[MM-14836] Prevent sharing of images over max pixels (#2733)

* Prevent sharing of images over max image size

* Prevent sharing of images over max image pixels

* Move readableMaxImagePixels

ios/MattermostShare/ShareViewController.swift

@@ -44,10 +44,16 @@ class ShareViewController: SLComposeServiceViewController {
   override func isContentValid() -> Bool {
     // Do validation of contentText and/or NSExtensionContext attachments here
     if (attachments.count > 0) {
+      let maxImagePixels = store.getMaxImagePixels()
+      if attachments.hasImageLargerThan(pixels: maxImagePixels) {
+        let readableMaxImagePixels = formatImagePixels(pixels: maxImagePixels)
+        showErrorMessage(title: "", message: "Image attachments shared in Mattermost must be less than \(readableMaxImagePixels).", VC: self)
+      }
+
       let maxFileSize = store.getMaxFileSize()
       if attachments.hasAttachementLargerThan(fileSize: maxFileSize) {
-        let readableMaxSize = formatFileSize(bytes: Double(maxFileSize))
-        showErrorMessage(title: "", message: "File attachments shared in Mattermost must be less than \(readableMaxSize).", VC: self)
+        let readableMaxFileSize = formatFileSize(fileSize: maxFileSize)
+        showErrorMessage(title: "", message: "File attachments shared in Mattermost must be less than \(readableMaxFileSize).", VC: self)
       }
     }
 
@@ -169,6 +175,26 @@ class ShareViewController: SLComposeServiceViewController {
     }
     return section
   }
+
+  func getImagePixels(imageUrl: URL) -> UInt64 {
+    guard let imageData = try? Data(contentsOf: imageUrl) else {
+      return 0
+    }
+
+    guard let image = UIImage.init(data: imageData) else {
+      return 0
+    }
+
+    return getImagePixels(image: image)
+  }
+
+  func getImagePixels(image: UIImage) -> UInt64 {
+    guard let cgImage = image.cgImage else {
+        return 0
+    }
+
+    return UInt64(cgImage.width * cgImage.height)
+  }
   
   func extractDataFromContext() {
     for item in extensionContext?.inputItems as! [NSExtensionItem] {
@@ -196,6 +222,7 @@ class ShareViewController: SLComposeServiceViewController {
                 let attachment = self.saveAttachment(url: url)
                 if (attachment != nil) {
                   attachment?.type = kUTTypeImage as String
+                  attachment?.imagePixels = self.getImagePixels(imageUrl: url)
                   self.attachments.append(attachment!)
                 }
               } else if let image = item as? UIImage {
@@ -207,6 +234,7 @@ class ShareViewController: SLComposeServiceViewController {
                     let attachment = self.saveAttachment(url: tempImageURL!)
                     if (attachment != nil) {
                       attachment?.type = kUTTypeImage as String
+                      attachment?.imagePixels = self.getImagePixels(image: image)
                       self.attachments.append(attachment!)
                     }
                   }
@@ -370,6 +398,7 @@ class ShareViewController: SLComposeServiceViewController {
       attachment.fileName = fileName
       attachment.fileURL = tempFileURL
       attachment.fileSize = attr.fileSize()
+
       return attachment
     } catch {
       return nil
@@ -388,22 +417,32 @@ class ShareViewController: SLComposeServiceViewController {
     VC.present(alert, animated: true, completion: nil)
   }
 
-  func formatFileSize(bytes: Double) -> String {
-    guard bytes > 0 else {
-      return "0 bytes"
+  func formatImagePixels(pixels: UInt64) -> String {
+    let suffixes = ["pixels", "KP", "MP", "GP", "TP", "PP", "EP", "ZP", "YP"]
+    let k: Double = 1000
+    return formatSize(size: Double(pixels), k: k, suffixes: suffixes)
+  }
+
+  func formatFileSize(fileSize: UInt64) -> String {
+    let suffixes = ["bytes", "KB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB"]
+    let k: Double = 1024
+    return formatSize(size: Double(fileSize), k: k, suffixes: suffixes)
+  }
+
+  func formatSize(size: Double, k: Double, suffixes: Array<String>) -> String {
+    guard size > 0 else {
+      return "0 \(suffixes[0])"
     }
 
     // Adapted from http://stackoverflow.com/a/18650828
-    let suffixes = ["bytes", "KB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB"]
-    let k: Double = 1024
-    let i = floor(log(bytes) / log(k))
+    let i = floor(log(size) / log(k))
 
-    // Format number with thousands separator and everything below 1 GB with no decimal places.
+    // Format number with thousands separator and everything below 1 giga with no decimal places.
     let numberFormatter = NumberFormatter()
     numberFormatter.maximumFractionDigits = i < 3 ? 0 : 1
     numberFormatter.numberStyle = .decimal
 
-    let numberString = numberFormatter.string(from: NSNumber(value: bytes / pow(k, i))) ?? "Unknown"
+    let numberString = numberFormatter.string(from: NSNumber(value: size / pow(k, i))) ?? "Unknown"
     let suffix = suffixes[Int(i)]
     return "\(numberString) \(suffix)"
   }

ios/UploadAttachments/UploadAttachments/AttachmentArray.swift

@@ -1,3 +1,5 @@
+import MobileCoreServices
+
 /// A thread-safe array.
 public class AttachmentArray<Element>: NSObject {
     fileprivate let queue = DispatchQueue(label: "com.mattermost.SynchronizedArray", attributes: .concurrent)
@@ -266,4 +268,17 @@ extension AttachmentArray {
         
         return exceed
     }
+
+    public func hasImageLargerThan(pixels: UInt64) -> Bool {
+        var exceed = false
+
+        self.queue.sync {
+            exceed = self.array.contains { element in
+                let attachment = element as! AttachmentItem
+                return attachment.imagePixels > pixels
+            }
+        }
+
+        return exceed
+    }
 }

ios/UploadAttachments/UploadAttachments/AttachmentItem.swift

@@ -5,6 +5,7 @@ public class AttachmentItem: NSObject {
     public var fileURL: URL?
     public var fileSize: UInt64 = 0
     public var type: String?
+    public var imagePixels:  UInt64 = 0
     
     public override init() {}
 }

ios/UploadAttachments/UploadAttachments/Constants.h

@@ -3,5 +3,6 @@
 
 @interface Constants : NSObject
 extern NSString *APP_GROUP_ID;
+extern UInt64 DEFAULT_SERVER_MAX_IMAGE_PIXELS;
 extern UInt64 DEFAULT_SERVER_MAX_FILE_SIZE;
 @end

ios/UploadAttachments/UploadAttachments/Constants.m

@@ -2,5 +2,6 @@
 
 @implementation Constants
 NSString *APP_GROUP_ID = @"group.com.mattermost.rnbeta";
+UInt64 DEFAULT_SERVER_MAX_IMAGE_PIXELS = 6048 * 4032;
 UInt64 DEFAULT_SERVER_MAX_FILE_SIZE = 50 * 1024 * 1024;
 @end

ios/UploadAttachments/UploadAttachments/StoreManager.h

@@ -14,6 +14,7 @@
 -(NSString *)getCurrentUserId;
 -(NSDictionary *)getDefaultChannel:(NSString *)forTeamId;
 -(NSDictionary *)getEntities:(BOOL)loadFromFile;
+-(UInt64)getMaxImagePixels;
 -(UInt64)getMaxFileSize;
 -(NSArray *)getMyTeams;
 -(NSString *)getServerUrl;

ios/UploadAttachments/UploadAttachments/StoreManager.m

@@ -150,16 +150,31 @@
   return [credentials objectForKey:@"token"];
 }
 
+-(UInt64)scanValueFromConfig:(NSDictionary *)config key:(NSString *)key {
+  NSString *value = [config objectForKey:key];
+  NSScanner *scanner = [NSScanner scannerWithString:value];
+  unsigned long long convertedValue = 0;
+  [scanner scanUnsignedLongLong:&convertedValue];
+  return convertedValue;
+}
+
+-(UInt64)getMaxImagePixels {
+  NSDictionary *config = [self getConfig];
+  NSString *key = @"MaxImagePixels";
+  if (config != nil && [config objectForKey:key]) {
+    return [self scanValueFromConfig:config key:key];
+  }
+
+  return DEFAULT_SERVER_MAX_IMAGE_PIXELS;
+}
+
 -(UInt64)getMaxFileSize {
   NSDictionary *config = [self getConfig];
-  if (config != nil && [config objectForKey:@"MaxFileSize"]) {
-    NSString *maxFileSize = [config objectForKey:@"MaxFileSize"];
-    NSScanner *scanner = [NSScanner scannerWithString:maxFileSize];
-    unsigned long long convertedValue = 0;
-    [scanner scanUnsignedLongLong:&convertedValue];
-    return convertedValue;
+  NSString *key = @"MaxFileSize";
+  if (config != nil && [config objectForKey:key]) {
+    return [self scanValueFromConfig:config key:key];
   }
-  
+
   return DEFAULT_SERVER_MAX_FILE_SIZE;
 }