Add muting of threads.

// FREEBIE

src/Contacts/TSThread.h

@@ -1,5 +1,6 @@
-//  Created by Frederic Jacobs on 16/11/14.
-//  Copyright (c) 2014 Open Whisper Systems. All rights reserved.
+//
+//  Copyright (c) 2017 Open Whisper Systems. All rights reserved.
+//
 
 #import "TSYapDatabaseObject.h"
 #import <UIKit/UIKit.h>
@@ -145,6 +146,32 @@ NS_ASSUME_NONNULL_BEGIN
  */
 - (void)setDraft:(NSString *)draftString transaction:(YapDatabaseReadWriteTransaction *)transaction;
 
+@property (atomic, readonly) BOOL isMuted;
+@property (atomic, readonly) NSDate *mutedUntilDate;
+
+// This model may be updated from many threads. We don't want to save
+// our local copy (this instance) since it may be out of date.  Instead, we
+// use these "updateWith..." methods to:
+//
+// a) Update a property of this instance.
+// b) Load an up-to-date instance of this model from from the data store.
+// c) Update and save that fresh instance.
+// d) If this instance hasn't yet been saved, save this local instance.
+//
+// After "updateWith...":
+//
+// a) An updated copy of this instance will always have been saved in the
+//    data store.
+// b) The local property on this instance will always have been updated.
+// c) Other properties on this instance may be out of date.
+//
+// All mutable properties of this class have been made read-only to
+// prevent accidentally modifying them directly.
+//
+// This isn't a perfect arrangement, but in practice this will prevent
+// data loss and will resolve all known issues.
+- (void)updateWithMutedUntilDate:(NSDate *)mutedUntilDate;
+
 @end
 
 NS_ASSUME_NONNULL_END

src/Contacts/TSThread.m

@@ -10,15 +10,18 @@
 #import "TSInvalidIdentityKeyReceivingErrorMessage.h"
 #import "TSOutgoingMessage.h"
 #import "TSStorageManager.h"
+#import <YapDatabase/YapDatabase.h>
+#import <YapDatabase/YapDatabaseTransaction.h>
 
 NS_ASSUME_NONNULL_BEGIN
 
 @interface TSThread ()
 
-@property (nonatomic, retain) NSDate *creationDate;
+@property (nonatomic) NSDate *creationDate;
 @property (nonatomic, copy) NSDate *archivalDate;
-@property (nonatomic, retain) NSDate *lastMessageDate;
+@property (nonatomic) NSDate *lastMessageDate;
 @property (nonatomic, copy) NSString *messageDraft;
+@property (atomic) NSDate *mutedUntilDate;
 
 - (TSInteraction *)lastInteraction;
 
@@ -295,6 +298,46 @@ NS_ASSUME_NONNULL_BEGIN
     [thread saveWithTransaction:transaction];
 }
 
+#pragma mark - Muted
+
+- (BOOL)isMuted
+{
+    NSDate *mutedUntilDate = self.mutedUntilDate;
+    NSDate *now = [NSDate date];
+    return (mutedUntilDate != nil &&
+            [mutedUntilDate timeIntervalSinceDate:now] > 0);
+}
+
+// This method does the work for the "updateWith..." methods.  Please see
+// the header for a discussion of those methods.
+- (void)applyChangeToSelfAndLatestThread:(YapDatabaseReadWriteTransaction *)transaction
+                             changeBlock:(void (^)(TSThread *))changeBlock
+{
+    OWSAssert(transaction);
+    
+    changeBlock(self);
+    
+    NSString *collection = [[self class] collection];
+    TSThread *latestInstance = [transaction objectForKey:self.uniqueId inCollection:collection];
+    if (latestInstance) {
+        changeBlock(latestInstance);
+        [latestInstance saveWithTransaction:transaction];
+    } else {
+        // This message has not yet been saved.
+        [self saveWithTransaction:transaction];
+    }
+}
+
+- (void)updateWithMutedUntilDate:(NSDate *)mutedUntilDate
+{
+    [self.dbConnection readWriteWithBlock:^(YapDatabaseReadWriteTransaction *transaction) {
+        [self applyChangeToSelfAndLatestThread:transaction
+                                            changeBlock:^(TSThread *thread) {
+                                                [thread setMutedUntilDate:mutedUntilDate];
+                                            }];
+    }];
+}
+
 #pragma mark - Logging
 
 + (NSString *)tag