Checkpoint commit for LastFm integration -- URL signing and working

`auth.getToken` call.

src/core/io/HttpClient.h

@@ -62,17 +62,10 @@ namespace musik { namespace core { namespace io {
             HttpClient<T>& Decorator(DecoratorCallback decoratorCb);
             HttpClient<T>& Canceled(CanceledCallback canceledCb);
 
-            const T& Stream() {
-                return this->ostream;
-            }
-
-            const HttpHeaders& ResponseHeaders() {
-                return this->responseHeaders;
-            }
-
-            const HttpHeaders& RequestHeaders() {
-                return this->requestHeaders;
-            }
+            const T& Stream() const { return this->ostream; }
+            const HttpHeaders& ResponseHeaders() const { return this->responseHeaders; }
+            const HttpHeaders& RequestHeaders() const { return this->requestHeaders; }
+            const std::string& Url() const { return this->url; }
 
             HttpClient<T>& Run(Callback callback = Callback());
             void Wait();
@@ -190,6 +183,7 @@ namespace musik { namespace core { namespace io {
         }
 
         this->curl = curl_easy_init();
+
         curl_easy_setopt(curl, CURLOPT_URL, url.c_str());
         curl_easy_setopt(curl, CURLOPT_HEADER, 0);
         curl_easy_setopt(curl, CURLOPT_HTTPGET, 1);
@@ -204,6 +198,11 @@ namespace musik { namespace core { namespace io {
         curl_easy_setopt(curl, CURLOPT_CONNECTTIMEOUT, 3000);
         curl_easy_setopt(curl, CURLOPT_LOW_SPEED_TIME, 7500);
         curl_easy_setopt(curl, CURLOPT_LOW_SPEED_LIMIT, 500);
+
+        if (this->decoratorCb) {
+            this->decoratorCb(this->curl);
+        }
+
         curl_easy_setopt(curl, CURLOPT_WRITEDATA, this);
         curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, &CurlWriteCallback);
         curl_easy_setopt(curl, CURLOPT_XFERINFODATA, this);
@@ -211,10 +210,6 @@ namespace musik { namespace core { namespace io {
         curl_easy_setopt(curl, CURLOPT_HEADERDATA, this);
         curl_easy_setopt(curl, CURLOPT_HEADERFUNCTION, &CurlHeaderCallback);
 
-        if (this->decoratorCb) {
-            this->decoratorCb(this->curl);
-        }
-
         if (this->requestHeaders.size()) {
             struct curl_slist* slist = nullptr;
             for (auto it : this->requestHeaders) {

src/musikcube/app/util/LastFm.cpp

@@ -0,0 +1,117 @@
+//////////////////////////////////////////////////////////////////////////////
+//
+// Copyright (c) 2007-2017 musikcube team
+//
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+//
+//    * Redistributions of source code must retain the above copyright notice,
+//      this list of conditions and the following disclaimer.
+//
+//    * Redistributions in binary form must reproduce the above copyright
+//      notice, this list of conditions and the following disclaimer in the
+//      documentation and/or other materials provided with the distribution.
+//
+//    * Neither the name of the author nor the names of other contributors may
+//      be used to endorse or promote products derived from this software
+//      without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+// POSSIBILITY OF SUCH DAMAGE.
+//
+//////////////////////////////////////////////////////////////////////////////
+
+#pragma once
+
+#include "stdafx.h"
+#include "LastFm.h"
+#include <curl/curl.h>
+#include <openssl/md5.h>
+#include <core/io/HttpClient.h>
+#include <json.hpp>
+#include <sstream>
+#include <map>
+
+/* http://www.last.fm/group/Last.fm+Web+Services/forum/21604/_/522900 -- it's ok to
+put our key in the code */
+static const std::string API_KEY = "502c69bd3f9946e8e0beee4fcb28c4cd";
+static const std::string URL_BASE = "http://ws.audioscrobbler.com/2.0/";
+static const std::string GET_TOKEN = "auth.gettoken";
+static const std::string ACCOUNT_LINK_URL_BASE = "http://www.last.fm/api/auth/?api_key=" + API_KEY + "&token=";
+
+using LastFmClient = musik::core::io::HttpClient<std::stringstream>;
+
+static std::unique_ptr<LastFmClient> createClient() {
+    return LastFmClient::Create(std::stringstream());
+}
+
+static std::string generateSignedUrl(
+    const std::string& method,
+    std::map<std::string, std::string>&& params = { })
+{
+    params["format"] = "json";
+    params["method"] = method;
+    params["api_key"] = API_KEY;
+
+    std::string toHash;
+    std::string url = URL_BASE;
+    bool first = true;
+
+    for (auto it : params) {
+        toHash += it.first + it.second;
+        url += (first ? "?" : "&") + it.first + "=" + it.second;
+        first = false;
+    }
+
+    /* compute the sum */
+    unsigned char rawDigest[MD5_DIGEST_LENGTH];
+    MD5((const unsigned char*)toHash.c_str(), toHash.length(), rawDigest);
+
+    /* convert to hex */
+    char hexDigest[33];
+    for (size_t i = 0; i < 16; i++) {
+        snprintf(&(hexDigest[i * 2]), 16 * 2, "%02x", (unsigned int)rawDigest[i]);
+    }
+    hexDigest[32] = 0;
+
+    url += "&api_sig=" + std::string(hexDigest);
+
+    return url;
+}
+
+namespace musik { namespace cube { namespace lastfm {
+
+    const std::string InitiateLink() {
+        std::string url = generateSignedUrl(GET_TOKEN);
+        std::string token;
+
+        auto client = createClient();
+        client->Url(url)
+            .Run([&token](LastFmClient* client, int statusCode, CURLcode curlCode) {
+                if (statusCode == 200) {
+                    try {
+                        auto json = nlohmann::json::parse(client->Stream().str());
+                        token = json.value("token", "");
+                    }
+                    catch (...) {
+                        /* not much we can do... */
+                    }
+                }
+            })
+            .Wait();
+
+        return token.size() ? (ACCOUNT_LINK_URL_BASE + token) : "";
+    }
+
+} } }

src/musikcube/app/util/LastFm.h

@@ -0,0 +1,41 @@
+//////////////////////////////////////////////////////////////////////////////
+//
+// Copyright (c) 2007-2017 musikcube team
+//
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+//
+//    * Redistributions of source code must retain the above copyright notice,
+//      this list of conditions and the following disclaimer.
+//
+//    * Redistributions in binary form must reproduce the above copyright
+//      notice, this list of conditions and the following disclaimer in the
+//      documentation and/or other materials provided with the distribution.
+//
+//    * Neither the name of the author nor the names of other contributors may
+//      be used to endorse or promote products derived from this software
+//      without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+// POSSIBILITY OF SUCH DAMAGE.
+//
+//////////////////////////////////////////////////////////////////////////////
+
+#pragma once
+
+#include "stdafx.h"
+
+namespace musik { namespace cube { namespace lastfm {
+    extern const std::string InitiateLink();
+} } }

src/musikcube/musikcube.vcxproj

@@ -165,6 +165,7 @@ xcopy "$(SolutionDir)src\3rdparty\bin\win32\font\*.ttf" "$(TargetDir)fonts\" /Y
     <ClCompile Include="app\overlay\VisualizerOverlay.cpp" />
     <ClCompile Include="app\util\GlobalHotkeys.cpp" />
     <ClCompile Include="app\util\Hotkeys.cpp" />
+    <ClCompile Include="app\util\LastFm.cpp" />
     <ClCompile Include="app\util\Playback.cpp" />
     <ClCompile Include="app\util\PreferenceKeys.cpp" />
     <ClCompile Include="app\util\UpdateCheck.cpp" />
@@ -224,6 +225,7 @@ xcopy "$(SolutionDir)src\3rdparty\bin\win32\font\*.ttf" "$(TargetDir)fonts\" /Y
     <ClInclude Include="app\overlay\VisualizerOverlay.h" />
     <ClInclude Include="app\util\GlobalHotkeys.h" />
     <ClInclude Include="app\util\Hotkeys.h" />
+    <ClInclude Include="app\util\LastFm.h" />
     <ClInclude Include="app\util\Messages.h" />
     <ClInclude Include="app\util\Playback.h" />
     <ClInclude Include="app\util\PreferenceKeys.h" />

src/musikcube/musikcube.vcxproj.filters

@@ -156,6 +156,9 @@
     <ClCompile Include="app\layout\CategorySearchLayout.cpp">
       <Filter>app\layout</Filter>
     </ClCompile>
+    <ClCompile Include="app\util\LastFm.cpp">
+      <Filter>app\util</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="stdafx.h" />
@@ -361,6 +364,9 @@
     <ClInclude Include="app\layout\CategorySearchLayout.h">
       <Filter>app\layout</Filter>
     </ClInclude>
+    <ClInclude Include="app\util\LastFm.h">
+      <Filter>app\util</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <Filter Include="cursespp">