//
//  SettingsView.swift
//  NetNewsWire-iOS
//
//  Created by Stuart Breckenridge on 12/11/2022.
//  Copyright © 2022 Ranchero Software. All rights reserved.
//

import SwiftUI
import Account
import UniformTypeIdentifiers
import UserNotifications

struct SettingsView: View {
	
	@Environment(\.dismiss) var dismiss
	@Environment(\.scenePhase) var scenePhase
	@StateObject private var appDefaults = AppDefaults.shared
	@StateObject private var viewModel = SettingsViewModel()
	
	@Binding var isConfigureAppearanceShown: Bool

	var body: some View {
		NavigationStack {
			List {
				devicePermissionsSection
				accountsAndOPMLSection
				appearanceSection
				helpSection
			}
			.tint(Color(uiColor: AppAssets.primaryAccentColor))
			.listStyle(.insetGrouped)
			.navigationTitle(Text("navigation.title.settings", comment: "Settings"))
			.navigationBarTitleDisplayMode(.inline)
			.toolbar {
				ToolbarItem(placement: .navigationBarLeading, content: {
					Button(action: { dismiss() }, label: { Text("button.title.done", comment: "Done") })
				})
			}
			.sheet(isPresented: $viewModel.showAddAccountView) {
				AddAccountListView()
			}
			.sheet(isPresented: $viewModel.showHelpSheet) {
				SafariView(url: viewModel.helpSheet.url)
			}
			.sheet(isPresented: $viewModel.showAbout) {
				AboutView()
			}
			.task {
				let settings = await UNUserNotificationCenter.current().notificationSettings()
				Task { await MainActor.run { self.viewModel.notificationPermissions = settings.authorizationStatus }}
			}
			.onChange(of: scenePhase, perform: { phase in
				if phase == .active {
					UNUserNotificationCenter.current().getNotificationSettings { settings in
						Task { await MainActor.run { self.viewModel.notificationPermissions = settings.authorizationStatus }}
					}
				}
			})
			.dismissOnExternalContextLaunch()
			.fileImporter(isPresented: $viewModel.showImportView, allowedContentTypes: OPMLDocument.readableContentTypes) { result in
				switch result {
				case .success(let url):
					if url.startAccessingSecurityScopedResource() {
						viewModel.importAccount!.importOPML(url) { importResult in
							switch importResult {
							case .success(_):
								viewModel.showImportSuccess = true
								url.stopAccessingSecurityScopedResource()
							case .failure(let error):
								viewModel.importExportError = error
								viewModel.showImportExportError = true
								url.stopAccessingSecurityScopedResource()
							}
						}
					}
				case .failure(let error):
					viewModel.importExportError = error
					viewModel.showImportExportError = true
				}
			}
			.fileExporter(isPresented: $viewModel.showExportView, document: viewModel.exportDocument, contentType: OPMLDocument.writableContentTypes.first!, onCompletion: { result in
				switch result {
				case .success(_):
					viewModel.showExportSuccess = true
				case .failure(let error):
					viewModel.importExportError = error
					viewModel.showImportExportError = true
				}
			})
			.alert(Text("alert.title.opml.opml-import-success", comment: "Alert title: Imported Successfully"),
				   isPresented: $viewModel.showImportSuccess,
				   actions: {},
				   message: { Text("alert.message.opml-import-success.%@", comment: "Subscriptions have been imported to your “%@“ account.") })
			.alert(Text("alert.title.opml.opml-export-success", comment: "Alert title: Exported Successfully"),
				   isPresented: $viewModel.showExportSuccess,
				   actions: {},
				   message: { Text("alert.message.opml.opml-export-success", comment: "Your subscriptions have been exported successfully.") })
			.alert(Text("alert.title.error", comment: "Error"),
				   isPresented: $viewModel.showImportExportError,
				   actions: {},
				   message: { Text(verbatim: viewModel.importExportError?.localizedDescription ?? "") } )
		}
		.navigationViewStyle(.stack)
	}

	@ViewBuilder
	private var devicePermissionsSection: some View {
		Section(header: Text("label.text.device-permissions", comment: "Device Permissions"),
				footer: Text("label.text.device-permissions-explainer", comment: "Configure NetNewsWire's access to Siri, background app refresh, mobile data, and more.")) {
			SettingsRow.openSystemSettings
		}
	}

	@ViewBuilder
	private var accountsAndOPMLSection: some View {
		Section(header: Text("label.text.accounts", comment: "Settings: Accounts section header."),
				footer: Text("label.text.account-explainer", comment: "Add, delete, enable, or disable accounts.")) {
			SettingsRow.addAccount
			SettingsRow.importOPML(showImportActionSheet: $viewModel.showImportActionSheet)
				.confirmationDialog(Text("actionsheet.title.choose-opml-destination", comment: "Choose an account to receive the imported feeds and folders"),
									isPresented: $viewModel.showImportActionSheet,
									titleVisibility: .visible) {
					ForEach(AccountManager.shared.sortedActiveAccounts, id: \.self) { account in
						Button(account.nameForDisplay) {
							viewModel.importAccount = account
							viewModel.showImportView = true
						}
					}
				}

			SettingsRow.exportOPML(showExportActionSheet: $viewModel.showExportActionSheet)
				.confirmationDialog(Text("actionsheet.title.choose-opml-export-account", comment: "Choose an account with the subscriptions to export"),
									isPresented: $viewModel.showExportActionSheet,
									titleVisibility: .visible) {
					ForEach(AccountManager.shared.sortedAccounts, id: \.self) { account in
						Button(account.nameForDisplay) {
							do {
								let document = try OPMLDocument(account)
								viewModel.exportDocument = document
								viewModel.showExportView = true
							} catch {
								viewModel.importExportError = error
								viewModel.showImportExportError = true
							}
						}
					}
				}
		}
	}

	@ViewBuilder
	private var appearanceSection: some View {
		Section(header: Text("label.text.appearance", comment: "Settings: Appearance section header."),
				footer: Text("label.text.appearance-explainer", comment: "Manage the look, feel, and behavior of NetNewsWire.")) {
			SettingsRow.configureAppearance($isConfigureAppearanceShown)
			if viewModel.notificationPermissions == .authorized {
				SettingsRow.configureNewArticleNotifications
			}
		}
	}

	@ViewBuilder
	private var helpSection: some View {
		Section {
			ForEach(0..<HelpSheet.allCases.count, id: \.self) { i in
				SettingsRow.showHelpSheet(sheet: HelpSheet.allCases[i], selectedSheet: $viewModel.helpSheet, $viewModel.showHelpSheet)
			}
			SettingsRow.aboutNetNewsWire
		}
	}
}