#include "rtlf.h"

#include "cassert"

static int write_header_block(FILE* file, __uint32_t car_id, const char* track_name) {
    RTLF_Header_Fixed header;
    const size_t track_len = strlen(track_name);

    memcpy(header.magic_number, RTLF_MAGIC_NUMBER, 4);
    header.version = RTLF_VERSION;
    header.car_id = car_id;
    header.track_name_len = static_cast<__uint32_t>(track_len);

    assert(fwrite(&header, sizeof(RTLF_Header_Fixed), 1, file) == 1);
    assert(fwrite(track_name, 1, track_len, file) == track_len);

    return 0;
}

RTLF_Context* rtlf_open_write(const char* filename, __uint32_t car_id, const char* track_name) {
    FILE* file = fopen(filename, "wb");

    assert(file != nullptr);

    write_header_block(file, car_id, track_name);
    auto* ctx = static_cast<RTLF_Context *>(malloc(sizeof(RTLF_Context)));
    if (!ctx) {
        fclose(file);
        return nullptr;
    }

    ctx->file = file;
    ctx->track_name = strdup(track_name);
    return ctx;
}

int rtlf_write_record(RTLF_Context* ctx, const RTLF_Data_Record* record) {
    if (!ctx || !ctx->file) return -1;
    if (fwrite(record, RTLF_RECORD_SIZE, 1, ctx->file) != 1) return -1;
    return 0;
}

void rtlf_close(RTLF_Context* ctx) {
    if (!ctx) return;
    if (ctx->file) fclose(ctx->file);
    if (ctx->track_name) free(ctx->track_name);
    free(ctx);
}