/* -*- Mode: C; indent-tabs-mode: ni; 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
 *
 *See COPYRIGHTS file for copyright information.
 */

/*
 *$Id$
 */

#include <string.h>
#include "cr-declaration.h"
#include "cr-statement.h"
#include "cr-parser.h"

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

/**
 *Dumps (serializes) one css declaration to a file.
 *@param a_this the current instance of #CRDeclaration.
 *@param a_fp the destination file pointer.
 *@param a_indent the number of indentation white char. 
 */
static void
dump (CRDeclaration *a_this, FILE *a_fp, glong a_indent)
{
	guchar *str = NULL, *tmp_str = NULL, *tmp_str2 = NULL;
	g_return_if_fail (a_this) ;

	if (a_this->property && a_this->property->str)
	{		
		tmp_str = g_strndup (a_this->property->str,
				     a_this->property->len) ;
		if (tmp_str)
		{
			tmp_str2 = g_strconcat (tmp_str, " : ", NULL) ;
			if (!tmp_str2) goto error ;
			if (tmp_str)
			{
				g_free (tmp_str) ;
				tmp_str = NULL ;
			}
			str = tmp_str2 ;	
		}

		if (str)
		{
			cr_utils_dump_n_chars (' ', a_fp, a_indent) ;
			fprintf (a_fp,"%s", str) ;
			g_free (str) ;
			str = NULL ;
		}
		else
			goto error ;

		if (a_this->value)
		{
			cr_term_dump (a_this->value, a_fp) ;
		}

	}

	
	return ;

 error:
	if (str)
	{
		g_free (str) ;
		str = NULL ;
	}
	if (tmp_str)
	{
		g_free (tmp_str) ;
		tmp_str = NULL ;
	}
	if (tmp_str2)
	{
		g_free (tmp_str2) ;
		tmp_str2 = NULL ;
	}
}

/**
 *Constructor of #CRDeclaration.
 *@param a_property the property string of the declaration
 *@param a_value the value expression of the declaration.
 *@return the newly built instance of #CRDeclaration, or NULL in
 *case of error.
 */
CRDeclaration *
cr_declaration_new (CRStatement *a_statement,
		    GString *a_property, 
		    CRTerm *a_value)
{
	CRDeclaration *result = NULL ;

	g_return_val_if_fail (a_property, NULL) ;

	if (a_statement)
		g_return_val_if_fail (a_statement 
				      && ((a_statement->type 
					   == RULESET_STMT) 
					  || (a_statement->type 
					      == AT_FONT_FACE_RULE_STMT)
					  || (a_statement->type 
					      == AT_PAGE_RULE_STMT)),
				      NULL) ;

	result = g_try_malloc (sizeof (CRDeclaration)) ;
	if (!result)
	{
		cr_utils_trace_info ("Out of memory") ;
		return NULL ;
	}
	memset (result, 0, sizeof (CRDeclaration)) ;
	result->property = a_property ;
	result->value = a_value ;

	if (a_value)
	{
		cr_term_ref (a_value) ;
	}
	result->parent_statement = a_statement ;
	return result ;
}


/**
 *Parses a text buffer that contains
 *a css declaration.
 *
 *@param a_statement the parent css2 statement of this
 *this declaration. Must be non NULL and of type
 *RULESET_STMT (must be a ruleset).
 *@param a_str the string that contains the statement.
 *@param a_enc the encoding of a_str.
 *@return the parsed declaration, or NULL in case of error.
 */
CRDeclaration *
cr_declaration_parse_from_buf (CRStatement *a_statement,
			       const guchar *a_str,
			       enum CREncoding a_enc)
{
	enum CRStatus status = CR_OK ;
	CRTerm *value = NULL ;
	GString *property = NULL;
	CRDeclaration *result = NULL ;
	CRParser * parser = NULL ;

	g_return_val_if_fail (a_str, NULL) ;
	if (a_statement)
		g_return_val_if_fail (a_statement->type == RULESET_STMT, 
				      NULL);

	parser = cr_parser_new_from_buf (a_str, 
					 strlen (a_str),
					 a_enc, FALSE) ;
	g_return_val_if_fail (parser, NULL) ;

	status = cr_parser_try_to_skip_spaces_and_comments (parser) ;
	if (status != CR_OK)
		goto cleanup ;

	status = cr_parser_parse_declaration (parser, &property,
					      &value) ;
	if (status != CR_OK || !property)
		goto cleanup ;

	result = cr_declaration_new (a_statement, property, value) ;
	if (result)
	{
		property = NULL ;
		value = NULL ;
	}

 cleanup:

	if (parser)
	{
		cr_parser_destroy (parser) ;
		parser = NULL ;
	}

	if (property)
	{
		g_string_free (property, TRUE) ;
		property = NULL ;
	}

	if (value)
	{
		cr_term_destroy (value) ;
		value = NULL ;
	}

	return result ;
}

/**
 *Parses a ';' separated list of properties declaration.
 *@param a_str the input buffer that contains the list of declaration to
 *parse.
 *@param a_enc the encoding of a_str
 *@return the parsed list of declaration, NULL if parsing failed.
 */
CRDeclaration *
cr_declaration_parse_list_from_buf (const guchar *a_str, enum CREncoding a_enc)
{

	enum CRStatus status = CR_OK ;
	CRTerm *value = NULL ;
	GString *property = NULL;
	CRDeclaration *result = NULL, *cur_decl = NULL ;
	CRParser * parser = NULL ;
	CRTknzr *tokenizer = NULL ;

	g_return_val_if_fail (a_str, NULL) ;

	parser = cr_parser_new_from_buf (a_str, 
					 strlen (a_str),
					 a_enc, FALSE) ;
	g_return_val_if_fail (parser, NULL) ;
	status = cr_parser_get_tknzr (parser, &tokenizer) ;
	if (status != CR_OK || !tokenizer)
	{
		if (status == CR_OK)
			status = CR_ERROR ;
		goto cleanup ;
	}
	status = cr_parser_try_to_skip_spaces_and_comments (parser) ;
	if (status != CR_OK)
		goto cleanup ;

	status = cr_parser_parse_declaration (parser, &property,
					      &value) ;
	if (status != CR_OK || !property)
	{
		if (status != CR_OK)
			status =  CR_ERROR ;
		goto cleanup ;
	}
	result = cr_declaration_new (NULL, property, value) ;
	if (result)
	{
		property = NULL ;
		value = NULL ;
	}
	/*now, go parse the other declarations*/
	for (;;)
	{
		guint32 c = 0 ;
		cr_parser_try_to_skip_spaces_and_comments (parser) ;
		status = cr_tknzr_peek_char (tokenizer, &c) ;
		if (status != CR_OK)
		{
			if (status == CR_END_OF_INPUT_ERROR)
				status = CR_OK ;
			goto cleanup ;
		}
		if (c == ';')
		{
			status = cr_tknzr_read_char (tokenizer, &c) ;
		}
		else
		{
			break ;
		}
		cr_parser_try_to_skip_spaces_and_comments (parser) ;
		status = cr_parser_parse_declaration (parser, &property,
						      &value) ;
		if (status != CR_OK || !property)
		{
			if (status == CR_END_OF_INPUT_ERROR)
			{
				status = CR_OK ;
			}
			break ;
		}
		cur_decl = cr_declaration_new (NULL, property, value) ;
		if (cur_decl)
		{
			result = cr_declaration_append (result, cur_decl) ;
			property = NULL ;
			value = NULL ;
			cur_decl = NULL;
		}
		else
		{
			break ;
		}
	}

 cleanup:

	if (parser)
	{
		cr_parser_destroy (parser) ;
		parser = NULL ;
	}

	if (property)
	{
		g_string_free (property, TRUE) ;
		property = NULL ;
	}

	if (value)
	{
		cr_term_destroy (value) ;
		value = NULL ;
	}

	if (status != CR_OK && result)
	{		
		cr_declaration_destroy (result) ;
		result = NULL ;
	}
	return result ;
}


/**
 *Appends a new declaration to the current declarations list.
 *@param a_this the current declaration list.
 *@param a_new the declaration to append.
 *@return the declaration list with a_new appended to it, or NULL
 *in case of error.
 */
CRDeclaration *
cr_declaration_append (CRDeclaration *a_this, CRDeclaration *a_new)
{
	CRDeclaration *cur = NULL ;

	g_return_val_if_fail (a_new, NULL) ;

	if (!a_this)
		return a_new ;

	for (cur = a_this ; cur && cur->next ; cur = cur->next) ;
	
	cur->next = a_new ;
	a_new->prev = cur ;

	return a_this ;
}

/**
 *Unlinks the declaration from the declaration list.
 *@param a_decl the declaration to unlink.
 *@return a pointer to the unlinked declaration in
 *case of a successfull completion, NULL otherwise.
 */
CRDeclaration *
cr_declaration_unlink (CRDeclaration * a_decl)
{
	CRDeclaration *result = a_decl ;

	g_return_val_if_fail (result, NULL) ;

	/*
	 *some sanity checks first
	 */
	if (a_decl->prev)
	{
		g_return_val_if_fail (a_decl->prev->next == a_decl, NULL) ;
		
	}
	if (a_decl->next)
	{
		g_return_val_if_fail (a_decl->next->prev == a_decl, NULL) ;
	}

	/*
	 *now, the real unlinking job.
	 */
	if (a_decl->prev)
	{
		a_decl->prev->next = a_decl->next ;
	}
	if (a_decl->next)
	{
		a_decl->next->prev = a_decl->prev ;
	}
	if (a_decl->parent_statement)
	{
		CRDeclaration **children_decl_ptr = NULL ;
		switch (a_decl->parent_statement->type)
		{
		case RULESET_STMT:
			if (a_decl->parent_statement->kind.ruleset)
			{
				children_decl_ptr =
					&a_decl->parent_statement->
					kind.ruleset->decl_list ;
			}
			
			break ;

		case AT_FONT_FACE_RULE_STMT:
			if (a_decl->parent_statement->kind.font_face_rule)
			{
				children_decl_ptr =
					&a_decl->parent_statement->
					kind.font_face_rule->decl_list ;
			}
			break ;
		case AT_PAGE_RULE_STMT:
			if (a_decl->parent_statement->kind.page_rule)
			{
				children_decl_ptr =
					&a_decl->parent_statement->
					kind.page_rule->decl_list ;
			}

		default:
			break ;
		}
		if (children_decl_ptr 
		    && *children_decl_ptr
		    && *children_decl_ptr == a_decl)
			*children_decl_ptr = 
				(*children_decl_ptr)->next ;
	}

	a_decl->next = NULL ;
	a_decl->prev = NULL ;
	a_decl->parent_statement = NULL ;

	return result ;
}

/**
 *prepends a declaration to the current declaration list.
 *@param a_this the current declaration list.
 *@param a_new the declaration to prepend.
 *@return the list with a_new prepended or NULL in case of error.
 */
CRDeclaration *
cr_declaration_prepend (CRDeclaration *a_this, CRDeclaration *a_new)
{
	CRDeclaration *cur = NULL ;

	g_return_val_if_fail (a_new, NULL) ;

	if (!a_this)
		return a_new ;

	a_this->prev = a_new ;
	a_new->next = a_this ;

	for (cur = a_new ; cur && cur->prev ; cur = cur->prev) ;

	return cur ;
}

/**
 *Appends a declaration to the current declaration list.
 *@param a_this the current declaration list.
 *@param a_prop the property string of the declaration to append.
 *@param a_value the value of the declaration to append.
 *@return the list with the new property appended to it, or NULL in
 *case of an error.
 */
CRDeclaration *
cr_declaration_append2 (CRDeclaration *a_this,
			GString *a_prop,
			CRTerm *a_value)
{
	CRDeclaration *new_elem = NULL ;

	if (a_this)
	{
		new_elem = cr_declaration_new (a_this->parent_statement,
					       a_prop, a_value) ;
	}
	else
	{
		new_elem = cr_declaration_new (NULL, a_prop, a_value) ;
	}

	g_return_val_if_fail (new_elem, NULL) ;
	
	return cr_declaration_append (a_this, new_elem) ;
}

/**
 *Dumps a declaration list to a file.
 *@param a_this the current instance of #CRDeclaration.
 *@param a_fp the destination file.
 *@param a_indent the number of indentation white char.
 */
void
cr_declaration_dump (CRDeclaration *a_this, FILE *a_fp, glong a_indent,
		     gboolean a_one_per_line)
{
	CRDeclaration *cur = NULL ;

	g_return_if_fail (a_this) ;

	for (cur = a_this ; cur ; cur = cur->next)
	{
		if (cur->prev)
		{
			if (a_one_per_line == TRUE)
				fprintf (a_fp,";\n") ;
			else
				fprintf (a_fp,"; ") ;
		}
		dump (cur, a_fp, a_indent) ;
	}
}

/**
 *Serializes the declaration into a string
 *@param a_this the current instance of #CRDeclaration.
 *@param a_indent the number of indentation white char
 *to put before the actual serialisation.
 */
guchar *
cr_declaration_to_string (CRDeclaration *a_this,
			  gulong a_indent)
{
	GString *stringue = NULL ;

	guchar *str = NULL, *result = NULL ;
	g_return_val_if_fail (a_this, NULL) ;

	stringue = g_string_new (NULL) ;

	if (a_this->property && a_this->property->str)
	{
		str = g_strndup (a_this->property->str,
				 a_this->property->len) ;
		if (str)
		{
			cr_utils_dump_n_chars2 (' ', stringue, 
						a_indent) ;
			g_string_append_printf (stringue, "%s",
						str) ;
			g_free (str) ;
			str = NULL ;
		}
		else
			goto error ;

		if (a_this->value)
		{
			guchar *value_str = NULL ;

			value_str = cr_term_to_string (a_this->value) ;
			if (value_str)
			{
				g_string_append_printf (stringue, " : %s",
							value_str) ;
				g_free (value_str) ;
			}
			else
				goto error ;
		}		
	}

	if (stringue && stringue->str)
	{
		result = stringue->str ;
		g_string_free (stringue, FALSE) ;
	}

	return result ;

 error:
	if (stringue)
	{
		g_string_free (stringue, TRUE) ;
		stringue = NULL ;
	}
	if (str)
	{
		g_free (str) ;
		str = NULL ;
	}

	return result ;
}

/**
 *Return the number of properties in the declaration;
 *@param a_this the current instance of #CRDeclaration.
 *@return number of properties in the declaration list.
 */
int
cr_declaration_nr_props (CRDeclaration *a_this)
{
	CRDeclaration *cur = NULL ;
	int nr = 0;

	g_return_if_fail (a_this) ;

	for (cur = a_this ; cur ; cur = cur->next)
		nr ++;
	return nr;
}

/**
 *Use an index to get a CRDeclaration from the declaration list.
 *@param a_this the current instance of #CRDeclaration.
 *@param itemnr the index into the declaration list.
 *@return CRDeclaration at position itemnr, if itemnr > number of declarations - 1,
 *it will return NULL.
 */
CRDeclaration *
cr_declaration_get_from_list (CRDeclaration *a_this, int itemnr)
{
	CRDeclaration *cur = NULL ;
	int nr = 0;

	g_return_if_fail (a_this) ;

	for (cur = a_this ; cur ; cur = cur->next)
		if (nr++ == itemnr)
			return cur;
	return NULL;
}

/**
 *Use property name to get a CRDeclaration from the declaration list.
 *@param a_this the current instance of #CRDeclaration.
 *@param a_prop the property name to search for.
 *@return CRDeclaration with property name a_prop, or NULL if not found.
 */
CRDeclaration *
cr_declaration_get_by_prop_name (CRDeclaration *a_this, const guchar *a_prop)
{
	CRDeclaration *cur = NULL ;

	g_return_if_fail (a_this) ;
	g_return_if_fail (a_prop) ;

	for (cur = a_this ; cur ; cur = cur->next)
		if (!strcmp (cur->property->str, a_prop))
			return cur;
	return NULL;
}

/**
 *Increases the ref count of the current instance of #CRDeclaration.
 *@param a_this the current instance of #CRDeclaration.
 */
void 
cr_declaration_ref (CRDeclaration *a_this)
{
	g_return_if_fail (a_this) ;

	a_this->ref_count ++ ;
}

/**
 *Decrements the ref count of the current instance of #CRDeclaration.
 *If the ref count reaches zero, the current instance of #CRDeclaration
 *if destroyed.
 *@param a_this the current instance of #CRDeclaration.
 *@return TRUE if the current instance of #CRDeclaration has been destroyed
 *(ref count reached zero), FALSE otherwise.
 */
gboolean
cr_declaration_unref (CRDeclaration *a_this)
{
	g_return_val_if_fail (a_this, FALSE) ;

	if (a_this->ref_count)
	{
		a_this->ref_count -- ;
	}

	if (a_this->ref_count == 0)
	{
		cr_declaration_destroy (a_this) ;
		return TRUE ;
	}
	return FALSE ;
}


/**
 *Destructor of the declaration list.
 *@param a_this the current instance of #CRDeclaration.
 */
void
cr_declaration_destroy (CRDeclaration *a_this)
{
	CRDeclaration *cur = NULL ;
	g_return_if_fail (a_this) ;

	/*
	 *Go get the tail of the list.
	 *Meanwhile, free each property/value pair contained in the list.
	 */
	for (cur = a_this ; cur && cur->next; cur = cur->next)
	{
		if (cur->property)
		{
			g_string_free (cur->property, TRUE) ;
			cur->property = NULL ;
		}
		
		if (cur->value)
		{
			cr_term_destroy (cur->value) ;
			cur->value = NULL ;
		}
	}

	if (cur)
	{
		if (cur->property)
		{
			g_string_free (cur->property, TRUE) ;
			cur->property = NULL ;
		}
		
		if (cur->value)
		{
			cr_term_destroy (cur->value) ;
			cur->value = NULL ;
		}
	}

	/*in case the list contains only one element*/
	if (cur && !cur->prev)
	{
		g_free (cur) ;
		return ;
	}

	/*walk backward the list and free each "next" element*/
	for (cur = cur->prev ; cur && cur->prev ; cur = cur->prev)
	{
		if (cur->next)
		{
			g_free (cur->next) ;
			cur->next = NULL ;
		}
	}
	
	if (!cur)
		return ;

	if (cur->next)
	{
		g_free (cur->next) ;
		cur->next = NULL ;
	}

	g_free (cur) ;
}