lastfm: rework service architecture a bit and implement getting full artist info

8 files changed, 187 insertions, 298 deletions

diff --git a/doc/bindings b/doc/bindings
index 679206ef..f4b846cd 100644
--- a/doc/bindings
+++ b/doc/bindings
@@ -505,9 +505,6 @@
 #  refetch_lyrics
 #
 #def_key "`"
-#  refetch_artist_info
-#
-#def_key "`"
 #  add_random_items
 #
 #def_key "ctrl_p"
diff --git a/src/actions.cpp b/src/actions.cpp
index daaf8004..27c51bc6 100644
--- a/src/actions.cpp
+++ b/src/actions.cpp
@@ -2072,22 +2072,6 @@ void RefetchLyrics::run()
 #	endif // HAVE_CURL_CURL_H
 }
 
-bool RefetchArtistInfo::canBeRun() const
-{
-#	ifdef HAVE_CURL_CURL_H
-	return myScreen == myLastfm;
-#	else
-	return false;
-#	endif // HAVE_CURL_CURL_H
-}
-
-void RefetchArtistInfo::run()
-{
-#	ifdef HAVE_CURL_CURL_H
-	myLastfm->Refetch();
-#	endif // HAVE_CURL_CURL_H
-}
-
 bool SetSelectedItemsPriority::canBeRun() const
 {
 	if (Mpd.Version() < 17)
@@ -2161,7 +2145,7 @@ bool ShowArtistInfo::canBeRun() const
 void ShowArtistInfo::run()
 {
 #	ifdef HAVE_CURL_CURL_H
-	if (myScreen == myLastfm || myLastfm->isDownloading())
+	if (myScreen == myLastfm)
 	{
 		myLastfm->switchTo();
 		return;
@@ -2181,8 +2165,11 @@ void ShowArtistInfo::run()
 		artist = s->getArtist();
 	}
 	
-	if (!artist.empty() && myLastfm->SetArtistInfoArgs(artist, Config.lastfm_preferred_language))
+	if (!artist.empty())
+	{
+		myLastfm->queueJob(LastFm::ArtistInfo(artist, Config.lastfm_preferred_language));
 		myLastfm->switchTo();
+	}
 #	endif // HAVE_CURL_CURL_H
 }
 
@@ -2540,7 +2527,6 @@ void populateActions()
 	insert_action(new Actions::ToggleLibraryTagType());
 	insert_action(new Actions::ToggleMediaLibrarySortMode());
 	insert_action(new Actions::RefetchLyrics());
-	insert_action(new Actions::RefetchArtistInfo());
 	insert_action(new Actions::SetSelectedItemsPriority());
 	insert_action(new Actions::FilterPlaylistOnPriorities());
 	insert_action(new Actions::ShowSongInfo());
diff --git a/src/actions.h b/src/actions.h
index afb53823..42112685 100644
--- a/src/actions.h
+++ b/src/actions.h
@@ -942,15 +942,6 @@ protected:
 	virtual void run();
 };
 
-struct RefetchArtistInfo : public BaseAction
-{
-	RefetchArtistInfo() : BaseAction(Type::RefetchArtistInfo, "refetch_artist_info") { }
-	
-protected:
-	virtual bool canBeRun() const;
-	virtual void run();
-};
-
 struct SetSelectedItemsPriority : public BaseAction
 {
 	SetSelectedItemsPriority()
diff --git a/src/curl_handle.h b/src/curl_handle.h
index e1b3eea5..072a3509 100644
--- a/src/curl_handle.h
+++ b/src/curl_handle.h
@@ -21,9 +21,7 @@
 #ifndef NCMPCPP_CURL_HANDLE_H
 #define NCMPCPP_CURL_HANDLE_H
 
-#ifdef HAVE_CONFIG_H
-# include "config.h"
-#endif
+#include "config.h"
 
 #ifdef HAVE_CURL_CURL_H
 
diff --git a/src/lastfm.cpp b/src/lastfm.cpp
index f6ff5004..e9baabca 100644
--- a/src/lastfm.cpp
+++ b/src/lastfm.cpp
@@ -22,27 +22,12 @@
 
 #ifdef HAVE_CURL_CURL_H
 
-#ifdef WIN32
-# include <io.h>
-#else
-# include <sys/stat.h>
-#endif // WIN32
-
-#include <cassert>
-#include <cerrno>
-#include <cstring>
-#include <boost/locale/conversion.hpp>
-#include <fstream>
-#include <iostream>
-
-#include "error.h"
 #include "helpers.h"
 #include "charset.h"
 #include "global.h"
 #include "statusbar.h"
 #include "title.h"
 #include "screen_switcher.h"
-#include "utility/string.h"
 
 using Global::MainHeight;
 using Global::MainStartY;
@@ -51,7 +36,6 @@ Lastfm *myLastfm;
 
 Lastfm::Lastfm()
 : Screen(NC::Scrollpad(0, MainStartY, COLS, MainHeight, "", Config.main_color, NC::Border::None))
-, isReadyToTake(0), isDownloadInProgress(0)
 { }
 
 void Lastfm::resize()
@@ -65,23 +49,13 @@ void Lastfm::resize()
 
 std::wstring Lastfm::title()
 {
-	return itsTitle;
+	return m_title;
 }
 
 void Lastfm::update()
 {
-	if (isReadyToTake)
-		Take();
-}
-
-void Lastfm::Take()
-{
-	assert(isReadyToTake);
-	pthread_join(itsDownloader, 0);
-	w.flush();
-	w.refresh();
-	isDownloadInProgress = 0;
-	isReadyToTake = 0;
+	if (m_worker.valid() && m_worker.is_ready())
+		getResult();
 }
 
 void Lastfm::switchTo()
@@ -90,134 +64,27 @@ void Lastfm::switchTo()
 	if (myScreen != this)
 	{
 		SwitchTo::execute(this);
-		// get an old info if it waits
-		if (isReadyToTake)
-			Take();
-		Load();
 		drawHeader();
 	}
 	else
 		switchToPreviousScreen();
 }
 
-void Lastfm::Load()
-{
-	if (isDownloadInProgress)
-		return;
-	
-	assert(itsService.get());
-	assert(itsService->checkArgs(itsArgs));
-	
-	SetTitleAndFolder();
-	
-	w.clear();
-	w.reset();
-	
-	std::string artist = itsArgs.find("artist")->second;
-	std::string file = boost::locale::to_lower(artist + ".txt");
-	removeInvalidCharsFromFilename(file, Config.generate_win32_compatible_filenames);
-	
-	itsFilename = itsFolder + "/" + file;
-	
-	mkdir(itsFolder.c_str()
-#	ifndef WIN32
-	, 0755
-#	endif // !WIN32
-	     );
-	
-	std::ifstream input(itsFilename.c_str());
-	if (input.is_open())
-	{
-		bool first = 1;
-		std::string line;
-		while (std::getline(input, line))
-		{
-			if (!first)
-				w << '\n';
-			w << Charset::utf8ToLocale(line);
-			first = 0;
-		}
-		input.close();
-		itsService->colorizeOutput(w);
-	}
-	else
-	{
-		w << "Fetching informations... ";
-		pthread_create(&itsDownloader, 0, DownloadWrapper, this);
-		isDownloadInProgress = 1;
-	}
-	w.flush();
-}
-
-void Lastfm::SetTitleAndFolder()
-{
-	if (dynamic_cast<ArtistInfo *>(itsService.get()))
-	{
-		itsTitle = L"Artist info - ";
-		itsTitle += ToWString(itsArgs.find("artist")->second);
-		itsFolder = Config.ncmpcpp_directory + "artists";
-	}
-}
-
-void *Lastfm::DownloadWrapper(void *this_ptr)
+void Lastfm::getResult()
 {
-	static_cast<Lastfm *>(this_ptr)->Download();
-	pthread_exit(0);
-}
-
-void Lastfm::Download()
-{
-	LastfmService::Result result = itsService->fetch(itsArgs);
-	
+	auto result = m_worker.get();
 	if (result.first)
 	{
-		Save(result.second);
 		w.clear();
 		w << Charset::utf8ToLocale(result.second);
-		itsService->colorizeOutput(w);
-	}
-	else
-		w << NC::Color::Red << result.second << NC::Color::End;
-	
-	isReadyToTake = 1;
-}
-
-void Lastfm::Save(const std::string &data)
-{
-	std::ofstream output(itsFilename.c_str());
-	if (output.is_open())
-	{
-		output << data;
-		output.close();
+		m_service->beautifyOutput(w);
 	}
 	else
-		std::cerr << "ncmpcpp: couldn't save file \"" << itsFilename << "\"\n";
-}
-
-void Lastfm::Refetch()
-{
-	if (remove(itsFilename.c_str()) && errno != ENOENT)
-	{
-		const char msg[] = "Couldn't remove \"%ls\": %s";
-		Statusbar::msg(msg, wideShorten(ToWString(itsFilename), COLS-const_strlen(msg)-25).c_str(), strerror(errno));
-		return;
-	}
-	Load();
-}
-
-bool Lastfm::SetArtistInfoArgs(const std::string &artist, const std::string &lang)
-{
-	if (isDownloading())
-		return false;
-	
-	itsService.reset(new ArtistInfo);
-	itsArgs.clear();
-	itsArgs["artist"] = artist;
-	if (!lang.empty())
-		itsArgs["lang"] = lang;
-	
-	return true;
+		w << " " << NC::Color::Red << result.second << NC::Color::End;
+	w.flush();
+	w.refresh();
+	// reset m_worker so it's no longer valid
+	m_worker = boost::unique_future<LastFm::Service::Result>();
 }
 
 #endif // HVAE_CURL_CURL_H
-
diff --git a/src/lastfm.h b/src/lastfm.h
index 6f81257b..ceda5a70 100644
--- a/src/lastfm.h
+++ b/src/lastfm.h
@@ -26,11 +26,12 @@
 #ifdef HAVE_CURL_CURL_H
 
 #include <memory>
-#include <pthread.h>
+#include <boost/thread/future.hpp>
 
 #include "interfaces.h"
 #include "lastfm_service.h"
 #include "screen.h"
+#include "utility/wide_string.h"
 
 struct Lastfm: Screen<NC::Scrollpad>, Tabbable
 {
@@ -49,37 +50,39 @@ struct Lastfm: Screen<NC::Scrollpad>, Tabbable
 	
 	virtual bool isMergable() OVERRIDE { return true; }
 	
-	// private members
-	void Refetch();
-	
-	bool isDownloading() { return isDownloadInProgress && !isReadyToTake; }
-	bool SetArtistInfoArgs(const std::string &artist, const std::string &lang = "");
+	template <typename ServiceT>
+	bool queueJob(ServiceT service)
+	{
+		auto old_service = dynamic_cast<ServiceT *>(m_service.get());
+		// if the same service and arguments were used, leave old info
+		if (old_service != nullptr && *old_service == service)
+			return true;
+		
+		// download in progress
+		if (m_worker.valid() && !m_worker.is_ready())
+			return false;
+		
+		m_service = std::make_shared<ServiceT>(std::forward<ServiceT>(service));
+		m_worker = boost::async(boost::launch::async, boost::bind(&LastFm::Service::fetch, m_service.get()));
+		
+		w.clear();
+		w << "Fetching information...";
+		w.flush();
+		m_title = ToWString(m_service->name());
+		
+		return true;
+	}
 	
 protected:
 	virtual bool isLockable() OVERRIDE { return false; }
 	
 private:
-	std::wstring itsTitle;
-	
-	std::string itsArtist;
-	std::string itsFilename;
-	
-	std::string itsFolder;
-	
-	std::auto_ptr<LastfmService> itsService;
-	LastfmService::Args itsArgs;
-	
-	void Load();
-	void Save(const std::string &data);
-	void SetTitleAndFolder();
+	void getResult();
 	
-	void Download();
-	static void *DownloadWrapper(void *);
+	std::wstring m_title;
 	
-	void Take();
-	bool isReadyToTake;
-	bool isDownloadInProgress;
-	pthread_t itsDownloader;
+	std::shared_ptr<LastFm::Service> m_service;
+	boost::unique_future<LastFm::Service::Result> m_worker;
 };
 
 extern Lastfm *myLastfm;
diff --git a/src/lastfm_service.cpp b/src/lastfm_service.cpp
index d0b11f52..87ddf729 100644
--- a/src/lastfm_service.cpp
+++ b/src/lastfm_service.cpp
@@ -23,152 +23,190 @@
 #ifdef HAVE_CURL_CURL_H
 
 #include <boost/algorithm/string/trim.hpp>
+#include <boost/locale/conversion.hpp>
+#include <fstream>
+#include "charset.h"
 #include "curl_handle.h"
 #include "settings.h"
 #include "utility/html.h"
 #include "utility/string.h"
 
-const char *LastfmService::baseURL = "http://ws.audioscrobbler.com/2.0/?api_key=d94e5b6e26469a2d1ffae8ef20131b79&method=";
+namespace {
 
-const char *LastfmService::msgParseFailed = "Fetched data could not be parsed";
+const char *apiUrl = "http://ws.audioscrobbler.com/2.0/?api_key=d94e5b6e26469a2d1ffae8ef20131b79&method=";
+const char *msgInvalidResponse = "Invalid response";
 
-LastfmService::Result LastfmService::fetch(Args &args)
+}
+
+namespace LastFm {
+
+Service::Result Service::fetch()
 {
 	Result result;
+	result.first = false;
 	
-	std::string url = baseURL;
+	std::string url = apiUrl;
 	url += methodName();
-	for (Args::const_iterator it = args.begin(); it != args.end(); ++it)
+	for (auto &arg : m_arguments)
 	{
 		url += "&";
-		url += it->first;
+		url += arg.first;
 		url += "=";
-		url += Curl::escape(it->second);
+		url += Curl::escape(arg.second);
 	}
 	
 	std::string data;
 	CURLcode code = Curl::perform(data, url);
 	
 	if (code != CURLE_OK)
-	{
 		result.second = curl_easy_strerror(code);
-		return result;
-	}
-	
-	if (actionFailed(data))
-	{
-		stripHtmlTags(data);
-		result.second = data;
-		return result;
-	}
-	
-	if (!parse(data))
+	else if (actionFailed(data))
+		result.second = msgInvalidResponse;
+	else
 	{
+		result = processData(data);
+		
 		// if relevant part of data was not found and one of arguments
 		// was language, try to fetch it again without that parameter.
 		// otherwise just report failure.
-		Args::iterator lang = args.find("lang");
-		if (lang != args.end())
+		if (!result.first && !m_arguments["lang"].empty())
 		{
-			args.erase(lang);
-			return fetch(args);
-		}
-		else
-		{
-			// parse should change data to error msg, if it fails
-			result.second = data;
-			return result;
+			m_arguments.erase("lang");
+			result = fetch();
 		}
 	}
 	
-	result.first = true;
-	result.second = data;
 	return result;
 }
 
-bool LastfmService::actionFailed(const std::string &data)
+bool Service::actionFailed(const std::string &data)
 {
 	return data.find("status=\"failed\"") != std::string::npos;
 }
 
-void LastfmService::postProcess(std::string &data)
-{
-	stripHtmlTags(data);
-	boost::trim(data);
-}
-
 /***********************************************************************/
 
-bool ArtistInfo::checkArgs(const Args &args)
+bool ArtistInfo::argumentsOk()
 {
-	return args.find("artist") != args.end();
+	return !m_arguments["artist"].empty();
 }
 
-void ArtistInfo::colorizeOutput(NC::Scrollpad &w)
+void ArtistInfo::beautifyOutput(NC::Scrollpad &w)
 {
-	w.setProperties(NC::Format::Bold, "\n\nSimilar artists:\n", NC::Format::NoBold, 0, boost::regex::literal);
+	w.setProperties(NC::Format::Bold, "\n\nSimilar artists:\n", NC::Format::NoBold, 0);
+	w.setProperties(NC::Format::Bold, "\n\nSimilar tags:\n", NC::Format::NoBold, 0);
 	w.setProperties(Config.color2, "\n * ", NC::Color::End, 0, boost::regex::literal);
 }
 
-bool ArtistInfo::parse(std::string &data)
+Service::Result ArtistInfo::processData(const std::string &data)
 {
 	size_t a, b;
-	bool parse_failed = false;
+	Service::Result result;
+	result.first = false;
 	
-	if ((a = data.find("<content>")) != std::string::npos)
+	boost::regex rx("<content>(.*?)</content>");
+	boost::smatch what;
+	if (boost::regex_search(data, what, rx))
 	{
-		a += const_strlen("<content>");
-		if ((b = data.find("</content>")) == std::string::npos)
-			parse_failed = true;
+		std::string desc = what[1];
+		// if there is a description...
+		if (desc.length() > 0)
+		{
+			// ...locate the link to wiki on last.fm...
+			rx.assign("<link rel=\"original\" href=\"(.*?)\"");
+			if (boost::regex_search(data, what, rx))
+			{
+				// ...try to get the content of it...
+				std::string wiki;
+				CURLcode code = Curl::perform(wiki, what[1]);
+				
+				if (code != CURLE_OK)
+				{
+					result.second = curl_easy_strerror(code);
+					return result;
+				}
+				else
+				{
+					// ...and filter it to get the whole description.
+					rx.assign("<div id=\"wiki\">(.*?)</div>");
+					if (boost::regex_search(wiki, what, rx))
+						desc = unescapeHtmlUtf8(what[1]);
+				}
+			}
+			else
+			{
+				// otherwise, get rid of CDATA wrapper.
+				rx.assign("<!\\[CDATA\\[(.*)\\]\\]>");
+				desc = boost::regex_replace(desc, rx, "\\1");
+			}
+			stripHtmlTags(desc);
+			boost::trim(desc);
+			result.second += desc;
+		}
+		else
+			result.second += "No description available for this artist.";
 	}
 	else
-		parse_failed = true;
-	
-	if (parse_failed)
 	{
-		data = msgParseFailed;
-		return false;
+		result.second = msgInvalidResponse;
+		return result;
 	}
 	
-	if (a == b)
+	auto add_similars = [&result](boost::sregex_iterator &it, const boost::sregex_iterator &last) {
+		for (; it != last; ++it)
+		{
+			std::string name = it->str(1);
+			std::string url = it->str(2);
+			stripHtmlTags(name);
+			stripHtmlTags(url);
+			result.second += "\n * ";
+			result.second += name;
+			result.second += " (";
+			result.second += url;
+			result.second += ")";
+		}
+	};
+	
+	a = data.find("<similar>");
+	b = data.find("</similar>");
+	if (a != std::string::npos && b != std::string::npos)
 	{
-		data = "No description available for this artist.";
-		return false;
+		rx.assign("<artist>.*?<name>(.*?)</name>.*?<url>(.*?)</url>.*?</artist>");
+		auto it = boost::sregex_iterator(data.begin()+a, data.begin()+b, rx);
+		auto last = boost::sregex_iterator();
+		if (it != last)
+			result.second += "\n\nSimilar artists:\n";
+		add_similars(it, last);
 	}
 	
-	std::vector< std::pair<std::string, std::string> > similars;
-	for (size_t i = data.find("<name>"), j, k = data.find("<url>"), l;
-		    i != std::string::npos; i = data.find("<name>", i), k = data.find("<url>", k))
+	a = data.find("<tags>");
+	b = data.find("</tags>");
+	if (a != std::string::npos && b != std::string::npos)
 	{
-		j = data.find("</name>", i);
-		i += const_strlen("<name>");
-		
-		l = data.find("</url>", k);
-		k += const_strlen("<url>");
-		
-		similars.push_back(std::make_pair(data.substr(i, j-i), data.substr(k, l-k)));
-		stripHtmlTags(similars.back().first);
+		rx.assign("<tag>.*?<name>(.*?)</name>.*?<url>(.*?)</url>.*?</tag>");
+		auto it = boost::sregex_iterator(data.begin()+a, data.begin()+b, rx);
+		auto last = boost::sregex_iterator();
+		if (it != last)
+			result.second += "\n\nSimilar tags:\n";
+		add_similars(it, last);
 	}
 	
-	a += const_strlen("<![CDATA[");
-	b -= const_strlen("]]>");
-	data = data.substr(a, b-a);
-	
-	postProcess(data);
+	// get artist we look for, it's the one before similar artists
+	rx.assign("<name>.*?</name>.*?<url>(.*?)</url>.*?<similar>");
 	
-	data += "\n\nSimilar artists:\n";
-	for (size_t i = 1; i < similars.size(); ++i)
+	if (boost::regex_search(data, what, rx))
 	{
-		 data += "\n * ";
-		 data += similars[i].first;
-		 data += " (";
-		 data += similars[i].second;
-		 data += ")";
+		std::string url = what[1];
+		stripHtmlTags(url);
+		result.second += "\n\n";
+		// add only url
+		result.second += url;
 	}
-	data += "\n\n";
-	data += similars.front().second;
 	
-	return true;
+	result.first = true;
+	return result;
+}
+
 }
 
 #endif
diff --git a/src/lastfm_service.h b/src/lastfm_service.h
index 3aa10b8e..a5c439b7 100644
--- a/src/lastfm_service.h
+++ b/src/lastfm_service.h
@@ -30,42 +30,51 @@
 
 #include "scrollpad.h"
 
-struct LastfmService
+namespace LastFm {
+
+struct Service
 {
-	typedef std::map<std::string, std::string> Args;
+	typedef std::map<std::string, std::string> Arguments;
 	typedef std::pair<bool, std::string> Result;
 	
+	Service(Arguments args) : m_arguments(args) { }
+	
 	virtual const char *name() = 0;
-	virtual Result fetch(Args &args);
+	virtual Result fetch();
 	
-	virtual bool checkArgs(const Args &args) = 0;
-	virtual void colorizeOutput(NC::Scrollpad &w) = 0;
+	virtual void beautifyOutput(NC::Scrollpad &w) = 0;
 	
 protected:
+	virtual bool argumentsOk() = 0;
 	virtual bool actionFailed(const std::string &data);
 	
-	virtual bool parse(std::string &data) = 0;
-	virtual void postProcess(std::string &data);
+	virtual Result processData(const std::string &data) = 0;
 	
 	virtual const char *methodName() = 0;
 	
-	static const char *baseURL;
-	static const char *msgParseFailed;
+	Arguments m_arguments;
 };
 
-struct ArtistInfo : public LastfmService
+struct ArtistInfo : public Service
 {
+	ArtistInfo(std::string artist, std::string lang)
+	: Service({{"artist", artist}, {"lang", lang}}) { }
+	
 	virtual const char *name() { return "Artist info"; }
 	
-	virtual bool checkArgs(const Args &args);
-	virtual void colorizeOutput(NC::Scrollpad &w);
+	virtual void beautifyOutput(NC::Scrollpad &w);
+	
+	bool operator==(const ArtistInfo &ai) const { return m_arguments == ai.m_arguments; }
 	
 protected:
-	virtual bool parse(std::string &data);
+	virtual bool argumentsOk();
+	virtual Result processData(const std::string &data);
 	
 	virtual const char *methodName() { return "artist.getinfo"; }
 };
 
+}
+
 #endif // HAVE_CURL_CURL_H
 
 #endif // NCMPCPP_LASTFM_SERVICE_H