//
//  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
		
		@State private var searchText: String = ""
		var filteredItems: [ExerciseTemplate] {
				if searchText.isEmpty {
						return exerciseTemplates
				} else {
						return exerciseTemplates.filter { $0.name.localizedCaseInsensitiveContains(searchText) }
				}
		}
		
		// TODO: Add search bar to the top
		
		var body: some View {
				NavigationView {
						Group {
								List {
										ForEach(filteredItems) { exerciseTemplate in
												NavigationLink {
														ExerciseDetail(exerciseTemplate: exerciseTemplate)
												} label: {
														Text(exerciseTemplate.name)
												}
										}
										.onDelete(perform: deleteExercise)
										if isAddingExerciseTemplate {
												TextField("New Exercise", text: $newExerciseName, onCommit: {
														newExerciseTemplate.name = newExerciseName
														saveExercise(exerciseTemplate: newExerciseTemplate)
														isAddingExerciseTemplate = false
												})
												.textInputAutocapitalization(.words)
												.focused($isInputFieldFocused)
										}
										AddItemButton(label: "Exercise", action: addExerciseTemplate)
								}
								.searchable(text: $searchText)
						}
						.navigationBarTitle("Exercises")
						.toolbar {
								ToolbarItem {
										EditButton()
								}
						}
				}
		}
		
		private func addExerciseTemplate() {
				withAnimation {
						newExerciseTemplate = ExerciseTemplate("")
						newExerciseName = ""
						isAddingExerciseTemplate = true
						isInputFieldFocused = true
				}
		}
		
		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)
}