/* Simple Raw HID functions for Linux - for use with Teensy RawHID example
 * http://www.pjrc.com/teensy/rawhid.html
 * Copyright (c) 2009 PJRC.COM, LLC
 *
 *  rawhid_open - open 1 or more devices
 *  rawhid_recv - receive a packet
 *  rawhid_send - send a packet
 *  rawhid_close - close a device
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * 
 * The above description, website URL and copyright notice and this permission
 * notice shall be included in all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 *
 * Version 1.0: Initial Release
 */

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <unistd.h>
#include <IOKit/IOKitLib.h>
#include <IOKit/hid/IOHIDLib.h>

#include "hid.h"

#define BUFFER_SIZE 64

#define printf(...) // comment this out to get lots of info printed


// a list of all opened HID devices, so the caller can
// simply refer to them by number
typedef struct hid_struct hid_t;
typedef struct buffer_struct buffer_t;
static hid_t *first_hid = NULL;
static hid_t *last_hid = NULL;
struct hid_struct {
	IOHIDDeviceRef ref;
	int open;
	uint8_t buffer[BUFFER_SIZE];
	buffer_t *first_buffer;
	buffer_t *last_buffer;
	struct hid_struct *prev;
	struct hid_struct *next;
};
struct buffer_struct {
	struct buffer_struct *next;
	uint32_t len;
	uint8_t buf[BUFFER_SIZE];
};

// private functions, not intended to be used from outside this file
static void add_hid(hid_t *);
static hid_t * get_hid(int);
static void free_all_hid(void);
static void hid_close(hid_t *);
static void attach_callback(void *, IOReturn, void *, IOHIDDeviceRef);
static void detach_callback(void *, IOReturn, void *hid_mgr, IOHIDDeviceRef dev);
static void timeout_callback(CFRunLoopTimerRef, void *);
static void input_callback(void *, IOReturn, void *, IOHIDReportType,
	 uint32_t, uint8_t *, CFIndex);



//  rawhid_recv - receive a packet
//    Inputs:
//	num = device to receive from (zero based)
//	buf = buffer to receive packet
//	len = buffer's size
//	timeout = time to wait, in milliseconds
//    Output:
//	number of bytes received, or -1 on error
//
int rawhid_recv(int num, void *buf, int len, int timeout)
{
	hid_t *hid;
	buffer_t *b;
	CFRunLoopTimerRef timer=NULL;
	CFRunLoopTimerContext context;
	int ret=0, timeout_occurred=0;

	if (len < 1) return 0;
	hid = get_hid(num);
	if (!hid || !hid->open) return -1;
	if ((b = hid->first_buffer) != NULL) {
		if (len > b->len) len = b->len;
		memcpy(buf, b->buf, len);
		hid->first_buffer = b->next;
		free(b);
		return len;
	}
	memset(&context, 0, sizeof(context));
	context.info = &timeout_occurred;
	timer = CFRunLoopTimerCreate(NULL, CFAbsoluteTimeGetCurrent() +
		(double)timeout / 1000.0, 0, 0, 0, timeout_callback, &context);
	CFRunLoopAddTimer(CFRunLoopGetCurrent(), timer, kCFRunLoopDefaultMode);
	while (1) {
		CFRunLoopRun();
		if ((b = hid->first_buffer) != NULL) {
			if (len > b->len) len = b->len;
			memcpy(buf, b->buf, len);
			hid->first_buffer = b->next;
			free(b);
			ret = len;
			break;
		}
		if (!hid->open) {
			printf("rawhid_recv, device not open\n");
			ret = -1;
			break;
		}
		if (timeout_occurred) break;
	}
	CFRunLoopTimerInvalidate(timer);
	CFRelease(timer);
	return ret;
}

static void input_callback(void *context, IOReturn ret, void *sender,
	IOHIDReportType type, uint32_t id, uint8_t *data, CFIndex len)
{
	buffer_t *n;
	hid_t *hid;

	printf("input_callback\n");
	if (ret != kIOReturnSuccess || len < 1) return;
	hid = context;
	if (!hid || hid->ref != sender) return;
	n = (buffer_t *)malloc(sizeof(buffer_t));
	if (!n) return;
	if (len > BUFFER_SIZE) len = BUFFER_SIZE;
	memcpy(n->buf, data, len);
	n->len = len;
	n->next = NULL;
	if (!hid->first_buffer || !hid->last_buffer) {
		hid->first_buffer = hid->last_buffer = n;
	} else {
		hid->last_buffer->next = n;
		hid->last_buffer = n;
	}
	CFRunLoopStop(CFRunLoopGetCurrent());
}

static void timeout_callback(CFRunLoopTimerRef timer, void *info)
{
	printf("timeout_callback\n");
	*(int *)info = 1;
	CFRunLoopStop(CFRunLoopGetCurrent());
}


void output_callback(void *context, IOReturn ret, void *sender,
	IOHIDReportType type, uint32_t id, uint8_t *data, CFIndex len)
{
	printf("output_callback, r=%d\n", ret);
	if (ret == kIOReturnSuccess) {
		*(int *)context = len;
	} else {
		// timeout if not success?
		*(int *)context = 0;
	}
	CFRunLoopStop(CFRunLoopGetCurrent());
}


//  rawhid_send - send a packet
//    Inputs:
//	num = device to transmit to (zero based)
//	buf = buffer containing packet to send
//	len = number of bytes to transmit
//	timeout = time to wait, in milliseconds
//    Output:
//	number of bytes sent, or -1 on error
//
int rawhid_send(int num, void *buf, int len, int timeout)
{
	hid_t *hid;
	int result=-100;

	hid = get_hid(num);
	if (!hid || !hid->open) return -1;
#if 1
	#warning "Send timeout not implemented on MACOSX"
	IOReturn ret = IOHIDDeviceSetReport(hid->ref, kIOHIDReportTypeOutput, 0, buf, len);
	result = (ret == kIOReturnSuccess) ? len : -1;
#endif
#if 0
	// No matter what I tried this never actually sends an output
	// report and output_callback never gets called.  Why??
	// Did I miss something?  This is exactly the same params as
	// the sync call that works.  Is it an Apple bug?
	// (submitted to Apple on 22-sep-2009, problem ID 7245050)
	//
	IOHIDDeviceScheduleWithRunLoop(hid->ref, CFRunLoopGetCurrent(), kCFRunLoopDefaultMode);
	// should already be scheduled with run loop by attach_callback,
	// sadly this doesn't make any difference either way

	// could this be related?
	// http://lists.apple.com/archives/usb/2008/Aug/msg00021.html
	//
	IOHIDDeviceSetReportWithCallback(hid->ref, kIOHIDReportTypeOutput,
		0, buf, len, (double)timeout / 1000.0, output_callback, &result);
	while (1) {
		printf("enter run loop (send)\n");
		CFRunLoopRun();
		printf("leave run loop (send)\n");
		if (result > -100) break;
		if (!hid->open) {
			result = -1;
			break;
		}
	}
#endif
	return result;
}


//  rawhid_open - open 1 or more devices
//
//    Inputs:
//	max = maximum number of devices to open
//	vid = Vendor ID, or -1 if any
//	pid = Product ID, or -1 if any
//	usage_page = top level usage page, or -1 if any
//	usage = top level usage number, or -1 if any
//    Output:
//	actual number of devices opened
//
int rawhid_open(int max, int vid, int pid, int usage_page, int usage)
{
        static IOHIDManagerRef hid_manager=NULL;
        CFMutableDictionaryRef dict;
        CFNumberRef num;
        IOReturn ret;
	hid_t *p;
	int count=0;

	if (first_hid) free_all_hid();
	printf("rawhid_open, max=%d\n", max);
	if (max < 1) return 0;
        // Start the HID Manager
        // http://developer.apple.com/technotes/tn2007/tn2187.html
	if (!hid_manager) {
        	hid_manager = IOHIDManagerCreate(kCFAllocatorDefault, kIOHIDOptionsTypeNone);
        	if (hid_manager == NULL || CFGetTypeID(hid_manager) != IOHIDManagerGetTypeID()) {
                	if (hid_manager) CFRelease(hid_manager);
                	return 0;
        	}
	}
	if (vid > 0 || pid > 0 || usage_page > 0 || usage > 0) {
		// Tell the HID Manager what type of devices we want
        	dict = CFDictionaryCreateMutable(kCFAllocatorDefault, 0,
                	&kCFTypeDictionaryKeyCallBacks, &kCFTypeDictionaryValueCallBacks);
        	if (!dict) return 0;
		if (vid > 0) {
			num = CFNumberCreate(kCFAllocatorDefault, kCFNumberIntType, &vid);
			CFDictionarySetValue(dict, CFSTR(kIOHIDVendorIDKey), num);
			CFRelease(num);
		}
		if (pid > 0) {
			num = CFNumberCreate(kCFAllocatorDefault, kCFNumberIntType, &pid);
			CFDictionarySetValue(dict, CFSTR(kIOHIDProductIDKey), num);
			CFRelease(num);
		}
		if (usage_page > 0) {
			num = CFNumberCreate(kCFAllocatorDefault, kCFNumberIntType, &usage_page);
			CFDictionarySetValue(dict, CFSTR(kIOHIDPrimaryUsagePageKey), num);
			CFRelease(num);
		}
		if (usage > 0) {
			num = CFNumberCreate(kCFAllocatorDefault, kCFNumberIntType, &usage);
			CFDictionarySetValue(dict, CFSTR(kIOHIDPrimaryUsageKey), num);
			CFRelease(num);
		}
        	IOHIDManagerSetDeviceMatching(hid_manager, dict);
        	CFRelease(dict);
	} else {
        	IOHIDManagerSetDeviceMatching(hid_manager, NULL);
	}
	// set up a callbacks for device attach & detach
        IOHIDManagerScheduleWithRunLoop(hid_manager, CFRunLoopGetCurrent(),
		kCFRunLoopDefaultMode);
        IOHIDManagerRegisterDeviceMatchingCallback(hid_manager, attach_callback, NULL);
	IOHIDManagerRegisterDeviceRemovalCallback(hid_manager, detach_callback, NULL);
        ret = IOHIDManagerOpen(hid_manager, kIOHIDOptionsTypeNone);
        if (ret != kIOReturnSuccess) {
                IOHIDManagerUnscheduleFromRunLoop(hid_manager,
                        CFRunLoopGetCurrent(), kCFRunLoopDefaultMode);
                CFRelease(hid_manager);
                return 0;
        }
	printf("run loop\n");
	// let it do the callback for all devices
	while (CFRunLoopRunInMode(kCFRunLoopDefaultMode, 0, true) == kCFRunLoopRunHandledSource) ;
	// count up how many were added by the callback
	for (p = first_hid; p; p = p->next) count++;
	return count;
}


//  rawhid_close - close a device
//
//    Inputs:
//	num = device to close (zero based)
//    Output
//	(nothing)
//
void rawhid_close(int num)
{
	hid_t *hid;

	hid = get_hid(num);
	if (!hid || !hid->open) return;
	hid_close(hid);
	hid->open = 0;
}


static void add_hid(hid_t *h)
{
	if (!first_hid || !last_hid) {
		first_hid = last_hid = h;
		h->next = h->prev = NULL;
		return;
	}
	last_hid->next = h;
	h->prev = last_hid;
	h->next = NULL;
	last_hid = h;
}


static hid_t * get_hid(int num)
{
	hid_t *p;
	for (p = first_hid; p && num > 0; p = p->next, num--) ;
	return p;
}


static void free_all_hid(void)
{
	hid_t *p, *q;

	for (p = first_hid; p; p = p->next) {
		hid_close(p);
	}
	p = first_hid;
	while (p) {
		q = p;
		p = p->next;
		free(q);
	}
	first_hid = last_hid = NULL;
}


static void hid_close(hid_t *hid)
{
	if (!hid || !hid->open || !hid->ref) return;
	IOHIDDeviceUnscheduleFromRunLoop(hid->ref, CFRunLoopGetCurrent( ), kCFRunLoopDefaultMode);
	IOHIDDeviceClose(hid->ref, kIOHIDOptionsTypeNone);
	hid->ref = NULL;
}

static void detach_callback(void *context, IOReturn r, void *hid_mgr, IOHIDDeviceRef dev)
{
	hid_t *p;

	printf("detach callback\n");
	for (p = first_hid; p; p = p->next) {
		if (p->ref == dev) {
			p->open = 0;
			CFRunLoopStop(CFRunLoopGetCurrent());
			return;
		}
	}
}


static void attach_callback(void *context, IOReturn r, void *hid_mgr, IOHIDDeviceRef dev)
{
	struct hid_struct *h;

	printf("attach callback\n");
	if (IOHIDDeviceOpen(dev, kIOHIDOptionsTypeNone) != kIOReturnSuccess) return;
	h = (hid_t *)malloc(sizeof(hid_t));
	if (!h) return;
	memset(h, 0, sizeof(hid_t));
	IOHIDDeviceScheduleWithRunLoop(dev, CFRunLoopGetCurrent(), kCFRunLoopDefaultMode);
	IOHIDDeviceRegisterInputReportCallback(dev, h->buffer, sizeof(h->buffer),
		input_callback, h);
	h->ref = dev;
	h->open = 1;
	add_hid(h);
}