/* -*- Mode: C; indent-tabs-mode:nil; c-basic-offset: 8-*- */

/*
 * This file is part of The Croco Library
 *
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of version 2.1 of the 
 * GNU Lesser General Public
 * License as published by the Free Software Foundation.
 *
 * 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 Lesser General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 * USA
 *
 * Author: Dodji Seketeli
 * See COPYRIGHTS file for copyrights information.
 */

/**
 *@file
 *The definition of the #CRParser class.
 */

#include "string.h"
#include "cr-parser.h"
#include "cr-num.h"
#include "cr-term.h"
#include "cr-simple-sel.h"
#include "cr-attr-sel.h"

/*
 *Random notes: 
 *CSS core syntax vs CSS level 2 syntax
 *=====================================
 *
 *One must keep in mind
 *that css UA must comply with two syntax.
 *
 *1/the specific syntax that defines the css language
 *for a given level of specificatin (e.g css2 syntax
 *defined in appendix D.1 of the css2 spec)
 *
 *2/the core (general) syntax that is there to allow
 *UAs to parse style sheets written in levels of CSS that
 *didn't exist at the time the UAs were created.
 *
 *the name  of parsing functions (or methods) contained in this  file
 *follows the following scheme: cr_parser_parse_<production_name> (...) ;
 *where <production_name> is the name 
 *of a production of the css2 language.
 *When a given production is 
 *defined by the css2 level grammar *and* by the
 *css core syntax, there will be two functions to parse that production:
 *one will parse the production defined by the css2 level grammar and the
 *other will parse the production defined by the css core grammar.
 *The css2 level grammar related parsing function will be called:
 *cr_parser_parse_<production_name> (...) ;
 *Then css core grammar related parsing function will be called:
 *cr_parser_parse_<production_name>_core (...) ;
 *
 *If a production is defined only by the css core grammar, then
 *it will be named:
 *cr_parser_parse_<production_name>_core (...) ;
 */

/* moved _CRParserError struct to make it public and not opaque
   modified by Iago Rubio to cssed */

/**
 *An abstraction of an error reported by by the
 *parsing routines.
 */

enum CRParserState {
        READY_STATE = 0,
        TRY_PARSE_CHARSET_STATE,
        CHARSET_PARSED_STATE,
        TRY_PARSE_IMPORT_STATE,
        IMPORT_PARSED_STATE,
        TRY_PARSE_RULESET_STATE,
        RULESET_PARSED_STATE,
        TRY_PARSE_MEDIA_STATE,
        MEDIA_PARSED_STATE,
        TRY_PARSE_PAGE_STATE,
        PAGE_PARSED_STATE,
        TRY_PARSE_FONT_FACE_STATE,
        FONT_FACE_PARSED_STATE
} ;

/**
 *The private attributes of
 *#CRParser.
 */
struct _CRParserPriv {
        /**
         *The tokenizer
         */
        CRTknzr *tknzr;

        /**
         *The sac handlers to call
         *to notify the parsing of
         *the css2 constructions.
         */
        CRDocHandler *sac_handler;

        /**
         *A stack of errors reported
         *by the parsing routines.
         *Contains instance of #CRParserError.
         *This pointer is the top of the stack.
         */
        GList *err_stack;

        enum CRParserState state;
        gboolean resolve_import;
        gboolean is_case_sensitive;
        gboolean use_core_grammar;
};

#define PRIVATE(obj) ((obj)->priv)

#define CHARS_TAB_SIZE 12

/**
 *return TRUE if the character is a number ([0-9]), FALSE otherwise
 *@param a_char the char to test.
 */
#define IS_NUM(a_char) (((a_char) >= '0' && (a_char) <= '9')?TRUE:FALSE)

/**
 *Checks if 'status' equals CR_OK. If not, goto the 'error' label.
 *
 *@param status the status (of type enum CRStatus) to test.
 *@param is_exception if set to FALSE, the final status returned 
 *by the current function will be CR_PARSING_ERROR. If set to TRUE, the
 *current status will be the current value of the 'status' variable.
 *
 */
#define CHECK_PARSING_STATUS(status, is_exception) \
if ((status) != CR_OK) \
{ \
        if (is_exception == FALSE) \
        { \
                status = CR_PARSING_ERROR ; \
        } \
        goto error ; \
}

/**
 *same as CHECK_PARSING_STATUS() but this one pushes an error
 *on the parser error stack when an error arises.
 *@param a_this the current instance of #CRParser .
 *@param a_status the status to check. Is of type enum #CRStatus.
 *@param a_is_exception in case of error, if is TRUE, the status
 *is set to CR_PARSING_ERROR before goto error. If is false, the
 *real low level status is kept and will be returned by the
 *upper level function that called this macro. Usally,this must
 *be set to FALSE.
 *
 */
#define CHECK_PARSING_STATUS_ERR(a_this, a_status, a_is_exception,\
                                 a_err_msg, a_err_status) \
if ((a_status) != CR_OK) \
{ \
        if (a_is_exception == FALSE) a_status = CR_PARSING_ERROR ; \
        cr_parser_push_error (a_this, a_err_msg, a_err_status) ; \
        goto error ; \
}

/**
 *Peeks the next char from the input stream of the current parser
 *by invoking cr_tknzr_input_peek_char().
 *invokes CHECK_PARSING_STATUS on the status returned by
 *cr_tknzr_peek_char().
 *
 *@param a_this the current instance of #CRParser.
 *@param a_to_char a pointer to the char where to store the
 *char peeked.
 */
#define PEEK_NEXT_CHAR(a_this, a_to_char) \
{\
enum CRStatus status ; \
status = cr_tknzr_peek_char  (PRIVATE (a_this)->tknzr, a_to_char) ; \
CHECK_PARSING_STATUS (status, TRUE) \
}

/**
 *Reads the next char from the input stream of the current parser.
 *In case of error, jumps to the "error:" label located in the
 *function where this macro is called.
 *@param a_this the curent instance of #CRParser
 *@param to_char a pointer to the guint32 char where to store
 *the character read.
 */
#define READ_NEXT_CHAR(a_this, a_to_char) \
status = cr_tknzr_read_char (PRIVATE (a_this)->tknzr, a_to_char) ; \
CHECK_PARSING_STATUS (status, TRUE)

/**
 *Gets information about the current position in
 *the input of the parser.
 *In case of failure, this macro returns from the 
 *calling function and
 *returns a status code of type enum #CRStatus.
 *@param a_this the current instance of #CRParser.
 *@param a_pos out parameter. A pointer to the position 
 *inside the current parser input. Must
 */
#define RECORD_INITIAL_POS(a_this, a_pos) \
status = cr_tknzr_get_cur_pos (PRIVATE \
(a_this)->tknzr, a_pos) ; \
g_return_val_if_fail (status == CR_OK, status)

/**
 *Gets the address of the current byte inside the
 *parser input.
 *@param parser the current instance of #CRParser.
 *@param addr out parameter a pointer (guchar*)
 *to where the address  must be put.
 */
#define RECORD_CUR_BYTE_ADDR(a_this, a_addr) \
status = cr_tknzr_get_cur_byte_addr \
            (PRIVATE (a_this)->tknzr, a_addr) ; \
CHECK_PARSING_STATUS (status, TRUE)

/**
 *Peeks a byte from the topmost parser input at
 *a given offset from the current position.
 *If it fails, goto the "error:" label.
 *
 *@param a_parser the current instance of #CRParser.
 *@param a_offset the offset of the byte to peek, the
 *current byte having the offset '0'.
 *@param a_byte_ptr out parameter a pointer (guchar*) to
 *where the peeked char is to be stored.
 */
#define PEEK_BYTE(a_parser, a_offset, a_byte_ptr) \
status = cr_tknzr_peek_byte (PRIVATE (a_this)->tknzr, \
                              a_offset, \
                              a_byte_ptr) ; \
CHECK_PARSING_STATUS (status, TRUE) ;

#define BYTE(a_parser, a_offset, a_eof) \
cr_tknzr_peek_byte2 (PRIVATE (a_this)->tknzr, a_offset, a_eof)

/**
 *Reads a byte from the topmost parser input
 *steam.
 *If it fails, goto the "error" label.
 *@param a_this the current instance of #CRParser.
 *@param a_byte_ptr the guchar * where to put the read char.
 */
#define READ_NEXT_BYTE(a_this, a_byte_ptr) \
status = cr_tknzr_read_byte (PRIVATE (a_this)->tknzr, a_byte_ptr) ; \
CHECK_PARSING_STATUS (status, TRUE) ;

/**
 *Skips a given number of byte in the topmost
 *parser input. Don't update line and column number.
 *In case of error, jumps to the "error:" label
 *of the surrounding function.
 *@param a_parser the current instance of #CRParser.
 *@param a_nb_bytes the number of bytes to skip.
 */
#define SKIP_BYTES(a_this, a_nb_bytes) \
status = cr_tknzr_seek_index (PRIVATE (a_this)->tknzr, \
                                        CR_SEEK_CUR, a_nb_bytes) ; \
CHECK_PARSING_STATUS (status, TRUE) ;

/**
 *Skip utf8 encoded characters.
 *Updates line and column numbers.
 *@param a_parser the current instance of #CRParser.
 *@param a_nb_chars the number of chars to skip. Must be of
 *type glong.
 */
#define SKIP_CHARS(a_parser, a_nb_chars) \
{ \
glong nb_chars = a_nb_chars ; \
status = cr_tknzr_consume_chars \
     (PRIVATE (a_parser)->tknzr,0, &nb_chars) ; \
CHECK_PARSING_STATUS (status, TRUE) ; \
}

/**
 *Tests the condition and if it is false, sets
 *status to "CR_PARSING_ERROR" and goto the 'error'
 *label.
 *@param condition the condition to test.
 */
#define ENSURE_PARSING_COND(condition) \
if (! (condition)) {status = CR_PARSING_ERROR; goto error ;}

#define ENSURE_PARSING_COND_ERR(a_this, a_condition, \
                                a_err_msg, a_err_status) \
if (! (a_condition)) \
{ \
        status = CR_PARSING_ERROR; \
        cr_parser_push_error (a_this, a_err_msg, a_err_status) ; \
        goto error ; \
}

#define GET_NEXT_TOKEN(a_this, a_token_ptr) \
status = cr_tknzr_get_next_token (PRIVATE (a_this)->tknzr, \
                                  a_token_ptr) ; \
ENSURE_PARSING_COND (status == CR_OK) ;

#ifdef WITH_UNICODE_ESCAPE_AND_RANGE
static enum CRStatus cr_parser_parse_unicode_escape (CRParser * a_this,
                                                     guint32 * a_unicode);
static enum CRStatus cr_parser_parse_escape (CRParser * a_this,
                                             guint32 * a_esc_code);

static enum CRStatus cr_parser_parse_unicode_range (CRParser * a_this,
                                                    CRString ** a_inf,
                                                    CRString ** a_sup);
#endif

static enum CRStatus cr_parser_parse_stylesheet_core (CRParser * a_this);

static enum CRStatus cr_parser_parse_atrule_core (CRParser * a_this);

static enum CRStatus cr_parser_parse_ruleset_core (CRParser * a_this);

static enum CRStatus cr_parser_parse_selector_core (CRParser * a_this);

static enum CRStatus cr_parser_parse_declaration_core (CRParser * a_this);

static enum CRStatus cr_parser_parse_any_core (CRParser * a_this);

static enum CRStatus cr_parser_parse_block_core (CRParser * a_this);

static enum CRStatus cr_parser_parse_value_core (CRParser * a_this);

static enum CRStatus cr_parser_parse_string (CRParser * a_this,
                                             CRString ** a_str);

static enum CRStatus cr_parser_parse_ident (CRParser * a_this,
                                            CRString ** a_str);

static enum CRStatus cr_parser_parse_uri (CRParser * a_this,
                                          CRString ** a_str);

static enum CRStatus cr_parser_parse_function (CRParser * a_this,
                                               CRString ** a_func_name,
                                               CRTerm ** a_expr);
static enum CRStatus cr_parser_parse_property (CRParser * a_this,
                                               CRString ** a_property);

static enum CRStatus cr_parser_parse_attribute_selector (CRParser * a_this,
                                                         CRAttrSel ** a_sel);

static enum CRStatus cr_parser_parse_simple_selector (CRParser * a_this,
                                                      CRSimpleSel ** a_sel);

static enum CRStatus cr_parser_parse_simple_sels (CRParser * a_this,
                                                  CRSimpleSel ** a_sel);

static CRParserError *cr_parser_error_new (const guchar * a_msg,
                                           enum CRStatus);

static void cr_parser_error_set_msg (CRParserError * a_this,
                                     const guchar * a_msg);

static void cr_parser_error_dump (CRParserError * a_this);

static void cr_parser_error_set_status (CRParserError * a_this,
                                        enum CRStatus a_status);

static void cr_parser_error_set_pos (CRParserError * a_this,
                                     glong a_line,
                                     glong a_column, glong a_byte_num);
static void
  cr_parser_error_destroy (CRParserError * a_this);

static enum CRStatus cr_parser_push_error (CRParser * a_this,
                                           const guchar * a_msg,
                                           enum CRStatus a_status);

static enum CRStatus cr_parser_dump_err_stack (CRParser * a_this,
                                               gboolean a_clear_errs);
static enum CRStatus
  cr_parser_clear_errors (CRParser * a_this);

/* **********************************************************
   Added by Iago Rubio to use it in cssed as syntax validator
   ********************************************************** */

GList*
cr_parser_get_error_stack(CRParser *a_this)
{
	GList *stack ;
	stack = g_list_copy(PRIVATE(a_this)->err_stack);
	return stack;
}
gulong
cr_parser_get_pos(CRParser *a_this)
{
	return cr_tknzr_get_cur_line(PRIVATE(a_this)->tknzr);		
}
/*****************************
 * end iago's changes
 *****************************/

/*****************************
 *error managemet methods
 *****************************/

/**
 *Constructor of #CRParserError class.
 *@param a_msg the brute error message.
 *@param a_status the error status.
 *@return the newly built instance of #CRParserError.
 */
static CRParserError *
cr_parser_error_new (const guchar * a_msg, enum CRStatus a_status)
{
        CRParserError *result = NULL;

        result = g_try_malloc (sizeof (CRParserError));

        if (result == NULL) {
                cr_utils_trace_info ("Out of memory");
                return NULL;
        }

        memset (result, 0, sizeof (CRParserError));

        cr_parser_error_set_msg (result, a_msg);
        cr_parser_error_set_status (result, a_status);

        return result;
}


/**
 *Sets the message associated to this instance of #CRError.
 *@param a_this the current instance of #CRParserError.
 *@param a_msg the new message.
 */
static void
cr_parser_error_set_msg (CRParserError * a_this, const guchar * a_msg)
{
        g_return_if_fail (a_this);

        if (a_this->msg) {
                g_free (a_this->msg);
        }

        a_this->msg = g_strdup (a_msg);
}

/**
 *Sets the error status.
 *@param a_this the current instance of #CRParserError.
 *@param a_status the new error status.
 *
 */
static void
cr_parser_error_set_status (CRParserError * a_this, enum CRStatus a_status)
{
        g_return_if_fail (a_this);

        a_this->status = a_status;
}

/**
 *Sets the position of the parser error.
 *@param a_this the current instance of #CRParserError.
 *@param a_line the line number.
 *@param a_column the column number.
 *@param a_byte_num the byte number.
 */
static void
cr_parser_error_set_pos (CRParserError * a_this,
                         glong a_line, glong a_column, glong a_byte_num)
{
        g_return_if_fail (a_this);

        a_this->line = a_line;
        a_this->column = a_column;
        a_this->byte_num = a_byte_num;
}

static void
cr_parser_error_dump (CRParserError * a_this)
{
        g_return_if_fail (a_this);

        g_printerr ("parsing error: %ld:%ld:", a_this->line, a_this->column);

        g_printerr ("%s\n", a_this->msg);
}

/**
 *The destructor of #CRParserError.
 *@param a_this the current instance of #CRParserError.
 */
static void
cr_parser_error_destroy (CRParserError * a_this)
{
        g_return_if_fail (a_this);

        if (a_this->msg) {
                g_free (a_this->msg);
                a_this->msg = NULL;
        }

        g_free (a_this);
}

/**
 *Pushes an error on the parser error stack.
 *@param a_this the current instance of #CRParser.
 *@param a_msg the error message.
 *@param a_status the error status.
 *@return CR_OK upon successfull completion, an error code otherwise.
 */
static enum CRStatus
cr_parser_push_error (CRParser * a_this,
                      const guchar * a_msg, enum CRStatus a_status)
{
        enum CRStatus status = CR_OK;

        CRParserError *error = NULL;
        CRInputPos pos;

        g_return_val_if_fail (a_this && PRIVATE (a_this)
                              && a_msg, CR_BAD_PARAM_ERROR);

        error = cr_parser_error_new (a_msg, a_status);

        g_return_val_if_fail (error, CR_ERROR);

        RECORD_INITIAL_POS (a_this, &pos);

        cr_parser_error_set_pos
                (error, pos.line, pos.col, pos.next_byte_index - 1);

        PRIVATE (a_this)->err_stack =
                g_list_prepend (PRIVATE (a_this)->err_stack, error);

        if (PRIVATE (a_this)->err_stack == NULL)
                goto error;

        return CR_OK;

      error:

        if (error) {
                cr_parser_error_destroy (error);
                error = NULL;
        }

        return status;
}

/**
 *Dumps the error stack on stdout.
 *@param a_this the current instance of #CRParser.
 *@param a_clear_errs whether to clear the error stack
 *after the dump or not.
 *@return CR_OK upon successfull completion, an error code
 *otherwise.
 */
static enum CRStatus
cr_parser_dump_err_stack (CRParser * a_this, gboolean a_clear_errs)
{
        GList *cur = NULL;

        g_return_val_if_fail (a_this && PRIVATE (a_this), CR_BAD_PARAM_ERROR);

        if (PRIVATE (a_this)->err_stack == NULL)
                return CR_OK;

        for (cur = PRIVATE (a_this)->err_stack; cur; cur = cur->next) {
                cr_parser_error_dump ((CRParserError *) cur->data);
        }

        if (a_clear_errs == TRUE) {
                cr_parser_clear_errors (a_this);
        }

        return CR_OK;
}

/**
 *Clears all the errors contained in the parser error stack.
 *Frees all the errors, and the stack that contains'em.
 *@param a_this the current instance of #CRParser.
 */
static enum CRStatus
cr_parser_clear_errors (CRParser * a_this)
{
        GList *cur = NULL;

        g_return_val_if_fail (a_this && PRIVATE (a_this), CR_BAD_PARAM_ERROR);

        for (cur = PRIVATE (a_this)->err_stack; cur; cur = cur->next) {
                if (cur->data) {
                        cr_parser_error_destroy ((CRParserError *)
                                                 cur->data);
                }
        }

        if (PRIVATE (a_this)->err_stack) {
                g_list_free (PRIVATE (a_this)->err_stack);
                PRIVATE (a_this)->err_stack = NULL;
        }

        return CR_OK;
}

/**
 *Same as cr_parser_try_to_skip_spaces() but this one skips
 *spaces and comments.
 *
 *@param a_this the current instance of #CRParser.
 *@return CR_OK upon successfull completion, an error code otherwise.
 */
enum CRStatus
cr_parser_try_to_skip_spaces_and_comments (CRParser * a_this)
{
        enum CRStatus status = CR_ERROR;
        CRToken *token = NULL;

        g_return_val_if_fail (a_this && PRIVATE (a_this)
                              && PRIVATE (a_this)->tknzr, CR_BAD_PARAM_ERROR);
        do {
                if (token) {
                        cr_token_destroy (token);
                        token = NULL;
                }

                status = cr_tknzr_get_next_token (PRIVATE (a_this)->tknzr,
                                                  &token);
                if (status != CR_OK)
                        goto error;
        }
        while ((token != NULL)
               && (token->type == COMMENT_TK || token->type == S_TK));

        cr_tknzr_unget_token (PRIVATE (a_this)->tknzr, token);

        return status;

      error:

        if (token) {
                cr_token_destroy (token);
                token = NULL;
        }

        return status;
}

/***************************************
 *End of Parser input handling routines
 ***************************************/


/*************************************
 *Non trivial terminal productions
 *parsing routines
 *************************************/

/**
 *Parses a css stylesheet following the core css grammar.
 *This is mainly done for test purposes.
 *During the parsing, no callback is called. This is just
 *to validate that the stylesheet is well formed according to the
 *css core syntax.
 *stylesheet  : [ CDO | CDC | S | statement ]*;
 *@param a_this the current instance of #CRParser.
 *@return CR_OK upon successfull completion, an error code otherwise.
 */
static enum CRStatus
cr_parser_parse_stylesheet_core (CRParser * a_this)
{
        CRToken *token = NULL;
        CRInputPos init_pos;
        enum CRStatus status = CR_ERROR;

        g_return_val_if_fail (a_this && PRIVATE (a_this), CR_BAD_PARAM_ERROR);

        RECORD_INITIAL_POS (a_this, &init_pos);

 continue_parsing:

        if (token) {
                cr_token_destroy (token);
                token = NULL;
        }

        cr_parser_try_to_skip_spaces_and_comments (a_this);
        status = cr_tknzr_get_next_token (PRIVATE (a_this)->tknzr, &token);
        if (status == CR_END_OF_INPUT_ERROR) {
                status = CR_OK;
                goto done;
        } else if (status != CR_OK) {
                goto error;
        }

        switch (token->type) {

        case CDO_TK:
        case CDC_TK:
                goto continue_parsing;
                break;
        default:
                status = cr_tknzr_unget_token (PRIVATE (a_this)->tknzr,
                                               token);
                CHECK_PARSING_STATUS (status, TRUE);
                token = NULL;
                status = cr_parser_parse_statement_core (a_this);
                cr_parser_clear_errors (a_this);
                if (status == CR_OK) {
                        goto continue_parsing;
                } else if (status == CR_END_OF_INPUT_ERROR) {
                        goto done;
                } else {
                        goto error;
                }
        }

 done:
        if (token) {
                cr_token_destroy (token);
                token = NULL;
        }

        cr_parser_clear_errors (a_this);
        return CR_OK;

 error:
        cr_parser_push_error
                (a_this, "could not recognize next production", CR_ERROR);

        //cr_parser_dump_err_stack (a_this, TRUE);

        if (token) {
                cr_token_destroy (token);
                token = NULL;
        }

        cr_tknzr_set_cur_pos (PRIVATE (a_this)->tknzr, &init_pos);

        return status;
}

/**
 *Parses an at-rule as defined by the css core grammar
 *in chapter 4.1 in the css2 spec.
 *at-rule     : ATKEYWORD S* any* [ block | ';' S* ];
 *@param a_this the current instance of #CRParser.
 *@return CR_OK upon successfull completion, an error code
 *otherwise.
 */
static enum CRStatus
cr_parser_parse_atrule_core (CRParser * a_this)
{
        CRToken *token = NULL;
        CRInputPos init_pos;
        enum CRStatus status = CR_ERROR;

        g_return_val_if_fail (a_this && PRIVATE (a_this), CR_BAD_PARAM_ERROR);

        RECORD_INITIAL_POS (a_this, &init_pos);

        status = cr_tknzr_get_next_token (PRIVATE (a_this)->tknzr, 
                                          &token);
        ENSURE_PARSING_COND (status == CR_OK
                             && token
                             &&
                             (token->type == ATKEYWORD_TK
                              || token->type == IMPORT_SYM_TK
                              || token->type == PAGE_SYM_TK
                              || token->type == MEDIA_SYM_TK
                              || token->type == FONT_FACE_SYM_TK
                              || token->type == CHARSET_SYM_TK));

        cr_token_destroy (token);
        token = NULL;

        cr_parser_try_to_skip_spaces_and_comments (a_this);

        do {
                status = cr_parser_parse_any_core (a_this);
        } while (status == CR_OK);

        status = cr_tknzr_get_next_token (PRIVATE (a_this)->tknzr,
                                          &token);
        ENSURE_PARSING_COND (status == CR_OK && token);

        if (token->type == CBO_TK) {
                cr_tknzr_unget_token (PRIVATE (a_this)->tknzr, 
                                      token);
                token = NULL;
                status = cr_parser_parse_block_core (a_this);
                CHECK_PARSING_STATUS (status,
                                      FALSE);
                goto done;
        } else if (token->type == SEMICOLON_TK) {
                goto done;
        } else {
                status = CR_PARSING_ERROR ;
                goto error;
        }

 done:
        if (token) {
                cr_token_destroy (token);
                token = NULL;
        }
        return CR_OK;

 error:
        if (token) {
                cr_token_destroy (token);
                token = NULL;
        }
        cr_tknzr_set_cur_pos (PRIVATE (a_this)->tknzr,
                              &init_pos);
        return status;
}

/**
 *Parses a ruleset as defined by the css core grammar in chapter
 *4.1 of the css2 spec.
 *ruleset ::= selector? '{' S* declaration? [ ';' S* declaration? ]* '}' S*;
 *@param a_this the current instance of #CRParser.
 *@return CR_OK upon successfull completion, an error code otherwise.
 */
static enum CRStatus
cr_parser_parse_ruleset_core (CRParser * a_this)
{
        CRToken *token = NULL;
        CRInputPos init_pos;
        enum CRStatus status = CR_ERROR;

        g_return_val_if_fail (a_this && PRIVATE (a_this), CR_BAD_PARAM_ERROR);
        RECORD_INITIAL_POS (a_this, &init_pos);

        status = cr_parser_parse_selector_core (a_this);

        ENSURE_PARSING_COND (status == CR_OK
                             || status == CR_PARSING_ERROR
                             || status == CR_END_OF_INPUT_ERROR);

        status = cr_tknzr_get_next_token (PRIVATE (a_this)->tknzr, &token);
        ENSURE_PARSING_COND (status == CR_OK && token
                             && token->type == CBO_TK);
        cr_token_destroy (token);
        token = NULL;

        cr_parser_try_to_skip_spaces_and_comments (a_this);
        status = cr_parser_parse_declaration_core (a_this);

      parse_declaration_list:
        if (token) {
                cr_token_destroy (token);
                token = NULL;
        }

        status = cr_tknzr_get_next_token (PRIVATE (a_this)->tknzr, &token);
        ENSURE_PARSING_COND (status == CR_OK && token);
        if (token->type == CBC_TK) {
                goto done;
        }

        ENSURE_PARSING_COND (status == CR_OK
                             && token && token->type == SEMICOLON_TK);

        cr_token_destroy (token);
        token = NULL;
        cr_parser_try_to_skip_spaces_and_comments (a_this);
        status = cr_parser_parse_declaration_core (a_this);
        cr_parser_clear_errors (a_this);
        ENSURE_PARSING_COND (status == CR_OK || status == CR_PARSING_ERROR);
        status = cr_tknzr_get_next_token (PRIVATE (a_this)->tknzr, &token);
        ENSURE_PARSING_COND (status == CR_OK && token);
        if (token->type == CBC_TK) {
                cr_token_destroy (token);
                token = NULL;
                cr_parser_try_to_skip_spaces_and_comments (a_this);
                goto done;
        } else {
                status = cr_tknzr_unget_token (PRIVATE (a_this)->tknzr,
                                               token);
                token = NULL;
                goto parse_declaration_list;
        }

      done:
        if (token) {
                cr_token_destroy (token);
                token = NULL;
        }

        if (status == CR_OK) {
                return CR_OK;
        }

      error:
        if (token) {
                cr_token_destroy (token);
                token = NULL;
        }

        cr_tknzr_set_cur_pos (PRIVATE (a_this)->tknzr, &init_pos);

        return status;
}

/**
 *Parses a "selector" as specified by the css core 
 *grammar.
 *selector    : any+;
 *@param a_this the current instance of #CRParser.
 *@return CR_OK upon successfull completion, an error code
 *otherwise.
 */
static enum CRStatus
cr_parser_parse_selector_core (CRParser * a_this)
{
        CRToken *token = NULL;
        CRInputPos init_pos;
        enum CRStatus status = CR_ERROR;

        g_return_val_if_fail (a_this && PRIVATE (a_this), CR_BAD_PARAM_ERROR);

        RECORD_INITIAL_POS (a_this, &init_pos);

        status = cr_parser_parse_any_core (a_this);
        CHECK_PARSING_STATUS (status, FALSE);

        do {
                status = cr_parser_parse_any_core (a_this);

        } while (status == CR_OK);

        return CR_OK;

 error:
        if (token) {
                cr_token_destroy (token);
                token = NULL;
        }

        cr_tknzr_set_cur_pos (PRIVATE (a_this)->tknzr, &init_pos);

        return status;
}

/**
 *Parses a "block" as defined in the css core grammar
 *in chapter 4.1 of the css2 spec.
 *block ::= '{' S* [ any | block | ATKEYWORD S* | ';' ]* '}' S*;
 *@param a_this the current instance of #CRParser.
 *FIXME: code this function.
 */
static enum CRStatus
cr_parser_parse_block_core (CRParser * a_this)
{
        CRToken *token = NULL;
        CRInputPos init_pos;
        enum CRStatus status = CR_ERROR;

        g_return_val_if_fail (a_this && PRIVATE (a_this), CR_BAD_PARAM_ERROR);

        RECORD_INITIAL_POS (a_this, &init_pos);

        status = cr_tknzr_get_next_token (PRIVATE (a_this)->tknzr, &token);
        ENSURE_PARSING_COND (status == CR_OK && token
                             && token->type == CBO_TK);

      parse_block_content:

        if (token) {
                cr_token_destroy (token);
                token = NULL;
        }

        cr_parser_try_to_skip_spaces_and_comments (a_this);

        status = cr_tknzr_get_next_token (PRIVATE (a_this)->tknzr, &token);
        ENSURE_PARSING_COND (status == CR_OK && token);

        if (token->type == CBC_TK) {
                cr_parser_try_to_skip_spaces_and_comments (a_this);
                goto done;
        } else if (token->type == SEMICOLON_TK) {
                goto parse_block_content;
        } else if (token->type == ATKEYWORD_TK) {
                cr_parser_try_to_skip_spaces_and_comments (a_this);
                goto parse_block_content;
        } else if (token->type == CBO_TK) {
                cr_tknzr_unget_token (PRIVATE (a_this)->tknzr, token);
                token = NULL;
                status = cr_parser_parse_block_core (a_this);
                CHECK_PARSING_STATUS (status, FALSE);
                goto parse_block_content;
        } else {
                cr_tknzr_unget_token (PRIVATE (a_this)->tknzr, token);
                token = NULL;
                status = cr_parser_parse_any_core (a_this);
                CHECK_PARSING_STATUS (status, FALSE);
                goto parse_block_content;
        }

      done:
        if (token) {
                cr_token_destroy (token);
                token = NULL;
        }

        if (status == CR_OK)
                return CR_OK;

      error:
        if (token) {
                cr_token_destroy (token);
                token = NULL;
        }

        cr_tknzr_set_cur_pos (PRIVATE (a_this)->tknzr, &init_pos);

        return status;
}

static enum CRStatus
cr_parser_parse_declaration_core (CRParser * a_this)
{
        CRToken *token = NULL;
        CRInputPos init_pos;
        enum CRStatus status = CR_ERROR;
        CRString *prop = NULL;

        g_return_val_if_fail (a_this && PRIVATE (a_this), CR_BAD_PARAM_ERROR);

        RECORD_INITIAL_POS (a_this, &init_pos);

        status = cr_parser_parse_property (a_this, &prop);
        CHECK_PARSING_STATUS (status, FALSE);
        cr_parser_clear_errors (a_this);
        ENSURE_PARSING_COND (status == CR_OK && prop);
        cr_string_destroy (prop);
        prop = NULL;

        status = cr_tknzr_get_next_token (PRIVATE (a_this)->tknzr, &token);
        ENSURE_PARSING_COND (status == CR_OK
                             && token
                             && token->type == DELIM_TK
                             && token->u.unichar == ':');
        cr_token_destroy (token);
        token = NULL;
        cr_parser_try_to_skip_spaces_and_comments (a_this);
        status = cr_parser_parse_value_core (a_this);
        CHECK_PARSING_STATUS (status, FALSE);

        return CR_OK;

      error:

        if (prop) {
                cr_string_destroy (prop);
                prop = NULL;
        }

        if (token) {
                cr_token_destroy (token);
                token = NULL;
        }

        cr_tknzr_set_cur_pos (PRIVATE (a_this)->tknzr, &init_pos);

        return status;
}

/**
 *Parses a "value" production as defined by the css core grammar
 *in chapter 4.1.
 *value ::= [ any | block | ATKEYWORD S* ]+;
 *@param a_this the current instance of #CRParser.
 *@return CR_OK upon successfull completion, an error code otherwise.
 */
static enum CRStatus
cr_parser_parse_value_core (CRParser * a_this)
{
        CRToken *token = NULL;
        CRInputPos init_pos;
        enum CRStatus status = CR_ERROR;
        glong ref = 0;

        g_return_val_if_fail (a_this && PRIVATE (a_this), CR_BAD_PARAM_ERROR);
        RECORD_INITIAL_POS (a_this, &init_pos);

      continue_parsing:

        if (token) {
                cr_token_destroy (token);
                token = NULL;
        }

        status = cr_tknzr_get_next_token (PRIVATE (a_this)->tknzr, &token);
        ENSURE_PARSING_COND (status == CR_OK && token);

        switch (token->type) {
        case CBO_TK:
                status = cr_tknzr_unget_token (PRIVATE (a_this)->tknzr,
                                               token);
                token = NULL;
                status = cr_parser_parse_block_core (a_this);
                CHECK_PARSING_STATUS (status, FALSE);
                ref++;
                goto continue_parsing;

        case ATKEYWORD_TK:
                cr_parser_try_to_skip_spaces_and_comments (a_this);
                ref++;
                goto continue_parsing;

        default:
                status = cr_tknzr_unget_token (PRIVATE (a_this)->tknzr,
                                               token);
                token = NULL;
                status = cr_parser_parse_any_core (a_this);
                if (status == CR_OK) {
                        ref++;
                        goto continue_parsing;
                } else if (status == CR_PARSING_ERROR) {
                        status = CR_OK;
                        goto done;
                } else {
                        goto error;
                }
        }

      done:
        if (token) {
                cr_token_destroy (token);
                token = NULL;
        }

        if (status == CR_OK && ref)
                return CR_OK;
      error:
        if (token) {
                cr_token_destroy (token);
                token = NULL;
        }

        cr_tknzr_set_cur_pos (PRIVATE (a_this)->tknzr, &init_pos);

        return status;
}

/**
 *Parses an "any" as defined by the css core grammar in the
 *css2 spec in chapter 4.1.
 *any ::= [ IDENT | NUMBER | PERCENTAGE | DIMENSION | STRING
 *        | DELIM | URI | HASH | UNICODE-RANGE | INCLUDES
 *        | FUNCTION | DASHMATCH | '(' any* ')' | '[' any* ']' ] S*;
 *
 *@param a_this the current instance of #CRParser.
 *@return CR_OK upon successfull completion, an error code otherwise.
 */
static enum CRStatus
cr_parser_parse_any_core (CRParser * a_this)
{
        CRToken *token1 = NULL,
                *token2 = NULL;
        CRInputPos init_pos;
        enum CRStatus status = CR_ERROR;

        g_return_val_if_fail (a_this, CR_BAD_PARAM_ERROR);

        RECORD_INITIAL_POS (a_this, &init_pos);

        status = cr_tknzr_get_next_token (PRIVATE (a_this)->tknzr, &token1);

        ENSURE_PARSING_COND (status == CR_OK && token1);

        switch (token1->type) {
        case IDENT_TK:
        case NUMBER_TK:
        case RGB_TK:
        case PERCENTAGE_TK:
        case DIMEN_TK:
        case EMS_TK:
        case EXS_TK:
        case LENGTH_TK:
        case ANGLE_TK:
        case FREQ_TK:
        case TIME_TK:
        case STRING_TK:
        case DELIM_TK:
        case URI_TK:
        case HASH_TK:
        case UNICODERANGE_TK:
        case INCLUDES_TK:
        case DASHMATCH_TK:
        case S_TK:
        case COMMENT_TK:
        case IMPORTANT_SYM_TK:
                status = CR_OK;
                break;
        case FUNCTION_TK:
                /*
                 *this case isn't specified by the spec but it
                 *does happen. So we have to handle it.
                 *We must consider function with parameters.
                 *We consider parameter as being an "any*" production.
                 */
                do {
                        status = cr_parser_parse_any_core (a_this);
                } while (status == CR_OK);

                ENSURE_PARSING_COND (status == CR_PARSING_ERROR);
                status = cr_tknzr_get_next_token (PRIVATE (a_this)->tknzr,
                                                  &token2);
                ENSURE_PARSING_COND (status == CR_OK
                                     && token2 && token2->type == PC_TK);
                break;
        case PO_TK:
                status = cr_tknzr_get_next_token (PRIVATE (a_this)->tknzr,
                                                  &token2);
                ENSURE_PARSING_COND (status == CR_OK && token2);

                if (token2->type == PC_TK) {
                        cr_token_destroy (token2);
                        token2 = NULL;
                        goto done;
                } else {
                        status = cr_tknzr_unget_token
                                (PRIVATE (a_this)->tknzr, token2);
                        token2 = NULL;
                }

                do {
                        status = cr_parser_parse_any_core (a_this);
                } while (status == CR_OK);

                ENSURE_PARSING_COND (status == CR_PARSING_ERROR);

                status = cr_tknzr_get_next_token (PRIVATE (a_this)->tknzr,
                                                  &token2);
                ENSURE_PARSING_COND (status == CR_OK
                                     && token2 && token2->type == PC_TK);
                status = CR_OK;
                break;

        case BO_TK:
                status = cr_tknzr_get_next_token (PRIVATE (a_this)->tknzr,
                                                  &token2);
                ENSURE_PARSING_COND (status == CR_OK && token2);

                if (token2->type == BC_TK) {
                        cr_token_destroy (token2);
                        token2 = NULL;
                        goto done;
                } else {
                        status = cr_tknzr_unget_token
                                (PRIVATE (a_this)->tknzr, token2);
                        token2 = NULL;
                }

                do {
                        status = cr_parser_parse_any_core (a_this);
                } while (status == CR_OK);

                ENSURE_PARSING_COND (status == CR_PARSING_ERROR);

                status = cr_tknzr_get_next_token (PRIVATE (a_this)->tknzr,
                                                  &token2);
                ENSURE_PARSING_COND (status == CR_OK
                                     && token2 && token2->type == BC_TK);
                status = CR_OK;
                break;
        default:
                status = CR_PARSING_ERROR;
                goto error;
        }

      done:
        if (token1) {
                cr_token_destroy (token1);
                token1 = NULL;
        }

        if (token2) {
                cr_token_destroy (token2);
                token2 = NULL;
        }

        return CR_OK;

      error:

        if (token1) {
                cr_token_destroy (token1);
                token1 = NULL;
        }

        if (token2) {
                cr_token_destroy (token2);
                token2 = NULL;
        }

        cr_tknzr_set_cur_pos (PRIVATE (a_this)->tknzr, &init_pos);
        return status;
}

/**
 *Parses an attribute selector as defined in the css2 spec in
 *appendix D.1:
 *attrib ::= '[' S* IDENT S* [ [ '=' | INCLUDES | DASHMATCH ] S*
 *            [ IDENT | STRING ] S* ]? ']'
 *
 *@param a_this the "this pointer" of the current instance of
 *#CRParser .
 *@param a_sel out parameter. The successfully parsed attribute selector.
 *@return CR_OK upon successfull completion, an error code otherwise.
 */
static enum CRStatus
cr_parser_parse_attribute_selector (CRParser * a_this, 
                                    CRAttrSel ** a_sel)
{
        enum CRStatus status = CR_OK;
        CRInputPos init_pos;
        CRToken *token = NULL;
        CRAttrSel *result = NULL;
        CRParsingLocation location = {0} ;

        g_return_val_if_fail (a_this && a_sel, CR_BAD_PARAM_ERROR);

        RECORD_INITIAL_POS (a_this, &init_pos);

        status = cr_tknzr_get_next_token (PRIVATE (a_this)->tknzr, &token);
        ENSURE_PARSING_COND (status == CR_OK && token
                             && token->type == BO_TK);
        cr_parsing_location_copy
                (&location, &token->location) ;
        cr_token_destroy (token);
        token = NULL;

        cr_parser_try_to_skip_spaces_and_comments (a_this);

        result = cr_attr_sel_new ();
        if (!result) {
                cr_utils_trace_info ("result failed")  ;
                status = CR_OUT_OF_MEMORY_ERROR ;
                goto error ;
        }
        cr_parsing_location_copy (&result->location,
                                  &location) ;
        status = cr_tknzr_get_next_token (PRIVATE (a_this)->tknzr, &token);
        ENSURE_PARSING_COND (status == CR_OK
                             && token && token->type == IDENT_TK);

        result->name = token->u.str;
        token->u.str = NULL;
        cr_token_destroy (token);
        token = NULL;

        cr_parser_try_to_skip_spaces_and_comments (a_this);

        status = cr_tknzr_get_next_token (PRIVATE (a_this)->tknzr, &token);
        ENSURE_PARSING_COND (status == CR_OK && token);

        if (token->type == INCLUDES_TK) {
                result->match_way = INCLUDES;
                goto parse_right_part;
        } else if (token->type == DASHMATCH_TK) {
                result->match_way = DASHMATCH;
                goto parse_right_part;
        } else if (token->type == DELIM_TK && token->u.unichar == '=') {
                result->match_way = EQUALS;
                goto parse_right_part;
        } else if (token->type == BC_TK) {
                result->match_way = SET;
                goto done;
        }

 parse_right_part:

        if (token) {
                cr_token_destroy (token);
                token = NULL;
        }

        cr_parser_try_to_skip_spaces_and_comments (a_this);

        status = cr_tknzr_get_next_token (PRIVATE (a_this)->tknzr, &token);
        ENSURE_PARSING_COND (status == CR_OK && token);
        
        if (token->type == IDENT_TK) {
                result->value = token->u.str;
                token->u.str = NULL;
        } else if (token->type == STRING_TK) {
                result->value = token->u.str;
                token->u.str = NULL;
        } else {
                status = CR_PARSING_ERROR;
                goto error;
        }

        if (token) {
                cr_token_destroy (token);
                token = NULL;
        }

        cr_parser_try_to_skip_spaces_and_comments (a_this);

        status = cr_tknzr_get_next_token (PRIVATE (a_this)->tknzr, &token);

        ENSURE_PARSING_COND (status == CR_OK && token
                             && token->type == BC_TK);
 done:
        if (token) {
                cr_token_destroy (token);
                token = NULL;
        }

        if (*a_sel) {
                status = cr_attr_sel_append_attr_sel (*a_sel, result);
                CHECK_PARSING_STATUS (status, FALSE);
        } else {
                *a_sel = result;
        }

        cr_parser_clear_errors (a_this);
        return CR_OK;

 error:

        if (result) {
                cr_attr_sel_destroy (result);
                result = NULL;
        }

        if (token) {
                cr_token_destroy (token);
                token = NULL;
        }

        cr_tknzr_set_cur_pos (PRIVATE (a_this)->tknzr, &init_pos);

        return status;
}

/**
 *Parses a "property" as specified by the css2 spec at [4.1.1]:
 *property : IDENT S*;
 *
 *@param a_this the "this pointer" of the current instance of #CRParser.
 *@param GString a_property out parameter. The parsed property without the
 *trailing spaces. If *a_property is NULL, this function allocates a
 *new instance of GString and set it content to the parsed property.
 *If not, the property is just appended to a_property's previous content.
 *In both cases, it is up to the caller to free a_property.
 *@return CR_OK upon successfull completion, CR_PARSING_ERROR if the
 *next construction was not a "property", or an error code.
 */
static enum CRStatus
cr_parser_parse_property (CRParser * a_this, 
                          CRString ** a_property)
{
        enum CRStatus status = CR_OK;
        CRInputPos init_pos;

        g_return_val_if_fail (a_this && PRIVATE (a_this)
                              && PRIVATE (a_this)->tknzr
                              && a_property, 
                              CR_BAD_PARAM_ERROR);

        RECORD_INITIAL_POS (a_this, &init_pos);

        status = cr_parser_parse_ident (a_this, a_property);
        CHECK_PARSING_STATUS (status, TRUE);
        
        cr_parser_try_to_skip_spaces_and_comments (a_this);

        cr_parser_clear_errors (a_this);
        return CR_OK;

      error:

        cr_tknzr_set_cur_pos (PRIVATE (a_this)->tknzr, &init_pos);

        return status;
}

/**
 *Parses a "term" as defined in the css2 spec, appendix D.1:
 *term ::= unary_operator? [NUMBER S* | PERCENTAGE S* | LENGTH S* | 
 *EMS S* | EXS S* | ANGLE S* | TIME S* | FREQ S* | function ] |
 *STRING S* | IDENT S* | URI S* | RGB S* | UNICODERANGE S* | hexcolor
 *
 *TODO: handle parsing of 'RGB'
 *
 *@param a_term out parameter. The successfully parsed term.
 *@return CR_OK upon successfull completion, an error code otherwise.
 */
enum CRStatus
cr_parser_parse_term (CRParser * a_this, CRTerm ** a_term)
{
        enum CRStatus status = CR_PARSING_ERROR;
        CRInputPos init_pos;
        CRTerm *result = NULL;
        CRTerm *param = NULL;
        CRToken *token = NULL;
        CRString *func_name = NULL;
        CRParsingLocation location = {0} ;

        g_return_val_if_fail (a_this && a_term, CR_BAD_PARAM_ERROR);

        RECORD_INITIAL_POS (a_this, &init_pos);

        result = cr_term_new ();

        status = cr_tknzr_get_next_token (PRIVATE (a_this)->tknzr, 
                                          &token);
        if (status != CR_OK || !token)
                goto error;

        cr_parsing_location_copy (&location, &token->location) ;
        if (token->type == DELIM_TK && token->u.unichar == '+') {
                result->unary_op = PLUS_UOP;
                cr_token_destroy (token) ;
                token = NULL ;
                cr_parser_try_to_skip_spaces_and_comments (a_this);
                status = cr_tknzr_get_next_token (PRIVATE (a_this)->tknzr, 
                                                  &token);
                if (status != CR_OK || !token)
                        goto error;
        } else if (token->type == DELIM_TK && token->u.unichar == '-') {
                result->unary_op = MINUS_UOP;
                cr_token_destroy (token) ;
                token = NULL ;
                cr_parser_try_to_skip_spaces_and_comments (a_this);
                status = cr_tknzr_get_next_token (PRIVATE (a_this)->tknzr, 
                                                  &token);
                if (status != CR_OK || !token)
                        goto error;
        }

        if (token->type == EMS_TK
            || token->type == EXS_TK
            || token->type == LENGTH_TK
            || token->type == ANGLE_TK
            || token->type == TIME_TK
            || token->type == FREQ_TK
            || token->type == PERCENTAGE_TK
            || token->type == NUMBER_TK) {
                status = cr_term_set_number (result, token->u.num);
                CHECK_PARSING_STATUS (status, TRUE);
                token->u.num = NULL;
                status = CR_OK;
        } else if (token && token->type == FUNCTION_TK) {
                status = cr_tknzr_unget_token (PRIVATE (a_this)->tknzr,
                                               token);
                token = NULL;
                status = cr_parser_parse_function (a_this, &func_name,
                                                   &param);

                if (status == CR_OK) {
                        status = cr_term_set_function (result,
                                                       func_name,
                                                       param);
                        CHECK_PARSING_STATUS (status, TRUE);
                }
        } else if (token && token->type == STRING_TK) {
                status = cr_term_set_string (result, 
                                             token->u.str);
                CHECK_PARSING_STATU…