/*
Port from c++ is protected by a GNU Lesser GPLv3
Copyright © 2013 Sylvain BERTRAND <sylvain.bertrand@gmail.com>
                                  <sylware@legeek.net>       
*/
/*XXX:have to go*/
#define _GNU_SOURCE
#include <endian.h>
#include <stdint.h>
#include <stddef.h>

#include "hb.h"
#include "hb-private.h"
#include "hb-open-file-private.h"

static struct ot_fnt_face *ttc_hdr_ver1_get_face(struct ttc_hdr_ver1
						 *ttc_hdr_ver1, unsigned i)
{
	uint32_t of;
	uint8_t *base;		/*the beginning of the file */

	if (!ttc_hdr_ver1)
		return NULL;

	of = be32toh(ttc_hdr_ver1->of_tbls_ofs[i]);
	base = (uint8_t *) ttc_hdr_ver1;
	return (struct ot_fnt_face *)(base + of);
}

static struct ot_fnt_face *ttc_hdr_get_face(struct ttc_hdr *ttc_hdr, unsigned i)
{
	if (!ttc_hdr)
		return NULL;

	switch (ttc_hdr->u.hdr.ver.major) {
	case 2:		/*version 2 is compatible with version 1 */
	case 1:
		return ttc_hdr_ver1_get_face(&ttc_hdr->u.ver1, i);
	default:
		return NULL;
	}
}

struct ot_fnt_face *ot_fnt_file_get_face(struct ot_fnt_file *ot_fnt_file,
					 unsigned i)
{
	uint32_t tag;

	if (!ot_fnt_file)
		return NULL;

	tag = be32toh(ot_fnt_file->u.tag);

	switch (tag) {
		/*Note: for non-collection SFNT data we ignore index.  This is because
		   Apple dfont container is a container of SFNT's.  So each SFNT is a
		   non-TTC, but the index is more than zero. */
	case CFF_TAG:		/*All the non-collection tags */
	case TRUE_TAG:
	case TYP1_TAG:
	case TRUETYPE_TAG:
		return &ot_fnt_file->u.fnt_face;
	case TTC_TAG:
		return ttc_hdr_get_face(&ot_fnt_file->u.ttc_hdr, i);
	default:
		return NULL;
	}
}

static struct tbl_rec *ot_fnt_face_get_tbl(struct ot_fnt_face *ot_fnt_face,
					   unsigned i)
{
	/*XXX:check is useless in known code paths */
	if (!ot_fnt_face)
		return NULL;

	if (i >= ot_fnt_face->tbls_n)
		return NULL;	/*XXX:original code use a "null" object */
	return &ot_fnt_face->tbls[i];
}

static hb_bool_t ot_fnt_face_find_tbl_idx(struct ot_fnt_face *ot_fnt_face,
					  hb_tag_t tag, unsigned *tbl_idx)
{
	unsigned cnt;
	unsigned i;

	/*XXX:check is useless in known code paths */
	if (!ot_fnt_face)
		return FALSE;

	cnt = ot_fnt_face->tbls_n;
	for (i = 0; i < cnt; ++i) {
		uint32_t tbl_tag;

		tbl_tag = be32toh(ot_fnt_face->tbls[i].tag);
		if (tag == tbl_tag) {
			if (tbl_idx)
				*tbl_idx = i;
			return TRUE;
		}
	}
	if (tbl_idx)
		*tbl_idx = IDX_NOT_FOUND;
	return FALSE;
}

struct tbl_rec *ot_fnt_face_get_tbl_by_tag(struct ot_fnt_face *ot_fnt_face,
					   hb_tag_t tag)
{
	unsigned tbl_idx;

	if (!ot_fnt_face)
		return NULL;

	ot_fnt_face_find_tbl_idx(ot_fnt_face, tag, &tbl_idx);
	return ot_fnt_face_get_tbl(ot_fnt_face, tbl_idx);
}