deltachat-ios/deltachat-ios/Extensions/Extensions.swift

//
//  String+Extension.swift
//  deltachat-ios
//
//  Created by Bastian van de Wetering on 03.04.19.
//  Copyright © 2019 Jonas Reinsch. All rights reserved.
//

import UIKit

extension String {
	func containsCharacters() -> Bool {
		return !trimmingCharacters(in: [" "]).isEmpty
	}

	// O(n) - returns indexes of subsequences -> can be used to highlight subsequence within string
	func contains(subSequence: String) -> [Int] {
		if subSequence.count > self.count {
			return []
		}

		let str = self.lowercased()
		let sub = subSequence.lowercased()

		var j = 0

		var foundIndexes:[Int] = []

		for (index, char) in str.enumerated() {
			if j == sub.count {
				break
			}

			if char == sub.subScript(j) {
				foundIndexes.append(index)
				j += 1

			}
		}
		return foundIndexes.count == sub.count ? foundIndexes : []
	}


	func subScript(_ i: Int) -> Character {
		return self[index(startIndex, offsetBy: i)]
	}

	func bold(indexes: [Int], fontSize: CGFloat?) -> NSAttributedString {
		let attributedText = NSMutableAttributedString.init(string: self)

		for index in indexes {
			attributedText.addAttribute(.font, value: UIFont.boldSystemFont(ofSize: fontSize ?? 18), range: NSMakeRange(index, 1))
		}
		return attributedText
	}
}

extension URL {
	public var queryParameters: [String: String]? {
		guard
			let components = URLComponents(url: self, resolvingAgainstBaseURL: true),
			let queryItems = components.queryItems else { return nil }
		return queryItems.reduce(into: [String: String]()) { result, item in
			result[item.name] = item.value
		}
	}
}

extension Dictionary {
	func percentEscaped() -> String {
		return map { key, value in
			let escapedKey = "\(key)".addingPercentEncoding(withAllowedCharacters: .urlQueryValueAllowed) ?? ""
			let escapedValue = "\(value)".addingPercentEncoding(withAllowedCharacters: .urlQueryValueAllowed) ?? ""
			return escapedKey + "=" + escapedValue
			}
			.joined(separator: "&")
	}
}

extension CharacterSet {
	static let urlQueryValueAllowed: CharacterSet = {
		let generalDelimitersToEncode = ":#[]@" // does not include "?" or "/" due to RFC 3986 - Section 3.4
		let subDelimitersToEncode = "!$&'()*+,;="

		var allowed = CharacterSet.urlQueryAllowed
		allowed.remove(charactersIn: "\(generalDelimitersToEncode)\(subDelimitersToEncode)")
		return allowed
	}()
}

extension URLSession {
	func synchronousDataTask(request: URLRequest) -> (Data?, URLResponse?, Error?) {
		var data: Data?
		var response: URLResponse?
		var error: Error?

		let semaphore = DispatchSemaphore(value: 0)

		let task = dataTask(with: request) {
			data = $0
			response = $1
			error = $2

			semaphore.signal()
		}
		task.resume()

		_ = semaphore.wait(timeout: .distantFuture)

		return (data, response, error)
	}
}

extension MRContact {
	func contains(searchText text: String) -> [ContactHighlights] {

		var nameIndexes = [Int]()
		var emailIndexes = [Int]()

		let contactString = name + email
		let subsequenceIndexes = contactString.contains(subSequence: text)

		if !subsequenceIndexes.isEmpty {
			for index in subsequenceIndexes {
				if index < name.count {
					nameIndexes.append(index)
				} else {
					let emailIndex = index - name.count
					emailIndexes.append(emailIndex)
				}
			}
			return [ContactHighlights(contactDetail: .NAME, indexes: nameIndexes), ContactHighlights(contactDetail: .EMAIL, indexes: emailIndexes)]
		} else {
			return []
		}
	}
}