/**
 * 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/>.
 */
import Foundation
import WhirlyGlobe
import shared

class UnitsViewModel: ObservableObject {
    @Inject var unitsController: UnitsController
    @Inject var geofenceController: GeofencesController
    
    let mainScope = MainScope.companion.createMainScope()
    
    enum UnitsDisplayMode {
        case map
        case list
    }
    
    var detailsUnit: UnitInformation? = nil
    var detailsAction = DeviceRow.Action.details
    
    @Published var searchQuery = "" {
        didSet {
            unitsDisplayMode = .list
            search(query: searchQuery)
        }
    }
    @Published var isEditing = false
    @Published var showDetails = false
    @Published var showUserInfo = false
    @Published var unitsDisplayMode: UnitsDisplayMode = .map
    @Published var units: [UnitInformation] = [] {
        didSet {
            markers = units.compactMap(Marker.companion.fromUnit)
        }
    }
    @Published var markers: [Marker] = []
    @Published var oldSelectedUnit: UnitInformation? = nil
    @Published var selectedUnit: UnitInformation? = nil {
        didSet {
            if selectedUnit?.device.id != oldSelectedUnit?.device.id {
                if let unit = selectedUnit {
                    selectedMarker = Marker.companion.fromUnit(unit: unit)
                } else {
                    selectedMarker = nil
                }
            }
        }
    }
    @Published var selectedMarker: Marker? = nil
    @Published var mapLayerType: MapLayer = .companion.defaultLayer
    @Published var geofences: [Int: Geofence] = [:] {
        didSet {
            flatGeofences = Array(geofences.values)
        }
    }
    @Published var flatGeofences: [Geofence] = []
    
    init() {
        unitsController.fetchUnits(scope: mainScope)
        setupObservers()
    }
    
    deinit {
        MainScope.companion.cancelScope(scope: mainScope)
    }
    
    private func setupObservers() {
        let unitsCollector = Collector<[UnitInformation]>(callback: setUnits)
        unitsController.displayedUnitsFlow.collect(collector: unitsCollector) { unit, error in }
        
        let geofencesCollector = Collector<[Int: Geofence]>(callback: setGeofences)
        geofenceController.geofencesFlow.collect(collector: geofencesCollector) { unit, error in }
    }
    
    private func setUnits(units: [UnitInformation]) {
        print("Positions")
        self.units = units
        updateSelectedUnit()
    }
    
    private func setGeofences(geofences: [Int: Geofence]) {
        self.geofences = geofences
    }
    
    func selectUnit(unit: UnitInformation?, switchToMap: Bool = true) {
        print ("Selecting unit \(unit?.device.name ?? "")")
        oldSelectedUnit = selectedUnit
        selectedUnit = unit
        if unit != nil && switchToMap {
            setDisplayMode(UnitsDisplayMode.map)
        }
    }
    
    func selectUnitWith(position id: Int32?, switchToMap: Bool = true) {
        if id == nil {
            print("Deselecting unit")
            selectUnit(unit: nil, switchToMap: switchToMap)
            return
        }
        print("Selecting unit with position id: \(id!)")
        let unit = units.first {
            Int32(truncating: $0.position?.id ?? 0) == id!
        }
        selectUnit(unit: unit, switchToMap: switchToMap)
    }
    
    private func selectUnitWith(id: Int32?, switchToMap: Bool = true) {
        if id == nil {
            print("Deselecting unit")
            selectUnit(unit: nil, switchToMap: switchToMap)
            return
        }
        print("Selecting unit with device id: \(id!)")
        let unit = units.first {
            $0.device.id == id!
        }
        selectUnit(unit: unit, switchToMap: switchToMap)
    }
    
    private func updateSelectedUnit() {
        if let selected = selectedUnit {
            print("Updating selected unit with id: \(selected.device.id)")
            selectUnitWith(id: selected.device.id, switchToMap: false)
        }
    }
    
    func setDisplayMode(_ displayMode: UnitsDisplayMode) {
        unitsDisplayMode = displayMode
    }
    
    func toggleDisplayMode() {
        switch unitsDisplayMode {
        case .map:
            setDisplayMode(.list)
        case .list:
            setDisplayMode(.map)
        }
    }
    
    func search(query: String) {
        unitsController.search(query: query)
    }
    
    func show(action: DeviceRow.Action, for unit: UnitInformation) {
        if action != .close {
            detailsAction = action
            detailsUnit = unit
            showDetails = true
        } else {
            selectedUnit = nil
        }
    }
}