//
//  DetailWebView.swift
//  NetNewsWire
//
//  Created by Brent Simmons on 2/10/18.
//  Copyright © 2018 Ranchero Software. All rights reserved.
//

import AppKit
import WebKit
import RSCore

final class DetailWebView: WKWebView {

	weak var keyboardDelegate: KeyboardDelegate?
	
	override func accessibilityLabel() -> String? {
		return NSLocalizedString("Article", comment: "Article")
	}

	// MARK: - NSResponder
	
	override func keyDown(with event: NSEvent) {
		if keyboardDelegate?.keydown(event, in: self) ?? false {
			return
		}
		super.keyDown(with: event)
	}

	// MARK: NSView

	override func willOpenMenu(_ menu: NSMenu, with event: NSEvent) {
		// There’s no API for affecting a WKWebView’s contextual menu.
		// (WebView had API for this.)
		//
		// This a minor hack. It hides unwanted menu items.
		// The menu item identifiers are not documented anywhere;
		// they could change, and this code would need updating.
		for menuItem in menu.items {
			if shouldHideMenuItem(menuItem) {
				menuItem.isHidden = true
			}
		}

		super.willOpenMenu(menu, with: event)
	}

	override func viewWillStartLiveResize() {
		super.viewWillStartLiveResize()
		evaluateJavaScript("document.body.style.overflow = 'hidden';", completionHandler: nil)
	}

	override func viewDidEndLiveResize() {
		super.viewDidEndLiveResize()
		evaluateJavaScript("document.body.style.overflow = 'visible';", completionHandler: nil)
		
		
		/// On macOS 11, when a user exits full screen or zoomed mode (full screen with menu bar showing), the webview's origin.y is offset by a sizeable amount. This function adjusts the height of the window height by 1pt which puts the webview back in the correct place. This is an issue with SwiftUI and AppKit.
		if #available(macOS 11, *) {
			guard var frame = window?.frame else {
				return
			}
			frame.size = NSSize(width: window!.frame.width, height: window!.frame.height - 1)
			window!.setFrame(frame, display: false)
			frame.size = NSSize(width: window!.frame.width, height: window!.frame.height + 1)
			window!.setFrame(frame, display: false)
		}
		
	}
}

// MARK: - Private

private extension NSUserInterfaceItemIdentifier {

	static let DetailMenuItemIdentifierReload = NSUserInterfaceItemIdentifier(rawValue: "WKMenuItemIdentifierReload")
	static let DetailMenuItemIdentifierOpenLink = NSUserInterfaceItemIdentifier(rawValue: "WKMenuItemIdentifierOpenLink")
}

private extension DetailWebView {

	static let menuItemIdentifiersToHide: [NSUserInterfaceItemIdentifier] = [.DetailMenuItemIdentifierReload, .DetailMenuItemIdentifierOpenLink]
	static let menuItemIdentifierMatchStrings = ["newwindow", "download"]

	func shouldHideMenuItem(_ menuItem: NSMenuItem) -> Bool {

		guard let identifier = menuItem.identifier else {
			return false
		}

		if DetailWebView.menuItemIdentifiersToHide.contains(identifier) {
			return true
		}

		let lowerIdentifier = identifier.rawValue.lowercased()
		for matchString in DetailWebView.menuItemIdentifierMatchStrings {
			if lowerIdentifier.contains(matchString) {
				return true
			}
		}

		return false
	}
}