelScope.launch {
        _singleEvents.emit(SingleEvent.OpenUrl(Uri.parse(URL_LEARN_MORE_ABOUT_TRACKERS)))
    }

    sealed class SingleEvent {
        data class ErrorEvent(val error: String) : SingleEvent()
        data class OpenUrl(val url: Uri) : SingleEvent()
    }
}