#include <stdio.h>
#include "pico/stdlib.h"
#include "hardware/spi.h"
uint8_t mosi=19;
uint8_t clock=18;
uint8_t cs=17;
uint8_t miso=16;
uint8_t dio0=0;
uint8_t dio5=1;

uint8_t RegFifo = 0x00;
uint8_t RegOpMode = 0x01;
uint8_t RegFrMsb = 0x06;
uint8_t RegFrMid = 0x07;
uint8_t RegFrLsb = 0x08;
uint8_t RegFifoAddrPtr = 0x0D;
uint8_t RegFifoTxBase = 0x0E;
uint8_t RegFifoRxBase = 0x0F;
uint8_t RegFifoRxCurrent = 0x10;
uint8_t RegIrqFlags = 0x12;
uint8_t RegRxNbBytes = 0x13;
uint8_t RegModemStat = 0x18;
uint8_t RegPktSnr = 0x19;
uint8_t RegPktRssi = 0x1A;
uint8_t RegRssi = 0x1B;
uint8_t RegModemConfig1 = 0x1D;
uint8_t RegModemConfig2 = 0x1E;
uint8_t RegDioMapping1 = 0x40;


uint8_t readReg(uint8_t reg);
void writeReg(uint8_t reg, uint8_t msg);

void writeFifo(uint8_t * msg, int count){
    writeReg(RegFifoAddrPtr,readReg(RegFifoTxBase));
    uint8_t package[count +1];
    package[0]=RegFifo | 0x80;
    for( int i=0;i<count;i++){
        package[i+1]=msg[i+1];
    }
    gpio_put(cs,0);
    spi_write_blocking(spi0,package, count+1);
    sleep_ms(10);
    gpio_put(cs,1);
}

void readFifo(uint8_t *buf, int count){
    gpio_put(cs,0);
    writeReg(RegFifoAddrPtr,readReg(RegFifoRxCurrent));
    spi_write_blocking(spi0,&RegFifo,1);
    spi_read_blocking(spi0,0,buf,count);
    sleep_ms(10);
    gpio_put(cs,1);
}

uint8_t readReg(uint8_t reg){
    uint8_t result;
    gpio_put(cs,0);
    spi_write_blocking(spi0,&reg,1);
    spi_read_blocking(spi0,0,&result, 1);
    sleep_ms(10);
    gpio_put(cs,1);
    return result;
}

void writeReg(uint8_t reg, uint8_t msg){
    uint8_t package[2];
    package[0]=reg | 0x80;
    package[1]=msg;
    gpio_put(cs,0);
    spi_write_blocking(spi0,package, 2);
    sleep_ms(10);
    gpio_put(cs,1);

}

void setMode(uint8_t mode){

    if(mode<8){
        writeReg(RegOpMode, 0x00);
        writeReg(RegOpMode,0x80 | mode);
    }
    else{
        printf("invalid mode\n");
    }
}

void loraInit(){
    gpio_init(cs);
    gpio_set_dir(cs,1);
    gpio_put(cs,1);
    gpio_init(dio0);
    gpio_set_dir(dio0,0);
    gpio_init(dio5);
    gpio_set_dir(dio5,0);

    spi_init(spi0,20000000);
    spi_set_format(spi0,8,0,0,SPI_MSB_FIRST);
    
    gpio_set_function(clock,GPIO_FUNC_SPI);
    gpio_set_function(mosi,GPIO_FUNC_SPI);
    gpio_set_function(miso,GPIO_FUNC_SPI);

    writeReg(RegOpMode,0x00);  
    writeReg(RegOpMode,0x00);
    writeReg(RegOpMode,0x80);
    writeReg(RegOpMode,0x85);
    writeReg(RegFrMsb,0xD9);
    writeReg(RegFrMid,0x40);

 //   writeReg(RegModemConfig1,0x98);
  //  writeReg(RegModemConfig2,0x70);
    writeReg(RegDioMapping1,0x01);

}
int main() {
    stdio_init_all();
    loraInit();
 
    
    while(1){
       if(gpio_get(dio0)){
           uint8_t msgSize = readReg(RegRxNbBytes);//read size of recieved packag
           printf("%d bytes recieved\n");
           uint8_t buf[msgSize];
           readFifo(buf, msgSize);
           writeReg(RegIrqFlags,0x40);
           printf("recieved message:\n");
           for(int i=0;i<msgSize; i++){
               printf("%d ",buf[i]);
           }
           printf("\n");
           
       } 
    printf("%x %x %x %d %x \n", readReg(RegFrMsb), readReg(RegFrMid), readReg(RegOpMode), readReg(RegRssi)-157, readReg(RegModemStat));     
    sleep_ms(500);
       
       
       
    }
}