/*
 * Author Jerry Lundström <jerry@dns-oarc.net>
 * Copyright (c) 2019-2023, OARC, Inc.
 * All rights reserved.
 *
 * This file is part of the dnswire library.
 *
 * dnswire library is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * dnswire library 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 Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with dnswire library.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <dnswire/dnswire.h>
#include <dnswire/encoder.h>
#include <dnswire/decoder.h>

#include <stdlib.h>

#ifndef __dnswire_h_writer
#define __dnswire_h_writer 1

enum dnswire_writer_state {
    dnswire_writer_encoding_ready  = 0,
    dnswire_writer_writing_ready   = 1,
    dnswire_writer_reading_accept  = 2,
    dnswire_writer_decoding_accept = 3,
    dnswire_writer_encoding        = 4,
    dnswire_writer_writing         = 5,
    dnswire_writer_stopping        = 6,
    dnswire_writer_encoding_stop   = 7,
    dnswire_writer_writing_stop    = 8,
    dnswire_writer_reading_finish  = 9,
    dnswire_writer_decoding_finish = 10,
    dnswire_writer_done            = 11,
};
extern const char* const dnswire_writer_state_string[];

/*
 * Attributes:
 * - size: The current size of the buffer
 * - inc: How much the buffer will be increased by if more spare is needed
 * - max: The maximum size the buffer is allowed to have
 * - at: Where in the buffer we are encoding to (end of data)
 * - left: How much data that is still left in the buffer before `at`
 */
struct dnswire_writer {
    enum dnswire_writer_state state;

    struct dnswire_encoder encoder;
    uint8_t*               buf;
    size_t                 size, inc, max, at, left, popped;

    struct dnswire_decoder decoder;
    uint8_t*               read_buf;
    size_t                 read_size, read_inc, read_max, read_at, read_left, read_pushed;

    bool bidirectional;
};

enum dnswire_result dnswire_writer_init(struct dnswire_writer*);

#define dnswire_writer_popped(w) (w).popped
#define dnswire_writer_set_dnstap(w, d) (w).encoder.dnstap = d
#define dnswire_writer_destroy(w) \
    free((w).buf);                \
    free((w).read_buf)

enum dnswire_result dnswire_writer_set_bidirectional(struct dnswire_writer*, bool);
enum dnswire_result dnswire_writer_set_bufsize(struct dnswire_writer*, size_t);
enum dnswire_result dnswire_writer_set_bufinc(struct dnswire_writer*, size_t);
enum dnswire_result dnswire_writer_set_bufmax(struct dnswire_writer*, size_t);

enum dnswire_result               dnswire_writer_pop(struct dnswire_writer*, uint8_t*, size_t, uint8_t*, size_t*);
enum dnswire_result               dnswire_writer_write(struct dnswire_writer*, int);
static inline enum dnswire_result dnswire_writer_fwrite(struct dnswire_writer* handle, FILE* fp)
{
    return dnswire_writer_write(handle, fileno(fp));
}
enum dnswire_result dnswire_writer_stop(struct dnswire_writer*);

#endif