/* This file is part of
 * ====================================================== 
 *
 *           LyX, The Document Processor
 *
 *           Copyright 2001 The LyX Team.
 *
 * ======================================================
 *
 * \file sp_pspell.C
 * \author Kevin Atkinson
 */

#include <config.h>

#ifdef __GNUG__
#pragma implementation
#endif

#include <unistd.h>
#include <fcntl.h>
#include <stdio.h>

#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 "debug.h"
#include "encoding.h"
#include "sp_ispell.h"

using std::endl;

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

/// can be found in src/insets/figinset.C
extern void sigchldchecker(pid_t pid, int * status);

///
// ------------------- start special pspell code/class --------------------
///
#ifdef USE_PSPELL

#include "support/LAssert.h"

#define USE_ORIGINAL_MANAGER_FUNCS 1
# include <pspell/pspell.h>

#include "sp_pspell.h"


PSpell::PSpell() 
	: sc(0), els(0), spell_error_object(0), flag(ISP_UNKNOWN),
	  alive_(false)
{
}


PSpell::PSpell(BufferParams const & params, string const & lang)
	: sc(0), els(0), spell_error_object(0), flag(ISP_UNKNOWN),
	  alive_(false)
{
	initialize(params, lang);
}


PSpell::~PSpell() 
{
	cleanUp();
	close();
	if (els)
		delete_pspell_string_emulation(els);
}
	

void PSpell::initialize(BufferParams const &, string const & lang)
{
	PspellConfig * config = new_pspell_config();
	config->replace("language-tag", lang.c_str());
	spell_error_object = new_pspell_manager(config);
	if (pspell_error_number(spell_error_object) != 0) {
		error_ = pspell_error_message(spell_error_object);
	} else {
		error_ = 0;
		sc = to_pspell_manager(spell_error_object);
		spell_error_object = 0;
		alive_ = true;
	}
}


void PSpell::cleanUp() 
{
	if (spell_error_object) {
		delete_pspell_can_have_error(spell_error_object);
		spell_error_object = 0;
	}
}


enum PSpell::spellStatus PSpell::check(string const & word)
{
	if (!sc)
		return flag;

	int word_ok = pspell_manager_check(sc, word.c_str());
	lyx::Assert(word_ok != -1);

	if (word_ok) {
		flag = ISP_OK;
	} else {
		PspellWordList const * sugs =
			pspell_manager_suggest(sc, word.c_str());
		lyx::Assert(sugs != 0);
		els = pspell_word_list_elements(sugs);
		if (pspell_word_list_empty(sugs)) 
			flag = ISP_UNKNOWN;
		else 
			flag = ISP_MISSED;
	}
	return flag;
}


void PSpell::close()
{
	if (sc)
		pspell_manager_save_all_word_lists(sc);
}


void PSpell::insert(string const & word)
{
	if (sc)
		pspell_manager_add_to_personal(sc, word.c_str());
}


void PSpell::accept(string const & word) 
{
	if (sc)
		pspell_manager_add_to_session(sc, word.c_str());
}


void PSpell::store(string const & mis, string const & cor)
{
	if (sc)
		pspell_manager_store_replacement(sc, mis.c_str(), cor.c_str());
}


char const * PSpell::nextMiss()
{
	if (els)
		return pspell_string_emulation_next(els);
	return "";
}


char const * PSpell::error()
{
	return error_;
}


void PSpell::sigchldhandler(pid_t pid, int * status)
{
	sigchldchecker(pid, status);
}

#endif

///
// ------------------- start special ispell code/class --------------------
///

ISpell::ISpell()
	: str(0), flag(ISP_UNKNOWN)
{}


ISpell::ISpell(BufferParams const & params, string const & lang)
	: str(0), flag(ISP_UNKNOWN)
{
	initialize(params, lang);
}


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


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


void ISpell::initialize(BufferParams const & params, string const & lang)
{
	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)
		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);
		
			// determine if the spell checker is really Aspell
			if (strstr(buf, "Aspell"))
				actual_spell_checker = ASC_ASPELL;
			else
				actual_spell_checker = ASC_ISPELL;

			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 ispell-process has died for some reason. *One* possible reason\n"
			"could be that you do not have a dictionary file\n"
			"for the language of this document installed.\n"
			"Check /usr/lib/ispell or set another\n"
			"dictionary in the Spellchecker Options menu.";
	} else {
		error_ = 0;
	}
}


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


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


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

	::fputs(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 ISP_UNKNOWN;

	switch (*buf) {
	case '*': // Word found
		flag = ISP_OK;
		break;
	case '+': // Word found through affix removal
		flag = ISP_ROOT;
		break;
	case '-': // Word found through compound formation
		flag = ISP_COMPOUNDWORD;
		break;
	case '\n': // Number or when in terse mode: no problems
		flag = ISP_IGNORE;
		break;
	case '#': // Not found, no near misses and guesses
		flag = ISP_UNKNOWN;
		break;
	case '?': // Not found, and no near misses, but guesses (guesses are ignored)
	case '&': // Not found, but we have near misses
	{
		flag = ISP_MISSED;
		char * p = strpbrk(buf, ":");
		str = new char[strlen(p) + 1];
		e   = str;
		strcpy(str, p);
		break;
	}
	default: // This shouldn't happend, but you know Murphy
		flag = ISP_UNKNOWN;
	}

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


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


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


void ISpell::store(string const & mis, string const & cor)
{
	if (actual_spell_checker == ASC_ASPELL) {
		::fputs("$$ra ", out);
		::fputs(mis.c_str(), out);
		::fputc(',', out);
		::fputs(cor.c_str(), out);
		::fputc('\n', out);
	}
}


void ISpell::sigchldhandler(pid_t pid, int * status)
{
	if (isp_pid > 0) {
		if (pid == isp_pid) {
			isp_pid = -1;
			// set the file descriptor to nonblocking so we can
			// continue 
			fcntl(isp_fd, F_SETFL, O_NONBLOCK);
		}
	}
	sigchldchecker(pid, status);
}


char const * ISpell::error()
{
	return error_;
}