#import <Cocoa/Cocoa.h>

#import "objc_workflow.h"


/* appInfo

 // NSLog(@"%@", appInfo);
  NSDictionary: {
  NSApplicationBundleIdentifier = "org.gnu.Emacs";
  NSApplicationName = Emacs;
  NSApplicationPath = "/Applications/Notes.app";
  NSApplicationProcessIdentifier = 40831;
  NSApplicationProcessSerialNumberHigh = 0;
  NSApplicationProcessSerialNumberLow = 4195328;
  NSWorkspaceApplicationKey = "<NSRunningApplication: 0x7fe3c0e08b30 (org.gnu.Emacs - 40831)>";
  }
*/


/* ProcessSerialNumber
https: //developer.apple.com/legacy/library/documentation/Carbon/Reference/Process_Manager/index.html#//apple_ref/doc/c_ref/ProcessSerialNumber

struct ProcessSerialNumber { unsigned long highLongOfPSN; unsigned long lowLongOfPSN; }; 
typedef  struct ProcessSerialNumber  ProcessSerialNumber; 
typedef  ProcessSerialNumber*        ProcessSerialNumberPtr;
*/


/* CGEventPostToPSN
https://developer.apple.com/library/mac/documentation/Carbon/Reference/QuartzEventServicesRef/index.html

void CGEventPostToPSN ( void *processSerialNumber, CGEventRef event );
*/


// private helpers

NSString* fromUTF8(const char* s) {
 return [[NSString alloc]
          initWithCString:s encoding:NSUTF8StringEncoding];
}

const char* toUTF8(NSString* s) {
  return [s cStringUsingEncoding:NSUTF8StringEncoding];
}

void printPSN(ProcessSerialNumber psn) {
  NSLog(@"ProcessSerialNumber: {%d,%d}", psn.highLongOfPSN, psn.lowLongOfPSN);
}

void printApplications() {
  NSLog(@"launchedApplications: %@", [[NSWorkspace sharedWorkspace] launchedApplications]);
}

// I think that uninitialized ProcessSerialNumber is always {0,0}.
// I *hope* it doesn't crash CGEventPostToPSN (hasn't yet) and that no application has both fields coinciding.
ProcessSerialNumber nullProcessSerialNumber = {0,0};

// returns pseudo-Just a pointer to a heap-allocated structure, must be freed.
// pseudo-Nothing if no application by that path is running
// TODO or pointer to a pointer to a structure (without a pointer can be null)?
// from full path or from name
ProcessSerialNumber* getApplicationPSN(const char* s) {
  // no maybe type...
  ProcessSerialNumber* psn = (ProcessSerialNumber*)malloc(sizeof(ProcessSerialNumber));
  *psn = nullProcessSerialNumber; // http://stackoverflow.com/questions/9127246/copy-struct-to-struct-in-c

  // existentially-quantified arrays...
  NSArray* appInfos = [[NSWorkspace sharedWorkspace] launchedApplications];  // runningApplications

  for (NSDictionary* appInfo in appInfos) {
    if (0 == strcmp(s, toUTF8([appInfo objectForKey:@"NSApplicationPath"]))) {
      psn->highLongOfPSN = [[appInfo objectForKey:@"NSApplicationProcessSerialNumberHigh"] unsignedIntValue];
      psn->lowLongOfPSN  = [[appInfo objectForKey:@"NSApplicationProcessSerialNumberLow"]  unsignedIntValue];
      return psn;
    }
  }

  for (NSDictionary* appInfo in appInfos) {
    if (0 == strcmp(s, toUTF8([appInfo objectForKey:@"NSApplicationName"]))) {
      psn->highLongOfPSN = [[appInfo objectForKey:@"NSApplicationProcessSerialNumberHigh"] unsignedIntValue];
      psn->lowLongOfPSN  = [[appInfo objectForKey:@"NSApplicationProcessSerialNumberLow"]  unsignedIntValue];
      return psn;
    }
  }

  return psn;
}

ProcessSerialNumber currentApplicationPSN() {
  NSDictionary *appInfo = [[NSWorkspace sharedWorkspace] activeApplication];  // frontmostApplication
  ProcessSerialNumber psn;
  psn.highLongOfPSN = [[appInfo objectForKey:@"NSApplicationProcessSerialNumberHigh"] unsignedIntValue];
  psn.lowLongOfPSN  = [[appInfo objectForKey:@"NSApplicationProcessSerialNumberLow"]  unsignedIntValue];
  return psn;
}



// public

const char* currentApplicationPath() {
  return toUTF8([[[NSWorkspace sharedWorkspace]
   activeApplication] // frontmostApplication
    objectForKey:@"NSApplicationPath"]);
}

// can be full path (e.g. "/Applications/Work.app"), or just the name (e.g. "Work")
void openApplication(const char* s) {
  [[NSWorkspace sharedWorkspace] launchApplication:fromUTF8(s)];
}

// simulates a key press from the keyboard. works in pop-ups like Alfred. 
void pressKey(CGEventFlags modifiers, CGKeyCode key) {
  // NSLog(@"pressKey");         // debug
    CGEventSourceRef source = CGEventSourceCreate(kCGEventSourceStateHIDSystemState); // kCGEventSourceStateCombinedSessionState

    // events to press a key
    CGEventRef event1 = CGEventCreateKeyboardEvent(source, key, true);  // key down
    CGEventRef event2 = CGEventCreateKeyboardEvent(source, key, false); // key up

    // add modifiers to event
    CGEventSetFlags(event1, modifiers);
    CGEventSetFlags(event2, modifiers);

    // send a keyboard event (a quartz event) "globally"
    CGEventPost(kCGHIDEventTap, event1); // kCGSessionEventTap
    CGEventPost(kCGHIDEventTap, event2); // kCGSessionEventTap

 // free memory
 CFRelease(event1);
 CFRelease(event2);
 CFRelease(source);
}

// may take up to 15s (!) when the keypresses sent to and after besides the one that's running the server
void pressKeyToCurrentApplication(CGEventFlags modifiers, CGKeyCode key) {
  pressKeyTo(modifiers, key, currentApplicationPSN());
}

// send a keypress to a specific process/application
void pressKeyTo(CGEventFlags modifiers, CGKeyCode key, ProcessSerialNumber psn) {

    // events to press a key
    CGEventRef event1 = CGEventCreateKeyboardEvent(NULL, key, true);  // key down
    CGEventRef event2 = CGEventCreateKeyboardEvent(NULL, key, false); // key up

    // add modifiers to event
    CGEventSetFlags(event1, modifiers);
    CGEventSetFlags(event2, modifiers);

    // send keyboard event to application process (a quartz event)
    CGEventPostToPSN(&psn, event1);
    CGEventPostToPSN(&psn, event2);

 // free memory
 CFRelease(event1);
 CFRelease(event2);
 // psn is a struct, that's been passed by value
}

const char* getClipboard() {
 return [[[NSPasteboard generalPasteboard]
   stringForType:NSStringPboardType]
    cStringUsingEncoding:NSUTF8StringEncoding];
}

void setClipboard(const char* contents) {
 [[NSPasteboard generalPasteboard] clearContents];
 [[NSPasteboard generalPasteboard] setString:fromUTF8(contents) forType:NSStringPboardType];
}

void openURL(const char* url) {
 [[NSWorkspace sharedWorkspace]
   openURL:[NSURL URLWithString: fromUTF8(url)]];
}


// CGEventRef CGEventCreateMouseEvent ( CGEventSourceRef source, CGEventType mouseType, CGPoint mouseCursorPosition, CGMouseButton mouseButton );
// http://stackoverflow.com/questions/1117065/cocoa-getting-the-current-mouse-position-on-the-screen
void clickMouse(CGEventFlags modifiers, CGMouseButton mouseButton, CGEventType mouseDown, CGEventType mouseUp, UInt32 numClicks) {

  CGPoint currentPosition = CGEventGetLocation(CGEventCreate(NULL));

  CGEventRef eventDown = CGEventCreateMouseEvent(NULL, kCGEventOtherMouseDown, currentPosition, mouseButton);
  CGEventRef eventUp   = CGEventCreateMouseEvent(NULL, kCGEventOtherMouseUp,   currentPosition, mouseButton);

// hold down modifiers
CGEventSetFlags(eventDown, modifiers);
CGEventSetFlags(eventUp,   modifiers);

// click numClicks times. each click must say which it is (1st, 2nd, 3rd, etc)

for (int nthClick=1; nthClick<=numClicks; nthClick++) {
  CGEventSetIntegerValueField(eventDown, kCGMouseEventClickState, nthClick);
  CGEventSetIntegerValueField(eventUp,   kCGMouseEventClickState, nthClick);
  CGEventPost(kCGHIDEventTap, eventDown);  
  CGEventPost(kCGHIDEventTap, eventUp);  
 }

// free memory
CFRelease(eventDown); 
CFRelease(eventUp);

}