#include <ctype.h>
#include <fcntl.h>
#include <signal.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#if defined(__linux__) && !defined(__ANDROID__)
// https://github.com/karelzak/util-linux/blob/master/misc-utils/kill.c
const char *sys_signame[NSIG] = {
    "zero", "HUP",   "INT",  "QUIT", "ILL",  "TRAP", "ABRT", "UNUSED", "FPE",
    "KILL", "USR1",  "SEGV", "USR2", "PIPE", "ALRM", "TERM", "STKFLT", "CHLD",
    "CONT", "STOP",  "TSTP", "TTIN", "TTOU", "URG",  "XCPU", "XFSZ",   "VTALRM",
    "PROF", "WINCH", "IO",   "PWR",  "SYS",  NULL};
#endif

#if defined(_WIN32) || defined(__CYGWIN__)
#include <windows.h>
// https://github.com/mirror/newlib-cygwin/blob/master/winsup/cygwin/strsig.cc
#undef NSIG
#define NSIG 33
const char *sys_signame[NSIG] = {
    "zero", "HUP",   "INT",  "QUIT", "ILL",  "TRAP", "IOT",  "EMT",  "FPE",
    "KILL", "BUS",   "SEGV", "SYS",  "PIPE", "ALRM", "TERM", "URG",  "STOP",
    "TSTP", "CONT",  "CHLD", "TTIN", "TTOU", "IO",   "XCPU", "XFSZ", "VTALRM",
    "PROF", "WINCH", "PWR",  "USR1", "USR2", NULL};
#endif

void *xmalloc(size_t size) {
  if (size == 0) return NULL;
  void *p = malloc(size);
  if (!p) abort();
  return p;
}

void *xrealloc(void *p, size_t size) {
  if ((size == 0) && (p == NULL)) return NULL;
  p = realloc(p, size);
  if (!p) abort();
  return p;
}

char *uppercase(char *str) {
  int i = 0;
  do {
    str[i] = (char)toupper(str[i]);
  } while (str[i++] != '\0');
  return str;
}

bool endswith(const char *str, const char *suffix) {
  size_t str_len = strlen(str);
  size_t suffix_len = strlen(suffix);
  return str_len > suffix_len && !strcmp(str + (str_len - suffix_len), suffix);
}

int get_sig_name(int sig, char *buf, size_t len) {
  int n =
      snprintf(buf, len, "SIG%s", sig < NSIG ? sys_signame[sig] : "unknown");
  uppercase(buf);
  return n;
}

int get_sig(const char *sig_name) {
  for (int sig = 1; sig < NSIG; sig++) {
    const char *name = sys_signame[sig];
    if (name != NULL && (strcasecmp(name, sig_name) == 0 ||
                         strcasecmp(name, sig_name + 3) == 0))
      return sig;
  }
  return atoi(sig_name);
}

int open_uri(char *uri) {
#ifdef __APPLE__
  char command[256];
  sprintf(command, "open %s > /dev/null 2>&1", uri);
  return system(command);
#elif defined(_WIN32) || defined(__CYGWIN__)
  return ShellExecute(0, 0, uri, 0, 0, SW_SHOW) > (HINSTANCE) 32 ? 0 : 1;
#else
  // check if X server is running
  if (system("xset -q > /dev/null 2>&1")) return 1;
  char command[256];
  sprintf(command, "xdg-open %s > /dev/null 2>&1", uri);
  return system(command);
#endif
}

// https://github.com/darkk/redsocks/blob/master/base64.c
char *base64_encode(const unsigned char *buffer, size_t length) {
  static const char b64[] =
      "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
  char *ret, *dst;
  unsigned i_bits = 0;
  int i_shift = 0;
  int bytes_remaining = (int)length;

  ret = dst = xmalloc((size_t)(((length + 2) / 3 * 4) + 1));
  while (bytes_remaining) {
    i_bits = (i_bits << 8) + *buffer++;
    bytes_remaining--;
    i_shift += 8;

    do {
      *dst++ = b64[(i_bits << 6 >> i_shift) & 0x3f];
      i_shift -= 6;
    } while (i_shift > 6 || (bytes_remaining == 0 && i_shift > 0));
  }
  while ((dst - ret) & 3) *dst++ = '=';
  *dst = '\0';

  return ret;
}

#ifdef _WIN32
char *strsep(char **sp, char *sep) {
  char *p, *s;
  if (sp == NULL || *sp == NULL || **sp == '\0') return(NULL);
  s = *sp;
  p = s + strcspn(s, sep);
  if (*p != '\0') *p++ = '\0';
  *sp = p;
  return(s);
}

// https://github.com/git/git/blob/306ee63a703ad67c54ba1209dc11dd9ea500dc1f/compat/mingw.c#L1111
const char *quote_arg(const char *arg) {
	int len = 0, n = 0;
	int force_quotes = 0;
	char *q, *d;
	const char *p = arg;
	if (!*p) force_quotes = 1;
	while (*p) {
		if (isspace(*p) || *p == '*' || *p == '?' || *p == '{' || *p == '\'')
			force_quotes = 1;
		else if (*p == '"')
			n++;
		else if (*p == '\\') {
			int count = 0;
			while (*p == '\\') {
				count++;
				p++;
				len++;
			}
			if (*p == '"' || !*p)
				n += count*2 + 1;
			continue;
		}
		len++;
		p++;
	}
	if (!force_quotes && n == 0)
		return arg;

	d = q = xmalloc(len + n + 3);
	*d++ = '"';
	while (*arg) {
		if (*arg == '"')
			*d++ = '\\';
		else if (*arg == '\\') {
			int count = 0;
			while (*arg == '\\') {
				count++;
				*d++ = *arg++;
			}
			if (*arg == '"' || !*arg) {
				while (count-- > 0)
					*d++ = '\\';
				if (!*arg)
					break;
				*d++ = '\\';
			}
		}
		*d++ = *arg++;
	}
	*d++ = '"';
	*d++ = '\0';
	return q;
}

void print_error(char *func) { 
    LPVOID buffer;
    DWORD dw = GetLastError(); 
    FormatMessage(
        FORMAT_MESSAGE_ALLOCATE_BUFFER | 
        FORMAT_MESSAGE_FROM_SYSTEM |
        FORMAT_MESSAGE_IGNORE_INSERTS,
        NULL,
        dw,
        MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
        (LPTSTR) &buffer,
        0, NULL );
    wprintf(L"== %s failed with error %d: %s", func, dw, buffer);
    LocalFree(buffer);
}
#endif