/*
 * render_cairo_common.c
 *
 * Copyright © 2019 Thomas White <taw@bitwiz.org.uk>
 *
 * This file is part of Colloquium.
 *
 * Colloquium 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 3 of the License, 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, see <http://www.gnu.org/licenses/>.
 *
 */


#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <string.h>
#include <stdio.h>
#include <pango/pango.h>

#include "storycode.h"

int runs_to_pangolayout(PangoLayout *layout, struct text_run *runs, int n_runs)
{
	size_t total_len = 0;
	int i;
	char *text;
	PangoAttrList *attrs;

	attrs = pango_layout_get_attributes(layout);

	/* Work out length of all text in item (paragraph) */
	for ( i=0; i<n_runs; i++ ) {
		total_len += strlen(runs[i].text);
	}

	/* Allocate the complete text */
	text = malloc(total_len+1);
	if ( text == NULL ) {
		fprintf(stderr, "Couldn't allocate combined text (%lli)\n",
		       (long long int)total_len);
		return 1;
	}

	/* Put all of the text together */
	text[0] = '\0';
	size_t pos = 0;
	for ( i=0; i<n_runs; i++ ) {

		PangoAttribute *attr = NULL;
		size_t run_len = strlen(runs[i].text);

		switch ( runs[i].type ) {

			case TEXT_RUN_NORMAL :
			break;

			case TEXT_RUN_BOLD:
			attr = pango_attr_weight_new(PANGO_WEIGHT_BOLD);
			break;

			case TEXT_RUN_ITALIC:
			attr = pango_attr_style_new(PANGO_STYLE_ITALIC);
			break;

			case TEXT_RUN_UNDERLINE:
			attr = pango_attr_underline_new(PANGO_UNDERLINE_SINGLE);
			break;

		}

		if ( attr != NULL ) {
			attr->start_index = pos;
			attr->end_index = pos + run_len;
			pango_attr_list_insert(attrs, attr);
		}

		/* FIXME: Should check that each bit of text finishes on a character boundary */
		pos += run_len;
		strcat(text, runs[i].text);

	}
	pango_layout_set_text(layout, text, -1);

	return 0;
}


PangoAlignment to_pangoalignment(enum alignment align)
{
	switch ( align ) {
		case ALIGN_LEFT : return PANGO_ALIGN_LEFT;
		case ALIGN_RIGHT : return PANGO_ALIGN_RIGHT;
		case ALIGN_CENTER : return PANGO_ALIGN_CENTER;
		default: return PANGO_ALIGN_LEFT;
	}
}