// Copyright (c) 2007, Rodrigo Braz Monteiro
// 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 Aegisub Group nor the names of its 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.
//
// Aegisub Project http://www.aegisub.org/

#ifdef WITH_UPDATE_CHECKER

#ifdef _MSC_VER
#pragma warning(disable : 4250) // 'boost::asio::basic_socket_iostream<Protocol>' : inherits 'std::basic_ostream<_Elem,_Traits>::std::basic_ostream<_Elem,_Traits>::_Add_vtordisp2' via dominance
#endif

#include "compat.h"
#include "format.h"
#include "options.h"
#include "string_codec.h"
#include "version.h"

#include <libaegisub/dispatch.h>
#include <libaegisub/exception.h>
#include <libaegisub/line_iterator.h>
#include <libaegisub/scoped_ptr.h>
#include <libaegisub/split.h>

#include <ctime>
#include <boost/beast/core.hpp>
#include <boost/beast/http.hpp>
#include <boost/beast/version.hpp>
#include <boost/asio/connect.hpp>
#include <boost/asio/ip/tcp.hpp>
#include <boost/asio/ssl/error.hpp>
#include <boost/asio/ssl/stream.hpp>
#include <functional>
#include <mutex>
#include <vector>
#include <wx/button.h>
#include <wx/checkbox.h>
#include <wx/dialog.h>
#include <wx/event.h>
#include <wx/hyperlink.h>
#include <wx/intl.h>
#include <wx/platinfo.h>
#include <wx/sizer.h>
#include <wx/statline.h>
#include <wx/stattext.h>
#include <wx/string.h>
#include <wx/textctrl.h>

#ifdef __APPLE__
#include <CoreFoundation/CoreFoundation.h>
#endif


namespace {
std::mutex VersionCheckLock;

namespace ssl = boost::asio::ssl;
namespace http = boost::beast::http;

struct AegisubUpdateDescription {
	int major;
	int minor;
	int patch;
	std::string extra;
	std::string description;
};

AegisubUpdateDescription ParseVersionString(std::string version_string) {
	std::vector<std::string> maj_min;
	std::vector<std::string> patch;
	agi::Split(maj_min, version_string, '.');
	agi::Split(patch, maj_min[2], '-');

	std::string extra = "";
	if (patch.size() > 1) {
		extra = patch[1];
	}

	return AegisubUpdateDescription{
		atoi(maj_min[0].c_str()),
		atoi(maj_min[1].c_str()),
		atoi(patch[0].c_str()),
		extra,
		""
	};
}

bool IsNewer(AegisubUpdateDescription update) {
	AegisubUpdateDescription current = ParseVersionString(GetReleaseVersion());

	if (update.major != current.major)
		return update.major > current.major;

	if (update.minor != current.minor)
		return update.minor > current.minor;

	if (update.patch != current.patch)
		return update.patch > current.patch;

	return update.extra.compare(current.extra) > 0;
}

std::string AegisubVersion(AegisubUpdateDescription update) {
	std::ostringstream s;
	s << update.major << "." << update.minor << "." << update.patch;
	if (!update.extra.empty())
		s << "-" << update.extra;

	return s.str();
}

class VersionCheckerResultDialog final : public wxDialog {
	void OnCloseButton(wxCommandEvent &evt);
	void OnRemindMeLater(wxCommandEvent &evt);
	void OnClose(wxCloseEvent &evt);

	wxCheckBox *automatic_check_checkbox;

public:
	VersionCheckerResultDialog(wxString const& main_text, const AegisubUpdateDescription update);

	bool ShouldPreventAppExit() const override { return false; }
};

VersionCheckerResultDialog::VersionCheckerResultDialog(wxString const& main_text, const AegisubUpdateDescription update)
: wxDialog(nullptr, -1, _("Version Checker"))
{
	const int controls_width = 500;

	wxSizer *main_sizer = new wxBoxSizer(wxVERTICAL);

	wxStaticText *text = new wxStaticText(this, -1, main_text);
	text->Wrap(controls_width);
	main_sizer->Add(text, 0, wxBOTTOM|wxEXPAND, 6);

	main_sizer->Add(new wxStaticLine(this), 0, wxEXPAND|wxALL, 6);

	if (IsNewer(update)) {
		text = new wxStaticText(this, -1, to_wx("Aegisub-Japan7"));
		wxFont boldfont = text->GetFont();
		boldfont.SetWeight(wxFONTWEIGHT_BOLD);
		text->SetFont(boldfont);
		main_sizer->Add(text, 0, wxEXPAND|wxBOTTOM, 6);

		wxTextCtrl *descbox = new wxTextCtrl(this, -1, to_wx(update.description), wxDefaultPosition, wxSize(controls_width,60), wxTE_MULTILINE|wxTE_READONLY);
		main_sizer->Add(descbox, 0, wxEXPAND|wxBOTTOM, 6);

		std::ostringstream surl;
		surl << "https://" << UPDATE_CHECKER_SERVER << UPDATE_CHECKER_BASE_URL << "/Aegisub-Japan7-" << AegisubVersion(update) << "-x64.exe";
		std::string url = surl.str();

		main_sizer->Add(new wxHyperlinkCtrl(this, -1, to_wx(url), to_wx(url)), 0, wxALIGN_LEFT|wxBOTTOM, 6);
	}

	automatic_check_checkbox = new wxCheckBox(this, -1, _("&Auto Check for Updates"));
	automatic_check_checkbox->SetValue(OPT_GET("App/Auto/Check For Updates")->GetBool());

	wxButton *remind_later_button = nullptr;
	if (IsNewer(update))
		remind_later_button = new wxButton(this, wxID_NO, _("Remind me again in a &week"));

	wxButton *close_button = new wxButton(this, wxID_OK, _("&Close"));
	SetAffirmativeId(wxID_OK);
	SetEscapeId(wxID_OK);

	if (IsNewer(update))
		main_sizer->Add(new wxStaticLine(this), 0, wxEXPAND|wxALL, 6);
	main_sizer->Add(automatic_check_checkbox, 0, wxEXPAND|wxBOTTOM, 6);

	auto button_sizer = new wxStdDialogButtonSizer();
	button_sizer->AddButton(close_button);
	if (remind_later_button)
		button_sizer->AddButton(remind_later_button);
	button_sizer->Realize();
	main_sizer->Add(button_sizer, 0, wxEXPAND, 0);

	wxSizer *outer_sizer = new wxBoxSizer(wxVERTICAL);
	outer_sizer->Add(main_sizer, 0, wxALL|wxEXPAND, 12);

	SetSizerAndFit(outer_sizer);
	Centre();
	Show();

	Bind(wxEVT_BUTTON, std::bind(&VersionCheckerResultDialog::Close, this, false), wxID_OK);
	Bind(wxEVT_BUTTON, &VersionCheckerResultDialog::OnRemindMeLater, this, wxID_NO);
	Bind(wxEVT_CLOSE_WINDOW, &VersionCheckerResultDialog::OnClose, this);
}

void VersionCheckerResultDialog::OnRemindMeLater(wxCommandEvent &) {
	// In one week
	time_t new_next_check_time = time(nullptr) + 7*24*60*60;
	OPT_SET("Version/Next Check")->SetInt(new_next_check_time);

	Close();
}

void VersionCheckerResultDialog::OnClose(wxCloseEvent &) {
	OPT_SET("App/Auto/Check For Updates")->SetBool(automatic_check_checkbox->GetValue());
	Destroy();
}

DEFINE_EXCEPTION(VersionCheckError, agi::Exception);

void PostErrorEvent(bool interactive, wxString const& error_text) {
	if (interactive) {
		agi::dispatch::Main().Async([=]{
			new VersionCheckerResultDialog(error_text, {});
		});
	}
}

static const char * GetOSShortName() {
	int osver_maj, osver_min;
	wxOperatingSystemId osid = wxGetOsVersion(&osver_maj, &osver_min);

	if (osid & wxOS_WINDOWS_NT) {
		if (osver_maj == 5 && osver_min == 0)
			return "win2k";
		else if (osver_maj == 5 && osver_min == 1)
			return "winxp";
		else if (osver_maj == 5 && osver_min == 2)
			return "win2k3"; // this is also xp64
		else if (osver_maj == 6 && osver_min == 0)
			return "win60"; // vista and server 2008
		else if (osver_maj == 6 && osver_min == 1)
			return "win61"; // 7 and server 2008r2
		else if (osver_maj == 6 && osver_min == 2)
			return "win62"; // 8
		else
			return "windows"; // future proofing? I doubt we run on nt4
	}
	// CF returns 0x10 for some reason, which wx has recently started
	// turning into 10
	else if (osid & wxOS_MAC_OSX_DARWIN && (osver_maj == 0x10 || osver_maj == 10)) {
		// ugliest hack in the world? nah.
		static char osxstring[] = "osx00";
		char minor = osver_min >> 4;
		char patch = osver_min & 0x0F;
		osxstring[3] = minor + ((minor<=9) ? '0' : ('a'-1));
		osxstring[4] = patch + ((patch<=9) ? '0' : ('a'-1));
		return osxstring;
	}
	else if (osid & wxOS_UNIX_LINUX)
		return "linux";
	else if (osid & wxOS_UNIX_FREEBSD)
		return "freebsd";
	else if (osid & wxOS_UNIX_OPENBSD)
		return "openbsd";
	else if (osid & wxOS_UNIX_NETBSD)
		return "netbsd";
	else if (osid & wxOS_UNIX_SOLARIS)
		return "solaris";
	else if (osid & wxOS_UNIX_AIX)
		return "aix";
	else if (osid & wxOS_UNIX_HPUX)
		return "hpux";
	else if (osid & wxOS_UNIX)
		return "unix";
	else if (osid & wxOS_OS2)
		return "os2";
	else if (osid & wxOS_DOS)
		return "dos";
	else
		return "unknown";
}

#ifdef WIN32
typedef BOOL (WINAPI * PGetUserPreferredUILanguages)(DWORD dwFlags, PULONG pulNumLanguages, wchar_t *pwszLanguagesBuffer, PULONG pcchLanguagesBuffer);

// Try using Win 6+ functions if available
static wxString GetUILanguage() {
	agi::scoped_holder<HMODULE, BOOL (__stdcall *)(HMODULE)> kernel32(LoadLibraryW(L"kernel32.dll"), FreeLibrary);
	if (!kernel32) return "";

	PGetUserPreferredUILanguages gupuil = (PGetUserPreferredUILanguages)GetProcAddress(kernel32, "GetUserPreferredUILanguages");
	if (!gupuil) return "";

	ULONG numlang = 0, output_len = 0;
	if (gupuil(MUI_LANGUAGE_NAME, &numlang, 0, &output_len) != TRUE || !output_len)
		return "";

	std::vector<wchar_t> output(output_len);
	if (!gupuil(MUI_LANGUAGE_NAME, &numlang, &output[0], &output_len) || numlang < 1)
		return "";

	// We got at least one language, just treat it as the only, and a null-terminated string
	return &output[0];
}

static wxString GetSystemLanguage() {
	wxString res = GetUILanguage();
	if (!res)
		// On an old version of Windows, let's just return the LANGID as a string
		res = fmt_wx("x-win%04x", GetUserDefaultUILanguage());

	return res;
}
#elif __APPLE__
static wxString GetSystemLanguage() {
	CFLocaleRef locale = CFLocaleCopyCurrent();
	CFStringRef localeName = (CFStringRef)CFLocaleGetValue(locale, kCFLocaleIdentifier);

	char buf[128] = { 0 };
	CFStringGetCString(localeName, buf, sizeof buf, kCFStringEncodingUTF8);
	CFRelease(locale);

	return wxString::FromUTF8(buf);

}
#else
static wxString GetSystemLanguage() {
	return wxLocale::GetLanguageInfo(wxLocale::GetSystemLanguage())->CanonicalName;
}
#endif

static wxString GetAegisubLanguage() {
	return to_wx(OPT_GET("App/Language")->GetString());
}

AegisubUpdateDescription GetLatestVersion() {

	boost::asio::io_context ioc;
	boost::asio::ssl::context ctx(ssl::context::method::sslv23_client);

	boost::asio::ip::tcp::resolver resolver(ioc);
	ssl::stream<boost::asio::ip::tcp::socket> stream(ioc, ctx);

	if(! SSL_set_tlsext_host_name(stream.native_handle(), UPDATE_CHECKER_SERVER)) {
            boost::system::error_code ec{static_cast<int>(::ERR_get_error()), boost::asio::error::get_ssl_category()};
            throw boost::system::system_error{ec};
        }

	auto const results = resolver.resolve(UPDATE_CHECKER_SERVER, "443");

	boost::asio::connect(stream.next_layer(), results.begin(), results.end());
	stream.handshake(boost::asio::ssl::stream_base::handshake_type::client);

	std::ostringstream s;
	s << UPDATE_CHECKER_BASE_URL;
	s << "/latest";
	std::string target = s.str();
	http::request<http::string_body> req(http::verb::get, target, 11);
	req.set(http::field::host, UPDATE_CHECKER_SERVER);
	req.set(http::field::user_agent, "Aegisub-Japan7");

	http::write(stream, req);

	boost::beast::flat_buffer buffer;

	http::response<http::string_body> res;

	http::read(stream, buffer, res);

	// Gracefully close the stream
        boost::system::error_code ec;
        stream.shutdown(ec);
        if(ec == boost::asio::error::eof)
        {
            // http://stackoverflow.com/questions/25587403/boost-asio-ssl-async-shutdown-always-finishes-with-an-error
            ec.assign(0, ec.category());
        }
        if(ec)
            throw boost::system::system_error{ec};

	std::string line;
	std::stringstream body(res.body().data());

	std::getline(body, line, '\n');

	AegisubUpdateDescription version = ParseVersionString(line);

	std::ostringstream desc;
	while (std::getline(body, line, '\n')) {
		desc << line;
	}

	version.description = desc.str();
	return version;

	throw VersionCheckError(from_wx(_("Could not get update from updates server.")));
}


void DoCheck(bool interactive) {
	AegisubUpdateDescription update = GetLatestVersion();

	if (IsNewer(update) || interactive) {
		agi::dispatch::Main().Async([=]{
			wxString text;
			if (IsNewer(update))
				text = _("An update to Aegisub was found.");
			else
				text = _("There are no updates to Aegisub.");

			new VersionCheckerResultDialog(text, update);
		});
	}
}
}

void PerformVersionCheck(bool interactive) {
	agi::dispatch::Background().Async([=]{
		if (!interactive) {
			// Automatic checking enabled?
			if (!OPT_GET("App/Auto/Check For Updates")->GetBool())
				return;

			// Is it actually time for a check?
			time_t next_check = OPT_GET("Version/Next Check")->GetInt();
			if (next_check > time(nullptr))
				return;
		}

		if (!VersionCheckLock.try_lock()) return;

		try {
			DoCheck(interactive);
		}
		catch (const agi::Exception &e) {
			PostErrorEvent(interactive, fmt_tl(
				"There was an error checking for updates to Aegisub:\n%s\n\nIf other applications can access the Internet fine, this is probably a temporary server problem on our end.",
				e.GetMessage()));
		}
		catch (...) {
			PostErrorEvent(interactive, _("An unknown error occurred while checking for updates to Aegisub."));
		}

		VersionCheckLock.unlock();

		agi::dispatch::Main().Async([]{
			time_t new_next_check_time = time(nullptr) + 60*60; // in one hour
			OPT_SET("Version/Next Check")->SetInt(new_next_check_time);
		});
	});
}

#endif