input/qobuz: parse and report message from error responses

Makefile.am

@@ -1382,6 +1382,7 @@ libinput_a_SOURCES += \
 	src/lib/gcrypt/MD5.cxx src/lib/gcrypt/MD5.hxx \
 	src/input/plugins/QobuzSession.hxx \
 	src/input/plugins/QobuzClient.cxx src/input/plugins/QobuzClient.hxx \
+	src/input/plugins/QobuzErrorParser.cxx src/input/plugins/QobuzErrorParser.hxx \
 	src/input/plugins/QobuzLoginRequest.cxx src/input/plugins/QobuzLoginRequest.hxx \
 	src/input/plugins/QobuzTrackRequest.cxx src/input/plugins/QobuzTrackRequest.hxx \
 	src/input/plugins/QobuzInputPlugin.cxx src/input/plugins/QobuzInputPlugin.hxx

src/input/plugins/QobuzErrorParser.cxx

@@ -0,0 +1,101 @@
+/*
+ * Copyright 2003-2018 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "config.h"
+#include "QobuzErrorParser.hxx"
+#include "lib/yajl/Callbacks.hxx"
+#include "util/ConstBuffer.hxx"
+#include "util/RuntimeError.hxx"
+
+using Wrapper = Yajl::CallbacksWrapper<QobuzErrorParser>;
+static constexpr yajl_callbacks qobuz_error_parser_callbacks = {
+	nullptr,
+	nullptr,
+	nullptr,
+	nullptr,
+	nullptr,
+	Wrapper::String,
+	nullptr,
+	Wrapper::MapKey,
+	Wrapper::EndMap,
+	nullptr,
+	nullptr,
+};
+
+QobuzErrorParser::QobuzErrorParser(unsigned _status,
+				   const std::multimap<std::string, std::string> &headers)
+	:status(_status),
+	 parser(&qobuz_error_parser_callbacks, nullptr, this)
+{
+	auto i = headers.find("content-type");
+	if (i == headers.end() || i->second.find("/json") == i->second.npos)
+		throw FormatRuntimeError("Status %u from Qobuz", status);
+}
+
+void
+QobuzErrorParser::OnData(ConstBuffer<void> data)
+{
+	parser.Parse((const unsigned char *)data.data, data.size);
+}
+
+void
+QobuzErrorParser::OnEnd()
+{
+	parser.CompleteParse();
+
+	if (!message.empty())
+		throw FormatRuntimeError("Error from Qobuz: %s",
+					 message.c_str());
+	else
+		throw FormatRuntimeError("Status %u from Qobuz", status);
+}
+
+inline bool
+QobuzErrorParser::String(StringView value) noexcept
+{
+	switch (state) {
+	case State::NONE:
+		break;
+
+	case State::MESSAGE:
+		message.assign(value.data, value.size);
+		break;
+	}
+
+	return true;
+}
+
+inline bool
+QobuzErrorParser::MapKey(StringView value) noexcept
+{
+	if (value.Equals("message"))
+		state = State::MESSAGE;
+	else
+		state = State::NONE;
+
+	return true;
+}
+
+inline bool
+QobuzErrorParser::EndMap() noexcept
+{
+	state = State::NONE;
+
+	return true;
+}

src/input/plugins/QobuzErrorParser.hxx

@@ -0,0 +1,74 @@
+/*
+ * Copyright 2003-2018 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef QOBUZ_ERROR_PARSER_HXX
+#define QOBUZ_ERROR_PARSER_HXX
+
+#include "check.h"
+#include "lib/yajl/Handle.hxx"
+
+#include <exception>
+#include <string>
+#include <map>
+
+template<typename T> struct ConstBuffer;
+struct StringView;
+
+/**
+ * Parse an error JSON response.
+ */
+class QobuzErrorParser {
+	const unsigned status;
+
+	Yajl::Handle parser;
+
+	enum class State {
+		NONE,
+		MESSAGE,
+	} state = State::NONE;
+
+	std::string message;
+
+public:
+	/**
+	 * May throw if there is a formal error in the response
+	 * headers.
+	 */
+	QobuzErrorParser(unsigned status,
+			 const std::multimap<std::string, std::string> &headers);
+
+	/**
+	 * Feed response body data into the JSON parser.
+	 */
+	void OnData(ConstBuffer<void> data);
+
+	/**
+	 * Throw an exception describing the error condition.  Call
+	 * this at the end of the response body.
+	 */
+	void OnEnd();
+
+public:
+	/* yajl callbacks */
+	bool String(StringView value) noexcept;
+	bool MapKey(StringView value) noexcept;
+	bool EndMap() noexcept;
+};
+
+#endif

src/input/plugins/QobuzLoginRequest.cxx

@@ -19,6 +19,7 @@
 
 #include "config.h"
 #include "QobuzLoginRequest.hxx"
+#include "QobuzErrorParser.hxx"
 #include "lib/curl/Form.hxx"
 #include "lib/yajl/Callbacks.hxx"
 #include "util/RuntimeError.hxx"
@@ -98,8 +99,10 @@ void
 QobuzLoginRequest::OnHeaders(unsigned status,
 			     std::multimap<std::string, std::string> &&headers)
 {
-	if (status != 200)
+	if (status != 200) {
-		throw FormatRuntimeError("Status %u from Qobuz", status);
+		error_parser = std::make_unique<QobuzErrorParser>(status, headers);
+		return;
+	}
 
 	auto i = headers.find("content-type");
 	if (i == headers.end() || i->second.find("/json") == i->second.npos)
@@ -111,12 +114,22 @@ QobuzLoginRequest::OnHeaders(unsigned status,
 void
 QobuzLoginRequest::OnData(ConstBuffer<void> data)
 {
+	if (error_parser) {
+		error_parser->OnData(data);
+		return;
+	}
+
 	parser.Parse((const unsigned char *)data.data, data.size);
 }
 
 void
 QobuzLoginRequest::OnEnd()
 {
+	if (error_parser) {
+		error_parser->OnEnd();
+		return;
+	}
+
 	parser.CompleteParse();
 
 	if (session.user_auth_token.empty())

src/input/plugins/QobuzLoginRequest.hxx

@@ -27,9 +27,11 @@
 #include "lib/yajl/Handle.hxx"
 
 #include <exception>
+#include <memory>
 #include <string>
 
 class CurlRequest;
+class QobuzErrorParser;
 
 class QobuzLoginHandler {
 public:
@@ -40,6 +42,8 @@ public:
 class QobuzLoginRequest final : CurlResponseHandler {
 	CurlRequest request;
 
+	std::unique_ptr<QobuzErrorParser> error_parser;
+
 	Yajl::Handle parser;
 
 	enum class State {

src/input/plugins/QobuzTrackRequest.cxx

@@ -19,6 +19,7 @@
 
 #include "config.h"
 #include "QobuzTrackRequest.hxx"
+#include "QobuzErrorParser.hxx"
 #include "QobuzClient.hxx"
 #include "lib/yajl/Callbacks.hxx"
 #include "util/RuntimeError.hxx"
@@ -71,8 +72,10 @@ void
 QobuzTrackRequest::OnHeaders(unsigned status,
 			     std::multimap<std::string, std::string> &&headers)
 {
-	if (status != 200)
+	if (status != 200) {
-		throw FormatRuntimeError("Status %u from Qobuz", status);
+		error_parser = std::make_unique<QobuzErrorParser>(status, headers);
+		return;
+	}
 
 	auto i = headers.find("content-type");
 	if (i == headers.end() || i->second.find("/json") == i->second.npos)
@@ -84,12 +87,22 @@ QobuzTrackRequest::OnHeaders(unsigned status,
 void
 QobuzTrackRequest::OnData(ConstBuffer<void> data)
 {
+	if (error_parser) {
+		error_parser->OnData(data);
+		return;
+	}
+
 	parser.Parse((const unsigned char *)data.data, data.size);
 }
 
 void
 QobuzTrackRequest::OnEnd()
 {
+	if (error_parser) {
+		error_parser->OnEnd();
+		return;
+	}
+
 	parser.CompleteParse();
 
 	if (url.empty())

src/input/plugins/QobuzTrackRequest.hxx

@@ -27,9 +27,11 @@
 #include "lib/yajl/Handle.hxx"
 
 #include <exception>
+#include <memory>
 #include <string>
 
 class QobuzClient;
+class QobuzErrorParser;
 struct QobuzSession;
 
 class QobuzTrackHandler
@@ -45,6 +47,8 @@ class QobuzTrackRequest final : CurlResponseHandler {
 
 	CurlRequest request;
 
+	std::unique_ptr<QobuzErrorParser> error_parser;
+
 	Yajl::Handle parser;
 
 	enum class State {