From 19754bacb99d3125508182ee9aefc2ab02ea1b5d Mon Sep 17 00:00:00 2001
From: Matthew Chen <charlesmchen@gmail.com>
Date: Mon, 24 Apr 2017 22:31:13 -0400
Subject: [PATCH] Add a "UTI type for file extension" method.

// FREEBIE
---
 src/Util/MIMETypeUtil.h | 7 ++++---
 src/Util/MIMETypeUtil.m | 9 +++++++++
 2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/src/Util/MIMETypeUtil.h b/src/Util/MIMETypeUtil.h
index 8ca864fe6..c5bc1e491 100644
--- a/src/Util/MIMETypeUtil.h
+++ b/src/Util/MIMETypeUtil.h
@@ -42,8 +42,9 @@ extern NSString *const OWSMimeTypeUnknownForTests;
 + (NSSet<NSString *> *)supportedImageUTITypes;
 + (NSSet<NSString *> *)supportedAnimatedImageUTITypes;
 
-+ (NSString *)utiTypeForMIMEType:(NSString *)mimeType;
-+ (NSString *)fileExtensionForUTIType:(NSString *)utiType;
-+ (NSString *)fileExtensionForMIMEType:(NSString *)mimeType;
++ (nullable NSString *)utiTypeForMIMEType:(NSString *)mimeType;
++ (nullable NSString *)utiTypeForFileExtension:(NSString *)fileExtension;
++ (nullable NSString *)fileExtensionForUTIType:(NSString *)utiType;
++ (nullable NSString *)fileExtensionForMIMEType:(NSString *)mimeType;
 
 @end
diff --git a/src/Util/MIMETypeUtil.m b/src/Util/MIMETypeUtil.m
index a838a0452..bbe2fb37f 100644
--- a/src/Util/MIMETypeUtil.m
+++ b/src/Util/MIMETypeUtil.m
@@ -1571,4 +1571,13 @@ NSString *const OWSMimeTypeUnknownForTests = @"unknown/mimetype";
     return fileExtension;
 }
 
++ (NSString *)utiTypeForFileExtension:(NSString *)fileExtension
+{
+    OWSAssert(fileExtension.length > 0);
+
+    NSString *utiType = (__bridge_transfer NSString *)UTTypeCreatePreferredIdentifierForTag(
+        kUTTagClassFilenameExtension, (__bridge CFStringRef)fileExtension, NULL);
+    return utiType;
+}
+
 @end