/*
 * usbkeybrd.c
 *
 * Copyright 2015 Edward V. Emelianov <eddy@sao.ru, edward.emelianoff@gmail.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 * MA 02110-1301, USA.
 */

#include "usbkeybrd.h"
#include "keycodes.h"

#define BUFLEN (1024)
static char sendbuf[BUFLEN];
static char *msg_start = sendbuf, *msg_end = sendbuf;
static const char *buf_end = sendbuf+BUFLEN;

usbd_device *usbd_dev;

const struct usb_device_descriptor dev = {
	.bLength = USB_DT_DEVICE_SIZE,
	.bDescriptorType = USB_DT_DEVICE,
	.bcdUSB = 0x0200,
	.bDeviceClass = 0,
	.bDeviceSubClass = 0,
	.bDeviceProtocol = 0,
	.bMaxPacketSize0 = 64,
// 0x045E 0x005C  - Microsoft Office Keyboard (106/109)
	.idVendor = 0x045E,
	.idProduct = 0x005C,
	.bcdDevice = 0x0200,
	.iManufacturer = 1,
	.iProduct = 2,
	.iSerialNumber = 3,
	.bNumConfigurations = 1,
};

static const uint8_t hid_report_descriptor[] = {
    0x05, 0x01, /* Usage Page (Generic Desktop)             */
    0x09, 0x06, /*		Usage (Keyboard)                    */
    0xA1, 0x01, /*		Collection (Application)            */
//    0x85, 0x02,  /*   Report ID  */
    0x05, 0x07, /*  	Usage (Key codes)                   */
    0x19, 0xE0, /*      Usage Minimum (224)                 */
    0x29, 0xE7, /*      Usage Maximum (231)                 */
    0x15, 0x00, /*      Logical Minimum (0)                 */
    0x25, 0x01, /*      Logical Maximum (1)                 */
    0x75, 0x01, /*      Report Size (1)                     */
    0x95, 0x08, /*      Report Count (8)                    */
    0x81, 0x02, /*      Input (Data, Variable, Absolute)    */
    0x95, 0x01, /*      Report Count (1)                    */
    0x75, 0x08, /*      Report Size (8)                     */
    0x81, 0x01, /*      Input (Constant)    ;5 bit padding  */
    0x95, 0x05, /*      Report Count (5)                    */
    0x75, 0x01, /*      Report Size (1)                     */
    0x05, 0x08, /*      Usage Page (Page# for LEDs)         */
    0x19, 0x01, /*      Usage Minimum (01)                  */
    0x29, 0x05, /*      Usage Maximum (05)                  */
    0x91, 0x02, /*      Output (Data, Variable, Absolute)   */
    0x95, 0x01, /*      Report Count (1)                    */
    0x75, 0x03, /*      Report Size (3)                     */
    0x91, 0x01, /*      Output (Constant)                   */
    0x95, 0x06, /*      Report Count (1)                    */
    0x75, 0x08, /*      Report Size (3)                     */
    0x15, 0x00, /*      Logical Minimum (0)                 */
    0x25, 0x65, /*      Logical Maximum (101)               */
    0x05, 0x07, /*  	Usage (Key codes)                   */
    0x19, 0x00, /*      Usage Minimum (00)                  */
    0x29, 0x65, /*      Usage Maximum (101)                 */
    0x81, 0x00, /*      Input (Data, Array)                 */
    0x09, 0x05, /*      Usage (Vendor Defined)              */
    0x15, 0x00, /*      Logical Minimum (0))                */
    0x26, 0xFF, 0x00, /* Logical Maximum (255))             */
    0x75, 0x08, /*      Report Count (2))                   */
    0x95, 0x02, /*      Report Size (8 bit))                */
    0xB1, 0x02, /*      Feature (Data, Variable, Absolute)  */
    0xC0        /* 		End Collection,End Collection       */
};

static const struct {
	struct usb_hid_descriptor hid_descriptor;
	struct {
		uint8_t bReportDescriptorType;
		uint16_t wDescriptorLength;
	} __attribute__((packed)) hid_report;
} __attribute__((packed)) hid_function = {
	.hid_descriptor = {
		.bLength = sizeof(hid_function),
		.bDescriptorType = USB_DT_HID,
		.bcdHID = 0x0100,
		.bCountryCode = 0,
		.bNumDescriptors = 1,
	},
	.hid_report = {
		.bReportDescriptorType = USB_DT_REPORT,
		.wDescriptorLength = sizeof(hid_report_descriptor),
	},
};

const struct usb_endpoint_descriptor hid_endpoint = {
	.bLength = USB_DT_ENDPOINT_SIZE,
	.bDescriptorType = USB_DT_ENDPOINT,
	.bEndpointAddress = 0x81,
	.bmAttributes = USB_ENDPOINT_ATTR_INTERRUPT,
	.wMaxPacketSize = 8,
	.bInterval = 0x10,
};

const struct usb_interface_descriptor hid_iface = {
	.bLength = USB_DT_INTERFACE_SIZE,
	.bDescriptorType = USB_DT_INTERFACE,
	.bInterfaceNumber = 0,
	.bAlternateSetting = 0,
	.bNumEndpoints = 1,
	.bInterfaceClass = USB_CLASS_HID,
	.bInterfaceSubClass = 1, // boot
	.bInterfaceProtocol = 1, // keyboard
	.iInterface = 0,

	.endpoint = &hid_endpoint,

	.extra = &hid_function,
	.extralen = sizeof(hid_function),
};

const struct usb_interface ifaces[] = {{
	.num_altsetting = 1,
	.altsetting = &hid_iface,
}};

const struct usb_config_descriptor config = {
	.bLength = USB_DT_CONFIGURATION_SIZE,
	.bDescriptorType = USB_DT_CONFIGURATION,
	.wTotalLength = 0,
	.bNumInterfaces = 1,
	.bConfigurationValue = 1,
	.iConfiguration = 0,
	.bmAttributes = 0xC0,
	.bMaxPower = 0x32,

	.interface = ifaces,
};

static const char *usb_strings[] = {
	"Timelapse keyboard",
	"EEV",
	"v01",
};

/* Buffer to be used for control requests. */
uint8_t usbd_control_buffer[128];
static int got_config = 0;
static int hid_control_request(usbd_device *usbddev, struct usb_setup_data *req, uint8_t **buf, uint16_t *len,
			void (**complete)(usbd_device *usbddev, struct usb_setup_data *req)){
	(void)complete;
	(void)usbddev;

	if ((req->bmRequestType != 0x81) ||
	   (req->bRequest != USB_REQ_GET_DESCRIPTOR) ||
	   (req->wValue != 0x2200))
		return 0;

	*buf = (uint8_t *)hid_report_descriptor;
	*len = sizeof(hid_report_descriptor);
	got_config = 1;
	return 1;
}

void hid_set_config(usbd_device *usbddev, uint16_t wValue){
	(void)wValue;
	(void)usbddev;
	usbd_ep_setup(usbd_dev, 0x81, USB_ENDPOINT_ATTR_INTERRUPT, 4, NULL);
	usbd_register_control_callback(
				usbddev,
				USB_REQ_TYPE_STANDARD | USB_REQ_TYPE_INTERFACE,
				USB_REQ_TYPE_TYPE | USB_REQ_TYPE_RECIPIENT,
				hid_control_request);
}

void usbkeybrd_setup(){
	usbd_dev = usbd_init(&stm32f103_usb_driver, &dev, &config, usb_strings, 3, usbd_control_buffer, sizeof(usbd_control_buffer));
	usbd_register_set_config_callback(usbd_dev, hid_set_config);
}

void put_char_to_buf(char ch){
	*(msg_end++) = ch;
	if(msg_end == buf_end)
		msg_end = sendbuf;
}

/**
 * put data into keyboard buffer
 * THERE's NO DATA CORRUPTION CONTROL HERE!!!
 */
void send_msg(char *msg){
	while(*msg){
		put_char_to_buf(*(msg++));
	}
}
/*
void newline(){
	put_char_to_buf('\n');
}*/

/**
 * send data from keyboard buffer
 */
void process_usbkbrd(){
	if(!got_config) return; // don't allow sending messages until first connection - to prevent hangs
	static uint8_t pressed = 0;
	if(pressed){ // the keyboard was "pressed"
		if(8 == usbd_ep_write_packet(usbd_dev, 0x81, release_key(), 8))
			pressed = 0;
	}else if(msg_start != msg_end){ // we need to send keypress event
		if(8 == usbd_ep_write_packet(usbd_dev, 0x81, press_key(*msg_start), 8)){
			if(++msg_start == buf_end)
				msg_start = sendbuf;
			pressed = 1;
		}
	}else return;
}

/**
 * Print buff as hex values
 * @param buf - buffer to print
 * @param l   - buf length
 * @param s   - function to send a byte
 */
void print_hex(uint8_t *buff, uint8_t l){
	inline void putc(char c){
		if(c < 10)
			put_char_to_buf(c + '0');
		else
			put_char_to_buf(c + 'a' - 10);
	}
	put_char_to_buf('0');
	put_char_to_buf('x');
	while(l--){
		putc(buff[l] >> 4);
		putc(buff[l] & 0x0f);
	}
}

/**
 * Print decimal integer value
 * @param N - value to print
 * @param s - function to send a byte
 */
void print_int(int32_t N){
	char buf[10];
	int32_t L = 0;
	if(N < 0){
		put_char_to_buf('-');
		N = -N;
	}
	if(N){
		while(N){
			buf[L++] = N % 10 + '0';
			N /= 10;
		}
		while(L--) put_char_to_buf(buf[L]);
	}else put_char_to_buf('0');
}

