/* xgettext Smalltalk backend.
   Copyright (C) 2002-2003, 2005 Free Software Foundation, Inc.

   This file was written by Bruno Haible <haible@clisp.cons.org>, 2002.

   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 2, 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, write to the Free Software Foundation,
   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */

#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

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

#include "message.h"
#include "xgettext.h"
#include "x-smalltalk.h"
#include "error.h"
#include "xalloc.h"
#include "exit.h"
#include "gettext.h"

#define _(s) gettext(s)

#define SIZEOF(a) (sizeof(a) / sizeof(a[0]))


/* The relevant parts of the Smalltalk syntax are:

     stringliteral ::= string | stringconst | symconst
     stringconst ::= "#"string
     string      ::= "'"[char]*"'"
     symconst    ::= "#"symbol
     symbol      ::= id | binsel | keysel[keysel]*
     keysel      ::= id":"
     id          ::= letter[letter|digit]*
     letter      ::= "A".."Z" | "a".."z"
     digit       ::= "0".."9"
     binsel      ::= selchar[selchar]
     selchar     ::= "+" | "-" | "*" | "/" | "~" | "|" | "," | "<" | ">"
                     | "=" | "&" | "@" | "?" | "%" | "\"

   Strings can contain any characters; to include the string delimiter itself,
   it must be duplicated.

   Character constants are written  "$"char

   Comments are enclosed within double quotes.

   In well-formed expressions, {} and [] and () are balanced.
 */


/* ======================== Reading of characters.  ======================== */


/* Real filename, used in error messages about the input file.  */
static const char *real_file_name;

/* Logical filename and line number, used to label the extracted messages.  */
static char *logical_file_name;
static int line_number;

/* The input file stream.  */
static FILE *fp;


/* 1. line_number handling.  */

static int
phase1_getc ()
{
  int c = getc (fp);

  if (c == EOF)
    {
      if (ferror (fp))
	error (EXIT_FAILURE, errno, _("error while reading \"%s\""),
	       real_file_name);
      return EOF;
    }

  if (c == '\n')
    line_number++;

  return c;
}

/* Supports only one pushback character.  */
static void
phase1_ungetc (int c)
{
  if (c != EOF)
    {
      if (c == '\n')
	--line_number;

      ungetc (c, fp);
    }
}


/* Accumulating comments.  */

static char *buffer;
static size_t bufmax;
static size_t buflen;

static inline void
comment_start ()
{
  buflen = 0;
}

static inline void
comment_add (int c)
{
  if (buflen >= bufmax)
    {
      bufmax = 2 * bufmax + 10;
      buffer = xrealloc (buffer, bufmax);
    }
  buffer[buflen++] = c;
}

static inline void
comment_line_end ()
{
  while (buflen >= 1
	 && (buffer[buflen - 1] == ' ' || buffer[buflen - 1] == '\t'))
    --buflen;
  if (buflen >= bufmax)
    {
      bufmax = 2 * bufmax + 10;
      buffer = xrealloc (buffer, bufmax);
    }
  buffer[buflen] = '\0';
  savable_comment_add (buffer);
}


/* These are for tracking whether comments count as immediately before
   keyword.  */
static int last_comment_line;
static int last_non_comment_line;


/* ========================== Reading of tokens.  ========================== */


enum token_type_ty
{
  token_type_eof,
  token_type_uniq,		/* # */
  token_type_symbol,		/* symbol */
  token_type_string_literal,	/* string, stringconst, symbolconst */
  token_type_other		/* misc. operator */
};
typedef enum token_type_ty token_type_ty;

typedef struct token_ty token_ty;
struct token_ty
{
  token_type_ty type;
  char *string;		/* for token_type_string_literal, token_type_symbol */
  int line_number;
};


/* 2. Combine characters into tokens.  Discard comments and whitespace.  */

static token_ty phase2_pushback[1];
static int phase2_pushback_length;

static void
phase2_get (token_ty *tp)
{
  static char *buffer;
  static int bufmax;
  int bufpos;
  int c;

  if (phase2_pushback_length)
    {
      *tp = phase2_pushback[--phase2_pushback_length];
      return;
    }

  tp->string = NULL;

  for (;;)
    {
      tp->line_number = line_number;
      c = phase1_getc ();
      switch (c)
	{
	case EOF:
	  tp->type = token_type_eof;
	  return;

	case '"':
	  {
	    /* Comment.  */
	    int lineno;

	    comment_start ();
	    lineno = line_number;
	    for (;;)
	      {
		c = phase1_getc ();
		if (c == '"' || c == EOF)
		  break;
		if (c == '\n')
		  {
		    comment_line_end ();
		    comment_start ();
		  }
		else
		  {
		    /* We skip all leading white space, but not EOLs.  */
		    if (!(buflen == 0 && (c == ' ' || c == '\t')))
		      comment_add (c);
		  }
	      }
	    comment_line_end ();
	    last_comment_line = lineno;
	    continue;
	  }

	case '\n':
	  if (last_non_comment_line > last_comment_line)
	    savable_comment_reset ();
	  /* FALLTHROUGH */
	case ' ':
	case '\t':
	case '\r':
	  /* Ignore whitespace.  */
	  continue;
	}

      last_non_comment_line = tp->line_number;

      switch (c)
	{
	case '\'':
	  /* String literal.  */
	  bufpos = 0;
	  for (;;)
	    {
	      c = phase1_getc ();
	      if (c == EOF)
		break;
	      if (c == '\'')
		{
		  c = phase1_getc ();
		  if (c != '\'')
		    {
		      phase1_ungetc (c);
		      break;
		    }
		}
	      if (bufpos >= bufmax)
		{
		  bufmax = 2 * bufmax + 10;
		  buffer = xrealloc (buffer, bufmax);
		}
	      buffer[bufpos++] = c;
	    }
	  if (bufpos >= bufmax)
	    {
	      bufmax = 2 * bufmax + 10;
	      buffer = xrealloc (buffer, bufmax);
	    }
	  buffer[bufpos] = 0;
	  tp->type = token_type_string_literal;
	  tp->string = xstrdup (buffer);
	  return;

	case '+':
	case '-':
	case '*':
	case '/':
	case '~':
	case '|':
	case ',':
	case '<':
	case '>':
	case '=':
	case '&':
	case '@':
	case '?':
	case '%':
	case '\\':
	  {
	    char *name;
	    int c2 = phase1_getc ();
	    switch (c2)
	      {
	      case '+':
	      case '-':
	      case '*':
	      case '/':
	      case '~':
	      case '|':
	      case ',':
	      case '<':
	      case '>':
	      case '=':
	      case '&':
	      case '@':
	      case '?':
	      case '%':
		name = xmalloc (3);
		name[0] = c;
		name[1] = c2;
		name[2] = '\0';
		tp->type = token_type_symbol;
		tp->string = name;
		return;
	      default:
		phase1_ungetc (c2);
		break;
	      }
	    name = xmalloc (2);
	    name[0] = c;
	    name[1] = '\0';
	    tp->type = token_type_symbol;
	    tp->string = name;
	    return;
	  }

	case 'A': case 'B': case 'C': case 'D': case 'E': case 'F':
	case 'G': case 'H': case 'I': case 'J': case 'K': case 'L':
	case 'M': case 'N': case 'O': case 'P': case 'Q': case 'R':
	case 'S': case 'T': case 'U': case 'V': case 'W': case 'X':
	case 'Y': case 'Z':
	case 'a': case 'b': case 'c': case 'd': case 'e': case 'f':
	case 'g': case 'h': case 'i': case 'j': case 'k': case 'l':
	case 'm': case 'n': case 'o': case 'p': case 'q': case 'r':
	case 's': case 't': case 'u': case 'v': case 'w': case 'x':
	case 'y': case 'z':
	  /* Recognize id or id":"[id":"]* or id":"[id":"]*id.  */
	  bufpos = 0;
	  for (;;)
	    {
	      if (bufpos >= bufmax)
		{
		  bufmax = 2 * bufmax + 10;
		  buffer = xrealloc (buffer, bufmax);
		}
	      buffer[bufpos++] = c;
	      c = phase1_getc ();
	      switch (c)
		{
		case 'A': case 'B': case 'C': case 'D': case 'E': case 'F':
		case 'G': case 'H': case 'I': case 'J': case 'K': case 'L':
		case 'M': case 'N': case 'O': case 'P': case 'Q': case 'R':
		case 'S': case 'T': case 'U': case 'V': case 'W': case 'X':
		case 'Y': case 'Z':
		case 'a': case 'b': case 'c': case 'd': case 'e': case 'f':
		case 'g': case 'h': case 'i': case 'j': case 'k': case 'l':
		case 'm': case 'n': case 'o': case 'p': case 'q': case 'r':
		case 's': case 't': case 'u': case 'v': case 'w': case 'x':
		case 'y': case 'z':
		case '0': case '1': case '2': case '3': case '4':
		case '5': case '6': case '7': case '8': case '9':
		  continue;
		case ':':
		  if (bufpos >= bufmax)
		    {
		      bufmax = 2 * bufmax + 10;
		      buffer = xrealloc (buffer, bufmax);
		    }
		  buffer[bufpos++] = c;
		  c = phase1_getc ();
		  switch (c)
		    {
		    case 'A': case 'B': case 'C': case 'D': case 'E': case 'F':
		    case 'G': case 'H': case 'I': case 'J': case 'K': case 'L':
		    case 'M': case 'N': case 'O': case 'P': case 'Q': case 'R':
		    case 'S': case 'T': case 'U': case 'V': case 'W': case 'X':
		    case 'Y': case 'Z':
		    case 'a': case 'b': case 'c': case 'd': case 'e': case 'f':
		    case 'g': case 'h': case 'i': case 'j': case 'k': case 'l':
		    case 'm': case 'n': case 'o': case 'p': case 'q': case 'r':
		    case 's': case 't': case 'u': case 'v': case 'w': case 'x':
		    case 'y': case 'z':
		      continue;
		    default:
		      phase1_ungetc (c);
		      break;
		    }
		  break;
		default:
		  phase1_ungetc (c);
		  break;
		}
	      break;
	    }
	  if (bufpos >= bufmax)
	    {
	      bufmax = 2 * bufmax + 10;
	      buffer = xrealloc (buffer, bufmax);
	    }
	  buffer[bufpos] = '\0';
	  tp->string = xstrdup (buffer);
	  tp->type = token_type_symbol;
	  return;

	case '#':
	  /* Uniquification operator.  */
	  tp->type = token_type_uniq;
	  return;

	case '$':
	  c = phase1_getc ();
	  tp->type = token_type_other;
	  return;

	default:
	  tp->type = token_type_other;
	  return;
	}
    }
}

/* Supports only one pushback token.  */
static void
phase2_unget (token_ty *tp)
{
  if (tp->type != token_type_eof)
    {
      if (phase2_pushback_length == SIZEOF (phase2_pushback))
	abort ();
      phase2_pushback[phase2_pushback_length++] = *tp;
    }
}


/* 3. Combine "# string_literal" and "# symbol" to a single token.  */

static void
x_smalltalk_lex (token_ty *tp)
{
  phase2_get (tp);
  if (tp->type == token_type_uniq)
    {
      token_ty token2;

      phase2_get (&token2);
      if (token2.type == token_type_symbol
	  || token2.type == token_type_string_literal)
	{
	  tp->type = token_type_string_literal;
	  tp->string = token2.string;
	}
      else
	phase2_unget (&token2);
    }
}


/* ========================= Extracting strings.  ========================== */

/* The file is broken into tokens.  Scan the token stream, looking for the
   following patterns
      NLS ? <string>
      NLS at: <string>
      NLS at: <string> plural: <string>
   where <string> is one of
      string_literal
      # string_literal
      # symbol
 */

void
extract_smalltalk (FILE *f,
		   const char *real_filename, const char *logical_filename,
		   flag_context_list_table_ty *flag_table,
		   msgdomain_list_ty *mdlp)
{
  message_list_ty *mlp = mdlp->item[0]->messages;

  fp = f;
  real_file_name = real_filename;
  logical_file_name = xstrdup (logical_filename);
  line_number = 1;

  last_comment_line = -1;
  last_non_comment_line = -1;

  /* Eat tokens until eof is seen.  */
  {
    /* 0 when no "NLS" has been seen.
       1 after "NLS".
       2 after "NLS ?".
       3 after "NLS at:".
       4 after "NLS at: <string>".
       5 after "NLS at: <string> plural:".  */
    int state;
    /* Remember the message containing the msgid, for msgid_plural.
       Non-NULL in states 4, 5.  */
    message_ty *plural_mp = NULL;

    /* Start state is 0.  */
    state = 0;

    for (;;)
      {
	token_ty token;

	x_smalltalk_lex (&token);

	switch (token.type)
	  {
	  case token_type_symbol:
	    state = (strcmp (token.string, "NLS") == 0 ? 1 :
		     strcmp (token.string, "?") == 0 && state == 1 ? 2 :
		     strcmp (token.string, "at:") == 0 && state == 1 ? 3 :
		     strcmp (token.string, "plural:") == 0 && state == 4 ? 5 :
		     0);
	    free (token.string);
	    break;

	  case token_type_string_literal:
	    if (state == 2)
	      {
		lex_pos_ty pos;
		pos.file_name = logical_file_name;
		pos.line_number = token.line_number;
		remember_a_message (mlp, NULL, token.string, null_context,
				    &pos, savable_comment);
		state = 0;
		break;
	      }
	    if (state == 3)
	      {
		lex_pos_ty pos;
		pos.file_name = logical_file_name;
		pos.line_number = token.line_number;
		plural_mp = remember_a_message (mlp, NULL, token.string,
						null_context, &pos,
						savable_comment);
		state = 4;
		break;
	      }
	    if (state == 5)
	      {
		lex_pos_ty pos;
		pos.file_name = logical_file_name;
		pos.line_number = token.line_number;
		remember_a_message_plural (plural_mp, token.string,
					   null_context, &pos,
					   savable_comment);
		state = 0;
		break;
	      }
	    state = 0;
	    free (token.string);
	    break;

	  case token_type_uniq:
	  case token_type_other:
	    state = 0;
	    break;

	  case token_type_eof:
	    break;

	  default:
	    abort ();
	  }

	if (token.type == token_type_eof)
	  break;
      }
  }

  /* Close scanner.  */
  fp = NULL;
  real_file_name = NULL;
  logical_file_name = NULL;
  line_number = 0;
}