/*-
 * Copyright (c) 2003, 2004 Lev Walkin <vlm@lionet.info>. All rights reserved.
 * Redistribution and modifications are permitted subject to BSD license.
 */
#include <asn_internal.h>
#include <BMPString.h>
#include <UTF8String.h>
#include <assert.h>

/*
 * BMPString basic type description.
 */
static ber_tlv_tag_t asn_DEF_BMPString_tags[] = {
	(ASN_TAG_CLASS_UNIVERSAL | (30 << 2)),	/* [UNIVERSAL 30] IMPLICIT ...*/
	(ASN_TAG_CLASS_UNIVERSAL | (4 << 2))	/* ... OCTET STRING */
};
asn_TYPE_descriptor_t asn_DEF_BMPString = {
	"BMPString",
	"BMPString",
	OCTET_STRING_free,          /* Implemented in terms of OCTET STRING */
	BMPString_print,
	asn_generic_no_constraint,  /* No constraint by default */
	OCTET_STRING_decode_ber,
	OCTET_STRING_encode_der,
	BMPString_decode_xer,		/* Convert from UTF-8 */
	BMPString_encode_xer,		/* Convert to UTF-8 */
	0, /* Use generic outmost tag fetcher */
	asn_DEF_BMPString_tags,
	sizeof(asn_DEF_BMPString_tags)
	  / sizeof(asn_DEF_BMPString_tags[0]) - 1,
	asn_DEF_BMPString_tags,
	sizeof(asn_DEF_BMPString_tags)
	  / sizeof(asn_DEF_BMPString_tags[0]),
	0, 0,	/* No members */
	0	/* No specifics */
};

/*
 * BMPString specific contents printer.
 */
static ssize_t
BMPString__dump(const BMPString_t *st,
		asn_app_consume_bytes_f *cb, void *app_key) {
	char scratch[128];			/* Scratchpad buffer */
	char *p = scratch;
	ssize_t wrote = 0;
	uint8_t *ch;
	uint8_t *end;

	ch = st->buf;
	end = (st->buf + st->size);
	for(end--; ch < end; ch += 2) {
		uint16_t wc = (ch[0] << 8) | ch[1];	/* 2 bytes */
		if(sizeof(scratch) - (p - scratch) < 3) {
			wrote += p - scratch;
			if(cb(scratch, p - scratch, app_key) < 0)
				return -1;
			p = scratch;
		}
		if(wc < 0x80) {
			*p++ = (char)wc;
		} else if(wc < 0x800) {
			*p++ = 0xc0 | ((wc >> 6));
			*p++ = 0x80 | ((wc & 0x3f));
		} else {
			*p++ = 0xe0 | ((wc >> 12));
			*p++ = 0x80 | ((wc >> 6) & 0x3f);
			*p++ = 0x80 | ((wc & 0x3f));
		}
	}

	wrote += p - scratch;
	if(cb(scratch, p - scratch, app_key) < 0)
		return -1;

	return wrote;
}

asn_dec_rval_t
BMPString_decode_xer(asn_codec_ctx_t *opt_codec_ctx,
	asn_TYPE_descriptor_t *td, void **sptr,
		const char *opt_mname, void *buf_ptr, size_t size) {
	asn_dec_rval_t rc;

	rc = OCTET_STRING_decode_xer_utf8(opt_codec_ctx, td, sptr, opt_mname,
		buf_ptr, size);
	if(rc.code == RC_OK) {
		/*
		 * Now we have a whole string in UTF-8 format.
		 * Convert it into UCS-2.
		 */
		uint32_t *wcs;
		size_t wcs_len;
		UTF8String_t *st;

		assert(*sptr);
		st = (UTF8String_t *)*sptr;
		assert(st->buf);
		wcs_len = UTF8String_to_wcs(st, 0, 0);

		wcs = (uint32_t *)MALLOC(4 * (wcs_len + 1));
		if(wcs == 0 || UTF8String_to_wcs(st, wcs, wcs_len) != wcs_len) {
			rc.code = RC_FAIL;
			rc.consumed = 0;
			return rc;
		} else {
			wcs[wcs_len] = 0;	/* nul-terminate */
		}

		if(1) {
			/* Swap byte order and trim encoding to 2 bytes */
			uint32_t *wc = wcs;
			uint32_t *wc_end = wcs + wcs_len + 1;
			uint16_t *dstwc = (uint16_t *)wcs;
			for(; wc < wc_end; wc++, dstwc++) {
				uint32_t wch = *wc;
				if(wch > 0xffff) {
					FREEMEM(wcs);
					rc.code = RC_FAIL;
					rc.consumed = 0;
					return rc;
				}
				*((uint8_t *)dstwc + 0) = wch >> 8;
				*((uint8_t *)dstwc + 1) = wch;
			}
			dstwc = (uint16_t *)REALLOC(wcs, 2 * (wcs_len + 1));
			if(!dstwc) {
				FREEMEM(wcs);
				rc.code = RC_FAIL;
				rc.consumed = 0;
				return rc;
			} else {
				wcs = (uint32_t *)dstwc;
			}
		}

		FREEMEM(st->buf);
		st->buf = (uint8_t *)wcs;
		st->size = 2 * wcs_len;
	}
	return rc;
}

asn_enc_rval_t
BMPString_encode_xer(asn_TYPE_descriptor_t *td, void *sptr,
	int ilevel, enum xer_encoder_flags_e flags,
		asn_app_consume_bytes_f *cb, void *app_key) {
	const BMPString_t *st = (const BMPString_t *)sptr;
	asn_enc_rval_t er;

	(void)ilevel;
	(void)flags;

	if(!st || !st->buf)
		_ASN_ENCODE_FAILED;

	er.encoded = BMPString__dump(st, cb, app_key);
	if(er.encoded < 0) _ASN_ENCODE_FAILED;

	return er;
}

int
BMPString_print(asn_TYPE_descriptor_t *td, const void *sptr, int ilevel,
		asn_app_consume_bytes_f *cb, void *app_key) {
	const BMPString_t *st = (const BMPString_t *)sptr;

	(void)td;	/* Unused argument */
	(void)ilevel;	/* Unused argument */

	if(!st || !st->buf)
		return (cb("<absent>", 8, app_key) < 0) ? -1 : 0;

	if(BMPString__dump(st, cb, app_key) < 0)
		return -1;

	return 0;
}