CLOUD: Add DownloadRequest stub

It reads the passed NetworkReadStream and prints its contents onto
console (for now). It would be writing contents into file.

To simplify work with raw NetworkReadStream there is a new CurlRequest.
It basically does nothing, but as ConnMan handles transfers only if
there is an active Request, you need some Request to get
NetworkReadStream working. Thus, there is a CurlRequest, which is active
until NetworkReadStream is completely read. CurlRequest also has useful
addHeader() and addPostField() methods in order to customize the request
easily. Use execute() method to get its NetworkReadStream.

DropboxStorage implements streamFile() and download() API methods. As
DownloadRequest is incomplete, it is not actually downloading a file,
though.

4 files changed, 28 insertions, 5 deletions

diff --git a/backends/cloud/dropbox/dropboxlistdirectoryrequest.cpp b/backends/cloud/dropbox/dropboxlistdirectoryrequest.cpp
index e28a445d63..5e5957b12c 100644
--- a/backends/cloud/dropbox/dropboxlistdirectoryrequest.cpp
+++ b/backends/cloud/dropbox/dropboxlistdirectoryrequest.cpp
@@ -24,6 +24,7 @@
 #include "backends/cloud/iso8601.h"
 #include "backends/networking/curl/connectionmanager.h"
 #include "backends/networking/curl/curljsonrequest.h"
+#include "common/json.h"
 
 namespace Cloud {
 namespace Dropbox {
diff --git a/backends/cloud/dropbox/dropboxlistdirectoryrequest.h b/backends/cloud/dropbox/dropboxlistdirectoryrequest.h
index 03b4fc121a..0c10512782 100644
--- a/backends/cloud/dropbox/dropboxlistdirectoryrequest.h
+++ b/backends/cloud/dropbox/dropboxlistdirectoryrequest.h
@@ -24,8 +24,8 @@
 #define BACKENDS_CLOUD_DROPBOX_DROPBOXLISTDIRECTORYREQUEST_H
 
 #include "backends/cloud/storage.h"
-#include "common/callback.h"
 #include "backends/networking/curl/request.h"
+#include "common/callback.h"
 
 namespace Cloud {
 namespace Dropbox {
diff --git a/backends/cloud/dropbox/dropboxstorage.cpp b/backends/cloud/dropbox/dropboxstorage.cpp
index 6de9424efc..1b6dc1b92f 100644
--- a/backends/cloud/dropbox/dropboxstorage.cpp
+++ b/backends/cloud/dropbox/dropboxstorage.cpp
@@ -23,6 +23,7 @@
 
 #include "backends/cloud/dropbox/dropboxstorage.h"
 #include "backends/cloud/dropbox/dropboxlistdirectoryrequest.h"
+#include "backends/cloud/downloadrequest.h"
 #include "backends/networking/curl/connectionmanager.h"
 #include "backends/networking/curl/curljsonrequest.h"
 #include "common/config-manager.h"
@@ -86,10 +87,28 @@ void DropboxStorage::listDirectory(Common::String path, FileArrayCallback outerC
 	ConnMan.addRequest(new DropboxListDirectoryRequest(_token, path, outerCallback, recursive));
 }
 
+Networking::NetworkReadStream *DropboxStorage::streamFile(Common::String path) {
+	Common::JSONObject jsonRequestParameters;
+	jsonRequestParameters.setVal("path", new Common::JSONValue(path));
+	Common::JSONValue value(jsonRequestParameters);
+
+	Networking::CurlRequest *request = new Networking::CurlRequest(0, "https://content.dropboxapi.com/2/files/download");
+	request->addHeader("Authorization: Bearer " + _token);
+	request->addHeader("Dropbox-API-Arg: " + Common::JSON::stringify(&value));
+	request->addHeader("Content-Type: "); //required to be empty (as we do POST, it's usually app/form-url-encoded)
+
+	return request->execute();
+}
+
+void DropboxStorage::download(Common::String path, BoolCallback callback) {
+	ConnMan.addRequest(new DownloadRequest(callback, streamFile(path)));
+}
+
 void DropboxStorage::syncSaves(BoolCallback callback) {
 	//this is not the real syncSaves() implementation	
 	//"" is root in Dropbox, not "/"
-	listDirectory("", new Common::Callback<DropboxStorage, Common::Array<StorageFile> >(this, &DropboxStorage::printFiles), true);
+	//listDirectory("", new Common::Callback<DropboxStorage, Common::Array<StorageFile> >(this, &DropboxStorage::printFiles), true);
+	download("/notempty.txt", 0);
 }
 
 void DropboxStorage::info(StorageInfoCallback outerCallback) {
diff --git a/backends/cloud/dropbox/dropboxstorage.h b/backends/cloud/dropbox/dropboxstorage.h
index c1c2e03497..92c3746da5 100644
--- a/backends/cloud/dropbox/dropboxstorage.h
+++ b/backends/cloud/dropbox/dropboxstorage.h
@@ -67,10 +67,13 @@ public:
 	virtual void listDirectory(Common::String path, FileArrayCallback callback, bool recursive = false);
 
 	/** Calls the callback when finished. */
-	virtual void upload(Common::String path, Common::ReadStream* contents, BoolCallback callback) {} //TODO
+	virtual void upload(Common::String path, Common::ReadStream *contents, BoolCallback callback) {} //TODO
 
-	/** Returns pointer to Common::ReadStream. */
-	virtual void download(Common::String path, ReadStreamCallback callback) {} //TODO
+	/** Returns pointer to Networking::NetworkReadStream. */
+	virtual Networking::NetworkReadStream *streamFile(Common::String path);
+
+	/** Calls the callback when finished. */
+	virtual void download(Common::String path, BoolCallback callback);
 
 	/** Calls the callback when finished. */
 	virtual void remove(Common::String path, BoolCallback callback) {} //TODO