#include <stdlib.h>
#include <stdio.h>
#include <stdarg.h>
#include <errno.h>
#include <string.h>
#include <ctype.h>

#include "common.h"

static void _generic_err_vargs (int use_stderr, const char *func, int perr, const char *fmt, va_list va) {
    FILE *stream = use_stderr ? stderr : stdin;

    if (func)
        fprintf(stream, "%s: ", func);
    
    vfprintf(stream, fmt, va);
    
    if (perr)
        fprintf(stream, ": %s\n", strerror(errno));

    fprintf(stream, "\n");
}

void _generic_err (int use_stderr, const char *func, int perr, const char *fmt, ...) {
    va_list va;

    va_start(va, fmt);
    _generic_err_vargs(use_stderr, func, perr, fmt, va);
    va_end(va);
}

void _generic_err_exit (int use_stderr, const char *func, int perr, const char *fmt, ...) {
    va_list va;

    va_start(va, fmt);
    _generic_err_vargs(use_stderr, func, perr, fmt, va);
    va_end(va);
      
    exit(EXIT_FAILURE);
}

int parse_hostport (char *hostport, char **host, char **port) {
    char *c;

    char brace = 0, colon = 0;

    *host = *port = NULL;

    for (c = hostport; *c != '\0'; c++) {
        if (isspace(*c))
            continue;

        switch (*c) {
            case '[':
                if (c > hostport) {
                    error("parse_hostport: %c must be first char, if any: %s", *c, hostport);
                    return -1;
                }
                
                brace = *c;
                break;

            case ']':
                if (!brace) {
                    error("parse_hostport: %c without matching brace: %s", *c, hostport);
                    return -1;
                }

                if (!*host) {
                    error("parse_hostport: empty hostname: %s", hostport);
                    return -1;
                }

                brace = 0;
                break;
            
            case ':':
                if (brace) {
                    // colons inside braces are left as-is
                    continue;
                }

                if (!*host) {
                    error("parse_hostport: colon before hostname: %s", hostport);
                    return -1;
                }

                if (*port) {
                    error("parse_hostport: colon after port: %s", hostport);
                    return -1;
                }

                if (colon) {
                    error("parse_hostport: too many colons: %s", hostport);
                    return -1;
                };

                // finished parsing the host part, move on to the port part
                colon = ':';
                *c = '\0';
                break;

            default:
                if (!*host) {
                    // first char of the host
                    *host = c;

                } else if (colon && !*port) {
                    // first char of the port
                    *port = c;

                } // else a part of either, don't care about it

                break;
        }
    }

    if (!*host) {
        error("parse_hostport: missing hostname: %s", hostport);
        return -1;
    }

    if (brace) {
        error("parse_hostport: missing close-brace for %c: %s", brace, hostport);
        return -1;
    }

    if (colon && !*port) {
        error("parse_hostport: missing port: %s", hostport);
        return -1;
    }

    return 0;
}