#include<stdlib.h>
#include<stdio.h>
#include<string.h>
#include<unistd.h>
#include<signal.h>
#ifndef NO_X
#include<X11/Xlib.h>
#endif
#ifdef __OpenBSD__
#define SIGPLUS			SIGUSR1+1
#define SIGMINUS		SIGUSR1-1
#else
#define SIGPLUS			SIGRTMIN
#define SIGMINUS		SIGRTMIN
#endif
#define LENGTH(X)               (sizeof(X) / sizeof (X[0]))
#define CMDLENGTH		50
#define MIN( a, b ) ( ( a < b) ? a : b )
#define STATUSLENGTH (LENGTH(blocks) * CMDLENGTH + 1)

typedef struct {
  char* icon;
  char* command;
  unsigned int interval;
  unsigned int signal;
} Block;
#ifndef __OpenBSD__
void dummysighandler(int num);
#endif
void sighandler(int num);
void getcmds(int time);
void getsigcmds(unsigned int signal);
void setupsignals();
void sighandler(int signum);
int getstatus(char *str, char *last);
void statusloop();
void termhandler();
void pstdout();
#ifndef NO_X
void setroot();
static void (*writestatus) () = setroot;
static int setupX();
static Display *dpy;
static int screen;
static Window root;
#else
static void (*writestatus) () = pstdout;
#endif


#include "blocks.h"

static char statusbar[LENGTH(blocks)][CMDLENGTH] = {0};
static char statusstr[2][STATUSLENGTH];
static int statusContinue = 1;
static int returnStatus = 0;

//opens process *cmd and stores output in *output
void getcmd(const Block *block, char *output)
{
  strcpy(output, block->icon);
  FILE *cmdf = popen(block->command, "r");
  if (!cmdf)
    return;
  int i = strlen(block->icon);
  fgets(output+i, CMDLENGTH-i-delimLen, cmdf);
  i = strlen(output);
  if (i == 0) {
    //return if block and command output are both empty
    pclose(cmdf);
    return;
  }
  if (delim[0] != '\0') {
    //only chop off newline if one is present at the end
    i = output[i-1] == '\n' ? i-1 : i;
    strncpy(output+i, delim, delimLen); 
  }
  else
    output[i++] = '\0';
  pclose(cmdf);
}

void getcmds(int time)
{
  const Block* current;
  for (unsigned int i = 0; i < LENGTH(blocks); i++) {
    current = blocks + i;
    if ((current->interval != 0 && time % current->interval == 0) || time == -1)
      getcmd(current,statusbar[i]);
  }
}

void getsigcmds(unsigned int signal)
{
  const Block *current;
  for (unsigned int i = 0; i < LENGTH(blocks); i++) {
    current = blocks + i;
    if (current->signal == signal)
      getcmd(current,statusbar[i]);
  }
}

void setupsignals()
{
#ifndef __OpenBSD__
  /* initialize all real time signals with dummy handler */
  for (int i = SIGRTMIN; i <= SIGRTMAX; i++)
    signal(i, dummysighandler);
#endif

  for (unsigned int i = 0; i < LENGTH(blocks); i++) {
    if (blocks[i].signal > 0)
      signal(SIGMINUS+blocks[i].signal, sighandler);
  }

}

int getstatus(char *str, char *last)
{
  strcpy(last, str);
  str[0] = '\0';
  for (unsigned int i = 0; i < LENGTH(blocks); i++)
    strcat(str, statusbar[i]);
  str[strlen(str)-strlen(delim)] = '\0';
  return strcmp(str, last);//0 if they are the same
}

#ifndef NO_X
void setroot()
{
  if (!getstatus(statusstr[0], statusstr[1]))//Only set root if text has changed.
    return;
  XStoreName(dpy, root, statusstr[0]);
  XFlush(dpy);
}

int setupX()
{
  dpy = XOpenDisplay(NULL);
  if (!dpy) {
    fprintf(stderr, "dwmblocks: Failed to open display\n");
    return 0;
  }
  screen = DefaultScreen(dpy);
  root = RootWindow(dpy, screen);
  return 1;
}
#endif

void pstdout()
{
  if (!getstatus(statusstr[0], statusstr[1]))//Only write out if text has changed.
    return;
  printf("%s\n",statusstr[0]);
  fflush(stdout);
}


void statusloop()
{
  setupsignals();
  int i = 0;
  getcmds(-1);
  while (1) {
    getcmds(i++);
    writestatus();
    if (!statusContinue)
      break;
    sleep(1.0);
  }
}

#ifndef __OpenBSD__
/* this signal handler should do nothing */
void dummysighandler(int signum)
{
  return;
}
#endif

void sighandler(int signum)
{
  getsigcmds(signum-SIGPLUS);
  writestatus();
}

void termhandler()
{
  statusContinue = 0;
}

int main(int argc, char** argv)
{
  for (int i = 0; i < argc; i++) {//Handle command line arguments
    if (!strcmp("-d",argv[i]))
      strncpy(delim, argv[++i], delimLen);
    else if (!strcmp("-p",argv[i]))
      writestatus = pstdout;
  }
#ifndef NO_X
  if (!setupX())
    return 1;
#endif
  delimLen = MIN(delimLen, strlen(delim));
  delim[delimLen++] = '\0';
  signal(SIGTERM, termhandler);
  signal(SIGINT, termhandler);
  statusloop();
#ifndef NO_X
  XCloseDisplay(dpy);
#endif
  return 0;
}
