/*
 * ZeroTier One - Global Peer to Peer Ethernet
 * Copyright (C) 2012-2013  ZeroTier Networks LLC
 *
 * 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 3 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, see <http://www.gnu.org/licenses/>.
 *
 * --
 *
 * ZeroTier may be used and distributed under the terms of the GPLv3, which
 * are available at: http://www.gnu.org/licenses/gpl-3.0.html
 *
 * If you would like to embed ZeroTier into a commercial application or
 * redistribute it in a modified binary form, please contact ZeroTier Networks
 * LLC. Start here: http://www.zerotier.com/
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <errno.h>

#include <string>
#include <stdexcept>

#include "node/Constants.hpp"

#ifdef __WINDOWS__
#include <WinSock2.h>
#include <Windows.h>
#include <tchar.h>
#include <wchar.h>
#else
#include <unistd.h>
#include <pwd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <signal.h>
#endif

#include "node/Constants.hpp"
#include "node/Defaults.hpp"
#include "node/Utils.hpp"
#include "node/Node.hpp"
#include "node/Condition.hpp"
#include "node/C25519.hpp"
#include "node/Identity.hpp"

using namespace ZeroTier;

static Node *node = (Node *)0;

static void printHelp(const char *cn,FILE *out)
{
	fprintf(out,"ZeroTier One version %d.%d.%d"ZT_EOL_S"(c)2012-2013 ZeroTier Networks LLC"ZT_EOL_S,Node::versionMajor(),Node::versionMinor(),Node::versionRevision());
	fprintf(out,"Licensed under the GNU General Public License v3"ZT_EOL_S""ZT_EOL_S);
#ifdef ZT_AUTO_UPDATE
	fprintf(out,"Auto-update enabled build, will update from URL:"ZT_EOL_S);
	fprintf(out,"  %s"ZT_EOL_S,ZT_DEFAULTS.updateLatestNfoURL.c_str());
	fprintf(out,"Update authentication signing authorities: "ZT_EOL_S);
	int no = 0;
	for(std::map< Address,Identity >::const_iterator sa(ZT_DEFAULTS.updateAuthorities.begin());sa!=ZT_DEFAULTS.updateAuthorities.end();++sa) {
		if (no == 0)
			fprintf(out,"  %s",sa->first.toString().c_str());
		else fprintf(out,", %s",sa->first.toString().c_str());
		if (++no == 6) {
			fprintf(out,ZT_EOL_S);
			no = 0;
		}
	}
	fprintf(out,ZT_EOL_S""ZT_EOL_S);
#else
	fprintf(out,"Auto-updates not enabled on this build. You must update manually."ZT_EOL_S""ZT_EOL_S);
#endif
	fprintf(out,"Usage: %s [-switches] [home directory]"ZT_EOL_S""ZT_EOL_S,cn);
	fprintf(out,"Available switches:"ZT_EOL_S);
	fprintf(out,"  -h                - Display this help"ZT_EOL_S);
	fprintf(out,"  -v                - Show version"ZT_EOL_S);
	fprintf(out,"  -p<port>          - Bind to this port for network I/O"ZT_EOL_S);
	fprintf(out,"  -c<port>          - Bind to this port for local control packets"ZT_EOL_S);
	fprintf(out,"  -q                - Send a query to a running service (zerotier-cli)"ZT_EOL_S);
	fprintf(out,"  -i                - Run idtool command (zerotier-idtool)"ZT_EOL_S);
}

namespace ZeroTierCLI { // ---------------------------------------------------

static void printHelp(FILE *out,const char *exename)
{
	fprintf(out,"Usage: %s [-switches] <command>"ZT_EOL_S,exename);
	fprintf(out,ZT_EOL_S);
	fprintf(out,"Available switches:"ZT_EOL_S);
	fprintf(out,"  -c<port>         - Communicate with daemon over this local port"ZT_EOL_S);
	fprintf(out,"  -t<token>        - Specify token on command line"ZT_EOL_S);
	fprintf(out,"  -T<file>         - Read token from file"ZT_EOL_S);
	fprintf(out,ZT_EOL_S);
	fprintf(out,"Use the 'help' command to get help from ZeroTier One itself."ZT_EOL_S);
}

static volatile unsigned int numResults = 0;
static Condition doneCondition;

static void resultHandler(void *arg,unsigned long id,const char *line)
{
	++numResults;
	if (strlen(line))
		fprintf(stdout,"%s"ZT_EOL_S,line);
	else doneCondition.signal();
}

// Runs instead of rest of main() if process is called zerotier-cli or if
// -q is specified as an option.
#ifdef __WINDOWS__
static int main(int argc,_TCHAR* argv[])
#else
static int main(int argc,char **argv)
#endif
{
	if (argc <= 1) {
		printHelp(stdout,argv[0]);
		return -1;
	}

	std::string authToken;
	std::string command;
	bool pastSwitches = false;
	unsigned int controlPort = 0;
	for(int i=1;i<argc;++i) {
		if ((argv[i][0] == '-')&&(!pastSwitches)) {
			if (strlen(argv[i]) <= 1) {
				printHelp(stdout,argv[0]);
				return -1;
			}
			switch(argv[i][1]) {
				case 'q': // does nothing, for invocation without binary path name aliasing
					if (argv[i][2]) {
						printHelp(argv[0],stderr);
						return 0;
					}
					break;
				case 'c':
					controlPort = Utils::strToUInt(argv[i] + 2);
					break;
				case 't':
					authToken.assign(argv[i] + 2);
					break;
				case 'T':
					if (!Utils::readFile(argv[i] + 2,authToken)) {
						fprintf(stdout,"FATAL ERROR: unable to read token from '%s'"ZT_EOL_S,argv[i] + 2);
						return -2;
					}
					break;
				default:
					return -1;
			}
		} else {
			pastSwitches = true;
			if (command.length())
				command.push_back(' ');
			command.append(argv[i]);
		}
	}

	if (!command.length()) {
		printHelp(stdout,argv[0]);
		return -1;
	}

	if (!authToken.length()) {
		const char *home = getenv("HOME");
		if (home) {
			std::string dotZeroTierAuthToken(home);
			dotZeroTierAuthToken.push_back(ZT_PATH_SEPARATOR);
			dotZeroTierAuthToken.append(".zerotierOneAuthToken");
			if (!Utils::readFile(dotZeroTierAuthToken.c_str(),authToken)) {
#ifndef __WINDOWS__
#ifdef __APPLE__
				const char *systemAuthTokenPath = "/Library/Application Support/ZeroTier/One/authtoken.secret";
#else
				const char *systemAuthTokenPath = "/var/lib/zerotier-one/authtoken.secret";
#endif
				if (!Utils::readFile(systemAuthTokenPath,authToken)) {
					fprintf(stdout,"FATAL ERROR: no token specified on command line and could not read '%s' or '%s'"ZT_EOL_S,dotZeroTierAuthToken.c_str(),systemAuthTokenPath);
					return -2;
				}
#else // __WINDOWS__
				fprintf(stdout,"FATAL ERROR: no token specified on command line and could not read '%s'"ZT_EOL_S,dotZeroTierAuthToken.c_str());
				return -2;
#endif // __WINDOWS__
			}
		}
	}
	if (!authToken.length()) {
		fprintf(stdout,"FATAL ERROR: could not find auth token"ZT_EOL_S);
		return -2;
	}

	Node::LocalClient client(authToken.c_str(),controlPort,&resultHandler,(void *)0);
	client.send(command.c_str());

	doneCondition.wait(1000);

	if (!numResults) {
		fprintf(stdout,"ERROR: no results received. Is ZeroTier One running?"ZT_EOL_S);
		return -1;
	}

	return 0;
}

} // namespace ZeroTierCLI ---------------------------------------------------

namespace ZeroTierIdTool { // ------------------------------------------------

static void printHelp(FILE *out,const char *pn)
{
	fprintf(out,"Usage: %s <command> [<args>]"ZT_EOL_S""ZT_EOL_S"Commands:"ZT_EOL_S,pn);
	fprintf(out,"  generate [<identity.secret>] [<identity.public>]"ZT_EOL_S);
	fprintf(out,"  validate <identity.secret/public>"ZT_EOL_S);
	fprintf(out,"  getpublic <identity.secret>"ZT_EOL_S);
	fprintf(out,"  sign <identity.secret> <file>"ZT_EOL_S);
	fprintf(out,"  verify <identity.secret/public> <file> <signature>"ZT_EOL_S);
}

static Identity getIdFromArg(char *arg)
{
	Identity id;
	if ((strlen(arg) > 32)&&(arg[10] == ':')) { // identity is a literal on the command line
		if (id.fromString(arg))
			return id;
	} else { // identity is to be read from a file
		std::string idser;
		if (Utils::readFile(arg,idser)) {
			if (id.fromString(idser))
				return id;
		}
	}
	return Identity();
}

// Runs instead of rest of main() if process is called zerotier-idtool or if
// -i is specified as an option.
#ifdef __WINDOWS__
static int main(int argc,_TCHAR* argv[])
#else
static int main(int argc,char **argv)
#endif
{
	if (argc < 2) {
		printHelp(stderr,argv[0]);
		return -1;
	}

	if (!strcmp(argv[1],"generate")) {
		Identity id;
		id.generate();
		std::string idser = id.toString(true);
		if (argc >= 3) {
			if (!Utils::writeFile(argv[2],idser)) {
				fprintf(stderr,"Error writing to %s"ZT_EOL_S,argv[2]);
				return -1;
			} else printf("%s written"ZT_EOL_S,argv[2]);
			if (argc >= 4) {
				idser = id.toString(false);
				if (!Utils::writeFile(argv[3],idser)) {
					fprintf(stderr,"Error writing to %s"ZT_EOL_S,argv[3]);
					return -1;
				} else printf("%s written"ZT_EOL_S,argv[3]);
			}
		} else printf("%s",idser.c_str());
	} else if (!strcmp(argv[1],"validate")) {
		if (argc < 3) {
			printHelp(stderr,argv[0]);
			return -1;
		}

		Identity id = getIdFromArg(argv[2]);
		if (!id) {
			fprintf(stderr,"Identity argument invalid or file unreadable: %s"ZT_EOL_S,argv[2]);
			return -1;
		}

		if (!id.locallyValidate()) {
			fprintf(stderr,"%s FAILED validation."ZT_EOL_S,argv[2]);
			return -1;
		} else printf("%s is a valid identity"ZT_EOL_S,argv[2]);
	} else if (!strcmp(argv[1],"getpublic")) {
		if (argc < 3) {
			printHelp(stderr,argv[0]);
			return -1;
		}

		Identity id = getIdFromArg(argv[2]);
		if (!id) {
			fprintf(stderr,"Identity argument invalid or file unreadable: %s"ZT_EOL_S,argv[2]);
			return -1;
		}

		printf("%s",id.toString(false).c_str());
	} else if (!strcmp(argv[1],"sign")) {
		if (argc < 4) {
			printHelp(stderr,argv[0]);
			return -1;
		}

		Identity id = getIdFromArg(argv[2]);
		if (!id) {
			fprintf(stderr,"Identity argument invalid or file unreadable: %s"ZT_EOL_S,argv[2]);
			return -1;
		}

		if (!id.hasPrivate()) {
			fprintf(stderr,"%s does not contain a private key (must use private to sign)"ZT_EOL_S,argv[2]);
			return -1;
		}

		std::string inf;
		if (!Utils::readFile(argv[3],inf)) {
			fprintf(stderr,"%s is not readable"ZT_EOL_S,argv[3]);
			return -1;
		}
		C25519::Signature signature = id.sign(inf.data(),inf.length());
		printf("%s",Utils::hex(signature.data,signature.size()).c_str());
	} else if (!strcmp(argv[1],"verify")) {
		if (argc < 4) {
			printHelp(stderr,argv[0]);
			return -1;
		}

		Identity id = getIdFromArg(argv[2]);
		if (!id) {
			fprintf(stderr,"Identity argument invalid or file unreadable: %s"ZT_EOL_S,argv[2]);
			return -1;
		}

		std::string inf;
		if (!Utils::readFile(argv[3],inf)) {
			fprintf(stderr,"%s is not readable"ZT_EOL_S,argv[3]);
			return -1;
		}

		std::string signature(Utils::unhex(argv[4]));
		if ((signature.length() > ZT_ADDRESS_LENGTH)&&(id.verify(inf.data(),inf.length(),signature.data(),signature.length()))) {
			printf("%s signature valid"ZT_EOL_S,argv[3]);
		} else {
			fprintf(stderr,"%s signature check FAILED"ZT_EOL_S,argv[3]);
			return -1;
		}
	} else {
		printHelp(stderr,argv[0]);
		return -1;
	}

	return 0;
}


} // namespace ZeroTierIdTool ------------------------------------------------

#ifdef __UNIX_LIKE__
static void sighandlerQuit(int sig)
{
	Node *n = node;
	if (n)
		n->terminate(Node::NODE_NORMAL_TERMINATION,"terminated by signal");
	else exit(0);
}
#endif

#ifdef __WINDOWS__
static BOOL WINAPI _handlerRoutine(DWORD dwCtrlType)
{
	switch(dwCtrlType) {
		case CTRL_C_EVENT:
		case CTRL_BREAK_EVENT:
		case CTRL_CLOSE_EVENT:
		case CTRL_SHUTDOWN_EVENT:
			Node *n = node;
			if (n)
				n->terminate(Node::NODE_NORMAL_TERMINATION,"terminated by signal");
			return TRUE;
	}
	return FALSE;
}
#endif

#ifdef __WINDOWS__
int _tmain(int argc, _TCHAR* argv[])
#else
int main(int argc,char **argv)
#endif
{
#ifdef __UNIX_LIKE__
	signal(SIGHUP,SIG_IGN);
	signal(SIGPIPE,SIG_IGN);
	signal(SIGUSR1,SIG_IGN);
	signal(SIGUSR2,SIG_IGN);
	signal(SIGALRM,SIG_IGN);
	signal(SIGINT,&sighandlerQuit);
	signal(SIGTERM,&sighandlerQuit);
	signal(SIGQUIT,&sighandlerQuit);
#endif

#ifdef __WINDOWS__
	WSADATA wsaData;
	WSAStartup(MAKEWORD(2,2),&wsaData);
	SetConsoleCtrlHandler(&_handlerRoutine,TRUE);
#endif

	if ((strstr(argv[0],"zerotier-cli"))||(strstr(argv[0],"ZEROTIER-CLI")))
		return ZeroTierCLI::main(argc,argv);
	if ((strstr(argv[0],"zerotier-idtool"))||(strstr(argv[0],"ZEROTIER-IDTOOL")))
		return ZeroTierIdTool::main(argc,argv);

	const char *homeDir = (const char *)0;
	unsigned int port = 0;
	unsigned int controlPort = 0;
	for(int i=1;i<argc;++i) {
		if (argv[i][0] == '-') {
			switch(argv[i][1]) {
				case 'p':
					port = Utils::strToUInt(argv[i] + 2);
					if (port > 65535) {
						printHelp(argv[0],stderr);
						return 1;
					}
					break;
				case 'v':
					printf("%s"ZT_EOL_S,Node::versionString());
					return 0;
				case 'c':
					controlPort = Utils::strToUInt(argv[i] + 2);
					if (controlPort > 65535) {
						printHelp(argv[0],stderr);
						return 1;
					}
					break;
				case 'q':
					if (argv[i][2]) {
						printHelp(argv[0],stderr);
						return 0;
					} else return ZeroTierCLI::main(argc,argv);
				case 'i':
					if (argv[i][2]) {
						printHelp(argv[0],stderr);
						return 0;
					} else return ZeroTierIdTool::main(argc,argv);
				case 'h':
				case '?':
				default:
					printHelp(argv[0],stderr);
					return 0;
			}
		} else {
			if (homeDir) {
				printHelp(argv[0],stderr);
				return 0;
			}
			homeDir = argv[i];
			break;
		}
	}

	if ((!homeDir)||(strlen(homeDir) == 0))
		homeDir = ZT_DEFAULTS.defaultHomePath.c_str();

#ifdef __UNIX_LIKE__
	if (getuid()) {
		fprintf(stderr,"%s: must be run as root (uid==0)\n",argv[0]);
		return 1;
	}
	mkdir(homeDir,0755); // will fail if it already exists
	{
		char pidpath[4096];
		Utils::snprintf(pidpath,sizeof(pidpath),"%s/zerotier-one.pid",homeDir);
		FILE *pf = fopen(pidpath,"w");
		if (pf) {
			fprintf(pf,"%ld",(long)getpid());
			fclose(pf);
		}
	}
#endif

	int exitCode = 0;

	try {
		node = new Node(homeDir,port,controlPort);
		switch(node->run()) {
			case Node::NODE_RESTART_FOR_UPGRADE: {
#ifdef __UNIX_LIKE__
				const char *upgPath = node->reasonForTermination();
				if (upgPath)
					execl(upgPath,upgPath,"-s",(char *)0); // -s = (re)start after install/upgrade
				exitCode = 2;
				fprintf(stderr,"%s: abnormal termination: unable to execute update at %s\n",argv[0],(upgPath) ? upgPath : "(unknown path)");
#endif
			}	break;
			case Node::NODE_UNRECOVERABLE_ERROR: {
				exitCode = 3;
				const char *termReason = node->reasonForTermination();
				fprintf(stderr,"%s: abnormal termination: %s\n",argv[0],(termReason) ? termReason : "(unknown reason)");
			}	break;
			default:
				break;
		}
		delete node;
		node = (Node *)0;
	} catch ( ... ) {}

#ifdef __UNIX_LIKE__
	{
		char pidpath[4096];
		Utils::snprintf(pidpath,sizeof(pidpath),"%s/zerotier-one.pid",homeDir);
		Utils::rm(pidpath);
	}
#endif

	return exitCode;
}