#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdint.h>
#include <stdbool.h>
#include <unistd.h>
#include <getopt.h>
#include <sys/stat.h>

static const char* str_usage = "Usage: %s [--nologo / -n] [--kernel / -k] [--unpack / -u] <infile> [<outfile>]\n";

static void error_load_infile() {
    printf("Error: cannot load input file\n");
    exit(1);
}

static void error_malloc_failed() {
    printf("Error: memory allocation failed\n");
    exit(1);
}

int main(int argc, char *argv[])
{
    bool flag_nologo = false;
    bool flag_kernel = false;
    bool flag_unpack = false;
    char *infile_name = NULL;
    char *outfile_name = NULL;
    int opt;
    static struct option long_options[] = {
        {"nologo", no_argument, NULL, 'n'},
        {"kernel", no_argument, NULL, 'k'},
        {"unpack", no_argument, NULL, 'u'},
        {0, 0, 0, 0} // must be zeros here
    };
    while ((opt = getopt_long(argc, argv, "nku", long_options, NULL)) != -1) {
        switch (opt) {
            case 'n':
                flag_nologo = true;
                break;
            case 'k':
                flag_kernel = true;
                break;
            case 'u':
                flag_unpack = true;
                break;
            default: // '?'
                fprintf(stderr, str_usage, argv[0]);
                return 1;
        }
    }
    // check for required infile
    if (optind >= argc) {
        printf("Error: Input file is required.\n");
        printf(str_usage, argv[0]);
        return 1;
    }
    infile_name = argv[optind];

    // optional outfile
    if (optind + 1 < argc) {
        outfile_name = argv[optind + 1];
        optind++;
    }

    // printf("argc = %d, optind = %d\n", argc - 1, optind);
    if (argc - 1 > optind) {
        printf("Error: too many arguments\n");
        printf(str_usage, argv[0]);
        return 1;
    }

    // for debug: print parsed options and args
    printf("nologo: %s\n", flag_nologo ? "true" : "false");
    printf("kernel: %s\n", flag_kernel ? "true" : "false");
    printf("unpack: %s\n", flag_unpack ? "true" : "false");
    printf("infile: %s\n", infile_name);
    printf("outfile: %s\n", outfile_name ? outfile_name : "Not specified");
    printf("\n");

    if (!flag_nologo) {
        printf("KPackC - Kolibri Packer in C\nUses LZMA v4.32 compression library\n\n");
    }

    struct stat64 statbuf;
    int res_stat = stat64(infile_name, &statbuf);
    if (res_stat == -1) {
        error_load_infile();
    }
    // printf("statbuf.st_size = %lld\n", statbuf.st_size);

    if (statbuf.st_size == 0 || statbuf.st_size >= 4294967296LL) {
        printf("Error: input file must be non zero and less than 4G\n");
        return 1;
    }
    unsigned infile_size = (unsigned int)statbuf.st_size;
    printf("infile_size = %u\n", infile_size);

    FILE *infile_handle = fopen(infile_name, "rb");
    if (!infile_handle) {
        error_load_infile();
    }

    unsigned char *infile_buf = malloc(infile_size);
    if (infile_buf == NULL) {
        error_malloc_failed();
    }
    size_t bytes_read = fread(infile_buf, 1, infile_size, infile_handle);
    if (bytes_read != infile_size) {
        error_load_infile();
    }
    fclose(infile_handle);

    // calculate maximum size of the output:
    unsigned bufsize = infile_size*9/8 + 0x400; // should be enough for header
    printf("bufsize = 0x%x\n", bufsize);
    unsigned char *buf = malloc(2*bufsize); // allocate memory for two copies of maximum output
    if (buf == NULL) {
        error_malloc_failed();
    }

    // TODO ...
    // https://git.kolibrios.org/KolibriOS/kolibrios/src/commit/293e1d195a14d01a0f8812a954ff1449048f6209/programs/other/kpack/kerpack_linux/kpack64.asm#L236

    return 0;
}