/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

#include "utils/agtype_ext.h"

/* define the type and size of the agt_header */
#define AGT_HEADER_TYPE uint32
#define AGT_HEADER_SIZE sizeof(AGT_HEADER_TYPE)

static void ag_deserialize_composite(char *base, enum agtype_value_type type,
                                     agtype_value *result);

static short ag_serialize_header(StringInfo buffer, uint32 type)
{
    short padlen;
    int offset;

    padlen = pad_buffer_to_int(buffer);
    offset = reserve_from_buffer(buffer, AGT_HEADER_SIZE);
    *((AGT_HEADER_TYPE *)(buffer->data + offset)) = type;

    return padlen;
}

/*
 * Function serializes the data into the buffer provided.
 * Returns false if the type is not defined. Otherwise, true.
 */
bool ag_serialize_extended_type(StringInfo buffer, agtentry *agtentry,
                                agtype_value *scalar_val)
{
    short padlen;
    int numlen;
    int offset;

    switch (scalar_val->type)
    {
    case AGTV_INTEGER:
        padlen = ag_serialize_header(buffer, AGT_HEADER_INTEGER);

        /* copy in the int_value data */
        numlen = sizeof(int64);
        offset = reserve_from_buffer(buffer, numlen);
        *((int64 *)(buffer->data + offset)) = scalar_val->val.int_value;

        *agtentry = AGTENTRY_IS_AGTYPE | (padlen + numlen + AGT_HEADER_SIZE);
        break;

    case AGTV_FLOAT:
        padlen = ag_serialize_header(buffer, AGT_HEADER_FLOAT);

        /* copy in the float_value data */
        numlen = sizeof(scalar_val->val.float_value);
        offset = reserve_from_buffer(buffer, numlen);
        *((float8 *)(buffer->data + offset)) = scalar_val->val.float_value;

        *agtentry = AGTENTRY_IS_AGTYPE | (padlen + numlen + AGT_HEADER_SIZE);
        break;

    case AGTV_VERTEX:
    {
        uint32 object_ae = 0;

        padlen = ag_serialize_header(buffer, AGT_HEADER_VERTEX);
        convert_extended_object(buffer, &object_ae, scalar_val);

        /*
         * Make sure that the end of the buffer is padded to the next offset and
         * add this padding to the length of the buffer used. This ensures that
         * everything stays aligned and eliminates errors caused by compounded
         * offsets in the deserialization routines.
         */
        object_ae += pad_buffer_to_int(buffer);

        *agtentry = AGTENTRY_IS_AGTYPE |
                    (padlen + (AGTENTRY_OFFLENMASK & (int)object_ae) + AGT_HEADER_SIZE);
        break;
    }

    case AGTV_EDGE:
    {
        uint32 object_ae = 0;

        padlen = ag_serialize_header(buffer, AGT_HEADER_EDGE);
        convert_extended_object(buffer, &object_ae, scalar_val);

        /*
         * Make sure that the end of the buffer is padded to the next offset and
         * add this padding to the length of the buffer used. This ensures that
         * everything stays aligned and eliminates errors caused by compounded
         * offsets in the deserialization routines.
         */
        object_ae += pad_buffer_to_int(buffer);

        *agtentry = AGTENTRY_IS_AGTYPE |
                    (padlen + (AGTENTRY_OFFLENMASK & (int)object_ae) + AGT_HEADER_SIZE);
        break;
    }

    case AGTV_PATH:
    {
        uint32 object_ae = 0;

        padlen = ag_serialize_header(buffer, AGT_HEADER_PATH);
        convert_extended_array(buffer, &object_ae, scalar_val);

        /*
         * Make sure that the end of the buffer is padded to the next offset and
         * add this padding to the length of the buffer used. This ensures that
         * everything stays aligned and eliminates errors caused by compounded
         * offsets in the deserialization routines.
         */
        object_ae += pad_buffer_to_int(buffer);

        *agtentry = AGTENTRY_IS_AGTYPE |
                    (padlen + (AGTENTRY_OFFLENMASK & (int)object_ae) + AGT_HEADER_SIZE);
        break;
    }

    default:
        return false;
    }
    return true;
}

/*
 * Function deserializes the data from the buffer pointed to by base_addr.
 * NOTE: This function writes to the error log and exits for any UNKNOWN
 * AGT_HEADER type.
 */
void ag_deserialize_extended_type(char *base_addr, uint32 offset,
                                  agtype_value *result)
{
    char *base = base_addr + INTALIGN(offset);
    AGT_HEADER_TYPE agt_header = *((AGT_HEADER_TYPE *)base);

    switch (agt_header)
    {
    case AGT_HEADER_INTEGER:
        result->type = AGTV_INTEGER;
        result->val.int_value = *((int64 *)(base + AGT_HEADER_SIZE));
        break;

    case AGT_HEADER_FLOAT:
        result->type = AGTV_FLOAT;
        result->val.float_value = *((float8 *)(base + AGT_HEADER_SIZE));
        break;

    case AGT_HEADER_VERTEX:
        ag_deserialize_composite(base, AGTV_VERTEX, result);
        break;

    case AGT_HEADER_EDGE:
        ag_deserialize_composite(base, AGTV_EDGE, result);
        break;

    case AGT_HEADER_PATH:
        ag_deserialize_composite(base, AGTV_PATH, result);
        break;

    default:
        ereport(ERROR, (errmsg("Invalid AGT header value: 0x%08x", agt_header)));
    }
}

/*
 * Deserializes a composite type.
 */
static void ag_deserialize_composite(char *base, enum agtype_value_type type,
                                     agtype_value *result)
{
    agtype_iterator *it = NULL;
    agtype_iterator_token tok;
    agtype_parse_state *parse_state = NULL;
    agtype_value *r = NULL;
    agtype_value *parsed_agtype_value = NULL;
    /* offset container by the extended type header */
    char *container_base = base + AGT_HEADER_SIZE;

    r = palloc(sizeof(agtype_value));

    it = agtype_iterator_init((agtype_container *)container_base);
    while ((tok = agtype_iterator_next(&it, r, true)) != WAGT_DONE)
    {
        parsed_agtype_value = push_agtype_value(
            &parse_state, tok, tok < WAGT_BEGIN_ARRAY ? r : NULL);
    }

    result->type = type;
    result->val = parsed_agtype_value->val;
}
