//
//  ExerciseLibraryView.swift
//  WorkoutsPlus
//
//  Created by Felix Förtsch on 10.08.24.
//

import SwiftUI
import SwiftData

struct ExerciseLibrary: View {
		@Environment(\.modelContext) private var modelContext
		@Query(sort: \ExerciseTemplate.name) private var exerciseTemplates: [ExerciseTemplate]
		
		@State private var newExerciseTemplate: ExerciseTemplate = ExerciseTemplate("")
		@State private var newExerciseName: String = ""
		@State private var isAddingExerciseTemplate: Bool = false
		
		@FocusState private var isInputFieldFocused: Bool
		
		// TODO: Add search bar to the top
		
		var body: some View {
				NavigationView {
						Group {
								if !exerciseTemplates.isEmpty {
										List {
												ForEach(exerciseTemplates) { exerciseTemplate in
														NavigationLink {
																ExerciseDetail(exerciseTemplate: exerciseTemplate)
														} label: {
																Text(exerciseTemplate.name)
														}
												}
												.onDelete(perform: deleteExercise)
												if isAddingExerciseTemplate {
																TextField("New Exercise", text: $newExerciseName, onCommit: {
																		newExerciseTemplate.name = newExerciseName
																		saveExercise(exerciseTemplate: newExerciseTemplate)
																		isAddingExerciseTemplate = false
																})
																.focused($isInputFieldFocused)
												}
												Button(action: {
														withAnimation {
																newExerciseTemplate = ExerciseTemplate("")
																newExerciseName = ""
																isAddingExerciseTemplate = true
																isInputFieldFocused = true
														}
												}) {
														HStack {
																Image(systemName: "plus.circle.fill")
																Text("Add Item")
														}
												}
										}
								} else {
										ContentUnavailableView {
												Label("No Exercises", systemImage: ExerciseTemplate.systemImage)
										}
								}
						}
						.navigationBarTitle("Exercises")
						.toolbar {
								ToolbarItem {
										EditButton()
								}
						}
				}
		}
		
		private func saveExercise(exerciseTemplate: ExerciseTemplate) {
				if !exerciseTemplate.name.isEmpty {
						modelContext.insert(exerciseTemplate)
						try? modelContext.save()
				}
		}
		
		private func deleteExercise(offsets: IndexSet) {
				withAnimation {
						for index in offsets {
								modelContext.delete(exerciseTemplates[index])
						}
						try? modelContext.save()
				}
		}
}

#Preview("With Sample Data") {
		ExerciseLibrary()
				.modelContainer(SampleData.shared.modelContainer)
}

#Preview("Empty Database") {
		ExerciseLibrary()
				.modelContainer(for: Exercise.self, inMemory: true)
}