Revert "Remove unused Gravatar"

This reverts commit 5f04d80.

Sources/WordPressUI/Extensions/Gravatar/Gravatar.swift

@@ -0,0 +1,148 @@
+import Foundation
+
+/// Helper Enum that specifies all of the available Gravatar Image Ratings
+/// TODO: Convert into a pure Swift String Enum. It's done this way to maintain ObjC Compatibility
+///
+@available(*, deprecated, message: "Use `Rating` from the Gravatar iOS SDK. See: https://github.com/Automattic/Gravatar-SDK-iOS.")
+@objc
+public enum GravatarRatings: Int {
+    case g
+    case pg
+    case r
+    case x
+    case `default`
+
+    func stringValue() -> String {
+        switch self {
+        case .default:
+            fallthrough
+        case .g:
+            return "g"
+        case .pg:
+            return "pg"
+        case .r:
+            return "r"
+        case .x:
+            return "x"
+        }
+    }
+}
+
+/// Helper Enum that specifies some of the options for default images
+/// To see all available options, visit : https://en.gravatar.com/site/implement/images/
+///
+@available(*, deprecated, message: "Use `DefaultAvatarOption` from the Gravatar iOS SDK. See: https://github.com/Automattic/Gravatar-SDK-iOS.")
+public enum GravatarDefaultImage: String {
+    case fileNotFound = "404"
+    case mp
+    case identicon
+}
+
+@available(*, deprecated, message: "Use `AvatarURL` from the Gravatar iOS SDK. See: https://github.com/Automattic/Gravatar-SDK-iOS")
+public struct Gravatar {
+    fileprivate struct Defaults {
+        static let scheme = "https"
+        static let host = "secure.gravatar.com"
+        static let unknownHash = "ad516503a11cd5ca435acc9bb6523536"
+        static let baseURL = "https://gravatar.com/avatar"
+        static let imageSize = 80
+    }
+
+    public let canonicalURL: URL
+
+    public func urlWithSize(_ size: Int, defaultImage: GravatarDefaultImage? = nil) -> URL {
+        var components = URLComponents(url: canonicalURL, resolvingAgainstBaseURL: false)!
+        components.query = "s=\(size)&d=\(defaultImage?.rawValue ?? GravatarDefaultImage.fileNotFound.rawValue)"
+        return components.url!
+    }
+
+    public static func isGravatarURL(_ url: URL) -> Bool {
+        guard let components = URLComponents(url: url, resolvingAgainstBaseURL: false) else {
+            return false
+        }
+
+        guard let host = components.host, host.hasSuffix(".gravatar.com") else {
+                return false
+        }
+
+        guard url.path.hasPrefix("/avatar/") else {
+                return false
+        }
+
+        return true
+    }
+
+    /// Returns the Gravatar URL, for a given email, with the specified size + rating.
+    ///
+    /// - Parameters:
+    ///     - email: the user's email
+    ///     - size: required download size
+    ///     - rating: image rating filtering
+    ///
+    /// - Returns: Gravatar's URL
+    ///
+    public static func gravatarUrl(for email: String,
+                                   defaultImage: GravatarDefaultImage? = nil,
+                                   size: Int? = nil,
+                                   rating: GravatarRatings = .default) -> URL? {
+        let hash = gravatarHash(of: email)
+        let targetURL = String(format: "%@/%@?d=%@&s=%d&r=%@",
+                               Defaults.baseURL,
+                               hash,
+                               defaultImage?.rawValue ?? GravatarDefaultImage.fileNotFound.rawValue,
+                               size ?? Defaults.imageSize,
+                               rating.stringValue())
+        return URL(string: targetURL)
+    }
+
+    /// Returns the gravatar hash of an email
+    ///
+    /// - Parameter email: the email associated with the gravatar
+    /// - Returns: hashed email
+    ///
+    /// This really ought to be in a different place, like Gravatar.swift, but there's
+    /// lots of duplication around gravatars -nh
+    private static func gravatarHash(of email: String) -> String {
+        return email
+            .lowercased()
+            .trimmingCharacters(in: .whitespaces)
+            .sha256Hash()
+    }
+}
+
+@available(*, deprecated, message: "Usage of the deprecated type: Gravatar.")
+extension Gravatar: Equatable {}
+
+@available(*, deprecated, message: "Usage of the deprecated type: Gravatar.")
+public func ==(lhs: Gravatar, rhs: Gravatar) -> Bool {
+    return lhs.canonicalURL == rhs.canonicalURL
+}
+
+@available(*, deprecated, message: "Usage of the deprecated type: Gravatar.")
+public extension Gravatar {
+    @available(*, deprecated, message: "Usage of the deprecated type: Gravatar.")
+    init?(_ url: URL) {
+        guard Gravatar.isGravatarURL(url) else {
+            return nil
+        }
+
+        guard var components = URLComponents(url: url, resolvingAgainstBaseURL: false) else {
+            return nil
+        }
+
+        components.scheme = Defaults.scheme
+        components.host = Defaults.host
+        components.query = nil
+
+        // Treat [email protected] as a nil url
+        guard url.lastPathComponent != Defaults.unknownHash else {
+            return nil
+        }
+
+        guard let sanitizedURL = components.url else {
+            return nil
+        }
+
+        self.canonicalURL = sanitizedURL
+    }
+}

Sources/WordPressUI/Extensions/UIImageView+Gravatar.swift

@@ -0,0 +1,194 @@
+import Foundation
+import UIKit
+
+#if SWIFT_PACKAGE
+import WordPressUIObjC
+#endif
+
+/// Wrapper class used to ensure removeObserver is called
+private class GravatarNotificationWrapper {
+    let observer: NSObjectProtocol
+
+    init(observer: NSObjectProtocol) {
+        self.observer = observer
+    }
+
+    deinit {
+        NotificationCenter.default.removeObserver(observer)
+    }
+}
+
+/// UIImageView Helper Methods that allow us to download a Gravatar, given the User's Email
+///
+extension UIImageView {
+
+    /// Downloads and sets the User's Gravatar, given his email.
+    /// TODO: This is a convenience method. Please, remove once all of the code has been migrated over to Swift.
+    ///
+    /// - Parameters:
+    ///     - email: the user's email
+    ///     - rating: expected image rating
+    ///
+    ///   This method uses deprecated types. Please check the deprecation warning in `GravatarRatings`. Also check out the UIImageView extension from the Gravatar iOS SDK as an alternative to download images. See: https://github.com/Automattic/Gravatar-SDK-iOS.
+    @available(*, deprecated, message: "Usage of the deprecated type: GravatarRatings.")
+    @objc
+    public func downloadGravatarWithEmail(_ email: String, rating: GravatarRatings) {
+        downloadGravatarWithEmail(email, rating: rating, placeholderImage: .gravatarPlaceholderImage)
+    }
+
+    /// Downloads and sets the User's Gravatar, given his email.
+    ///
+    /// - Parameters:
+    ///     - email: the user's email
+    ///     - rating: expected image rating
+    ///     - placeholderImage: Image to be used as Placeholder
+    ///   This method uses deprecated types. Please check the deprecation warning in `GravatarRatings`. Also check out the UIImageView extension from the Gravatar iOS SDK as an alternative to download images. See: https://github.com/Automattic/Gravatar-SDK-iOS.
+    @available(*, deprecated, message: "Usage of the deprecated type: GravatarRatings.")
+    @objc
+    public func downloadGravatarWithEmail(_ email: String, rating: GravatarRatings = .default, placeholderImage: UIImage = .gravatarPlaceholderImage) {
+        let gravatarURL = Gravatar.gravatarUrl(for: email, size: gravatarDefaultSize(), rating: rating)
+
+        listenForGravatarChanges(forEmail: email)
+        downloadImage(from: gravatarURL, placeholderImage: placeholderImage)
+    }
+
+    /// Configures the UIImageView to listen for changes to the gravatar it is displaying
+    public func listenForGravatarChanges(forEmail trackedEmail: String) {
+        if let currentObersver = gravatarWrapper?.observer {
+            NotificationCenter.default.removeObserver(currentObersver)
+            gravatarWrapper = nil
+        }
+
+        let observer = NotificationCenter.default.addObserver(forName: .GravatarImageUpdateNotification, object: nil, queue: nil) { [weak self] (notification) in
+            guard let userInfo = notification.userInfo,
+                let email = userInfo[Defaults.emailKey] as? String,
+                email == trackedEmail,
+                let image = userInfo[Defaults.imageKey] as? UIImage else {
+                    return
+            }
+
+            self?.image = image
+        }
+        gravatarWrapper = GravatarNotificationWrapper(observer: observer)
+    }
+
+    /// Stores the gravatar observer
+    ///
+    fileprivate var gravatarWrapper: GravatarNotificationWrapper? {
+        get {
+            return objc_getAssociatedObject(self, &Defaults.gravatarWrapperKey) as? GravatarNotificationWrapper
+        }
+        set {
+            objc_setAssociatedObject(self, &Defaults.gravatarWrapperKey, newValue as AnyObject, .OBJC_ASSOCIATION_RETAIN_NONATOMIC)
+        }
+    }
+
+    /// Downloads the provided Gravatar.
+    ///
+    /// - Parameters:
+    ///     - gravatar: the user's Gravatar
+    ///     - placeholder: Image to be used as Placeholder
+    ///     - animate: enable/disable fade in animation
+    ///     - failure: Callback block to be invoked when an error occurs while fetching the Gravatar image
+    ///
+    ///   This method uses deprecated types. Please check the deprecation warning in `GravatarRatings`. Also check out the UIImageView extension from the Gravatar iOS SDK as an alternative to download images. See: https://github.com/Automattic/Gravatar-SDK-iOS.
+    @available(*, deprecated, message: "Usage of the deprecated type: Gravatar.")
+    public func downloadGravatar(_ gravatar: Gravatar?, placeholder: UIImage, animate: Bool, failure: ((Error?) -> Void)? = nil) {
+        guard let gravatar = gravatar else {
+            self.image = placeholder
+            return
+        }
+
+        // Starting with iOS 10, it seems `initWithCoder` uses a default size
+        // of 1000x1000, which was messing with our size calculations for gravatars
+        // on newly created table cells.
+        // Calling `layoutIfNeeded()` forces UIKit to calculate the actual size.
+        layoutIfNeeded()
+
+        let size = Int(ceil(frame.width * UIScreen.main.scale))
+        let url = gravatar.urlWithSize(size)
+
+        self.downloadImage(from: url,
+                           placeholderImage: placeholder,
+                           success: { image in
+                            guard image != self.image else {
+                                return
+                            }
+
+                            self.image = image
+                            if animate {
+                                self.fadeInAnimation()
+                            }
+        }, failure: { error in
+            failure?(error)
+        })
+    }
+
+    /// Sets an Image Override in both, AFNetworking's Private Cache + NSURLCache
+    ///
+    /// - Parameters:
+    ///   - image: new UIImage
+    ///   - rating: rating for the new image.
+    ///   - email: associated email of the new gravatar
+    /// - Note: You may want to use `updateGravatar(image:, email:)` instead
+    ///
+    /// *WHY* is this required?. *WHY* life has to be so complicated?, is the universe against us?
+    /// This has been implemented as a workaround. During Upload, we want any async calls made to the
+    /// `downloadGravatar` API to return the "Fresh" image.
+    ///
+    /// Note II:
+    /// We cannot just clear NSURLCache, since the helper that's supposed to do that, is broken since iOS 8.
+    /// Ref: Ref: http://blog.airsource.co.uk/2014/10/11/nsurlcache-ios8-broken/
+    ///
+    /// P.s.:
+    /// Hope buddah, and the code reviewer, can forgive me for this hack.
+    ///
+    @available(*, deprecated, message: "Usage of the deprecated type: GravatarRatings.")
+    @objc public func overrideGravatarImageCache(_ image: UIImage, rating: GravatarRatings, email: String) {
+        guard let gravatarURL = Gravatar.gravatarUrl(for: email, size: gravatarDefaultSize(), rating: rating) else {
+            return
+        }
+
+        listenForGravatarChanges(forEmail: email)
+        overrideImageCache(for: gravatarURL, with: image)
+    }
+
+    /// Updates the gravatar image for the given email, and notifies all gravatar image views
+    ///
+    /// - Parameters:
+    ///   - image: the new UIImage
+    ///   - email: associated email of the new gravatar
+    @objc public func updateGravatar(image: UIImage, email: String?) {
+        self.image = image
+        guard let email = email else {
+            return
+        }
+        NotificationCenter.default.post(name: .GravatarImageUpdateNotification, object: self, userInfo: [Defaults.emailKey: email, Defaults.imageKey: image])
+    }
+
+    // MARK: - Private Helpers
+
+    /// Returns the required gravatar size. If the current view's size is zero, falls back to the default size.
+    ///
+    private func gravatarDefaultSize() -> Int {
+        guard bounds.size.equalTo(.zero) == false else {
+            return Defaults.imageSize
+        }
+
+        let targetSize = max(bounds.width, bounds.height) * UIScreen.main.scale
+        return Int(targetSize)
+    }
+
+    /// Private helper structure: contains the default Gravatar parameters
+    ///
+    private struct Defaults {
+        static let imageSize = 80
+        static var gravatarWrapperKey = 0x1000
+        static let emailKey = "email"
+        static let imageKey = "image"
+    }
+}
+
+public extension NSNotification.Name {
+    static let GravatarImageUpdateNotification = NSNotification.Name(rawValue: "GravatarImageUpdateNotification")
+}

Sources/WordPressUI/Extensions/UIImageView+Networking.swift

@@ -1,6 +1,10 @@
 import Foundation
 import UIKit
 
+#if SWIFT_PACKAGE
+import WordPressUIObjC
+#endif
+
 public extension UIImageView {
     enum ImageDownloadError: Error {
         case noURLSpecifiedInRequest

Sources/WordPressUIObjC/Extensions/NSString+Gravatar.h

@@ -0,0 +1,7 @@
+#import <Foundation/Foundation.h>
+
+@interface NSString (Gravatar)
+
+- (NSString *)sha256Hash;
+
+@end

Sources/WordPressUIObjC/Extensions/NSString+Gravatar.m

@@ -0,0 +1,21 @@
+#import "NSString+Gravatar.h"
+#import <CommonCrypto/CommonDigest.h>
+
+
+@implementation NSString (Gravatar)
+
+- (NSString *)sha256Hash
+{
+    const char *cStr = [self UTF8String];
+    unsigned char result[CC_SHA256_DIGEST_LENGTH];
+
+    CC_SHA256(cStr, (CC_LONG)strlen(cStr), result);
+
+    NSMutableString *hashString = [NSMutableString stringWithCapacity:CC_SHA256_DIGEST_LENGTH*2];
+    for (int i = 0; i < CC_SHA256_DIGEST_LENGTH; i++) {
+        [hashString appendFormat:@"%02x",result[i]];
+    }
+    return hashString;
+}
+
+@end

Sources/WordPressUIObjC/include/NSString+Gravatar.h

@@ -0,0 +1 @@
+../Extensions/NSString+Gravatar.h