/**
 * \file vc-backend.C
 * This file is part of LyX, the document processor.
 * Licence details can be found in the file COPYING.
 *
 * \author Lars Gullik Bjønnes
 *
 * Full author contact details are available in file CREDITS.
 */

#include <config.h>

#include "vc-backend.h"
#include "debug.h"
#include "buffer.h"

#include "support/path.h"
#include "support/filetools.h"
#include "support/fs_extras.h"
#include "support/lstrings.h"
#include "support/systemcall.h"

#include <boost/filesystem/operations.hpp>
#include <boost/regex.hpp>

#include <fstream>


namespace lyx {

using support::addName;
using support::addPath;
using support::contains;
using support::FileName;
using support::onlyFilename;
using support::onlyPath;
using support::quoteName;
using support::rtrim;
using support::split;
using support::Systemcall;

using boost::regex;
using boost::regex_match;
using boost::smatch;

#ifndef CXX_GLOBAL_CSTD
using std::asctime;
using std::gmtime;
#endif

using std::endl;
using std::getline;
using std::string;
using std::ifstream;

namespace fs = boost::filesystem;


int VCS::doVCCommand(string const & cmd, string const & path)
{
	lyxerr[Debug::LYXVC] << "doVCCommand: " << cmd << endl;
	Systemcall one;
	support::Path p(path);
	int const ret = one.startscript(Systemcall::Wait, cmd);
	return ret;
}


RCS::RCS(FileName const & m)
{
	master_ = m;
	scanMaster();
}


FileName const RCS::find_file(FileName const & file)
{
	// Check if *,v exists.
	FileName tmp(file.absFilename() + ",v");
	lyxerr[Debug::LYXVC] << "Checking if file is under rcs: "
			     << tmp << endl;
	if (fs::is_readable(tmp.toFilesystemEncoding())) {
		lyxerr[Debug::LYXVC] << "Yes " << file
				     << " is under rcs." << endl;
		return tmp;
	} else {
		// Check if RCS/*,v exists.
		tmp = FileName(addName(addPath(onlyPath(file.absFilename()), "RCS"), file.absFilename()) + ",v");
		lyxerr[Debug::LYXVC] << "Checking if file is under rcs: "
				     << tmp << endl;
		if (fs::is_readable(tmp.toFilesystemEncoding())) {
			lyxerr[Debug::LYXVC] << "Yes " << file
					     << " it is under rcs."<< endl;
			return tmp;
		}
	}
	return FileName();
}


void RCS::retrieve(FileName const & file)
{
	lyxerr[Debug::LYXVC] << "LyXVC::RCS: retrieve.\n\t" << file << endl;
	VCS::doVCCommand("co -q -r " + quoteName(file.toFilesystemEncoding()),
			 string());
}


void RCS::scanMaster()
{
	lyxerr[Debug::LYXVC] << "LyXVC::RCS: scanMaster." << endl;

	ifstream ifs(master_.toFilesystemEncoding().c_str());

	string token;
	bool read_enough = false;

	while (!read_enough && ifs >> token) {
		lyxerr[Debug::LYXVC]
			<< "LyXVC::scanMaster: current lex text: `"
			<< token << '\'' << endl;

		if (token.empty())
			continue;
		else if (token == "head") {
			// get version here
			string tmv;
			ifs >> tmv;
			tmv = rtrim(tmv, ";");
			version_ = tmv;
			lyxerr[Debug::LYXVC] << "LyXVC: version found to be "
					     << tmv << endl;
		} else if (contains(token, "access")
			   || contains(token, "symbols")
			   || contains(token, "strict")) {
			// nothing
		} else if (contains(token, "locks")) {
			// get locker here
			if (contains(token, ';')) {
				locker_ = "Unlocked";
				vcstatus = UNLOCKED;
				continue;
			}
			string tmpt;
			string s1;
			string s2;
			do {
				ifs >> tmpt;
				s1 = rtrim(tmpt, ";");
				// tmp is now in the format <user>:<version>
				s1 = split(s1, s2, ':');
				// s2 is user, and s1 is version
				if (s1 == version_) {
					locker_ = s2;
					vcstatus = LOCKED;
					break;
				}
			} while (!contains(tmpt, ';'));

		} else if (token == "comment") {
			// we don't need to read any further than this.
			read_enough = true;
		} else {
			// unexpected
			lyxerr[Debug::LYXVC]
				<< "LyXVC::scanMaster(): unexpected token"
				<< endl;
		}
	}
}


void RCS::registrer(string const & msg)
{
	string cmd = "ci -q -u -i -t-\"";
	cmd += msg;
	cmd += "\" ";
	cmd += quoteName(onlyFilename(owner_->fileName()));
	doVCCommand(cmd, owner_->filePath());
}


void RCS::checkIn(string const & msg)
{
	doVCCommand("ci -q -u -m\"" + msg + "\" "
		    + quoteName(onlyFilename(owner_->fileName())),
		    owner_->filePath());
}


void RCS::checkOut()
{
	owner_->markClean();
	doVCCommand("co -q -l " + quoteName(onlyFilename(owner_->fileName())),
		    owner_->filePath());
}


void RCS::revert()
{
	doVCCommand("co -f -u" + version() + " "
		    + quoteName(onlyFilename(owner_->fileName())),
		    owner_->filePath());
	// We ignore changes and just reload!
	owner_->markClean();
}


void RCS::undoLast()
{
	lyxerr[Debug::LYXVC] << "LyXVC: undoLast" << endl;
	doVCCommand("rcs -o" + version() + " "
		    + quoteName(onlyFilename(owner_->fileName())),
		    owner_->filePath());
}


void RCS::getLog(FileName const & tmpf)
{
	doVCCommand("rlog " + quoteName(onlyFilename(owner_->fileName()))
		    + " > " + tmpf.toFilesystemEncoding(),
		    owner_->filePath());
}


CVS::CVS(FileName const & m, FileName const & f)
{
	master_ = m;
	file_ = f;
	scanMaster();
}


FileName const CVS::find_file(FileName const & file)
{
	// First we look for the CVS/Entries in the same dir
	// where we have file.
	FileName const dir(onlyPath(file.absFilename()) + "/CVS/Entries");
	string const tmpf = '/' + onlyFilename(file.absFilename()) + '/';
	lyxerr[Debug::LYXVC] << "LyXVC: checking in `" << dir
			     << "' for `" << tmpf << '\'' << endl;
	if (fs::is_readable(dir.toFilesystemEncoding())) {
		// Ok we are at least in a CVS dir. Parse the CVS/Entries
		// and see if we can find this file. We do a fast and
		// dirty parse here.
		ifstream ifs(dir.toFilesystemEncoding().c_str());
		string line;
		while (getline(ifs, line)) {
			lyxerr[Debug::LYXVC] << "\tEntries: " << line << endl;
			if (contains(line, tmpf))
				return dir;
		}
	}
	return FileName();
}


void CVS::scanMaster()
{
	lyxerr[Debug::LYXVC] << "LyXVC::CVS: scanMaster. \n     Checking: "
			     << master_ << endl;
	// Ok now we do the real scan...
	ifstream ifs(master_.toFilesystemEncoding().c_str());
	string tmpf = '/' + onlyFilename(file_.absFilename()) + '/';
	lyxerr[Debug::LYXVC] << "\tlooking for `" << tmpf << '\'' << endl;
	string line;
	static regex const reg("/(.*)/(.*)/(.*)/(.*)/(.*)");
	while (getline(ifs, line)) {
		lyxerr[Debug::LYXVC] << "\t  line: " << line << endl;
		if (contains(line, tmpf)) {
			// Ok extract the fields.
			smatch sm;

			regex_match(line, sm, reg);

			//sm[0]; // whole matched string
			//sm[1]; // filename
			version_ = sm.str(2);
			string const file_date = sm.str(3);

			//sm[4]; // options
			//sm[5]; // tag or tagdate
			// FIXME: must double check file is stattable/existing
			time_t mod = fs::last_write_time(file_.toFilesystemEncoding());
			string mod_date = rtrim(asctime(gmtime(&mod)), "\n");
			lyxerr[Debug::LYXVC]
				<<  "Date in Entries: `" << file_date
				<< "'\nModification date of file: `"
				<< mod_date << '\'' << endl;
			if (file_date == mod_date) {
				locker_ = "Unlocked";
				vcstatus = UNLOCKED;
			} else {
				// Here we should also to some more checking
				// to see if there are conflicts or not.
				locker_ = "Locked";
				vcstatus = LOCKED;
			}
			break;
		}
	}
}


void CVS::registrer(string const & msg)
{
	doVCCommand("cvs -q add -m \"" + msg + "\" "
		    + quoteName(onlyFilename(owner_->fileName())),
		    owner_->filePath());
}


void CVS::checkIn(string const & msg)
{
	doVCCommand("cvs -q commit -m \"" + msg + "\" "
		    + quoteName(onlyFilename(owner_->fileName())),
		    owner_->filePath());
}


void CVS::checkOut()
{
	// cvs update or perhaps for cvs this should be a noop
	lyxerr << "Sorry not implemented." << endl;
}


void CVS::revert()
{
	// Reverts to the version in CVS repository and
	// gets the updated version from the repository.
	string const fil = quoteName(onlyFilename(owner_->fileName()));

	doVCCommand("rm -f " + fil + "; cvs update " + fil,
		    owner_->filePath());
	owner_->markClean();
}


void CVS::undoLast()
{
	// merge the current with the previous version
	// in a reverse patch kind of way, so that the
	// result is to revert the last changes.
	lyxerr << "Sorry not implemented." << endl;
}


void CVS::getLog(FileName const & tmpf)
{
	doVCCommand("cvs log " + quoteName(onlyFilename(owner_->fileName()))
		    + " > " + tmpf.toFilesystemEncoding(),
		    owner_->filePath());
}


} // namespace lyx