//

// FaviconUserScript.swift

// Core

//

// Copyright © 2020 DuckDuckGo. All rights reserved.

//

// Licensed under the Apache License, Version 2.0 (the "License");

// you may not use this file except in compliance with the License.

// You may obtain a copy of the License at

//

// http://www.apache.org/licenses/LICENSE-2.0

//

// Unless required by applicable law or agreed to in writing, software

// distributed under the License is distributed on an "AS IS" BASIS,

// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

// See the License for the specific language governing permissions and

// limitations under the License.

//

import WebKit

import UserScript

public protocol FaviconUserScriptDelegate: NSObjectProtocol {

func faviconUserScript(_ script: FaviconUserScript, didRequestUpdateFaviconForHost host: String, withUrl url: URL?)

}

public class FaviconUserScript: NSObject, UserScript {

public var source: String = """

(function() {

function getFavicon() {

return findFavicons()[0];

};

function findFavicons() {

var selectors = [

"link[rel~='icon']",

"link[rel='apple-touch-icon']",

"link[rel='apple-touch-icon-precomposed']"

];

var favicons = [];

while (selectors.length > 0) {

var selector = selectors.pop()

var icons = document.head.querySelectorAll(selector);

for (var i = 0; i < icons.length; i++) {

var href = icons[i].href;

// Exclude SVGs since we can't handle them

if (href.indexOf("svg") >= 0 || (icons[i].type && icons[i].type.indexOf("svg") >= 0)) {

continue;

}

favicons.push(href)

}

}

return favicons;

};

try {

var favicon = getFavicon();

webkit.messageHandlers.faviconFound.postMessage(favicon);

} catch(error) {

// webkit might not be defined

}

}) ();

"""

public var injectionTime: WKUserScriptInjectionTime = .atDocumentEnd

public var forMainFrameOnly: Bool = true

public var messageNames: [String] = ["faviconFound"]

public weak var delegate: FaviconUserScriptDelegate?

public func userContentController(_ userContentController: WKUserContentController, didReceive message: WKScriptMessage) {

let url: URL?

if let body = message.body as? String {

url = URL(string: body)

} else {

url = nil

}

let host = message.messageHost

delegate?.faviconUserScript(self, didRequestUpdateFaviconForHost: host, withUrl: url)

}

}