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

#include "empack.h"



#define USAGE                                                          \
"empack_cli [OPTIONS] <file | msgpack hex>\r\n"                        \
"    file: File to read binary Msgpack data from, \"-\" for stdin\r\n" \
"    msgpack hex: Hex string of Msgpack data\r\n"                      \
"\r\n"                                                                 \
"OPTIONS\r\n"                                                          \
"    -h/--help: Print this message\r\n"



static int
char_to_nibble(char c, uint8_t *nibble)
{
    if ((c >= '0') && (c <= '9')) {
        (*nibble) = c - '0';
    } else if ((c >= 'a') && (c <= 'f')) {
        (*nibble) = c - 'a' + 0x0a;
    } else if ((c >= 'A') && (c <= 'F')) {
        (*nibble) = c - 'A' + 0x0a;
    } else {
        return (-1);
    }

    return (0);
}

static void
print_func(const char *buf, uint32_t buflen, void *arg)
{
    printf("%.*s", buflen, buf);
}



int
main(int argc, char **argv)
{
    empack_t empack;
    uint8_t arena[0x4000];
    struct stat file_stat;
    uint8_t *input = NULL;
    size_t input_len = 0;
    size_t input_bufsz = 0;
    uint32_t chars_printed = 0;

    if (argc != 2) {
        fprintf(stderr, USAGE);
        return (-1);
    }

    if ((!strcmp(argv[1], "-h")) || (!strcmp(argv[1], "--help"))) {
        printf(USAGE);
        return (0);
    }

    if (!strcmp(argv[1], "-")) {
        /* read bytes from stdin */
        while (1) {
            size_t read;

            input_bufsz += 1024;
            input = realloc(input, input_bufsz);

            read = fread(&input[input_len], 1, input_bufsz, stdin);
            if (read == 0) {
                break;
            }

            input_len += read;
        }
    } else if (stat(argv[1], &file_stat) == 0) {
        /* read bytes from a file */
        FILE *fd = fopen(argv[1], "r");
        if (fd == NULL) {
            fprintf(stderr, "Failed to open file \"%s\"\r\n", argv[1]);
            return (-1);
        }

        input_bufsz = file_stat.st_size;
        input = malloc(input_bufsz);
        input_len = fread(input, 1, input_bufsz, fd);
        fclose(fd);

        if (input_len != input_bufsz) {
            fprintf(stderr, "Failed to read file \"%s\"\r\n", argv[1]);
            return (-1);
        }
    } else {
        /* interpret argument as hex data */
        size_t arg_sz = strlen(argv[1]);
        if ((arg_sz % 2) != 0) {
            fprintf(stderr, "Invalid hex data - odd number of characters\r\n");
            return (-1);
        }

        input_bufsz = arg_sz / 2;
        input = malloc(input_bufsz);
        if (input == NULL) {
            fprintf(stderr, "Failed to allocate appropriate resources\r\n");
            return (-1);
        }

        for (size_t i = 0; i < arg_sz; i += 2) {
            uint8_t hi;
            uint8_t lo;

            if (char_to_nibble(argv[1][i], &hi) ||
                char_to_nibble(argv[1][i+1], &lo)) {
                fprintf(stderr, "Invalid hex byte at offset %u\r\n", (uint32_t)(i / 2));
                free(input);
                return (-1);
            }

            input[input_len] = (hi << 4) | lo;
            input_len++;
        }
    }

    empack_init(&empack, arena, sizeof(arena));

    if (empack_parse(&empack, input, input_len)) {
        fprintf(stderr, "Parsing error\r\n");
        free(input);
        return (-1);
    }

    chars_printed = empack_print(&empack, print_func, NULL, "  ");
    printf("\r\n-- Stats --\r\n"
           "Characters Printed: %u\r\n"
           "Arena Memory Used:  %u/%uB (%u%%)\r\n"
           "-----------\r\n",
           chars_printed,
           empack.arena_used,
           empack.arena_sz,
           (empack.arena_used * 100) / empack.arena_sz);

    free(input);
    return (0);
}