Try/remote post hash

Podfile

@@ -38,9 +38,9 @@ end
 
 def wordpress_kit
 
-    pod 'WordPressKit', '~> 4.18.0-beta'
+    #pod 'WordPressKit', '~> 4.18.0-beta'
     #pod 'WordPressKit', :git => 'https://github.com/wordpress-mobile/WordPressKit-iOS.git', :tag => ''
-    #pod 'WordPressKit', :git => 'https://github.com/wordpress-mobile/WordPressKit-iOS.git', :branch => ''
+    pod 'WordPressKit', :git => 'https://github.com/Deco354/WordPressKit-iOS.git', :branch => 'feature/remote-content-hash'
     #pod 'WordPressKit', :git => 'https://github.com/wordpress-mobile/WordPressKit-iOS.git', :commit => ''
     #pod 'WordPressKit', :path => '../WordPressKit-iOS'
 end

Podfile.lock

@@ -407,7 +407,7 @@ PODS:
     - WordPressKit (~> 4.18-beta)
     - WordPressShared (~> 1.12-beta)
     - WordPressUI (~> 1.7.0)
-  - WordPressKit (4.18.0):
+  - WordPressKit (4.19-beta.3):
     - Alamofire (~> 4.8.0)
     - CocoaLumberjack (~> 3.4)
     - NSObject-SafeExpectations (= 0.0.4)
@@ -506,7 +506,7 @@ DEPENDENCIES:
   - SVProgressHUD (= 2.2.5)
   - WordPress-Editor-iOS (~> 1.19.3)
   - WordPressAuthenticator (~> 1.26.0-beta)
-  - WordPressKit (~> 4.18.0-beta)
+  - WordPressKit (from `https://github.com/Deco354/WordPressKit-iOS.git`, branch `feature/remote-content-hash`)
   - WordPressMocks (~> 0.0.8)
   - WordPressShared (~> 1.12.0)
   - WordPressUI (~> 1.7.1)
@@ -556,7 +556,6 @@ SPEC REPOS:
     - WordPress-Aztec-iOS
     - WordPress-Editor-iOS
     - WordPressAuthenticator
-    - WordPressKit
     - WordPressMocks
     - WordPressShared
     - WordPressUI
@@ -657,6 +656,9 @@ EXTERNAL SOURCES:
     :commit: 5ff93360313e9919c7a4b7f0faa1cb9e5e9c3542
     :git: http://github.com/wordpress-mobile/gutenberg-mobile/
     :submodules: true
+  WordPressKit:
+    :branch: feature/remote-content-hash
+    :git: https://github.com/Deco354/WordPressKit-iOS.git
   Yoga:
     :podspec: https://raw.githubusercontent.com/wordpress-mobile/gutenberg-mobile/5ff93360313e9919c7a4b7f0faa1cb9e5e9c3542/third-party-podspecs/Yoga.podspec.json
 
@@ -675,6 +677,9 @@ CHECKOUT OPTIONS:
     :commit: 5ff93360313e9919c7a4b7f0faa1cb9e5e9c3542
     :git: http://github.com/wordpress-mobile/gutenberg-mobile/
     :submodules: true
+  WordPressKit:
+    :commit: 7dc25bbdbdd22dfe2772ac38da2c058087ce5f9b
+    :git: https://github.com/Deco354/WordPressKit-iOS.git
 
 SPEC CHECKSUMS:
   1PasswordExtension: f97cc80ae58053c331b2b6dc8843ba7103b33794
@@ -756,7 +761,7 @@ SPEC CHECKSUMS:
   WordPress-Aztec-iOS: b7ac8b30f746992e85d9668453ac87c2cdcecf4f
   WordPress-Editor-iOS: 1886f7fe464d79ee64ccfe7985281f8cf45f75eb
   WordPressAuthenticator: 31bceb4ab25de663a327b791e76a405b9c903b73
-  WordPressKit: 1d10fa14ea185600472d31cf25e677c7d938b17d
+  WordPressKit: 8a7cf458497a593cf8b1bfa6c965dcfd5d072ec0
   WordPressMocks: b4064b99a073117bbc304abe82df78f2fbe60992
   WordPressShared: 38cb62e9cb998d4dc3c1611f17934c6875a6b3e8
   WordPressUI: 9da5d966b8beb091950cd96880db398d7f30e246
@@ -772,6 +777,6 @@ SPEC CHECKSUMS:
   ZendeskSupportSDK: a87ab1e4badace92c75eb11dc77ede1e995b2adc
   ZIPFoundation: 249fa8890597086cd536bb2df5c9804d84e122b0
 
-PODFILE CHECKSUM: 6141b62876d49dbc9b2e5735cff154f0244a888f
+PODFILE CHECKSUM: 267bf560442ff5d1b7cadc184cd0a691b3eb5c10
 
 COCOAPODS: 1.9.3

WordPress/Classes/Models/AbstractPost+HashHelpers.m

@@ -1,6 +1,7 @@
 #import "AbstractPost+HashHelpers.h"
 #import "Media+WPMediaAsset.h"
 #import "WordPress-Swift.h"
+@import WordPressKit;
 
 @implementation AbstractPost (HashHelpers)
 
@@ -10,25 +11,23 @@ - (NSString *)calculateConfirmedChangesContentHash {
     // that's the purpose of the `-additionalContentHashes` extension point.
 
     NSArray<NSData *> *hashedContents = @[
-                                          [self hashForNSInteger:self.blog.dotComID.integerValue],
-                                          [self hashForNSInteger:self.postID.integerValue],
-                                          [self hashForString:self.postTitle],
-                                          [self hashForString:self.content],
-                                          [self hashForDouble:self.dateCreated.timeIntervalSinceReferenceDate],
-                                          [self hashForString:self.permaLink],
-                                          [self hashForString:self.mt_excerpt],
-                                          [self hashForString:self.status],
-                                          [self hashForString:self.password],
-                                          [self hashForString:self.author],
-                                          [self hashForNSInteger:self.authorID.integerValue],
-                                          [self hashForString:self.featuredImage.identifier],
-                                          [self hashForString:self.wp_slug]];
+                                          [SHAHasher hashForNSInteger:self.blog.dotComID.integerValue],
+                                          [SHAHasher hashForNSInteger:self.postID.integerValue],
+                                          [SHAHasher hashForString:self.postTitle],
+                                          [SHAHasher hashForString:self.content],
+                                          [SHAHasher hashForDouble:self.dateCreated.timeIntervalSinceReferenceDate],
+                                          [SHAHasher hashForString:self.permaLink],
+                                          [SHAHasher hashForString:self.mt_excerpt],
+                                          [SHAHasher hashForString:self.status],
+                                          [SHAHasher hashForString:self.password],
+                                          [SHAHasher hashForString:self.author],
+                                          [SHAHasher hashForNSInteger:self.authorID.integerValue],
+                                          [SHAHasher hashForString:self.featuredImage.identifier],
+                                          [SHAHasher hashForString:self.wp_slug]];
 
 
     NSArray<NSData *> *finalHashes = [hashedContents arrayByAddingObjectsFromArray:self.additionalContentHashes];
 
-    NSMutableData *mutableData = [NSMutableData data];
-
     // So, there are multiple ways of combining all those hashes. You need to be careful not to lose the entropy though.
     // Initially, I wanted to just XOR them together, which is totally reasonable thing to do!
     // ...however, things get tricky when you XOR things that might be similar/the same.
@@ -42,64 +41,11 @@ - (NSString *)calculateConfirmedChangesContentHash {
     // What I'm doing here instead is just treating all the "partial" hashes as a dumb bag of bits,
     // combining them together and the final hash is SHA256 of _that_.
     // Hopefully that'll be enough.
-
-    for (NSData *hash in finalHashes) {
-        [mutableData appendData:hash];
-    }
-
-    unsigned char finalDigest[CC_SHA256_DIGEST_LENGTH];
-
-    CC_SHA256(mutableData.bytes, (CC_LONG)mutableData.length, finalDigest);
-
-    return [self sha256StringFromData:[NSData dataWithBytes:finalDigest length:CC_SHA256_DIGEST_LENGTH]];
+    return [SHAHasher combineHashes:finalHashes];
 }
 
-
 - (NSArray<NSData *> *)additionalContentHashes {
     return @[];
 }
 
-#pragma mark - SHA256 calculations
-
-- (NSData *)hashForString:(NSString *) string {
-    if (!string) {
-        return [[NSMutableData dataWithLength:CC_SHA256_DIGEST_LENGTH] copy];
-    }
-
-    NSData *encodedBytes = [string dataUsingEncoding:NSUTF8StringEncoding];
-    unsigned char digest[CC_SHA256_DIGEST_LENGTH];
-
-    CC_SHA256(encodedBytes.bytes, (CC_LONG)encodedBytes.length, digest);
-
-    return [NSData dataWithBytes:digest length:CC_SHA256_DIGEST_LENGTH];
-}
-
-- (NSData *)hashForNSInteger:(NSInteger)integer {
-    unsigned char digest[CC_SHA256_DIGEST_LENGTH];
-
-    CC_SHA256(&integer, sizeof(integer), digest);
-
-    return [NSData dataWithBytes:digest length:CC_SHA256_DIGEST_LENGTH];
-}
-
-- (NSData *)hashForDouble:(double)dbl {
-    unsigned char digest[CC_SHA256_DIGEST_LENGTH];
-
-    CC_SHA256(&dbl, sizeof(dbl), digest);
-
-    return [NSData dataWithBytes:digest length:CC_SHA256_DIGEST_LENGTH];
-}
-
-- (NSString *)sha256StringFromData:(NSData *)data {
-    NSMutableString *mutableString = [NSMutableString string];
-
-    const char *hashBytes = [data bytes];
-
-    for (int i = 0; i < data.length; i++) {
-        [mutableString appendFormat:@"%02.2hhx", hashBytes[i]];
-    }
-
-    return [mutableString copy];
-}
-
 @end

WordPress/Classes/Models/AbstractPost.h

@@ -59,6 +59,7 @@ typedef NS_ENUM(NSUInteger, AbstractPostRemoteStatus) {
 @property (nonatomic, copy, nullable) NSNumber *autosaveIdentifier;
 
 @property (nonatomic) BOOL hasVersionConflict;
+@property (nonatomic, copy, nullable) NSString *lastRemoteUpdateHash;
 
 // Revision management
 - (AbstractPost *)createRevision;

WordPress/Classes/Models/AbstractPost.m

@@ -39,6 +39,7 @@ @implementation AbstractPost
 @dynamic autosaveModifiedDate;
 @dynamic autosaveIdentifier;
 @dynamic hasVersionConflict;
+@dynamic lastRemoteUpdateHash;
 
 @synthesize restorableStatus;
 

WordPress/Classes/Models/Post.swift

@@ -318,12 +318,12 @@ class Post: AbstractPost {
             return acc + obj
         } ?? ""
 
-        return [hash(for: publicID ?? ""),
-                hash(for: tags ?? ""),
-                hash(for: postFormat ?? ""),
-                hash(for: stringifiedCategories),
-                hash(for: geolocation?.latitude ?? 0),
-                hash(for: geolocation?.longitude ?? 0),
-                hash(for: isStickyPost ? 1 : 0)]
+        return [SHAHasher.hash(for: publicID ?? ""),
+                SHAHasher.hash(for: tags ?? ""),
+                SHAHasher.hash(for: postFormat ?? ""),
+                SHAHasher.hash(for: stringifiedCategories),
+                SHAHasher.hash(for: geolocation?.latitude ?? 0),
+                SHAHasher.hash(for: geolocation?.longitude ?? 0),
+                SHAHasher.hash(for: isStickyPost ? 1 : 0)]
     }
 }

WordPress/Classes/Services/PostService.m

@@ -775,21 +775,22 @@ - (NSDictionary *)remoteSyncParametersDictionaryForRemote:(nonnull id <PostServi
 }
 
 - (void)updatePost:(AbstractPost *)post withRemotePost:(RemotePost *)remotePost {
+    NSString *remotePostHash = [remotePost contentHash];
     NSNumber *previousPostID = post.postID;
     post.postID = remotePost.postID;
     post.author = remotePost.authorDisplayName;
     post.authorID = remotePost.authorID;
     post.date_created_gmt = remotePost.date;
+    post.dateModified = remotePost.dateModified;
     post.postTitle = remotePost.title;
     post.permaLink = [remotePost.URL absoluteString];
     post.content = remotePost.content;
     post.status = remotePost.status;
     post.password = remotePost.password;
-    if (post.dateModified != remotePost.dateModified) {
+    if (post.lastRemoteUpdateHash != nil && ![post.lastRemoteUpdateHash isEqualToString:remotePostHash]) {
         post.hasVersionConflict = post.hasRevision;
         post.revision.hasVersionConflict = post.hasRevision;
     }
-    post.dateModified = remotePost.dateModified;
 
     if (remotePost.postThumbnailID != nil) {
         post.featuredImage = [Media existingOrStubMediaWithMediaID: remotePost.postThumbnailID inBlog:post.blog];
@@ -881,6 +882,7 @@ - (void)updatePost:(AbstractPost *)post withRemotePost:(RemotePost *)remotePost
     }
 
     post.statusAfterSync = post.status;
+    post.lastRemoteUpdateHash = remotePostHash;
 }
 
 - (RemotePost *)remotePostWithPost:(AbstractPost *)post

WordPress/Classes/ViewRelated/Post/PostCardStatusViewModel.swift

@@ -94,6 +94,10 @@ class PostCardStatusViewModel: NSObject {
             return .neutral(.shade70)
         }
 
+        if post.hasVersionConflict {
+            return .error(.shade50)
+        }
+
         if MediaCoordinator.shared.isUploadingMedia(for: post) || post.remoteStatus == .pushing {
             return .neutral(.shade30)
         }
@@ -111,10 +115,6 @@ class PostCardStatusViewModel: NSObject {
             return (autoUploadAction == .upload || post.wasAutoUploadCancelled) ? .warning : .error
         }
 
-        if post.hasVersionConflict {
-            return .error(.shade50)
-        }
-
         if post.hasAutosaveRevision {
             return .warning(.shade40)
         }

WordPress/Classes/WordPress.xcdatamodeld/.xccurrentversion

@@ -3,6 +3,6 @@
 <plist version="1.0">
 <dict>
 	<key>_XCCurrentVersionName</key>
-	<string>WordPress 100.xcdatamodel</string>
+	<string>WordPress 101.xcdatamodel</string>
 </dict>
 </plist>