net/base/platform_mime_util_apple.mm

// Copyright 2012 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "net/base/platform_mime_util.h"

#import <Foundation/Foundation.h>
#import <UniformTypeIdentifiers/UniformTypeIdentifiers.h>

#include <string>

#include "base/apple/bridging.h"
#include "base/apple/foundation_util.h"
#include "base/apple/scoped_cftyperef.h"
#include "base/notreached.h"
#include "base/strings/sys_string_conversions.h"
#include "build/build_config.h"

#if BUILDFLAG(IS_IOS)
#include <MobileCoreServices/MobileCoreServices.h>
#else
#include <CoreServices/CoreServices.h>
#endif  // BUILDFLAG(IS_IOS)

namespace net {

bool PlatformMimeUtil::GetPlatformMimeTypeFromExtension(
    const base::FilePath::StringType& ext,
    std::string* result) const {
  std::string ext_nodot = ext;
  if (ext_nodot.length() >= 1 && ext_nodot[0] == L'.') {
    ext_nodot.erase(ext_nodot.begin());
  }

  UTType* uttype =
      [UTType typeWithFilenameExtension:base::SysUTF8ToNSString(ext_nodot)];
  // Dynamic UTTypes are made by the system in the event that there's a
  // non-identifiable mime type. For now, we should treat dynamic UTTypes as a
  // nonstandard format.
  if (uttype.dynamic || uttype.preferredMIMEType == nil) {
    return false;
  }
  *result = base::SysNSStringToUTF8(uttype.preferredMIMEType);
  return true;
}

bool PlatformMimeUtil::GetPlatformPreferredExtensionForMimeType(
    std::string_view mime_type,
    base::FilePath::StringType* ext) const {
  UTType* uttype = [UTType typeWithMIMEType:base::SysUTF8ToNSString(mime_type)];
  if (uttype.dynamic || uttype.preferredFilenameExtension == nil) {
    return false;
  }
  *ext = base::SysNSStringToUTF8(uttype.preferredFilenameExtension);
  return true;
}

void PlatformMimeUtil::GetPlatformExtensionsForMimeType(
    std::string_view mime_type,
    std::unordered_set<base::FilePath::StringType>* extensions) const {
  NSArray<UTType*>* types =
      [UTType typesWithTag:base::SysUTF8ToNSString(mime_type)
                  tagClass:UTTagClassMIMEType
          conformingToType:nil];
  bool extensions_found = false;
  if (types) {
    for (UTType* type in types) {
      if (!type || type.preferredFilenameExtension == nil) {
        continue;
      }
      extensions_found = true;
      NSArray<NSString*>* extensions_list =
          type.tags[UTTagClassFilenameExtension];
      for (NSString* extension in extensions_list) {
        extensions->insert(base::SysNSStringToUTF8(extension));
      }
    }
  }

  if (extensions_found) {
    return;
  }

  base::FilePath::StringType ext;
  if (GetPlatformPreferredExtensionForMimeType(mime_type, &ext)) {
    extensions->insert(ext);
  }
}

}  // namespace net