/*
    ChibiOS - Copyright (C) 2006..2015 Giovanni Di Sirio
    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.
    You may obtain a copy of the License at
        http://www.apache.org/licenses/LICENSE-2.0
    Unless required by applicable law or agreed to in writing, software
    distributed under the License is distributed on an "AS IS" BASIS,
    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    See the License for the specific language governing permissions and
    limitations under the License.
*/
/*
 * This file 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 3 of the License, or
 * (at your option) any later version.
 *
 * This file 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, see <http://www.gnu.org/licenses/>.
 *
 * Modified for use in AP_HAL by Andrew Tridgell and Siddharth Bharat Purohit
 */
#include "hal.h"
#include "hwdef.h"

#include <stdlib.h>
#include <string.h>

// #pragma GCC optimize("O0")

#ifdef HAL_USB_PRODUCT_ID

/* Virtual serial port over USB.*/
SerialUSBDriver SDU1;

/*
 * Endpoints to be used for USBD1.
 */
#define USBD1_DATA_REQUEST_EP           1
#define USBD1_DATA_AVAILABLE_EP         1
#define USBD1_INTERRUPT_REQUEST_EP      2

/*
 * USB Device Descriptor.
 */
static const uint8_t vcom_device_descriptor_data[18] = {
    USB_DESC_DEVICE(
        0x0110,             /* bcdUSB (1.1).                    */
        0x02,               /* bDeviceClass (CDC).              */
        0x00,               /* bDeviceSubClass.                 */
        0x00,               /* bDeviceProtocol.                 */
        0x40,               /* bMaxPacketSize.                  */
        HAL_USB_VENDOR_ID,  /* idVendor (ST).                   */
        HAL_USB_PRODUCT_ID, /* idProduct.                       */
        0x0200,             /* bcdDevice.                       */
        1,                  /* iManufacturer.                   */
        2,                  /* iProduct.                        */
        3,                  /* iSerialNumber.                   */
        1)                  /* bNumConfigurations.              */
};

/*
 * Device Descriptor wrapper.
 */
static const USBDescriptor vcom_device_descriptor = {
  sizeof vcom_device_descriptor_data,
  vcom_device_descriptor_data
};

/* Configuration Descriptor tree for a CDC.*/
static const uint8_t vcom_configuration_descriptor_data[67] = {
  /* Configuration Descriptor.*/
  USB_DESC_CONFIGURATION(67,            /* wTotalLength.                    */
                         0x02,          /* bNumInterfaces.                  */
                         0x01,          /* bConfigurationValue.             */
                         0,             /* iConfiguration.                  */
                         0xC0,          /* bmAttributes (self powered).     */
                         50),           /* bMaxPower (100mA).               */
  /* Interface Descriptor.*/
  USB_DESC_INTERFACE    (0x00,          /* bInterfaceNumber.                */
                         0x00,          /* bAlternateSetting.               */
                         0x01,          /* bNumEndpoints.                   */
                         0x02,          /* bInterfaceClass (Communications
                                           Interface Class, CDC section
                                           4.2).                            */
                         0x02,          /* bInterfaceSubClass (Abstract
                                         Control Model, CDC section 4.3).   */
                         0x01,          /* bInterfaceProtocol (AT commands,
                                           CDC section 4.4).                */
                         0),            /* iInterface.                      */
  /* Header Functional Descriptor (CDC section 5.2.3).*/
  USB_DESC_BYTE         (5),            /* bLength.                         */
  USB_DESC_BYTE         (0x24),         /* bDescriptorType (CS_INTERFACE).  */
  USB_DESC_BYTE         (0x00),         /* bDescriptorSubtype (Header
                                           Functional Descriptor.           */
  USB_DESC_BCD          (0x0110),       /* bcdCDC.                          */
  /* Call Management Functional Descriptor. */
  USB_DESC_BYTE         (5),            /* bFunctionLength.                 */
  USB_DESC_BYTE         (0x24),         /* bDescriptorType (CS_INTERFACE).  */
  USB_DESC_BYTE         (0x01),         /* bDescriptorSubtype (Call Management
                                           Functional Descriptor).          */
  USB_DESC_BYTE         (0x00),         /* bmCapabilities (D0+D1).          */
  USB_DESC_BYTE         (0x01),         /* bDataInterface.                  */
  /* ACM Functional Descriptor.*/
  USB_DESC_BYTE         (4),            /* bFunctionLength.                 */
  USB_DESC_BYTE         (0x24),         /* bDescriptorType (CS_INTERFACE).  */
  USB_DESC_BYTE         (0x02),         /* bDescriptorSubtype (Abstract
                                           Control Management Descriptor).  */
  USB_DESC_BYTE         (0x02),         /* bmCapabilities.                  */
  /* Union Functional Descriptor.*/
  USB_DESC_BYTE         (5),            /* bFunctionLength.                 */
  USB_DESC_BYTE         (0x24),         /* bDescriptorType (CS_INTERFACE).  */
  USB_DESC_BYTE         (0x06),         /* bDescriptorSubtype (Union
                                           Functional Descriptor).          */
  USB_DESC_BYTE         (0x00),         /* bMasterInterface (Communication
                                           Class Interface).                */
  USB_DESC_BYTE         (0x01),         /* bSlaveInterface0 (Data Class
                                           Interface).                      */
  /* Endpoint 2 Descriptor.*/
  USB_DESC_ENDPOINT     (USBD1_INTERRUPT_REQUEST_EP|0x80,
                         0x03,          /* bmAttributes (Interrupt).        */
                         0x0008,        /* wMaxPacketSize.                  */
                         0xFF),         /* bInterval.                       */
  /* Interface Descriptor.*/
  USB_DESC_INTERFACE    (0x01,          /* bInterfaceNumber.                */
                         0x00,          /* bAlternateSetting.               */
                         0x02,          /* bNumEndpoints.                   */
                         0x0A,          /* bInterfaceClass (Data Class
                                           Interface, CDC section 4.5).     */
                         0x00,          /* bInterfaceSubClass (CDC section
                                           4.6).                            */
                         0x00,          /* bInterfaceProtocol (CDC section
                                           4.7).                            */
                         0x00),         /* iInterface.                      */
  /* Endpoint 3 Descriptor.*/
  USB_DESC_ENDPOINT     (USBD1_DATA_AVAILABLE_EP,       /* bEndpointAddress.*/
                         0x02,          /* bmAttributes (Bulk).             */
                         0x0040,        /* wMaxPacketSize.                  */
                         0x00),         /* bInterval.                       */
  /* Endpoint 1 Descriptor.*/
  USB_DESC_ENDPOINT     (USBD1_DATA_REQUEST_EP|0x80,    /* bEndpointAddress.*/
                         0x02,          /* bmAttributes (Bulk).             */
                         0x0040,        /* wMaxPacketSize.                  */
                         0x00)          /* bInterval.                       */
};

/*
 * Configuration Descriptor wrapper.
 */
static const USBDescriptor vcom_configuration_descriptor = {
  sizeof vcom_configuration_descriptor_data,
  vcom_configuration_descriptor_data
};

/*
 * U.S. English language identifier.
 */
static const uint8_t vcom_string0[] = {
  USB_DESC_BYTE(4),                     /* bLength.                         */
  USB_DESC_BYTE(USB_DESCRIPTOR_STRING), /* bDescriptorType.                 */
  USB_DESC_WORD(0x0409)                 /* wLANGID (U.S. English).          */
};

/*
 * Strings wrappers array. The strings are created dynamically to
 * allow them to be setup with apj_tool
 */
static USBDescriptor vcom_strings[] = {
  {sizeof vcom_string0, vcom_string0},
  {0, NULL}, // manufacturer
  {0, NULL}, // product
  {0, NULL}, // version
};

#define USB_DESC_MAX_STRLEN 100
static uint8_t vcom_buffers[3][2+2*USB_DESC_MAX_STRLEN];

/*
  check if one string contains another
 */
static bool string_contains(const char *haystack, const char *needle)
{
    uint8_t needle_len = strlen(needle);
    while (*haystack) {
        if (strncmp(haystack, needle, needle_len) == 0) {
            return true;
        }
        haystack++;
    }
    return false;
}

/*
  handle substitution of variables in strings for USB descriptors
 */
static void string_substitute(const char *str, char *str2)
{
    const char *board = "%BOARD%";
    const char *serial = "%SERIAL%";
    uint8_t new_len = strlen(str);
    if (string_contains(str, board)) {
        new_len += strlen(HAL_BOARD_NAME) - strlen(board);
    }
    if (string_contains(str, serial)) {
        new_len += 24 - strlen(serial);
    }
    if (new_len+1 > USB_DESC_MAX_STRLEN) {
        strcpy(str2, str);
        return;
    }
    char *p = str2;
    while (*str) {
        char c = *str;
        if (c == '%') {
            if (strncmp(str, board, strlen(board)) == 0) {
                memcpy(p, HAL_BOARD_NAME, strlen(HAL_BOARD_NAME));
                str += 7;
                p += strlen(HAL_BOARD_NAME);
                continue;
            }
            if (strncmp(str, serial, strlen(serial)) == 0) {
                const char *hex = "0123456789ABCDEF";
                const uint8_t *cpu_id = (const uint8_t *)UDID_START;
                uint8_t i;
                for (i=0; i<12; i++) {
                    *p++ = hex[(cpu_id[i]>>4)&0xF];
                    *p++ = hex[cpu_id[i]&0xF];
                }
                str += 8;
                continue;
            }
        }
        *p++ = *str++;
    }
    *p = 0;
}


/*
  dynamically allocate a USB descriptor string
 */
static void setup_usb_string(USBDescriptor *desc, const char *str, uint8_t *b)
{
    char str2[USB_DESC_MAX_STRLEN];
    string_substitute(str, str2);
    uint8_t len = strlen(str2);
    desc->ud_size = 2+2*len;
    desc->ud_string = (const uint8_t *)b;
    b[0] = USB_DESC_BYTE(desc->ud_size);
    b[1] = USB_DESC_BYTE(USB_DESCRIPTOR_STRING);
    uint8_t i;
    for (i=0; i<len; i++) {
        b[2+i*2] = str2[i];
        b[2+i*2+1] = 0;
    }
}

/*
  dynamically allocate a USB descriptor strings
 */
void setup_usb_strings(void)
{
    setup_usb_string(&vcom_strings[1], HAL_USB_STRING_MANUFACTURER, vcom_buffers[0]);
    setup_usb_string(&vcom_strings[2], HAL_USB_STRING_PRODUCT, vcom_buffers[1]);
    setup_usb_string(&vcom_strings[3], HAL_USB_STRING_SERIAL, vcom_buffers[2]);
}

/*
 * Handles the GET_DESCRIPTOR callback. All required descriptors must be
 * handled here.
 */
static const USBDescriptor *get_descriptor(USBDriver *usbp,
                                           uint8_t dtype,
                                           uint8_t dindex,
                                           uint16_t lang) {

  (void)usbp;
  (void)lang;
  switch (dtype) {
  case USB_DESCRIPTOR_DEVICE:
    return &vcom_device_descriptor;
  case USB_DESCRIPTOR_CONFIGURATION:
    return &vcom_configuration_descriptor;
  case USB_DESCRIPTOR_STRING:
      if (dindex < 4) {
          return &vcom_strings[dindex];
      }
  }
  return NULL;
}

/**
 * @brief   IN EP1 state.
 */
static USBInEndpointState ep1instate;

/**
 * @brief   OUT EP1 state.
 */
static USBOutEndpointState ep1outstate;

/**
 * @brief   EP1 initialization structure (both IN and OUT).
 */
static const USBEndpointConfig ep1config = {
  USB_EP_MODE_TYPE_BULK,
  NULL,
  sduDataTransmitted,
  sduDataReceived,
  0x0040,
  0x0040,
  &ep1instate,
  &ep1outstate,
  2,
  NULL
};

/**
 * @brief   IN EP2 state.
 */
static USBInEndpointState ep2instate;

/**
 * @brief   EP2 initialization structure (IN only).
 */
static const USBEndpointConfig ep2config = {
  USB_EP_MODE_TYPE_INTR,
  NULL,
  sduInterruptTransmitted,
  NULL,
  0x0010,
  0x0000,
  &ep2instate,
  NULL,
  1,
  NULL
};

/*
 * Handles the USB driver global events.
 */
static void usb_event(USBDriver *usbp, usbevent_t event) {
  extern SerialUSBDriver SDU1;

  switch (event) {
  case USB_EVENT_ADDRESS:
    return;
  case USB_EVENT_CONFIGURED:
    chSysLockFromISR();

    /* Enables the endpoints specified into the configuration.
       Note, this callback is invoked from an ISR so I-Class functions
       must be used.*/
    usbInitEndpointI(usbp, USBD1_DATA_REQUEST_EP, &ep1config);
    usbInitEndpointI(usbp, USBD1_INTERRUPT_REQUEST_EP, &ep2config);

    /* Resetting the state of the CDC subsystem.*/
    sduConfigureHookI(&SDU1);

    chSysUnlockFromISR();
    return;
  case USB_EVENT_RESET:
    /* Falls into.*/
  case USB_EVENT_UNCONFIGURED:
    /* Falls into.*/
  case USB_EVENT_SUSPEND:
    chSysLockFromISR();

    /* Disconnection event on suspend.*/
    sduSuspendHookI(&SDU1);

    chSysUnlockFromISR();
    return;
  case USB_EVENT_WAKEUP:
    chSysLockFromISR();

    /* Disconnection event on suspend.*/
    sduWakeupHookI(&SDU1);

    chSysUnlockFromISR();
    return;
  case USB_EVENT_STALLED:
    return;
  }
  return;
}

/*
 * Handles the USB driver global events.
 */
static void sof_handler(USBDriver *usbp) {

  (void)usbp;

  osalSysLockFromISR();
  sduSOFHookI(&SDU1);
  osalSysUnlockFromISR();
}

/*
 * USB driver configuration.
 */
const USBConfig usbcfg = {
  usb_event,
  get_descriptor,
  sduRequestsHook,
  sof_handler
};

/*
 * Serial over USB driver configuration.
 */
const SerialUSBConfig serusbcfg = {
  &USBD1,
  USBD1_DATA_REQUEST_EP,
  USBD1_DATA_AVAILABLE_EP,
  USBD1_INTERRUPT_REQUEST_EP
};

#endif // HAL_USB_PRODUCT_ID