#import <Cocoa/Cocoa.h>
#import <libproc.h>
#import <string.h>
#import <stdlib.h>
#import <stdio.h>

bool activate_window_of_id(long wid) {
  bool success = false;
  const CGWindowLevel kScreensaverWindowLevel = CGWindowLevelForKey(kCGScreenSaverWindowLevelKey);
  CFArrayRef windowArray = CGWindowListCopyWindowInfo(kCGWindowListOptionOnScreenOnly | kCGWindowListExcludeDesktopElements, kCGNullWindowID);
  CFIndex windowCount = 0;
  if ((windowCount = CFArrayGetCount(windowArray))) {
    for (CFIndex i = 0; i < windowCount; i++) {
      NSDictionary *windowInfoDictionary = (__bridge NSDictionary *)((CFDictionaryRef)CFArrayGetValueAtIndex(windowArray, i));
      NSNumber *ownerPID = (NSNumber *)(windowInfoDictionary[(id)kCGWindowOwnerPID]);
      NSNumber *level = (NSNumber *)(windowInfoDictionary[(id)kCGWindowLayer]);
      if (level.integerValue < kScreensaverWindowLevel) {
        NSNumber *windowID = windowInfoDictionary[(id)kCGWindowNumber];
        if (wid == windowID.integerValue) {
          CFIndex appCount = [[[NSWorkspace sharedWorkspace] runningApplications] count];
          for (CFIndex j = 0; j < appCount; j++) {
            if (ownerPID.integerValue == [[[[NSWorkspace sharedWorkspace] runningApplications] objectAtIndex:j] processIdentifier]) {
              NSRunningApplication *appWithPID = [[[NSWorkspace sharedWorkspace] runningApplications] objectAtIndex:j];
              [appWithPID activateWithOptions:NSApplicationActivateAllWindows | NSApplicationActivateIgnoringOtherApps];
              char buf[PROC_PIDPATHINFO_MAXSIZE];
              proc_pidpath(ownerPID.integerValue, buf, sizeof(buf));
              NSString *buffer = [NSString stringWithUTF8String:buf];
              long location = [buffer rangeOfString:@".app/Contents/MacOS/" options:NSBackwardsSearch].location;
              NSString *path = (location != NSNotFound) ? [buffer substringWithRange:NSMakeRange(0, location)] : buffer;
              NSString *app = [@" of application \\\"" stringByAppendingString:[path lastPathComponent]];
              NSString *index = [@"set index of window id " stringByAppendingString:[windowID stringValue]];
              NSString *execScript = [[index stringByAppendingString:app] stringByAppendingString:@"\\\" to 1"];
              char *pointer = NULL;
              size_t buffer_size = 0;
              NSMutableArray *array = [[NSMutableArray alloc] init];
              FILE *file = popen([[[@"osascript -e \"" stringByAppendingString:execScript] stringByAppendingString:@"\""] UTF8String], "r");
              while (getline(&pointer, &buffer_size, file) != -1)
                [array addObject:[NSString stringWithUTF8String:pointer]];
              char *error = (char *)[[array componentsJoinedByString:@""] UTF8String];
              if (strlen(error) > 0 && error[strlen(error) - 1] == '\n')
                error[strlen(error) - 1] = '\0';
              if ([[NSString stringWithUTF8String:error] isEqualToString:@""])
                success = true;
              [array release];
              free(pointer);
              pclose(file);
              break;
            }
          }
        }
      }
    }
  }

  CFRelease(windowArray);
  return success;
}