import SwiftUI
import SwiftData

struct ActiveWorkoutSession: View {
		@Environment(\.modelContext) private var modelContext
		
		@Default(\.isWorkingOut) var isWorkingOut
		@State var isTimerRunning: Bool = true
		
		@Query(sort: \WorkoutSession.name) var workoutSessions: [WorkoutSession]
		@State var activeWorkoutSession: WorkoutSession?
		@Default(\.activeWorkoutSessionId) var activeWorkoutSessionId
		
		@Query(sort: \Workout.name) var workouts: [Workout]
		@State var activeWorkout: Workout?
		@Default(\.activeWorkoutId) var activeWorkoutId
		
		var body: some View {
				VStack {
						List {
								Section(header: Text("Workout"), footer: Text(activeWorkoutSession?.creationDate.ISO8601Format() ?? "Unknown Date")) {
										NavigationLink(destination: {
												ItemPicker<Workout>(selectedItem: $activeWorkout, items: workouts)
										}) {
												Text(activeWorkout?.name ?? "Select Workout")
										}
										.onChange(of: activeWorkout) { _, newWorkout in
												if let newWorkout {
														activeWorkoutId = newWorkout.id.uuidString
														activeWorkoutSession?.workout = newWorkout
												}
										}
								}
								
								if let activeWorkout {
										Section(header: Text("Exercises")) {
												ForEach(getActiveWorkoutItems(activeWorkout: activeWorkout)) { workoutItem in
														ActiveWorkoutSessionListItem(workoutItem: workoutItem)
												}
										}
								} else {
										ContentUnavailableView {
												Label("Select a Workout", systemImage: "arrow.up")
										}
								}
						}
						// MARK: Workout Controls
						if (isWorkingOut) {
								if activeWorkoutSession != nil {
										ActiveWorkoutSessionControls(
												session: Binding(
														get: { self.activeWorkoutSession! },
														set: { self.activeWorkoutSession = $0 }
												))
								}
						}
				}
				.navigationTitle("Session")
				.toolbar {
						if (isWorkingOut) {
								Button(action: {
										isWorkingOut = false
										activeWorkoutSession?.stop()
								}) {
										HStack {
												Image(systemName: "stop.fill")
												Text("Stop")
										}
								}
								.bold()
								.fontDesign(.rounded)
								.tint(.red)
						} else {
								Button(action: {
										isWorkingOut = true
										if let activeWorkout {
												activeWorkoutSession?.start(with: activeWorkout)
										}
								}) {
										HStack {
												Image(systemName: "play.fill")
												Text("Start")
										}
								}
								.bold()
								.fontDesign(.rounded)
								.tint(.green)
						}
				}
				.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 getActiveWorkoutItems(activeWorkout: Workout?) -> [WorkoutItem] {
				guard let activeWorkout else { return [] }
				return activeWorkout.getWorkoutItems()
		}
		
		//		TODO: Put this somewhere general
		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("RR Selected") {
		@Previewable @State var activeWorkout = Workout.sampleData.first!
		NavigationStack {
				ActiveWorkoutSession(activeWorkout: activeWorkout)
		}
		.onAppear {
				Defaults.shared.isWorkingOut = false
		}
		.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()
		}
}