#include "commit.h"
#include <errno.h>
#include <string.h>
#include <zstd.h>

static void nfl_commit_default(FILE *f, nfl_header_t *header, nfl_entry_t *store,
                               uint32_t store_size) {
    uint32_t written;
    header->raw_size = store_size;

    // Write header
    written = fwrite(header, 1, sizeof(nfl_header_t), f);
    ERR(written != sizeof(nfl_header_t), strerror(errno));

    // Write store
    written = fwrite(store, 1, store_size, f);
    ERR(written != store_size, strerror(errno));
}

static void nfl_commit_lz4(FILE *f, nfl_header_t *header, nfl_entry_t *store,
                           uint32_t store_size) {
    /* TODO */
}

static void nfl_commit_zstd(FILE *f, nfl_header_t *header, nfl_entry_t *store,
                            uint32_t store_size) {
    size_t const bufsize = ZSTD_compressBound(store_size);
    void *buf;

    ERR(!(buf = malloc(bufsize)), "zstd: cannot malloc");
    size_t const csize = ZSTD_compress(buf, bufsize, store, store_size, 1);
    if (ZSTD_isError(csize))
        FATAL("zstd: %s \n", ZSTD_getErrorName(csize));

    nfl_commit_default(f, header, buf, csize);
    free(buf);
}

void nfl_commit_worker(nfl_header_t *header, nfl_entry_t *store,
                       enum nfl_compression_t compression_opt,
                       bool truncate,
                       const char *filename) {
    FILE *f;
    const char *mode = truncate ? "wb" : "ab";

    debug("Comm worker #%u: commit to file %s\n", header->id, filename);
    ERR((f = fopen(filename, mode)) == NULL, strerror(errno));

    // commit store
    uint32_t store_size = sizeof(nfl_entry_t) * header->max_n_entries;
    switch (compression_opt) {
    case COMPRESS_NONE:
        debug("Comm worker #%u: commit without compression\n", header->id)
            nfl_commit_default(f, header, store, store_size);
        break;
    case COMPRESS_LZ4:
        debug("Comm worker #%u: commit with compression algorithm: lz4",
              header->id) nfl_commit_lz4(f, header, store, store_size);
        break;
    case COMPRESS_ZSTD:
        debug("Comm worker #%u: commit with compression algorithm: zstd",
              header->id) nfl_commit_zstd(f, header, store, store_size);
        break;
    // Must not reach here ...
    default:
        FATAL("Unknown compression option detected");
    }

    // Do fsync ?
    fclose(f);
}