/**
 * \file ispell.C
 * Copyright 2002 the LyX Team
 * Read the file COPYING
 *
 * \author unknown
 * \author John Levon <levon@movementarian.org>
 */

#include <config.h>

#ifdef __GNUG__
#pragma implementation
#endif

#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <fcntl.h>
#include <cstdio>

// FIXME: do we need any of this horrible gook ? 
#if TIME_WITH_SYS_TIME
# include <sys/time.h>
# include <ctime>
#else
# if HAVE_SYS_TIME_H
#  include <sys/time.h>
# else
#  include <ctime>
# endif
#endif

#ifdef HAVE_SYS_SELECT_H
# ifdef HAVE_STRINGS_H
   // <strings.h> is needed at least on AIX because FD_ZERO uses bzero().
   // BUT we cannot include both string.h and strings.h on Irix 6.5 :(
#  ifdef _AIX
#   include <strings.h>
#  endif
# endif
#include <sys/select.h>
#endif

#include "LString.h"
#include "support/lstrings.h"
#include "lyxrc.h"
#include "language.h"
#include "debug.h"
#include "encoding.h"
#include "ispell.h"
#include "WordLangTuple.h"

#ifndef CXX_GLOBAL_CSTD
using std::strcpy;
using std::strlen;
using std::strpbrk;
using std::strstr;
#endif

using std::endl;

namespace {
	/// pid for the `ispell' process.
	pid_t isp_pid = -1;
}


ISpell::ISpell(BufferParams const & params, string const & lang)
	: str(0)
{
	static char o_buf[BUFSIZ];  // jc: it could be smaller
	int pipein[2];
	int pipeout[2];
	char * argv[14];
	int argc;

	isp_pid = -1;

	if (pipe(pipein) == -1 || pipe(pipeout) == -1) {
		lyxerr << "LyX: Can't create pipe for spellchecker!" << endl;
		goto END;
	}

	if ((out = fdopen(pipein[1], "w")) == 0) {
		lyxerr << "LyX: Can't create stream for pipe for spellchecker!"
		       << endl;
		goto END;
	}

	if ((in = fdopen(pipeout[0], "r")) == 0) {
		lyxerr <<"LyX: Can't create stream for pipe for spellchecker!"
		       << endl;
		goto END;
	}

	setvbuf(out, o_buf, _IOLBF, BUFSIZ);

	isp_fd = pipeout[0];

	isp_pid = fork();

	if (isp_pid == -1) {
		lyxerr << "LyX: Can't create child process for spellchecker!"
		       << endl;
		goto END;
	}

	if (isp_pid == 0) {
		/* child process */
		dup2(pipein[0], STDIN_FILENO);
		dup2(pipeout[1], STDOUT_FILENO);
		::close(pipein[0]);
		::close(pipein[1]);
		::close(pipeout[0]);
		::close(pipeout[1]);

		argc = 0;
		char * tmp = new char[lyxrc.isp_command.length() + 1];
		lyxrc.isp_command.copy(tmp, lyxrc.isp_command.length());
		tmp[lyxrc.isp_command.length()] = '\0';
		argv[argc++] = tmp;
		tmp = new char[3];
		string("-a").copy(tmp, 2); tmp[2] = '\0'; // pipe mode
		argv[argc++] = tmp;

		if (lang != "default") {
			tmp = new char[3];
			string("-d").copy(tmp, 2); tmp[2] = '\0'; // Dictionary file
			argv[argc++] = tmp;
			tmp = new char[lang.length() + 1];
			lang.copy(tmp, lang.length()); tmp[lang.length()] = '\0';
			argv[argc++] = tmp;
		}

		if (lyxrc.isp_accept_compound) {
			// Consider run-together words as legal compounds
			tmp = new char[3];
			string("-C").copy(tmp, 2); tmp[2] = '\0';
			argv[argc++] = tmp;
		} else {
			// Report run-together words with
			// missing blanks as errors
			tmp = new char[3];
			string("-B").copy(tmp, 2); tmp[2] = '\0';
			argv[argc++] = tmp;
		}
		if (lyxrc.isp_use_esc_chars) {
			// Specify additional characters that
			// can be part of a word
			tmp = new char[3];
			string("-w").copy(tmp, 2); tmp[2] = '\0';
			argv[argc++] = tmp;
			// Put the escape chars in ""s
			string tms = "\"" + lyxrc.isp_esc_chars + "\"";
			tmp = new char[tms.length() + 1];
			tms.copy(tmp, tms.length()); tmp[tms.length()] = '\0';
			argv[argc++] = tmp;
		}
		if (lyxrc.isp_use_pers_dict) {
			// Specify an alternate personal dictionary
			tmp = new char[3];
			string("-p").copy(tmp, 2);
			tmp[2]= '\0';
			argv[argc++] = tmp;
			tmp = new char[lyxrc.isp_pers_dict.length() + 1];
			lyxrc.isp_pers_dict.copy(tmp, lyxrc.isp_pers_dict.length());
			tmp[lyxrc.isp_pers_dict.length()] = '\0';
			argv[argc++] = tmp;
		}
		if (lyxrc.isp_use_input_encoding &&
		    params.inputenc != "default") {
			string enc = (params.inputenc == "auto")
				? params.language->encoding()->LatexName()
				: params.inputenc;
			string::size_type n = enc.length();
			tmp = new char[3];
			string("-T").copy(tmp, 2);
			tmp[2] = '\0';
			argv[argc++] = tmp; // Input encoding
			tmp = new char[n + 1];
			enc.copy(tmp, n);
			tmp[n] = '\0';
			argv[argc++] = tmp;
		}

		argv[argc++] = 0;

		execvp(argv[0], const_cast<char * const *>(argv));

		// free the memory used by string::copy in the
		// setup of argv
		for (int i = 0; i < argc - 1; ++i)
			delete[] argv[i];

		lyxerr << "LyX: Failed to start ispell!" << endl;
		_exit(0);
	}
	{
		/* Parent process: Read ispells identification message */
		// Hmm...what are we using this id msg for? Nothing? (Lgb)
		// Actually I used it to tell if it's truly Ispell or if it's
		// aspell -- (kevinatk@home.com)
		// But no code actually used the results for anything useful
		// so I removed it again. Perhaps we can remove this code too. 
		// - jbl
		char buf[2048];
		fd_set infds;
		struct timeval tv;
		int retval = 0;
		FD_ZERO(&infds);
		FD_SET(pipeout[0], &infds);
		tv.tv_sec = 15; // fifteen second timeout. Probably too much,
		// but it can't really hurt.
		tv.tv_usec = 0;

		// Configure provides us with macros which are supposed to do
		// the right typecast.
		retval = select(SELECT_TYPE_ARG1 (pipeout[0]+1),
				SELECT_TYPE_ARG234 (&infds),
				0,
				0,
				SELECT_TYPE_ARG5 (&tv));

		if (retval > 0) {
			// Ok, do the reading. We don't have to FD_ISSET since
			// there is only one fd in infds.
			fgets(buf, 2048, in);

			fputs("!\n", out); // Set terse mode (silently accept correct words)

		} else if (retval == 0) {
			// timeout. Give nice message to user.
			lyxerr << "Ispell read timed out, what now?" << endl;
			// This probably works but could need some thought
			isp_pid = -1;
			::close(pipeout[0]);
			::close(pipeout[1]);
			::close(pipein[0]);
			::close(pipein[1]);
			isp_fd = -1;
		} else {
			// Select returned error
			lyxerr << "Select on ispell returned error, what now?" << endl;
		}
	}
  END:
	if (isp_pid == -1) {
		error_ =
			"\n\n"
			"The spellcheck-process has died for some reason.\n"
			"*One* possible reason could be that you do not have\n"
			"a dictionary file for the language of this document\n"
			"installed.\n"
			"Check your spellchecker or set another dictionary\n"
			"in the Spellchecker Options menu.\n\n";
	} else {
		error_ = 0;
	}
}


ISpell::~ISpell()
{
	delete[] str;
}


/* FIXME: this is a minimalist solution until the above
 * code is able to work with forkedcall.h. We only need
 * to reap the zombies here.
 */
void reapSpellchecker(void)
{
	if (isp_pid == -1)
		return;

	waitpid(isp_pid, 0, WNOHANG);
}


string const ISpell::nextMiss()
{
	if (str == 0 || *(e+1) == '\0')
		return "";
	char * b = e + 2;
	e = strpbrk(b, ",\n");
	*e = '\0';
	if (b)
		return b;
	return "";
}


bool ISpell::alive()
{
	return isp_pid != -1;
}


void ISpell::cleanUp()
{
	::fclose(out);
}


enum ISpell::Result ISpell::check(WordLangTuple const & word)
{
	// FIXME Please rewrite to use string.

	Result res;
 
	::fputs(word.word().c_str(), out);
	::fputc('\n', out);

	char buf[1024];
	::fgets(buf, 1024, in);

	// I think we have to check if ispell is still alive here because
	// the signal-handler could have disabled blocking on the fd
	if (!alive())
		return UNKNOWN;

	switch (*buf) {
	case '*':
		res = OK;
		break;
	case '+':
		res = ROOT;
		break;
	case '-':
		res = COMPOUNDWORD;
		break;
	case '\n':
		res = IGNORE;
		break;
	case '#': // Not found, no near misses and guesses
		res = UNKNOWN;
		break;
	case '?': // Not found, and no near misses, but guesses (guesses are ignored)
	case '&': // Not found, but we have near misses
	{
		res = MISSED;
		char * p = strpbrk(buf, ":");
		str = new char[strlen(p) + 1];
		e   = str;
		strcpy(str, p);
		break;
	}
	default: // This shouldn't happen, but you know Murphy
		res = UNKNOWN;
	}

	*buf = 0;
	if (res != IGNORE) {
		/* wait for ispell to finish */
		while (*buf!= '\n')
			fgets(buf, 255, in);
	}
	return res;
}


void ISpell::close()
{
	// Note: If you decide to optimize this out when it is not
	// needed please note that when Aspell is used this command
	// is also needed to save the replacement dictionary.
	// -- Kevin Atkinson (kevinatk@home.com)

	fputs("#\n", out); // Save personal dictionary

	fflush(out);
	fclose(out);
}


void ISpell::insert(WordLangTuple const & word)
{
	::fputc('*', out); // Insert word in personal dictionary
	::fputs(word.word().c_str(), out);
	::fputc('\n', out);
}


void ISpell::accept(WordLangTuple const & word)
{
	::fputc('@', out); // Accept in this session
	::fputs(word.word().c_str(), out);
	::fputc('\n', out);
}


string const ISpell::error()
{
	if (error_)
		return error_;
	return "";
}