// enzstd -- .warc.zst compressor
// Copyright (C) 2021-2024 Sergey Matveev <stargrave@stargrave.org>
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, version 3 of the License.
//
// This program 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 General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

#include <inttypes.h>
#include <stdio.h>
#include <stdlib.h>

#include <zstd.h>

#ifdef __FreeBSD__
#include "capsicum.c.in"
#endif // __FreeBSD__

int
main(int argc, char **argv)
{
#ifdef __FreeBSD__
    capsicum_start();
#endif // __FreeBSD__
    ZSTD_CCtx *ctx = ZSTD_createCCtx();
    if (ctx == NULL) {
        fputs("can not initialize ZSTD_createCCtx\n", stderr);
        return EXIT_FAILURE;
    }
    size_t zCode = ZSTD_CCtx_setParameter(ctx, ZSTD_c_checksumFlag, 1);
    if (ZSTD_isError(zCode)) {
        fprintf(stderr, "can not setParameter: %s\n", ZSTD_getErrorName(zCode));
        return EXIT_FAILURE;
    }
    zCode = ZSTD_CCtx_setParameter(ctx, ZSTD_c_compressionLevel, ZSTD_maxCLevel());
    if (ZSTD_isError(zCode)) {
        fprintf(stderr, "can not setParameter: %s\n", ZSTD_getErrorName(zCode));
        return EXIT_FAILURE;
    }

    unsigned char *src = NULL;
    unsigned char *dst = NULL;
    int rc = EXIT_FAILURE;
    size_t srcSize = 8;
    src = malloc(srcSize);
    if (src == NULL) {
        fprintf(stderr, "can not allocate memory: %zu\n", srcSize);
        goto Exit;
    }
    size_t dstSize = 0;
    size_t srcWantSize = 0;
    size_t dstWantSize = 0;
    size_t n = 0;
    for (;;) {
        n = fread(src, 1, 8, stdin);
        if (n < 8) {
            if (feof(stdin)) {
                break;
            }
            perror("can not fread(stdin)");
            goto Exit;
        }
        srcWantSize = ((uint64_t)(src[0]) << 56) | ((uint64_t)(src[1]) << 48) |
                      ((uint64_t)(src[2]) << 40) | ((uint64_t)(src[3]) << 32) |
                      ((uint64_t)(src[4]) << 24) | ((uint64_t)(src[5]) << 16) |
                      ((uint64_t)(src[6]) << 8) | (uint64_t)(src[7]);
        if (srcWantSize > srcSize) {
            free(src);
            srcSize = srcWantSize;
            src = malloc(srcSize);
            if (src == NULL) {
                fprintf(stderr, "can not allocate memory: %zu\n", srcSize);
                goto Exit;
            }
        }
        n = fread(src, 1, srcWantSize, stdin);
        if (n < srcWantSize) {
            fputs("insufficient data fed\n", stderr);
            goto Exit;
        }
        dstWantSize = ZSTD_compressBound(srcWantSize);
        if (dstWantSize > dstSize) {
            free(dst);
            dstSize = dstWantSize;
            dst = malloc(dstSize);
            if (dst == NULL) {
                fprintf(stderr, "can not allocate memory: %zu\n", dstSize);
                goto Exit;
            }
        }
        zCode = ZSTD_compress2(ctx, dst, dstSize, src, srcWantSize);
        if (ZSTD_isError(zCode)) {
            fprintf(stderr, "can not compress: %s\n", ZSTD_getErrorName(zCode));
            goto Exit;
        }
        n = fwrite(dst, 1, zCode, stdout);
        if (n < zCode) {
            perror("can not fwrite(stdout)");
            goto Exit;
        }
    }
    rc = EXIT_SUCCESS;

Exit:
    free(dst);
    free(src);
    ZSTD_freeCCtx(ctx);
    return rc;
}