Initial commit for Chrome metainstaller on Mac.

chrome/installer/mac/app/downloader.m

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#import <Foundation/Foundation.h>
+#import "downloader.h"
+#import "parser.h"
+#import "NetworkCommunication.h"
+#import "DownloadDelegate.h"
+
+@implementation Downloader
+
++ (NSString*)getDownloadsFilePath {
+  NSArray* downloadPaths = NSSearchPathForDirectoriesInDomains(NSDownloadsDirectory, NSUserDomainMask, YES);
+  NSString* filePathToDownloads = [downloadPaths objectAtIndex:0];
+  NSArray* filenameComposition = @[filePathToDownloads, @"GoogleChrome.dmg"];
+  NSString* completeFilePath = [NSString pathWithComponents:
+                                filenameComposition];
+  return completeFilePath;
+}
+
+// The URLs extracted from parseXML are incomplete and need the filename (which
+// is the same for all the links) appended to the end. Iterates through
+// chromeIncompleteDownloadURLs_ and appends chromeImageFilename_ to each URL.
+- (NSMutableArray*)appendFilename:(NSString*)filename
+                           toURLs:(NSArray*)incompleteURLs {
+  NSMutableArray* completeURLs = [[NSMutableArray alloc] init];
+
+  for (NSString* URL in incompleteURLs) {
+    [completeURLs addObject:[NSString stringWithFormat:@"%@%@",URL,filename]];
+  }
+  return completeURLs;
+}
+
+// Extract URLs and the filename from the omahaResponseXML. Then complete the
+// URLs by appending filename and returns the first complete URL.
+- (NSURL*)getChromeImageURLFromOmahaResponse:(NSData*)omahaResponseXML {
+  NSError *err = [[NSError alloc] init];
+
+  Parser* parser = [[Parser alloc] init];
+  NSArray *incompleteURLs = [parser parseXML:omahaResponseXML error:&err];
+
+  if ([incompleteURLs count] < 1) {
+    // TODO: Error handling and implement way to verify URL is working. Error
+    // information saved in "err".
+  }
+
+  NSMutableArray* completeURLs =
+      [self appendFilename:parser.chromeImageFilename
+                    toURLs:incompleteURLs];
+
+  NSString* chromeURLString = [completeURLs firstObject];
+
+  return [NSURL URLWithString:chromeURLString];
+}
+
+// Downloads contents of chromeURL to downloads folders and delegates the work
+// to the DownloadDelegate class.
+- (BOOL)writeChromeImageToDownloadsDirectory:(NSURL*)chromeURL {
+  DownloadDelegate *delegate = [[DownloadDelegate alloc] init];
+  NetworkCommunication* downloadTask = [[NetworkCommunication alloc]
+                                        initWithDelegate:delegate];
+
+  //TODO: What if file already exists?
+  [downloadTask createRequestWithURLasString:[NSString stringWithFormat:@"%@",
+                                              chromeURL] andXMLBody:nil];
+  [downloadTask sendDownloadRequest];
+
+  NSFileManager* manager = [[NSFileManager alloc] init];
+  if (![manager fileExistsAtPath:[Downloader getDownloadsFilePath]]){
+    return false;
+  }
+  return true;
+}
+
+// Pieces together the getting the URL portion and downloading the contents of
+// URL portion.
+- (BOOL)downloadChromeImageToDownloadsDirectory: (NSData*)omahaResponseXML {
+  NSURL* chromeURL = [self getChromeImageURLFromOmahaResponse:omahaResponseXML];
+  BOOL writeWasSuccessful = [self writeChromeImageToDownloadsDirectory:chromeURL];
+  if(!writeWasSuccessful){
+    NSLog(@"Unsuccesful write to Downloads.");
+    return false;
+  }
+  return true;
+}
+
+@end