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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
import UIKit
class SearchEngine: NSObject, NSCoding {
let name: String
let image: UIImage?
var isCustom = false
private let searchTemplate: String
private let suggestionsTemplate: String?
private let SearchTermComponent = "{searchTerms}"
fileprivate var suggestTemplate: String?
fileprivate lazy var searchQueryComponentKey: String? = self.getQueryArgFromTemplate()
init(name: String, image: UIImage?, searchTemplate: String, suggestionsTemplate: String?, isCustom: Bool = false) {
self.name = name
self.image = image ?? SearchEngine.generateImage(name: name)
self.searchTemplate = searchTemplate
self.suggestionsTemplate = suggestionsTemplate
self.isCustom = isCustom
}
required init?(coder aDecoder: NSCoder) {
guard let name = aDecoder.decodeObject(forKey: "name") as? String,
let searchTemplate = aDecoder.decodeObject(forKey: "searchTemplate") as? String else {
return nil
}
self.name = name
self.searchTemplate = searchTemplate
image = aDecoder.decodeObject(forKey: "image") as? UIImage
suggestionsTemplate = aDecoder.decodeObject(forKey: "suggestionsTemplate") as? String
}
func urlForSuggestions(_ query: String) -> URL? {
// Escape the search template as well in case it contains not-safe characters like symbols
let templateAllowedSet = NSMutableCharacterSet()
templateAllowedSet.formUnion(with: .urlAllowed)
// Allow brackets since we use them in our template as our insertion point
templateAllowedSet.formUnion(with: CharacterSet(charactersIn: "{}"))
let trimmed = query.trimmingCharacters(in: .whitespaces)
guard let suggestTemplate = suggestionsTemplate,
let escaped = trimmed.addingPercentEncoding(withAllowedCharacters: .urlQueryParameterAllowed),
let encodedSearchTemplate = suggestTemplate.addingPercentEncoding(withAllowedCharacters: templateAllowedSet as CharacterSet) else {
debugPrint("Missing Suggestions")
return nil
}
let urlString = encodedSearchTemplate
.replacingOccurrences(of: SearchTermComponent, with: escaped, options: .literal, range: nil)
return URL(string: urlString, invalidCharacters: false)
}
func urlForQuery(_ query: String) -> URL? {
let trimmed = query.trimmingCharacters(in: .whitespaces)
guard let escaped = trimmed.addingPercentEncoding(withAllowedCharacters: .urlQueryParameterAllowed) else {
assertionFailure("Invalid search URL")
return nil
}
guard let urlString = searchTemplate.replacingOccurrences(of: SearchTermComponent, with: escaped)
.addingPercentEncoding(withAllowedCharacters: .urlAllowed) else {
assertionFailure("Invalid search URL")
return nil
}
return URL(string: urlString, invalidCharacters: false)
}
func encode(with aCoder: NSCoder) {
aCoder.encode(name, forKey: "name")
aCoder.encode(image, forKey: "image")
aCoder.encode(searchTemplate, forKey: "searchTemplate")
aCoder.encode(suggestionsTemplate, forKey: "suggestionsTemplate")
}
func getNameOrCustom() -> String {
return isCustom ? "custom" : name
}
private static func generateImage(name: String) -> UIImage {
let faviconLetter = name.uppercased()[name.startIndex]
let faviconLabel = SmartLabel(frame: CGRect(x: 0, y: 0, width: 24, height: 24))
faviconLabel.backgroundColor = .purple80
faviconLabel.text = String(faviconLetter)
faviconLabel.textAlignment = .center
faviconLabel.font = .body18Medium
faviconLabel.textColor = UIColor.white
let imageRenderer = UIGraphicsImageRenderer(size: faviconLabel.bounds.size)
return imageRenderer.image(actions: { (context) in
faviconLabel.layer.render(in: context.cgContext)
})
}
/**
* check that the URL host contains the name of the search engine somewhere inside it
**/
fileprivate func isSearchURLForEngine(_ url: URL?) -> Bool {
guard let urlHost = url?.shortDisplayString,
let queryEndIndex = searchTemplate.range(of: "?")?.lowerBound,
let templateURL = URL(string: String(searchTemplate[..<queryEndIndex]), invalidCharacters: false)
else { return false }
return urlHost == templateURL.shortDisplayString
}
/**
* Returns the query that was used to construct a given search URL
**/
func queryForSearchURL(_ url: URL?) -> String? {
guard isSearchURLForEngine(url), let key = searchQueryComponentKey else { return nil }
if let value = url?.getQuery()[key] {
return value.replacingOccurrences(of: "+", with: " ").removingPercentEncoding
} else {
// If search term could not found in query, it may be exist inside fragment
var components = URLComponents()
components.query = url?.fragment?.removingPercentEncoding
guard let value = components.url?.getQuery()[key] else { return nil }
return value.replacingOccurrences(of: "+", with: " ").removingPercentEncoding
}
}
/**
* Returns the search suggestion URL for the given query.
*/
func suggestURLForQuery(_ query: String) -> URL? {
if let suggestTemplate = suggestTemplate {
return getURLFromTemplate(suggestTemplate, query: query)
}
return nil
}
fileprivate func getURLFromTemplate(_ searchTemplate: String, query: String) -> URL? {
if let escapedQuery = query.addingPercentEncoding(withAllowedCharacters: .searchTermsAllowed) {
// Escape the search template as well in case it contains not-safe characters like symbols
let templateAllowedSet = NSMutableCharacterSet()
templateAllowedSet.formUnion(with: .urlAllowed)
// Allow brackets since we use them in our template as our insertion point
templateAllowedSet.formUnion(with: CharacterSet(charactersIn: "{}"))
if let encodedSearchTemplate = searchTemplate.addingPercentEncoding(withAllowedCharacters: templateAllowedSet as CharacterSet) {
let urlString = encodedSearchTemplate
.replacingOccurrences(of: SearchTermComponent, with: escapedQuery, options: .literal, range: nil)
return URL(string: urlString)
}
}
return nil
}
/**
* Return the arg that we use for searching for this engine
* Problem: the search terms may not be a query arg, they may be part of the URL - how to deal with this?
**/
fileprivate func getQueryArgFromTemplate() -> String? {
// we have the replace the templates SearchTermComponent in order to make the template
// a valid URL, otherwise we cannot do the conversion to NSURLComponents
// and have to do flaky pattern matching instead.
let placeholder = "PLACEHOLDER"
let template = searchTemplate.replacingOccurrences(of: SearchTermComponent, with: placeholder)
var components = URLComponents(string: template)
if let retVal = extractQueryArg(in: components?.queryItems, for: placeholder) {
return retVal
} else {
// Query arg may be exist inside fragment
components = URLComponents()
components?.query = URL(string: template, invalidCharacters: false)?.fragment
return extractQueryArg(in: components?.queryItems, for: placeholder)
}
}
fileprivate func extractQueryArg(in queryItems: [URLQueryItem]?, for placeholder: String) -> String? {
let searchTerm = queryItems?.filter { item in
return item.value == placeholder
}
return searchTerm?.first?.name
}
}
extension CharacterSet {
public static let searchTermsAllowed = CharacterSet(charactersIn: "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789*-_.")
}