#include <sysinit.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <stdint.h>
#include "basic/basic.h"
#include "lcd/render.h"
#include "lcd/allfonts.h"
#include "basic/ecc.h"
#include "funk/nrf24l01p.h"
#include "filesystem/ff.h"
#include "filesystem/diskio.h"
#include "funk/filetransfer.h"
#include "lcd/print.h"

uint8_t mac[5] = {1,2,3,2,1};

void ram(void)
{
    if( sendKeys() )
        return;

    char priv[42];
    UINT readbytes;
    FIL file;

    if( f_open(&file, "priv.key", FA_OPEN_EXISTING|FA_READ) ){
        return;
    }
    if( f_read(&file, priv, 41, &readbytes) || readbytes != 41 ){
        return;
    }
    f_close(&file);
    priv[41] = 0;

    uint8_t done = 0;
    uint8_t key;
    uint8_t k1[16], k2[16], rx[4*NUMWORDS], ry[4*NUMWORDS];
 
    while( !done ){
        lcdClear();
        lcdPrintln("Receiving file");
        lcdPrintln("Down=Abort");
        lcdRefresh();
        key = getInput();
        delayms(20);
        if( key == BTN_DOWN ){
            return -1;
        }
        if( receiveR(rx,ry) )
            continue;
        lcdPrintln("Creating key");
        lcdRefresh();
        ECIES_decryptkeygen(rx, ry, k1, k2, priv);
        if( filetransfer_receive(mac,(uint32_t*)k1) < 0 )
            continue;
        lcdPrintln("Right=OK");
        lcdPrintln("Left=Retry");
        lcdPrintln("Down=Abort");
        lcdRefresh();

        while(1){
            key = getInput();
            delayms(20);
            if( key == BTN_LEFT ){
                break;
            }else if( key == BTN_RIGHT ){
                done = 1;
                break;
            }else if( key == BTN_DOWN ){
                return -1;
            }
        }
    }
}

void sendPublicKey(void)
{
    uint8_t exp[2 + 4*NUMWORDS + 2];
    char buf[42];
    UINT readbytes;
    FIL file;

    if( f_open(&file, "pubx.key", FA_OPEN_EXISTING|FA_READ) ){
        return;
    }
    if( f_read(&file, buf, 41, &readbytes) || readbytes != 41 ){
        return;
    }
    f_close(&file);
    buf[41] = 0;

    exp[0] = 'P';
    bitstr_parse_export((char*)exp+2, buf);
    exp[1] = 'X';
    nrf_snd_pkt_crc(32, exp);
    delayms(10);

    if( f_open(&file, "puby.key", FA_OPEN_EXISTING|FA_READ) ){
        return;
    }
    if( f_read(&file, buf, 41, &readbytes) || readbytes != 41 ){
        return;
    }
    f_close(&file);
    buf[41] = 0;

    exp[1] = 'Y';
    bitstr_parse_export((char*)exp+2, buf);
    nrf_snd_pkt_crc(32, exp);
    delayms(10);
}


int receiveKey(uint8_t type, uint8_t *x, uint8_t *y)
{
    uint8_t buf[32];
    uint8_t n;
    
    n = nrf_rcv_pkt_time(1000, 32, buf);
    if( n == 32 && buf[0] == type && buf[1] == 'X' ){
        for(int i=0; i<NUMWORDS*4; i++)
            x[i] = buf[i+2];
        n = nrf_rcv_pkt_time(100, 32, buf);
        if( n == 32 && buf[0] ==type && buf[1] == 'Y' ){
            for(int i=0; i<NUMWORDS*4; i++)
                y[i] = buf[i+2];
            return 0;
        }
    }
    return -1;
}

int receiveR(uint8_t *rx, uint8_t *ry)
{
    return receiveKey('R',rx,ry);
}

void sendMac(void)
{
    uint8_t buf[32];
    buf[0] = 'M';
    buf[1] = 'C';
    buf[2] = mac[0];
    buf[3] = mac[1];
    buf[4] = mac[2];
    buf[5] = mac[3];
    buf[6] = mac[4];
    nrf_snd_pkt_crc(32, buf);
    delayms(10);
}

int sendKeys(void)
{
    uint8_t done = 0;
    char key;
    while( !done ){
        lcdClear();
        lcdPrintln("Sending PUBKEY");lcdRefresh();
        sendPublicKey();
        sendMac();
        lcdPrintln("Done");
        lcdPrintln("Right=OK");
        lcdPrintln("Left=Retry");
        lcdPrintln("Down=Abort");
        lcdRefresh();

        while(1){
            key = getInput();
            delayms(20);
            if( key == BTN_LEFT ){
                break;
            }else if( key == BTN_RIGHT ){
                done = 1;
                break;
            }else if( key == BTN_DOWN ){
                return -1;
            }
        }
    }
    return 0;
}