/**
 * TrackerMap
 * Copyright (C) 2021-2022  Iván Ávalos <avalos@disroot.org>, Henoch Ojeda <imhenoch@protonmail.com>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */
package mx.trackermap.TrackerMap.android.units

import android.util.Log
import androidx.lifecycle.*
import com.mousebird.maply.Point2d
import kotlinx.coroutines.DelicateCoroutinesApi
import kotlinx.coroutines.flow.collect
import kotlinx.coroutines.launch
import mx.trackermap.TrackerMap.client.models.Geofence
import mx.trackermap.TrackerMap.client.models.MapLayer
import mx.trackermap.TrackerMap.client.models.UnitInformation
import mx.trackermap.TrackerMap.controllers.GeofencesController
import mx.trackermap.TrackerMap.controllers.UnitsController
import org.koin.core.component.KoinComponent
import org.koin.core.component.inject
import kotlin.time.ExperimentalTime


@DelicateCoroutinesApi
@ExperimentalTime
class UnitsViewModel(
    savedStateHandle: SavedStateHandle
) : ViewModel(), KoinComponent {

    enum class UnitsDisplayMode {
        MAP, LIST
    }

    data class Camera (
        val point: Point2d,
        val animated: Boolean,
    )

    private val unitsController: UnitsController by inject()
    private val geofenceController: GeofencesController by inject()

    private var _searchQuery = savedStateHandle.getLiveData("searchQuery", "")
    private var _unitsDisplayMode = MutableLiveData(UnitsDisplayMode.MAP)
    private var _units = MutableLiveData<List<UnitInformation>>()
    private var _displayedUnits = MutableLiveData<List<UnitInformation>>()
    private var _oldSelectedUnit = MutableLiveData<UnitInformation?>()
    private var _selectedUnit = MutableLiveData<UnitInformation?>()
    private var _mapLayerType = MutableLiveData<MapLayer.Type>()
    private var _geofences = MutableLiveData<Map<Int, Geofence>>()
    private val _camera = MutableLiveData<Camera?>()

    val searchQuery: LiveData<String> get() = _searchQuery
    val unitsDisplayMode: LiveData<UnitsDisplayMode> get() = _unitsDisplayMode
    val units: LiveData<List<UnitInformation>> get() = _units
    val displayedUnits: LiveData<List<UnitInformation>> get() = _displayedUnits
    val oldSelectedUnit: LiveData<UnitInformation?> get() = _oldSelectedUnit
    val selectedUnit: LiveData<UnitInformation?> get() = _selectedUnit
    val mapLayerType: LiveData<MapLayer.Type> get() = _mapLayerType
    val geofences: LiveData<Map<Int, Geofence>> get() = _geofences
    val camera: LiveData<Camera?> get() = _camera

    init {
        Log.d("UnitsViewModel", "Initializing Units View Model")
        unitsController.fetchUnits(viewModelScope)
        viewModelScope.launch {
            setupUnitsObserver()
        }
        viewModelScope.launch {
            setupDisplayedUnitsObserver()
        }

        viewModelScope.launch {
            setupGeofenceObserver()
        }
    }

    private suspend fun setupUnitsObserver() {
        unitsController.displayedUnitsFlow.collect { units ->
            Log.d("UnitsViewModel", "Collecting units")
            this._displayedUnits.value = units
        }
    }

    private suspend fun setupDisplayedUnitsObserver() {
        unitsController.unitsFlow.collect { units ->
            Log.d("UnitsViewModel", "Collecting displayed units")
            this._units.value = units
            updateSelectedUnit()
        }
    }

    private suspend fun setupGeofenceObserver() {
        geofenceController.geofencesFlow.collect {
            Log.d("UnitsViewModel", "Collecting geofences")
            this._geofences.postValue(it)
        }
    }

    fun selectUnit(unit: UnitInformation?, switchToMap: Boolean = true) {
        Log.d("UnitsViewModel", "Selecting unit ${unit?.device?.name}")
        _oldSelectedUnit.postValue(_selectedUnit.value)
        _selectedUnit.postValue(unit)
        if (unit != null && switchToMap) {
            setDisplayMode(UnitsDisplayMode.MAP)
        }
    }

    fun selectUnitWithPositionId(id: Int?, switchToMap: Boolean = true) {
        if (id == null) {
            Log.d("UnitsViewModel", "Deselecting unit")
            selectUnit(null, switchToMap = switchToMap)
            return
        }

        Log.d("UnitsViewModel", "Selecting unit with position id: $id")
        val unit = _units.value?.find { it.position?.id == id }
        selectUnit(unit, switchToMap = switchToMap)
    }

    private fun selectUnitWithUnitId(id: Int?, switchToMap: Boolean = true) {
        if (id == null) {
            Log.d("UnitsViewModel", "Deselecting unit")
            selectUnit(null, switchToMap = switchToMap)
            return
        }

        Log.d("UnitsViewModel", "Selecting unit with device id: $id")
        val unit = _units.value?.find { it.device.id == id }
        selectUnit(unit, switchToMap = switchToMap)
    }

    private fun updateSelectedUnit() {
        selectedUnit.value?.let { selected ->
            Log.d("UnitsViewModel", "Updating selected unit with id: ${selected.device.id}")
            selectUnitWithUnitId(selected.device.id, switchToMap = false)
        }

    }

    fun setDisplayMode(displayMode: UnitsDisplayMode) {
        Log.d("UnitsViewModel", "Setting Display mode to $displayMode")
        _unitsDisplayMode.postValue(displayMode)
    }

    fun setMapLayerType(layer: MapLayer.Type) {
        _mapLayerType.postValue(layer)
    }

    fun toggleDisplayMode() {
        Log.d("UnitsViewModel", "Toggling Display mode")
        val newDisplayMode =
            if (unitsDisplayMode.value == UnitsDisplayMode.MAP) {
                _selectedUnit.postValue(null)
                UnitsDisplayMode.LIST
            } else {
                UnitsDisplayMode.MAP
            }
        _unitsDisplayMode.postValue(newDisplayMode)
    }

    fun search(query: String) {
        unitsController.search(query)
    }

    fun moveCamera(point: Camera) {
        _camera.postValue(point)
    }

    fun clearCamera() {
        _camera.postValue(null)
    }
}