/*-
 * 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 <BIT_STRING.h>
#include <asn_internal.h>

/*
 * BIT STRING basic type description.
 */
static const ber_tlv_tag_t asn_DEF_BIT_STRING_tags[] = {
	(ASN_TAG_CLASS_UNIVERSAL | (3 << 2))
};
asn_OCTET_STRING_specifics_t asn_SPC_BIT_STRING_specs = {
	sizeof(BIT_STRING_t),
	offsetof(BIT_STRING_t, _asn_ctx),
	ASN_OSUBV_BIT
};
asn_TYPE_operation_t asn_OP_BIT_STRING = {
	OCTET_STRING_free,         /* Implemented in terms of OCTET STRING */
	BIT_STRING_print,
	BIT_STRING_compare,
	OCTET_STRING_decode_ber,   /* Implemented in terms of OCTET STRING */
	OCTET_STRING_encode_der,   /* Implemented in terms of OCTET STRING */
	OCTET_STRING_decode_xer_binary,
	BIT_STRING_encode_xer,
#ifdef	ASN_DISABLE_OER_SUPPORT
	0,
	0,
#else
	BIT_STRING_decode_oer,
	BIT_STRING_encode_oer,
#endif  /* ASN_DISABLE_OER_SUPPORT */
#ifdef	ASN_DISABLE_PER_SUPPORT
	0,
	0,
#else
	OCTET_STRING_decode_uper,	/* Unaligned PER decoder */
	OCTET_STRING_encode_uper,	/* Unaligned PER encoder */
#endif  /* ASN_DISABLE_PER_SUPPORT */
	BIT_STRING_random_fill,
	0	/* Use generic outmost tag fetcher */
};
asn_TYPE_descriptor_t asn_DEF_BIT_STRING = {
	"BIT STRING",
	"BIT_STRING",
	&asn_OP_BIT_STRING,
	asn_DEF_BIT_STRING_tags,
	sizeof(asn_DEF_BIT_STRING_tags)
	  / sizeof(asn_DEF_BIT_STRING_tags[0]),
	asn_DEF_BIT_STRING_tags,	/* Same as above */
	sizeof(asn_DEF_BIT_STRING_tags)
	  / sizeof(asn_DEF_BIT_STRING_tags[0]),
	{ 0, 0, BIT_STRING_constraint },
	0, 0,	/* No members */
	&asn_SPC_BIT_STRING_specs
};

/*
 * BIT STRING generic constraint.
 */
int
BIT_STRING_constraint(asn_TYPE_descriptor_t *td, const void *sptr,
		asn_app_constraint_failed_f *ctfailcb, void *app_key) {
	const BIT_STRING_t *st = (const BIT_STRING_t *)sptr;

	if(st && st->buf) {
		if((st->size == 0 && st->bits_unused)
		|| st->bits_unused < 0 || st->bits_unused > 7) {
			ASN__CTFAIL(app_key, td, sptr,
				"%s: invalid padding byte (%s:%d)",
				td->name, __FILE__, __LINE__);
			return -1;
		}
	} else {
		ASN__CTFAIL(app_key, td, sptr,
			"%s: value not given (%s:%d)",
			td->name, __FILE__, __LINE__);
		return -1;
	}

	return 0;
}

static const char *_bit_pattern[16] = {
	"0000", "0001", "0010", "0011", "0100", "0101", "0110", "0111",
	"1000", "1001", "1010", "1011", "1100", "1101", "1110", "1111"
};

asn_enc_rval_t
BIT_STRING_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) {
	asn_enc_rval_t er;
	char scratch[128];
	char *p = scratch;
	char *scend = scratch + (sizeof(scratch) - 10);
	const BIT_STRING_t *st = (const BIT_STRING_t *)sptr;
	int xcan = (flags & XER_F_CANONICAL);
	uint8_t *buf;
	uint8_t *end;

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

	er.encoded = 0;

	buf = st->buf;
	end = buf + st->size - 1;	/* Last byte is special */

	/*
	 * Binary dump
	 */
	for(; buf < end; buf++) {
		int v = *buf;
		int nline = xcan?0:(((buf - st->buf) % 8) == 0);
		if(p >= scend || nline) {
			ASN__CALLBACK(scratch, p - scratch);
			p = scratch;
			if(nline) ASN__TEXT_INDENT(1, ilevel);
		}
		memcpy(p + 0, _bit_pattern[v >> 4], 4);
		memcpy(p + 4, _bit_pattern[v & 0x0f], 4);
		p += 8;
	}

	if(!xcan && ((buf - st->buf) % 8) == 0)
		ASN__TEXT_INDENT(1, ilevel);
	ASN__CALLBACK(scratch, p - scratch);
	p = scratch;

	if(buf == end) {
		int v = *buf;
		int ubits = st->bits_unused;
		int i;
		for(i = 7; i >= ubits; i--)
			*p++ = (v & (1 << i)) ? 0x31 : 0x30;
		ASN__CALLBACK(scratch, p - scratch);
	}

	if(!xcan) ASN__TEXT_INDENT(1, ilevel - 1);

	ASN__ENCODED_OK(er);
cb_failed:
	ASN__ENCODE_FAILED;
}


/*
 * BIT STRING specific contents printer.
 */
int
BIT_STRING_print(asn_TYPE_descriptor_t *td, const void *sptr, int ilevel,
		asn_app_consume_bytes_f *cb, void *app_key) {
	const char * const h2c = "0123456789ABCDEF";
	char scratch[64];
	const BIT_STRING_t *st = (const BIT_STRING_t *)sptr;
	uint8_t *buf;
	uint8_t *end;
	char *p = scratch;

	(void)td;	/* Unused argument */

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

	ilevel++;
	buf = st->buf;
	end = buf + st->size;

	/*
	 * Hexadecimal dump.
	 */
	for(; buf < end; buf++) {
		if((buf - st->buf) % 16 == 0 && (st->size > 16)
				&& buf != st->buf) {
			_i_INDENT(1);
			/* Dump the string */
			if(cb(scratch, p - scratch, app_key) < 0) return -1;
			p = scratch;
		}
		*p++ = h2c[*buf >> 4];
		*p++ = h2c[*buf & 0x0F];
		*p++ = 0x20;
	}

	if(p > scratch) {
		p--;	/* Eat the tailing space */

		if((st->size > 16)) {
			_i_INDENT(1);
		}

		/* Dump the incomplete 16-bytes row */
		if(cb(scratch, p - scratch, app_key) < 0)
			return -1;
	}

	return 0;
}

/*
 * Lexicographically compare the common prefix of both strings,
 * and if it is the same return -1 for the smallest string.
 */
int
BIT_STRING_compare(const asn_TYPE_descriptor_t *td, const void *aptr,
                   const void *bptr) {
    const BIT_STRING_t *a = aptr;
    const BIT_STRING_t *b = bptr;

    (void)td;

    if(a && b) {
        size_t common_prefix_size = a->size <= b->size ? a->size : b->size;
        int ret = memcmp(a->buf, b->buf, common_prefix_size);
        if(ret == 0) {
            /* Figure out which string with equal prefixes is longer. */
            if(a->size < b->size) {
                return -1;
            } else if(a->size > b->size) {
                return 1;
            } else {
                /* Figure out how many unused bits */
                if(a->bits_unused < b->bits_unused) {
                    return -1;
                } else if(a->bits_unused > b->bits_unused) {
                    return 1;
                } else {
                    return 0;
                }
            }
        } else {
            return ret;
        }
    } else if(!a && !b) {
        return 0;
    } else if(!a) {
        return -1;
    } else {
        return 1;
    }
}


asn_random_fill_result_t
BIT_STRING_random_fill(const asn_TYPE_descriptor_t *td, void **sptr,
                       const asn_encoding_constraints_t *constraints,
                       size_t max_length) {
    asn_OCTET_STRING_specifics_t *specs =
        td->specifics ? (asn_OCTET_STRING_specifics_t *)td->specifics
                      : &asn_SPC_BIT_STRING_specs;
    asn_random_fill_result_t result_ok = {ARFILL_OK, 1};
    asn_random_fill_result_t result_failed = {ARFILL_FAILED, 0};
    asn_random_fill_result_t result_skipped = {ARFILL_SKIPPED, 0};
    static unsigned lengths[] = {0,     1,     2,     3,     4,     8,
                                 126,   127,   128,   16383, 16384, 16385,
                                 65534, 65535, 65536, 65537};
    uint8_t *buf;
    uint8_t *bend;
    uint8_t *b;
    size_t rnd_bits, rnd_len;
    BIT_STRING_t *st;

    if(max_length == 0) return result_skipped;

    switch(specs->subvariant) {
    case ASN_OSUBV_ANY:
        return result_failed;
    case ASN_OSUBV_BIT:
        break;
    default:
        break;
    }

    /* Figure out how far we should go */
    rnd_bits = lengths[asn_random_between(
        0, sizeof(lengths) / sizeof(lengths[0]) - 1)];
    if(constraints->per_constraints) {
        const asn_per_constraint_t *pc =
            &td->encoding_constraints.per_constraints->size;
        if(pc->flags & APC_CONSTRAINED) {
            if(max_length < (size_t)pc->lower_bound) {
                return result_skipped;
            }
            rnd_bits = asn_random_between(pc->lower_bound, pc->upper_bound);
        } else {
            rnd_bits = asn_random_between(0, max_length - 1);
        }
    } else if(rnd_bits >= max_length) {
        rnd_bits = asn_random_between(0, max_length - 1);
    }

    rnd_len = (rnd_bits + 7) / 8;
    buf = CALLOC(1, rnd_len + 1);
    if(!buf) return result_failed;

    bend = &buf[rnd_len];

    for(b = buf; b < bend; b++) {
        *(uint8_t *)b = asn_random_between(0, 255);
    }

    if(*sptr) {
        st = *sptr;
        FREEMEM(st->buf);
    } else {
        st = (BIT_STRING_t *)(*sptr = CALLOC(1, specs->struct_size));
        if(!st) {
            FREEMEM(buf);
            return result_failed;
        }
    }

    st->buf = buf;
    st->size = rnd_len;
    st->bits_unused = (8 - (rnd_bits & 0x7)) & 0x7;
    if(st->bits_unused) {
        assert(st->size > 0);
        st->buf[st->size-1] &= 0xff << st->bits_unused;
    }

    result_ok.length = st->size;
    return result_ok;
}