import SwiftUI
import SwiftData

struct ActiveWorkoutSession: View {
		@Environment(\.modelContext) private var modelContext
		
		@Default(\.isWorkingOut) var isWorkingOut
		
		@Query(sort: \WorkoutSession.name) private var workoutSessions: [WorkoutSession]
		@State private var activeWorkoutSession: WorkoutSession?
		@Default(\.activeWorkoutSessionId) var activeWorkoutSessionId
		
		@Query(sort: \Workout.name) private var workouts: [Workout]
		@State private var activeWorkout: Workout?
		@Default(\.activeWorkoutId) var activeWorkoutId
		
		var body: some View {
				VStack {
						List {
								Section(footer: Text(activeWorkoutSession?.creationDate.ISO8601Format() ?? "Unknown Date")) {
										NavigationLink(destination: {
												ItemPicker<Workout>(items: workouts, selectedItem: $activeWorkout)
										}) {
												Text(activeWorkout?.name ?? "Select your next Workout")
										}
										.onChange(of: activeWorkout) { _, newWorkout in
												if let workout = newWorkout {
														activeWorkoutId = workout.id.uuidString
														activeWorkoutSession?.workout = workout
												}
										}
								}
								
								if let activeWorkout = activeWorkout {
										Section(header: Text("Exercises")) {
												ForEach(activeWorkout.workoutItems.sorted(by: { $0.position < $1.position })) { workoutItem in
														HStack {
																Text(String(workoutItem.reps))
																Text(workoutItem.name)
																Spacer()
																Button(action: {
																		// TODO: Implement a sheet view; don't use ExerciseDetail since its purpose is editing
																}) {
																		Image(systemName: "info.circle")
																				.foregroundColor(.blue)
																}
														}
												}
										}
								}
						}
						
						if true { // This condition should be more meaningful.
								VStack {
										HStack {
												Text(String(workoutSessions.count))
												Button(action: {
														// save(workoutSession: activeWorkoutSession)
												}) {
														Text("Save Session")
												}
												.buttonStyle(.borderedProminent)
										}
								}
						}
						
						// MARK: -- Workout Controls
						Group {
								if activeWorkoutSession?.workout != nil {
										if isWorkingOut {
												// MARK: -- Stop Workout
												VStack {
														ProgressView("", value: 10, total: 100)
														TimerView(isActive: $isWorkingOut)
																.font(.title)
																.bold()
														Button(action: {
																isWorkingOut = false
																activeWorkoutSession?.startWorkoutSession()
														}) {
																HStack {
																		Image(systemName: "stop.fill")
																		Text("Stop Workout")
																}
														}
														.buttonStyle(.borderedProminent)
														.bold()
														.tint(.red)
												}
										} else {
												// MARK: -- Start Workout
												Button(action: {
														isWorkingOut = true
														activeWorkoutSession?.stopWorkoutSession()
												}) {
														HStack {
																Image(systemName: "play.fill")
																Text("Start Workout")
														}
												}
												.buttonStyle(.borderedProminent)
												.bold()
												.tint(.green)
										}
								}
						}
				}
				.navigationTitle("Workout Session")
				.onAppear {
						// Load the active workout session and workout onAppear
						if let activeWorkoutSession = getItem(from: workoutSessions, by: activeWorkoutSessionId) {
								self.activeWorkoutSession = activeWorkoutSession
								if let workout = getItem(from: workouts, by: activeWorkoutId) {
										self.activeWorkout = workout
								}
						} else {
								createNewWorkoutSession()
						}
				}
		}
		
		private func createNewWorkoutSession() {
				let newWorkoutSession = WorkoutSession()
				activeWorkoutSessionId = newWorkoutSession.id.uuidString
				if let selectedWorkout = getItem(from: workouts, by: activeWorkoutId) {
						newWorkoutSession.workout = selectedWorkout
				}
				self.activeWorkoutSession = newWorkoutSession
		}
		
		private func getItem<Item: Nameable>(from array: [Item], by id: String) -> Item? {
				let filteredItems = array.filter { $0.id == UUID(uuidString: id) }
				return filteredItems.count == 1 ? filteredItems.first : nil
		}
}

#Preview {
		NavigationStack {
				ActiveWorkoutSession()
		}
		.modelContainer(SampleData.shared.modelContainer)
}

#Preview("No Workout Selected") {
		NavigationStack {
				ActiveWorkoutSession()
		}
		.onAppear {
				Defaults.shared.isWorkingOut = false
		}
		.modelContainer(SampleData.shared.modelContainer)
}

#Preview("No Workout Data available") {
		NavigationStack {
				ActiveWorkoutSession()
		}
}