/*
 * This file is part of NetSurf, http://netsurf.sourceforge.net/
 * Licensed under the GNU General Public License,
 *		  http://www.opensource.org/licenses/gpl-license
 * Copyright 2006 James Bursa <bursa@users.sourceforge.net>
 */

/** \file
 * Font handling (RISC OS implementation).
 *
 * The RUfl is used handle and render fonts.
 */

#include <assert.h>
#include <string.h>
#include "oslib/wimp.h"
#include "rufl.h"
#include "netsurf/css/css.h"
#include "netsurf/render/font.h"
#include "netsurf/riscos/gui.h"
#include "netsurf/riscos/options.h"
#include "netsurf/utils/log.h"
#include "netsurf/utils/messages.h"
#include "netsurf/utils/utils.h"


wimp_menu *font_menu;


static void nsfont_check_option(char **option, const char *family,
		const char *fallback);
static int nsfont_list_cmp(const void *keyval, const void *datum);
static void nsfont_check_fonts(void);
static void nsfont_init_menu(void);


/**
 * Initialize font handling.
 *
 * Exits through die() on error.
 */

void nsfont_init(void)
{
	const char *fallback;
	rufl_code code;

	nsfont_check_fonts();

	code = rufl_init();
	if (code != rufl_OK) {
		if (code == rufl_FONT_MANAGER_ERROR)
			LOG(("rufl_init: rufl_FONT_MANAGER_ERROR: 0x%x: %s",
					rufl_fm_error->errnum,
					rufl_fm_error->errmess));
		else
			LOG(("rufl_init: 0x%x", code));
		die("The Unicode font library could not be initialized. "
				"Please report this to the developers.");
	}

	if (rufl_family_list_entries == 0)
		die("No fonts could be found. At least one font must be "
				"installed.");

	fallback = nsfont_fallback_font();

	nsfont_check_option(&option_font_sans, "Homerton", fallback);
	nsfont_check_option(&option_font_serif, "Trinity", fallback);
	nsfont_check_option(&option_font_mono, "Corpus", fallback);
	nsfont_check_option(&option_font_cursive, "Churchill", fallback);
	nsfont_check_option(&option_font_fantasy, "Sassoon", fallback);

	if (option_font_default != CSS_FONT_FAMILY_SANS_SERIF &&
			option_font_default != CSS_FONT_FAMILY_SERIF &&
			option_font_default != CSS_FONT_FAMILY_MONOSPACE &&
			option_font_default != CSS_FONT_FAMILY_CURSIVE &&
			option_font_default != CSS_FONT_FAMILY_FANTASY)
		option_font_default = CSS_FONT_FAMILY_SANS_SERIF;

	nsfont_init_menu();
}


/**
 * Retrieve the fallback font name
 *
 * \return Fallback font name
 */
const char *nsfont_fallback_font(void)
{
	const char *fallback = "Homerton";

	if (!nsfont_exists(fallback))
		fallback = rufl_family_list[0];

	return fallback;
}

/**
 * Check that a font option is valid, and fix it if not.
 *
 * \param  option    pointer to option, as used by options.[ch]
 * \param  family    font family to use if option is not set, or the set
 *                   family is not available
 * \param  fallback  font family to use if family is not available either
 */

void nsfont_check_option(char **option, const char *family,
		const char *fallback)
{
	if (*option && !nsfont_exists(*option)) {
		free(*option);
		*option = 0;
	}
	if (!*option) {
		if (nsfont_exists(family))
			*option = strdup(family);
		else
			*option = strdup(fallback);
	}
}


/**
 * Check if a font family is available.
 *
 * \param  font_family  name of font family
 * \return  true if the family is available
 */

bool nsfont_exists(const char *font_family)
{
	if (bsearch(font_family, rufl_family_list,
			rufl_family_list_entries, sizeof rufl_family_list[0],
			nsfont_list_cmp))
		return true;
	return false;
}


int nsfont_list_cmp(const void *keyval, const void *datum)
{
	const char *key = keyval;
	const char * const *entry = datum;
	return strcasecmp(key, *entry);
}


/**
 * Check that at least Homerton.Medium is available.
 */

void nsfont_check_fonts(void)
{
	char s[252];
	font_f font;
	os_error *error;

	error = xfont_find_font("Homerton.Medium\\ELatin1",
			160, 160, 0, 0, &font, 0, 0);
	if (error) {
		if (error->errnum == error_FILE_NOT_FOUND) {
			xwimp_start_task("TaskWindow -wimpslot 200K -quit "
					"<NetSurf$Dir>.FixFonts", 0);
			die("FontBadInst");
		} else {
			LOG(("xfont_find_font: 0x%x: %s",
					error->errnum, error->errmess));
			snprintf(s, sizeof s, messages_get("FontError"),
					error->errmess);
			die(s);
		}
	}

	error = xfont_lose_font(font);
	if (error) {
		LOG(("xfont_lose_font: 0x%x: %s",
				error->errnum, error->errmess));
		snprintf(s, sizeof s, messages_get("FontError"),
				error->errmess);
		die(s);
	}
}


/**
 * Prepare the menu of font families.
 */

void nsfont_init_menu(void)
{
	unsigned int i;

	font_menu = malloc(wimp_SIZEOF_MENU(rufl_family_list_entries));
	if (!font_menu)
		die("NoMemory");
	font_menu->title_data.indirected_text.text = messages_get("Fonts");
	font_menu->title_fg = wimp_COLOUR_BLACK;
	font_menu->title_bg = wimp_COLOUR_LIGHT_GREY;
	font_menu->work_fg = wimp_COLOUR_BLACK;
	font_menu->work_bg = wimp_COLOUR_WHITE;
	font_menu->width = 200;
	font_menu->height = wimp_MENU_ITEM_HEIGHT;
	font_menu->gap = wimp_MENU_ITEM_GAP;
	for (i = 0; i != rufl_family_list_entries; i++) {
		font_menu->entries[i].menu_flags = 0;
		font_menu->entries[i].sub_menu = wimp_NO_SUB_MENU;
		font_menu->entries[i].icon_flags = wimp_ICON_TEXT |
				wimp_ICON_INDIRECTED |
			(wimp_COLOUR_BLACK << wimp_ICON_FG_COLOUR_SHIFT) |
			(wimp_COLOUR_WHITE << wimp_ICON_BG_COLOUR_SHIFT);
		font_menu->entries[i].data.indirected_text.text =
				rufl_family_list[i];
		font_menu->entries[i].data.indirected_text.validation =
				(char *) -1;
		font_menu->entries[i].data.indirected_text.size =
				strlen(rufl_family_list[i]);
	}
	font_menu->entries[0].menu_flags = wimp_MENU_TITLE_INDIRECTED;
	font_menu->entries[i - 1].menu_flags |= wimp_MENU_LAST;
}


/**
 * Measure the width of a string.
 *
 * \param  style   css_style for this text, with style->font_size.size ==
 *                 CSS_FONT_SIZE_LENGTH
 * \param  string  UTF-8 string to measure
 * \param  length  length of string
 * \param  width   updated to width of string[0..length)
 * \return  true on success, false on error and error reported
 */

bool nsfont_width(const struct css_style *style,
		const char *string, size_t length,
		int *width)
{
	const char *font_family;
	unsigned int font_size;
	rufl_style font_style;
	rufl_code code;

	nsfont_read_style(style, &font_family, &font_size, &font_style);

	code = rufl_width(font_family, font_style, font_size,
			string, length,
			width);
	if (code != rufl_OK) {
		if (code == rufl_FONT_MANAGER_ERROR)
			LOG(("rufl_width: rufl_FONT_MANAGER_ERROR: 0x%x: %s",
					rufl_fm_error->errnum,
					rufl_fm_error->errmess));
		else
			LOG(("rufl_width: 0x%x", code));
/* 		warn_user("MiscError", "font error"); */
		return false;
	}

	*width /= 2;
	return true;
}


/**
 * Find the position in a string where an x coordinate falls.
 *
 * \param  style        css_style for this text, with style->font_size.size ==
 *                      CSS_FONT_SIZE_LENGTH
 * \param  string       UTF-8 string to measure
 * \param  length       length of string
 * \param  x            x coordinate to search for
 * \param  char_offset  updated to offset in string of actual_x, [0..length]
 * \param  actual_x     updated to x coordinate of character closest to x
 * \return  true on success, false on error and error reported
 */

bool nsfont_position_in_string(const struct css_style *style,
		const char *string, size_t length,
		int x, size_t *char_offset, int *actual_x)
{
	const char *font_family;
	unsigned int font_size;
	rufl_style font_style;
	rufl_code code;

	nsfont_read_style(style, &font_family, &font_size, &font_style);

	code = rufl_x_to_offset(font_family, font_style, font_size,
			string, length,
			x * 2, char_offset, actual_x);
	if (code != rufl_OK) {
		if (code == rufl_FONT_MANAGER_ERROR)
			LOG(("rufl_x_to_offset: rufl_FONT_MANAGER_ERROR: "
					"0x%x: %s",
					rufl_fm_error->errnum,
					rufl_fm_error->errmess));
		else
			LOG(("rufl_x_to_offset: 0x%x", code));
/* 		warn_user("MiscError", "font error"); */
		return false;
	}

	*actual_x /= 2;
	return true;
}


/**
 * Find where to split a string to make it fit a width.
 *
 * \param  style        css_style for this text, with style->font_size.size ==
 *                      CSS_FONT_SIZE_LENGTH
 * \param  string       UTF-8 string to measure
 * \param  length       length of string
 * \param  x            width available
 * \param  char_offset  updated to offset in string of actual_x, [0..length]
 * \param  actual_x     updated to x coordinate of character closest to x
 * \return  true on success, false on error and error reported
 *
 * On exit, [char_offset == 0 ||
 *           string[char_offset] == ' ' ||
 *           char_offset == length]
 */

bool nsfont_split(const struct css_style *style,
		const char *string, size_t length,
		int x, size_t *char_offset, int *actual_x)
{
	const char *font_family;
	unsigned int font_size;
	rufl_style font_style;
	rufl_code code;

	nsfont_read_style(style, &font_family, &font_size, &font_style);

	code = rufl_split(font_family, font_style, font_size,
			string, length,
			x * 2, char_offset, actual_x);
	if (code != rufl_OK) {
		if (code == rufl_FONT_MANAGER_ERROR)
			LOG(("rufl_split: rufl_FONT_MANAGER_ERROR: "
					"0x%x: %s",
					rufl_fm_error->errnum,
					rufl_fm_error->errmess));
		else
			LOG(("rufl_split: 0x%x", code));
/* 		warn_user("MiscError", "font error"); */
		return false;
	}

	while (*char_offset && string[*char_offset] != ' ')
		(*char_offset)--;

	code = rufl_width(font_family, font_style, font_size,
			string, *char_offset,
			actual_x);
	if (code != rufl_OK) {
		if (code == rufl_FONT_MANAGER_ERROR)
			LOG(("rufl_width: rufl_FONT_MANAGER_ERROR: 0x%x: %s",
					rufl_fm_error->errnum,
					rufl_fm_error->errmess));
		else
			LOG(("rufl_width: 0x%x", code));
/* 		warn_user("MiscError", "font error"); */
		return false;
	}

	*actual_x /= 2;
	return true;
}


/**
 * Paint a string.
 *
 * \param  style   css_style for this text, with style->font_size.size ==
 *                 CSS_FONT_SIZE_LENGTH
 * \param  string  UTF-8 string to measure
 * \param  length  length of string
 * \param  x       x coordinate
 * \param  y       y coordinate
 * \param  scale   scale to apply to font size
 * \param  bg      background colour
 * \param  c       colour for text
 * \return  true on success, false on error and error reported
 */

bool nsfont_paint(struct css_style *style, const char *string,
		size_t length, int x, int y, float scale)
{
	const char *font_family;
	unsigned int font_size;
	rufl_style font_style;
	rufl_code code;

	nsfont_read_style(style, &font_family, &font_size, &font_style);

	code = rufl_paint(font_family, font_style, font_size * scale,
			string, length, x, y, rufl_BLEND_FONT);
	if (code != rufl_OK) {
		if (code == rufl_FONT_MANAGER_ERROR)
			LOG(("rufl_paint: rufl_FONT_MANAGER_ERROR: 0x%x: %s",
					rufl_fm_error->errnum,
					rufl_fm_error->errmess));
		else
			LOG(("rufl_paint: 0x%x", code));
	}

	return true;
}


/**
 * Convert a css_style to a font family, size and rufl_style.
 *
 * \param  style        css_style for this text, with style->font_size.size ==
 *                      CSS_FONT_SIZE_LENGTH
 * \param  font_family  updated to font family
 * \param  font_size    updated to font size
 * \param  font_style   updated to font style
 */

void nsfont_read_style(const struct css_style *style,
		const char **font_family, unsigned int *font_size,
		rufl_style *font_style)
{
	assert(style->font_size.size == CSS_FONT_SIZE_LENGTH);
	*font_size = css_len2px(&style->font_size.value.length, style) *
			72.0 / 90.0 * 16.;
	if (*font_size < option_font_min_size * 1.6)
		*font_size = option_font_min_size * 1.6;
	if (1600 < *font_size)
		*font_size = 1600;

	switch (style->font_family) {
	case CSS_FONT_FAMILY_SANS_SERIF:
		*font_family = option_font_sans;
		break;
	case CSS_FONT_FAMILY_SERIF:
		*font_family = option_font_serif;
		break;
	case CSS_FONT_FAMILY_MONOSPACE:
		*font_family = option_font_mono;
		break;
	case CSS_FONT_FAMILY_CURSIVE:
		*font_family = option_font_cursive;
		break;
	case CSS_FONT_FAMILY_FANTASY:
		*font_family = option_font_fantasy;
		break;
	default:
		*font_family = option_font_sans;
		break;
	}

	switch (style->font_style) {
	case CSS_FONT_STYLE_ITALIC:
	case CSS_FONT_STYLE_OBLIQUE:
		*font_style = rufl_SLANTED;
		break;
	default:
		*font_style = 0;
		break;
	}

	switch (style->font_weight) {
	case CSS_FONT_WEIGHT_100:
		*font_style |= rufl_WEIGHT_100;
		break;
	case CSS_FONT_WEIGHT_200:
		*font_style |= rufl_WEIGHT_200;
		break;
	case CSS_FONT_WEIGHT_300:
		*font_style |= rufl_WEIGHT_300;
		break;
	case CSS_FONT_WEIGHT_NORMAL:
	case CSS_FONT_WEIGHT_400:
		*font_style |= rufl_WEIGHT_400;
		break;
	case CSS_FONT_WEIGHT_500:
		*font_style |= rufl_WEIGHT_500;
		break;
	case CSS_FONT_WEIGHT_600:
		*font_style |= rufl_WEIGHT_600;
		break;
	case CSS_FONT_WEIGHT_BOLD:
	case CSS_FONT_WEIGHT_700:
		*font_style |= rufl_WEIGHT_700;
		break;
	case CSS_FONT_WEIGHT_800:
		*font_style |= rufl_WEIGHT_800;
		break;
	case CSS_FONT_WEIGHT_900:
		*font_style |= rufl_WEIGHT_900;
		break;
	default:
		*font_style |= rufl_WEIGHT_400;
		break;
	}
}





void nsfont_txtenum(void *font, const char *text,
		size_t length,
		unsigned int *width,
		const char **rofontname,
		const char **rotext,
		size_t *rolength,
		size_t *consumed) { }