#include "RedragonK556Controller.h"

#include <cstring>

RedragonK556Controller::RedragonK556Controller(hid_device* dev_handle)
{
    dev = dev_handle;
}

void RedragonK556Controller::SetKeyboardColors
    (
    unsigned char *     color_data,
    unsigned int        size
    )
{
    unsigned int    packet_size = 0;
    unsigned int    packet_offset = 0;

    while(size > 0)
    {
        if(size >= REDRAGON_K556_MAX_PACKET_SIZE)
        {
            packet_size     = REDRAGON_K556_MAX_PACKET_SIZE;
        }
        else
        {
            packet_size     = size;
        }
        
        SendKeyboardData
            (
            &color_data[packet_offset],
            packet_size,
            packet_offset
            );

        size           -= packet_size;
        packet_offset  += packet_size;
    }
}

/*-------------------------------------------------------------------------------------------------*\
| Private packet sending functions.                                                                 |
\*-------------------------------------------------------------------------------------------------*/

void RedragonK556Controller::ComputeChecksum
    (
    char                usb_buf[64]
    )
{
    unsigned short checksum = 0;

    for(unsigned int byte_idx = 0x03; byte_idx < 64; byte_idx++)
    {
        checksum += usb_buf[byte_idx];
    }

    usb_buf[0x01] = checksum & 0xFF;
    usb_buf[0x02] = checksum >> 8;
}

void RedragonK556Controller::SendKeyboardBegin()
{
    char usb_buf[64];

    /*-----------------------------------------------------*\
    | Zero out buffer                                       |
    \*-----------------------------------------------------*/
    memset(usb_buf, 0x00, sizeof(usb_buf));

    /*-----------------------------------------------------*\
    | Set up Keyboard Begin (0x01) packet                   |
    |   Note: Not computing checksum as packet contents are |
    |         fixed                                         |
    \*-----------------------------------------------------*/
    usb_buf[0x00]           = 0x04;
    usb_buf[0x01]           = 0x01;
    usb_buf[0x02]           = 0x00;
    usb_buf[0x03]           = 0x01;
    
    /*-----------------------------------------------------*\
    | Send packet                                           |
    \*-----------------------------------------------------*/
    hid_write(dev, (unsigned char *)usb_buf, 64);
    hid_read(dev, (unsigned char *)usb_buf, 64);
}

void RedragonK556Controller::SendKeyboardEnd()
{
    char usb_buf[64];

    /*-----------------------------------------------------*\
    | Zero out buffer                                       |
    \*-----------------------------------------------------*/
    memset(usb_buf, 0x00, sizeof(usb_buf));

    /*-----------------------------------------------------*\
    | Set up Keyboard End (0x02) packet                     |
    |   Note: Not computing checksum as packet contents are |
    |         fixed                                         |
    \*-----------------------------------------------------*/
    usb_buf[0x00]           = 0x04;
    usb_buf[0x01]           = 0x02;
    usb_buf[0x02]           = 0x00;
    usb_buf[0x03]           = 0x02;
    
    /*-----------------------------------------------------*\
    | Send packet                                           |
    \*-----------------------------------------------------*/
    hid_write(dev, (unsigned char *)usb_buf, 64);
    hid_read(dev, (unsigned char *)usb_buf, 64);
}

void RedragonK556Controller::SendKeyboardData
    (
    unsigned char *     data,
    unsigned char       data_size,
    unsigned short      data_offset
    )
{
    char usb_buf[64];

    /*-----------------------------------------------------*\
    | Zero out buffer                                       |
    \*-----------------------------------------------------*/
    memset(usb_buf, 0x00, sizeof(usb_buf));

    /*-----------------------------------------------------*\
    | Set up Keyboard Color Data (0x11) packet              |
    \*-----------------------------------------------------*/
    usb_buf[0x00]           = 0x04;
    usb_buf[0x03]           = 0x11;

    usb_buf[0x04]           = data_size;
    usb_buf[0x05]           = data_offset & 0x00FF;
    usb_buf[0x06]           = data_offset >> 8;

    /*-----------------------------------------------------*\
    | Copy in data bytes                                    |
    \*-----------------------------------------------------*/
    memcpy(&usb_buf[0x08], data, data_size);
    
    /*-----------------------------------------------------*\
    | Compute Checksum                                      |
    \*-----------------------------------------------------*/
    ComputeChecksum(usb_buf);

    /*-----------------------------------------------------*\
    | Send packet                                           |
    \*-----------------------------------------------------*/
    hid_write(dev, (unsigned char *)usb_buf, 64);
    hid_read(dev, (unsigned char *)usb_buf, 64);
}

void RedragonK556Controller::SendKeyboardMode
    (
    unsigned char       mode
    )
{
    char usb_buf[64];

    /*-----------------------------------------------------*\
    | Zero out buffer                                       |
    \*-----------------------------------------------------*/
    memset(usb_buf, 0x00, sizeof(usb_buf));

    /*-----------------------------------------------------*\
    | Set up Keyboard Parameter (0x06) packet               |
    \*-----------------------------------------------------*/
    usb_buf[0x00]           = 0x04;
    usb_buf[0x03]           = 0x06;
    usb_buf[0x04]           = 0x01;

    usb_buf[0x08]           = mode;
    
    /*-----------------------------------------------------*\
    | Compute Checksum                                      |
    \*-----------------------------------------------------*/
    ComputeChecksum(usb_buf);

    /*-----------------------------------------------------*\
    | Send packet                                           |
    \*-----------------------------------------------------*/
    hid_write(dev, (unsigned char *)usb_buf, 64);
    hid_read(dev, (unsigned char *)usb_buf, 64);
}