/*
 *  (LIBGLABELS) Template library for GLABELS
 *
 *  xml.c:  GLabels xml utilities module
 *
 *  Copyright (C) 2003, 2004  Jim Evins <evins@snaught.com>.
 *
 *  This file is part of the LIBGLABELS library.
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Library General Public
 *  License as published by the Free Software Foundation; either
 *  version 2 of the License, or (at your option) any later version.
 *
 *  This library 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
 *  Library General Public License for more details.
 *
 *  You should have received a copy of the GNU Library General Public
 *  License along with this library; if not, write to the Free
 *  Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
 *  MA 02111-1307, USA
 */
#include <config.h>

#include "xml.h"

#include <glib/gi18n.h>
#include <glib/gstrfuncs.h>
#include <glib/gmessages.h>

#include "libglabels-private.h"


/*========================================================*/
/* Private macros and constants.                          */
/*========================================================*/

#define POINTS_PER_POINT    1.0 /* internal units are points. */
#define POINTS_PER_INCH    72.0
#define POINTS_PER_MM       2.83464566929
#define POINTS_PER_CM       (10.0*POINTS_PER_MM)
#define POINTS_PER_PICA     (1.0/12.0)

/*========================================================*/
/* Private types.                                         */
/*========================================================*/

typedef struct {
	gchar       *name;
	gdouble      points_per_unit;
} UnitTableEntry;

/*========================================================*/
/* Private globals.                                       */
/*========================================================*/

static UnitTableEntry unit_table[] = {

	/* These names are identical to the absolute length units supported in
	   the CSS2 Specification (Section 4.3.2) */

	/* This table must be sorted exactly as the enumerations in glUnitsType */

	/* [GL_UNITS_POINT] */   {"pt",      POINTS_PER_POINT},
	/* [GL_UNITS_INCH]  */   {"in",      POINTS_PER_INCH},
	/* [GL_UNITS_MM]    */   {"mm",      POINTS_PER_MM},
	/* [GL_UNITS_CM]    */   {"cm",      POINTS_PER_CM},
	/* [GL_UNITS_PICA]  */   {"pc",      POINTS_PER_PICA},

};

static glUnitsType  default_units        = GL_UNITS_POINT;


/****************************************************************************/

/**
 * gl_xml_get_prop_double:
 * @node:        the libxml2 #xmlNodePtr of the node
 * @property:    the property name
 * @default_val: a default value to return if property not found
 *
 * Return value of property as a double.
 *
 * Returns: the property as a double.
 *
 */
gdouble
gl_xml_get_prop_double (xmlNodePtr   node,
			const gchar *property,
			gdouble      default_val)
{
	gdouble  val;
	xmlChar *string;

	string = xmlGetProp (node, property);
	if ( string != NULL ) {
		val = g_strtod (string, NULL);
		xmlFree (string);
		return val;
	}

	return default_val;
}


/**
 * gl_xml_get_prop_boolean:
 * @node:        the libxml2 #xmlNodePtr of the node
 * @property:    the property name
 * @default_val: a default value to return if property not found
 *
 * Return value of property as a boolean.
 *
 * Returns: the property as a boolean.
 *
 */
gboolean
gl_xml_get_prop_boolean (xmlNodePtr   node,
			 const gchar *property,
			 gboolean     default_val)
{
	gboolean  val;
	xmlChar  *string;

	string = xmlGetProp (node, property);
	if ( string != NULL ) {
		val = !((xmlStrcasecmp (string, "false") == 0) ||
			xmlStrEqual (string, "0"));;
		xmlFree (string);
		return val;
	}

	return default_val;
}


/**
 * gl_xml_get_prop_int:
 * @node:        the libxml2 #xmlNodePtr of the node
 * @property:    the property name
 * @default_val: a default value to return if property not found
 *
 * Return value of property as an integer.
 *
 * Returns: the property as an integer.
 *
 */
gint
gl_xml_get_prop_int (xmlNodePtr   node,
		     const gchar *property,
		     gint         default_val)
{
	gint     val;
	xmlChar *string;

	string = xmlGetProp (node, property);
	if ( string != NULL ) {
		val = strtol (string, NULL, 0);
		xmlFree (string);
		return val;
	}

	return default_val;
}


/**
 * gl_xml_get_prop_uint:
 * @node:        the libxml2 #xmlNodePtr of the node
 * @property:    the property name
 * @default_val: a default value to return if property not found
 *
 * Return value of property (usually formatted in hex) as an unsigned integer.
 *
 * Returns: the property as an unsigned integer.
 *
 */
guint
gl_xml_get_prop_uint (xmlNodePtr   node,
		      const gchar *property,
		      guint        default_val)
{
	guint    val;
	xmlChar *string;

	string = xmlGetProp (node, property);
	if ( string != NULL ) {
		val = strtoul (string, NULL, 0);
		xmlFree (string);
		return val;
	}

	return default_val;
}


/**
 * gl_xml_get_prop_length:
 * @node:        the libxml2 #xmlNodePtr of the node
 * @property:    the property name
 * @default_val: a default value to return if property not found
 *
 * Return value of a length property as a double, converting to internal
 * units (points).  The property is expected to be formatted as a number
 * followed by a units string.  If there is no units string, the length
 * is assumed to be in points.  Valid units strings are "pt" for points,
 * "in" for inches, "mm" for millimeters, "cm" for centimeters, and
 * "pc" for picas.
 *
 * Returns: the length in points.
 *
 */
gdouble
gl_xml_get_prop_length (xmlNodePtr   node,
			const gchar *property,
			gdouble      default_val)
{
	gdouble  val;
	xmlChar *string;
	xmlChar *unit;
	gint     i;

	string = xmlGetProp (node, property);
	if ( string != NULL ) {

		val = g_strtod (string, (gchar **)&unit);

		if (unit != string) {
			unit = g_strchug (unit);
			if (strlen (unit) > 0 ) {
				for (i=GL_UNITS_FIRST; i<=GL_UNITS_LAST; i++) {
					if (xmlStrcasecmp (unit, unit_table[i].name) == 0) {
						val *= unit_table[i].points_per_unit;
						break;
					}
				}
				if (i>GL_UNITS_LAST) {
					g_warning ("Line %d, Node \"%s\", Property \"%s\": Unknown unit \"%s\", assuming points",
						   xmlGetLineNo (node), node->name, property,
						   unit);
				}
			}
		}
		else {
			val = 0.0;
		}

		xmlFree (string);
		return val;
	}

	return default_val;
}


/**
 * gl_xml_set_prop_double:
 * @node:        the libxml2 #xmlNodePtr of the node
 * @property:    the property name
 * @val:         the value to set
 *
 * Set a property from a double.
 *
 */
void
gl_xml_set_prop_double (xmlNodePtr    node,
			const gchar  *property,
			gdouble       val)
{
	gchar  *string, buffer[G_ASCII_DTOSTR_BUF_SIZE];

	/* Guarantee "C" locale by use of g_ascii_formatd */
	string = g_ascii_formatd (buffer, G_ASCII_DTOSTR_BUF_SIZE, "%g", val);

	xmlSetProp (node, property, string);
}


/**
 * gl_xml_set_prop_boolean:
 * @node:        the libxml2 #xmlNodePtr of the node
 * @property:    the property name
 * @val:         the value to set
 *
 * Set a property from a boolean.
 *
 */
void
gl_xml_set_prop_boolean (xmlNodePtr    node,
			 const gchar  *property,
			 gboolean      val)
{
	xmlSetProp (node, property, (val ? "True" : "False"));
}

/**
 * gl_xml_set_prop_int:
 * @node:        the libxml2 #xmlNodePtr of the node
 * @property:    the property name
 * @val:         the value to set
 *
 * Set a property from an integer.
 *
 */
void
gl_xml_set_prop_int (xmlNodePtr    node,
		     const gchar  *property,
		     gint          val)
{
	gchar  *string;

	string = g_strdup_printf ("%d", val);
	xmlSetProp (node, property, string);
	g_free (string);
}

/**
 * gl_xml_set_prop_uint_hex:
 * @node:        the libxml2 #xmlNodePtr of the node
 * @property:    the property name
 * @val:         the value to set
 *
 * Set a property from an unsigned integer and format in hex.
 *
 */
void
gl_xml_set_prop_uint_hex (xmlNodePtr    node,
			  const gchar  *property,
			  guint         val)
{
	gchar  *string;

	string = g_strdup_printf ("0x%08x", val);
	xmlSetProp (node, property, string);
	g_free (string);
}

/**
 * gl_xml_set_prop_length:
 * @node:        the libxml2 #xmlNodePtr of the node
 * @property:    the property name
 * @val:         the length to set in internal units (points)
 *
 * Set a property from a length, performing any necessary conversion.
 * Length properties are formatted as a number followed by a units string.
 * The units of the formatted property is determined by the most recent call to
 * gl_xml_set_default_units().
 *
 */
void
gl_xml_set_prop_length (xmlNodePtr    node,
			const gchar  *property,
			gdouble       val)
{
	gchar  *string, buffer[G_ASCII_DTOSTR_BUF_SIZE];
	gchar  *string_unit;

	/* Convert to default units */
	val /= unit_table[default_units].points_per_unit;

	/* Guarantee "C" locale by use of g_ascii_formatd */
	string = g_ascii_formatd (buffer, G_ASCII_DTOSTR_BUF_SIZE, "%g", val);

	string_unit = g_strdup_printf ("%s%s", string, unit_table[default_units].name);
	xmlSetProp (node, property, string_unit);
        g_free (string_unit);
}

/**
 * gl_xml_set_default_units:
 * @units:       default units selection (#glUnitsType)
 *
 * Set the default units when formatting lengths.  See
 * gl_xml_set_prop_length().
 *
 */
void
gl_xml_set_default_units (glUnitsType   units)
{
	g_return_if_fail ((units >= GL_UNITS_FIRST) && (units <= GL_UNITS_LAST));

	default_units = units;
}