//
//  PositionConfig.swift
//  Meshtastic Apple
//
//  Copyright (c) Garth Vander Houwen 6/11/22.
//

import SwiftUI
import MeshtasticProtobufs
import OSLog

struct PositionFlags: OptionSet {
	let rawValue: Int
	static let Altitude = PositionFlags(rawValue: 1)
	static let AltitudeMsl = PositionFlags(rawValue: 2)
	static let GeoidalSeparation = PositionFlags(rawValue: 4)
	static let Dop = PositionFlags(rawValue: 8)
	static let Hvdop = PositionFlags(rawValue: 16)
	static let Satsinview = PositionFlags(rawValue: 32)
	static let SeqNo = PositionFlags(rawValue: 64)
	static let Timestamp = PositionFlags(rawValue: 128)
	static let Speed = PositionFlags(rawValue: 256)
	static let Heading = PositionFlags(rawValue: 512)
}

struct PositionConfig: View {
	
	@Environment(\.modelContext) private var context
	@EnvironmentObject var accessoryManager: AccessoryManager
	@Environment(\.dismiss) private var goBack
	var node: NodeInfoEntity?
	@State var hasChanges = false
	@State var hasFlagChanges = false
	@State var smartPositionEnabled = true
	@State var deviceGpsEnabled = true
	@State var gpsMode = 0
	@State var rxGpio = 0
	@State var txGpio = 0
	@State var gpsEnGpio = 0
	@State var fixedPosition = false
	@State var gpsUpdateInterval = 0
	@State private var positionBroadcastSeconds: UpdateInterval = UpdateInterval(from: 0)
	@State var broadcastSmartMinimumDistance = 0
	@State private var broadcastSmartMinimumIntervalSecs: UpdateInterval = UpdateInterval(from: 0)
	@State var positionFlags = 811
	
	/// Position Flags
	/// Altitude value - 1
	@State var includeAltitude = false
	/// Altitude value is MSL - 2
	@State var includeAltitudeMsl = false
	/// Include geoidal separation - 4
	@State var includeGeoidalSeparation = false
	/// Include the DOP value ; PDOP used by default, see below - 8
	@State var includeDop = false
	/// If POS_DOP set, send separate HDOP / VDOP values instead of PDOP - 16
	@State var includeHvdop = false
	/// Include number of "satellites in view" - 32
	@State var includeSatsinview = false
	/// Include a sequence number incremented per packet - 64
	@State var includeSeqNo = false
	/// Include positional timestamp (from GPS solution) - 128
	@State var includeTimestamp = false
	/// Include positional heading - 256
	/// Intended for use with vehicle not walking speeds
	/// walking speeds are likely to be error prone like the compass
	@State var includeSpeed = false
	/// Include positional speed - 512
	/// Intended for use with vehicle not walking speeds
	/// walking speeds are likely to be error prone like the compass
	@State var includeHeading = false
	/// Minimum Version for fixed postion admin messages
	@State var minimumVersion = "2.3.3"
	@State private var supportedVersion = true
	@State private var showingSetFixedAlert = false
	// @State private var showingRemoveFixedAlert = false
	
	@ViewBuilder
	var positionPacketSection: some View {
		Section(header: Text("Position Packet")) {
			
			VStack(alignment: .leading) {
				UpdateIntervalPicker(
					config: .broadcastMedium,
					pickerLabel: "Broadcast Interval",
					selectedInterval: $positionBroadcastSeconds
				)
				Text("The maximum interval that can elapse without a node broadcasting a position")
					.foregroundColor(.gray)
					.font(.callout)
			}
			
			Toggle(isOn: $smartPositionEnabled) {
				Label("Smart Position", systemImage: "brain")
			}
			.toggleStyle(SwitchToggleStyle(tint: .accentColor))
			
			if smartPositionEnabled {
				VStack(alignment: .leading) {
					UpdateIntervalPicker(
						config: .smartBroadcastMinimum,
						pickerLabel: "Minimum Interval",
						selectedInterval: $broadcastSmartMinimumIntervalSecs
					)
					Text("The fastest that position updates will be sent if the minimum distance has been satisfied")
						.foregroundColor(.gray)
						.font(.callout)
				}
				VStack(alignment: .leading) {
					Picker("Minimum Distance", selection: $broadcastSmartMinimumDistance) {
						ForEach(10..<151) {
							if $0 == 0 {
								Text("Unset")
							} else {
								if $0.isMultiple(of: 5) {
									Text("\($0)")
										.tag($0)
								}
							}
						}
					}
					.pickerStyle(DefaultPickerStyle())
					Text("The minimum distance change in meters to be considered for a smart position broadcast.")
						.foregroundColor(.gray)
						.font(.callout)
				}
			}
		}
	}
	
	@ViewBuilder
	var deviceGPSSection: some View {
		Section(header: Text("Device GPS")) {
			Picker("", selection: $gpsMode) {
				ForEach(GpsMode.allCases, id: \.self) { at in
					Text(at.description)
						.tag(at.id)
				}
			}
			.pickerStyle(SegmentedPickerStyle())
			.padding(.top, 5)
			.padding(.bottom, 5)
			.disabled(fixedPosition && !(gpsMode == 1))
			if gpsMode == 1 {
				Text("Positions will be provided by your device GPS, if you select disabled or not present you can set a fixed position.")
					.foregroundColor(.gray)
					.font(.callout)
				VStack(alignment: .leading) {
					Picker("Update Interval", selection: $gpsUpdateInterval) {
						ForEach(GpsUpdateIntervals.allCases) { ui in
							Text(ui.description)
						}
					}
					Text("How often should we try to get a GPS position.")
						.foregroundColor(.gray)
						.font(.callout)
				}
			}
			if (gpsMode != 1 && node?.num ?? 0 == accessoryManager.activeDeviceNum ?? -1) || fixedPosition {
				VStack(alignment: .leading) {
					Toggle(isOn: $fixedPosition) {
						Label("Fixed Position", systemImage: "location.square.fill")
						if !(node?.positionConfig?.fixedPosition ?? false) {
							Text("Your current location will be set as the fixed position and broadcast over the mesh on the position interval.")
						} else {
							
						}
					}
					.toggleStyle(SwitchToggleStyle(tint: .accentColor))
				}
			}
		}
	}
	
	@ViewBuilder
	var positionFlagsSection: some View {
		Section(header: Text("Position Flags")) {
			
			Text("Optional fields to include when assembling position messages. the more fields are included, the larger the message will be - leading to longer airtime and a higher risk of packet loss")
				.foregroundColor(.gray)
				.font(.callout)
			
			Toggle(isOn: $includeAltitude) {
				Label("Altitude", systemImage: "arrow.up")
			}
			.toggleStyle(SwitchToggleStyle(tint: .accentColor))
			.onChange(of: includeAltitude) { _, newIncludeAltitude in
				if newIncludeAltitude != PositionFlags(rawValue: self.positionFlags).contains(.Altitude) { hasChanges = true }
			}
			
			Toggle(isOn: $includeSatsinview) {
				Label("Number of satellites", systemImage: "skew")
			}
			.toggleStyle(SwitchToggleStyle(tint: .accentColor))
			.onChange(of: includeSatsinview) { _, newIncludeSatsinview in
				if newIncludeSatsinview != PositionFlags(rawValue: self.positionFlags).contains(.Satsinview) { hasChanges = true }
			}
			
			Toggle(isOn: $includeSeqNo) { // 64
				Label("Sequence number", systemImage: "number")
			}
			.toggleStyle(SwitchToggleStyle(tint: .accentColor))
			.onChange(of: includeSeqNo) { _, newIncludeSeqNo in
				if newIncludeSeqNo != PositionFlags(rawValue: self.positionFlags).contains(.SeqNo) { hasChanges = true }
			}
			
			Toggle(isOn: $includeTimestamp) { // 128
				Label("Timestamp", systemImage: "clock")
			}
			.toggleStyle(SwitchToggleStyle(tint: .accentColor))
			.onChange(of: includeTimestamp) { _, newIncludeTimestamp in
				if newIncludeTimestamp != PositionFlags(rawValue: self.positionFlags).contains(.Timestamp) { hasChanges = true }
			}
			
			Toggle(isOn: $includeHeading) { // 128
				Label("Vehicle heading", systemImage: "location.circle")
			}
			.toggleStyle(SwitchToggleStyle(tint: .accentColor))
			.onChange(of: includeHeading) { _, newIncludeHeading in
				if newIncludeHeading != PositionFlags(rawValue: self.positionFlags).contains(.Heading) { hasChanges = true }
			}
			
			Toggle(isOn: $includeSpeed) { // 128
				Label("Vehicle speed", systemImage: "speedometer")
			}
			.toggleStyle(SwitchToggleStyle(tint: .accentColor))
			.onChange(of: includeSpeed) { _, newIncludeSpeed in
				if newIncludeSpeed != PositionFlags(rawValue: self.positionFlags).contains(.Speed) { hasChanges = true }
			}
		}
	}
	
	@ViewBuilder
	var advancedPositionFlagsSection: some View {
		Section(header: Text("Advanced Position Flags")) {
			
			if includeAltitude {
				Toggle(isOn: $includeAltitudeMsl) {
					Label("Altitude is Mean Sea Level", systemImage: "arrow.up.to.line.compact")
				}
				.toggleStyle(SwitchToggleStyle(tint: .accentColor))
				.onChange(of: includeAltitudeMsl) { _, newIncludeAltitudeMsl in
					if newIncludeAltitudeMsl != PositionFlags(rawValue: self.positionFlags).contains(.AltitudeMsl) { hasChanges = true }
				}
				
				Toggle(isOn: $includeGeoidalSeparation) {
					Label("Altitude Geoidal Separation", systemImage: "globe.americas")
				}
				.toggleStyle(SwitchToggleStyle(tint: .accentColor))
				.onChange(of: includeGeoidalSeparation) { _, newIncludeGeoidalSeparation in
					if newIncludeGeoidalSeparation != PositionFlags(rawValue: self.positionFlags).contains(.GeoidalSeparation) { hasChanges = true }
				}
			}
			
			Toggle(isOn: $includeDop) {
				Text("Dilution of precision (DOP) PDOP used by default")
			}
			.toggleStyle(SwitchToggleStyle(tint: .accentColor))
			.onChange(of: includeDop) { _, newIncludeDop in
				if newIncludeDop != PositionFlags(rawValue: self.positionFlags).contains(.Dop) { hasChanges = true }
			}
			
			if includeDop {
				Toggle(isOn: $includeHvdop) {
					Text("If DOP is set, use HDOP / VDOP values instead of PDOP")
				}
				.toggleStyle(SwitchToggleStyle(tint: .accentColor))
				.onChange(of: includeHvdop) { _, newIncludeHvdop in
					if newIncludeHvdop != PositionFlags(rawValue: self.positionFlags).contains(.Hvdop) { hasChanges = true }
				}
			}
		}
	}
	
	@ViewBuilder
	var advancedDeviceGPSSection: some View {
		Section(header: Text("Advanced Device GPS")) {
			Picker("GPS Receive GPIO", selection: $rxGpio) {
				ForEach(0..<49) {
					if $0 == 0 {
						Text("Unset")
					} else {
						Text("Pin \($0)")
					}
				}
			}
			.pickerStyle(DefaultPickerStyle())
			Picker("GPS Transmit GPIO", selection: $txGpio) {
				ForEach(0..<49) {
					if $0 == 0 {
						Text("Unset")
					} else {
						Text("Pin \($0)")
					}
				}
			}
			.pickerStyle(DefaultPickerStyle())
			Picker("GPS EN GPIO", selection: $gpsEnGpio) {
				ForEach(0..<49) {
					if $0 == 0 {
						Text("Unset")
					} else {
						Text("Pin \($0)")
					}
				}
			}
			.pickerStyle(DefaultPickerStyle())
			Text("(Re)define PIN_GPS_EN for your board.")
				.font(.caption)
		}
	}
	var saveButton: some View {
		SaveConfigButton(node: node, hasChanges: $hasChanges) {
			if fixedPosition && !supportedVersion {
				Task {
					try await accessoryManager.sendPosition(channel: 0, destNum: node?.num ?? 0, wantResponse: true)
				}
			}
			if let deviceNum = accessoryManager.activeDeviceNum, let connectedNode = getNodeInfo(id: deviceNum, context: context) {
				var pc = Config.PositionConfig()
				pc.positionBroadcastSmartEnabled = smartPositionEnabled
				pc.gpsEnabled = gpsMode == 1
				pc.gpsMode = Config.PositionConfig.GpsMode(rawValue: gpsMode) ?? Config.PositionConfig.GpsMode.notPresent
				pc.fixedPosition = fixedPosition
				pc.gpsUpdateInterval = UInt32(gpsUpdateInterval)
				pc.positionBroadcastSecs = UInt32(positionBroadcastSeconds.intValue)
				pc.broadcastSmartMinimumIntervalSecs = UInt32(broadcastSmartMinimumIntervalSecs.intValue)
				pc.broadcastSmartMinimumDistance = UInt32(broadcastSmartMinimumDistance)
				pc.rxGpio = UInt32(rxGpio)
				pc.txGpio = UInt32(txGpio)
				pc.gpsEnGpio = UInt32(gpsEnGpio)
				var pf: PositionFlags = []
				if includeAltitude { pf.insert(.Altitude) }
				if includeAltitudeMsl { pf.insert(.AltitudeMsl) }
				if includeGeoidalSeparation { pf.insert(.GeoidalSeparation) }
				if includeDop { pf.insert(.Dop) }
				if includeHvdop { pf.insert(.Hvdop) }
				if includeSatsinview { pf.insert(.Satsinview) }
				if includeSeqNo { pf.insert(.SeqNo) }
				if includeTimestamp { pf.insert(.Timestamp) }
				if includeSpeed { pf.insert(.Speed) }
				if includeHeading { pf.insert(.Heading) }
				pc.positionFlags = UInt32(pf.rawValue)
				Task {
					_ = try await accessoryManager.savePositionConfig(config: pc, fromUser: connectedNode.user!, toUser: node!.user!)
					Task { @MainActor in
						// Disable the button after a successful save
						hasChanges = false
						goBack()
					}
				}
			}
		}
	}
	
	var setFixedAlertTitle: String {
		if node?.positionConfig?.fixedPosition == true {
			return "Remove Fixed Position"
		} else {
			return "Set Fixed Position"
		}
	}
	
	var body: some View {
		
		Form {
			ConfigHeader(title: "Position", config: \.positionConfig, node: node, onAppear: setPositionValues)
			positionPacketSection
			deviceGPSSection
			positionFlagsSection
			advancedPositionFlagsSection
			if gpsMode == 1 {
				advancedDeviceGPSSection
			}
		}
		.disabled(!accessoryManager.isConnected || node?.positionConfig == nil)
		.alert(setFixedAlertTitle, isPresented: $showingSetFixedAlert) {
			Button("Cancel", role: .cancel) {
				fixedPosition = !fixedPosition
			}
			if node?.positionConfig?.fixedPosition ?? false {
				Button("Remove", role: .destructive) {
					removeFixedPosition()
				}
			} else {
				Button("Set") {
					setFixedPosition()
				}
			}
		} message: {
			Text(node?.positionConfig?.fixedPosition ?? false ? "This will disable fixed position and remove the currently set position." : "This will send a current position from your phone and enable fixed position.")
		}
		.safeAreaInset(edge: .bottom, alignment: .center) {
			HStack(spacing: 0) {
				saveButton
			}
		}
		.navigationTitle("Position Config")
		.navigationBarItems(
			trailing: ZStack {
				ConnectedDevice(deviceConnected: accessoryManager.isConnected, name: accessoryManager.activeConnection?.device.shortName ?? "?")
			}
		)
		.onFirstAppear {
			supportedVersion = accessoryManager.checkIsVersionSupported(forVersion: minimumVersion)
			// Need to request a NetworkConfig from the remote node before allowing changes
			if let deviceNum = accessoryManager.activeDeviceNum, let node {
				let connectedNode = getNodeInfo(id: deviceNum, context: context)
				if let connectedNode {
					if node.num != deviceNum {
						if UserDefaults.enableAdministration {
							/// 2.5 Administration with session passkey
							let expiration = node.sessionExpiration ?? Date()
							if expiration < Date() || node.positionConfig == nil {
								Task {
									do {
										Logger.mesh.info("⚙️ Empty or expired position config requesting via PKI admin")
										try await accessoryManager.requestPositionConfig(fromUser: connectedNode.user!, toUser: node.user!)
									} catch {
										Logger.mesh.info("🚨 Position config request failed")
									}
								}
							}
						} else {
							/// Legacy Administration
							Logger.mesh.info("☠️ Using insecure legacy admin that is no longer supported, please upgrade your firmware.")
						}
					}
				}
			}
		}
		.onChange(of: fixedPosition) { _, newFixed in
			if supportedVersion {
				if let positionConfig = node?.positionConfig {
					/// Fixed Position is off to start
					if !positionConfig.fixedPosition && newFixed {
						showingSetFixedAlert = true
					} else if positionConfig.fixedPosition && !newFixed {
						/// Fixed Position is on to start
						showingSetFixedAlert = true
					}
				}
			}
		}
		.onChange(of: gpsMode) { _, newGpsMode in
			if newGpsMode != node?.positionConfig?.gpsMode ?? 0 { hasChanges = true }
		}
		.onChange(of: rxGpio) { _, newRxGpio in
			if newRxGpio != node?.positionConfig?.rxGpio ?? 0 { hasChanges = true }
		}
		.onChange(of: txGpio) { _, newTxGpio in
			if newTxGpio != node?.positionConfig?.txGpio ?? 0 { hasChanges = true }
		}
		.onChange(of: gpsEnGpio) { _, newGpsEnGpio in
			if newGpsEnGpio != node?.positionConfig?.gpsEnGpio ?? 0 { hasChanges = true }
		}
		.onChange(of: smartPositionEnabled) { _, newSmartPositionEnabled in
			if newSmartPositionEnabled != node?.positionConfig?.smartPositionEnabled { hasChanges = true }
		}
		.onChange(of: positionBroadcastSeconds.intValue) { _, newPositionBroadcastSeconds in
			if newPositionBroadcastSeconds != node?.positionConfig?.positionBroadcastSeconds ?? 0 { hasChanges = true }
		}
		.onChange(of: broadcastSmartMinimumIntervalSecs.intValue) { _, newBroadcastSmartMinimumIntervalSecs in
			if newBroadcastSmartMinimumIntervalSecs != node?.positionConfig?.broadcastSmartMinimumIntervalSecs ?? 0 { hasChanges = true }
		}
		.onChange(of: broadcastSmartMinimumDistance) { _, newBroadcastSmartMinimumDistance in
			if newBroadcastSmartMinimumDistance != node?.positionConfig?.broadcastSmartMinimumDistance ?? 0 { hasChanges = true }
		}
		.onChange(of: gpsUpdateInterval) { _, newGpsUpdateInterval in
			if newGpsUpdateInterval != node?.positionConfig?.gpsUpdateInterval ?? 0 { hasChanges = true }
		}
	}
	
	func handlePositionFlagtChanges() {
		guard (node?.positionConfig) != nil else { return }
		let pf = PositionFlags(rawValue: self.positionFlags)
		hasChanges =
		pf.contains(.Altitude) ||
		pf.contains(.AltitudeMsl) ||
		pf.contains(.Satsinview) ||
		pf.contains(.SeqNo) ||
		pf.contains(.Timestamp) ||
		pf.contains(.Speed) ||
		pf.contains(.Heading) ||
		pf.contains(.GeoidalSeparation) ||
		pf.contains(.Dop) ||
		pf.contains(.Hvdop)
	}
	
	func setPositionValues() {
		self.smartPositionEnabled = node?.positionConfig?.smartPositionEnabled ?? true
		self.deviceGpsEnabled = node?.positionConfig?.deviceGpsEnabled ?? false
		self.gpsMode = Int(node?.positionConfig?.gpsMode ?? 0)
		if node?.positionConfig?.deviceGpsEnabled ?? false && gpsMode != 1 {
			self.gpsMode = 1
		}
		self.rxGpio = Int(node?.positionConfig?.rxGpio ?? 0)
		self.txGpio = Int(node?.positionConfig?.txGpio ?? 0)
		self.gpsEnGpio = Int(node?.positionConfig?.gpsEnGpio ?? 0)
		self.fixedPosition = node?.positionConfig?.fixedPosition ?? false
		self.gpsUpdateInterval = Int(node?.positionConfig?.gpsUpdateInterval ?? 30)
		self.positionBroadcastSeconds = UpdateInterval(from: Int(node?.positionConfig?.positionBroadcastSeconds ?? 3600))
		self.broadcastSmartMinimumIntervalSecs = UpdateInterval(from: Int(node?.positionConfig?.broadcastSmartMinimumIntervalSecs ?? 30))
		self.broadcastSmartMinimumDistance = Int(node?.positionConfig?.broadcastSmartMinimumDistance ?? 50)
		self.positionFlags = Int(node?.positionConfig?.positionFlags ?? 3)
		let pf = PositionFlags(rawValue: self.positionFlags)
		self.includeAltitude = pf.contains(.Altitude)
		self.includeAltitudeMsl = pf.contains(.AltitudeMsl)
		self.includeGeoidalSeparation = pf.contains(.GeoidalSeparation)
		self.includeDop = pf.contains(.Dop)
		self.includeHvdop = pf.contains(.Hvdop)
		self.includeSatsinview = pf.contains(.Satsinview)
		self.includeSeqNo = pf.contains(.SeqNo)
		self.includeTimestamp = pf.contains(.Timestamp)
		self.includeSpeed = pf.contains(.Speed)
		self.includeHeading = pf.contains(.Heading)
		self.hasChanges = false
	}
	
	private func setFixedPosition() {
		guard let nodeNum = accessoryManager.activeDeviceNum,
			  nodeNum > 0 else { return }
		Task {
			do {
				try await accessoryManager.setFixedPosition(fromUser: node!.user!, channel: 0)
			} catch {
				Logger.mesh.error("Set Position Failed")
			}
		}
		node?.positionConfig?.fixedPosition = true
		do {
			try context.save()
			Logger.data.info("💾 Updated Position Config with Fixed Position = true")
		} catch {
			context.rollback()
			let nsError = error as NSError
			Logger.data.error("Error Saving Position Config Entity \(nsError, privacy: .public)")
		}
	}
	
	private func removeFixedPosition() {
		guard let nodeNum = accessoryManager.activeDeviceNum,
			  nodeNum > 0 else { return }
		Task {
			do {
				try await accessoryManager.removeFixedPosition(fromUser: node!.user!, channel: 0)
			} catch {
				Logger.mesh.error("Remove Fixed Position Failed")
			}
		}
		node?.positions = []
		node?.positionConfig?.fixedPosition = false
		do {
			try context.save()
			Logger.data.info("💾 Updated Position Config with Fixed Position = false")
		} catch {
			context.rollback()
			let nsError = error as NSError
			Logger.data.error("Error Saving Position Config Entity \(nsError, privacy: .public)")
		}
	}
}

#Preview {
	PositionConfig(node: nil)
		.environmentObject(AccessoryManager.shared)
		.modelContainer(PersistenceController.preview.container)
}