//
//  AdminUIKit.swift
//  FTStore Admin
//
//  The three UIKit helpers FTStore Admin borrows from FTStore's engine, inlined
//  so this app needs no Swift package at all: it links nothing but the system
//  frameworks, which is what keeps a decrypted IPA down to a login form.
//
//  Adapted from NimbleKit (`manager/NimbleKit`, MIT — Copyright 2025 CLARATION):
//  `UIImage+resize.swift` and `UlActivityViewController+Present.swift`. The
//  presenter lookup is rewritten against `UIWindowScene`, since the original
//  went through the long-deprecated `UIApplication.keyWindow`.
//

import UIKit
import AVFoundation

// MARK: - Presentation

extension UIApplication {
	/// The view controller a modal should be presented from: the foreground
	/// scene's key window, walked down through navigation/tab/presented
	/// controllers.
	///
	/// The starting point is resolved in the body rather than as a default
	/// argument — a default argument is evaluated at the call site, which is not
	/// main-actor isolated, and reading `foregroundKeyWindow` there doesn't
	/// compile.
	@MainActor
	static func topViewController() -> UIViewController? {
		_topViewController(from: shared.foregroundKeyWindow?.rootViewController)
	}

	@MainActor
	private static func _topViewController(from controller: UIViewController?) -> UIViewController? {
		if let navigation = controller as? UINavigationController {
			return _topViewController(from: navigation.visibleViewController)
		}
		if let tab = controller as? UITabBarController, let selected = tab.selectedViewController {
			return _topViewController(from: selected)
		}
		if let presented = controller?.presentedViewController {
			return _topViewController(from: presented)
		}
		return controller
	}

	@MainActor
	var foregroundKeyWindow: UIWindow? {
		connectedScenes
			.compactMap { $0 as? UIWindowScene }
			.first { $0.activationState == .foregroundActive }?
			.windows
			.first { $0.isKeyWindow }
			?? connectedScenes
				.compactMap { $0 as? UIWindowScene }
				.flatMap(\.windows)
				.first { $0.isKeyWindow }
	}
}

extension UIActivityViewController {
	/// Present a share sheet from the top-most controller. Used for the settings
	/// backup export, which is a file the operator hands off to somewhere else.
	@MainActor
	static func show(activityItems: [Any], applicationActivities: [UIActivity]? = nil) {
		guard let presenter = UIApplication.topViewController() else { return }

		let controller = Self(
			activityItems: activityItems,
			applicationActivities: applicationActivities
		)

		// iPad presents this as a popover and crashes without an anchor.
		if let popover = controller.popoverPresentationController {
			popover.sourceView = presenter.view
			popover.sourceRect = CGRect(
				x: presenter.view.bounds.midX,
				y: presenter.view.bounds.midY,
				width: 0,
				height: 0
			)
			popover.permittedArrowDirections = []
		}

		presenter.present(controller, animated: true)
	}
}

// MARK: - Images

extension UIImage {
	/// Centre-crop to a square, so a tweak icon picked from Photos or the camera
	/// isn't letterboxed when the server scales it.
	func resizeToSquare() -> UIImage? {
		let side = min(size.width, size.height)
		let origin = CGPoint(x: (size.width - side) / 2, y: (size.height - side) / 2)

		UIGraphicsBeginImageContextWithOptions(CGSize(width: side, height: side), false, scale)
		draw(at: CGPoint(x: -origin.x, y: -origin.y))
		let square = UIGraphicsGetImageFromCurrentImageContext()
		UIGraphicsEndImageContext()

		return square
	}

	/// Aspect-fit into `width` × `height` at scale 1, so the uploaded icon is the
	/// pixel size the caller asked for rather than a Retina multiple of it.
	func resize(_ width: Int, _ height: Int) -> UIImage {
		let target = AVFoundation.AVMakeRect(
			aspectRatio: size,
			insideRect: CGRect(origin: .zero, size: CGSize(width: width, height: height))
		).size

		let format = UIGraphicsImageRendererFormat()
		format.scale = 1

		return UIGraphicsImageRenderer(size: target, format: format).image { _ in
			draw(in: CGRect(origin: .zero, size: target))
		}
	}
}