#include <msp430.h>
#define TX_ADDR 0x0077
#define BUFFER 256
/*
 * main.c
 */
unsigned char buffer[BUFFER];
unsigned char exit_buf[BUFFER + 3];

int b = 0;

void init_ports();
void init_clock();
void init_usart();
void init_dma();
void convert(unsigned char* a, int length);
void send_response(unsigned char tab[], int length);

int main(void) {
	init_ports();
	init_clock();
	init_usart();
	init_dma();
    _BIS_SR(GIE);

    while(1){
    	 _BIS_SR(CPUOFF);
    	 _NOP();

    	 if (b == BUFFER-1) {
    		 send_response("BUFFER OVERFLOW", 15);
    	 }
    	 else convert(buffer, b-1);

    }
}

#pragma vector=USART0RX_VECTOR
__interrupt void receive(void)
{
	buffer[b] = U0RXBUF;
	if (buffer[b] == 0x0D || b == BUFFER-1) {
		LPM0_EXIT;
		ME1 &= ~URXE0; //wylacz receive
	}
	else b++;

}

#pragma vector=DACDMA_VECTOR
__interrupt void turn_off(void)
{
	DMA0CTL &= ~DMAEN;
	b = 0;
	DMA0CTL &= ~DMAIFG;
}

void init_ports() {
	WDTCTL = WDTPW | WDTHOLD;	// Stop watchdog timer
	P3SEL |= 0x30;
	P3DIR |= 0x10;
	P4DIR = 0xFF;
	P4OUT = 0x00;
}

void init_clock() {
	BCSCTL2 |= SELM1 + SELS;
}

void init_usart() {
	U0CTL |= SWRST;
	U0CTL |= CHAR + PENA + PEV + SPB;// + LISTEN;
	U0TCTL |= SSEL1;

	U0BR1 = 0x00;
	U0BR0 = 64;
	U0MCTL = 0x00;

	ME1 |= UTXE0 + URXE0;
	U0CTL &= ~SWRST;
	U0TXBUF = '?';
	IE1 |= URXIE0;
}

void init_dma() {
    DMACTL0 |= DMA0TSEL_4;
    DMA0CTL |= DMADT2 + DMASRCINCR0 + DMASRCINCR1 + DMADSTBYTE + DMASRCBYTE;
    DMA0SA = (unsigned int)exit_buf;
    DMA0DA = TX_ADDR;
    DMA0SZ = 0;
}


void convert(unsigned char* a, int length) {
    int i=0;
    int op=0;//"opóŸnienie" jednego rejestru wzglêdem drugiego
    int k = 0;
    unsigned char work_buf[BUFFER] = {0};
    //printf("wczytano: %s\n",a);


    ///pierwszy znak
    if((a[0]>=48 && a[0]<=57) || (a[0]>=65 && a[0]<=90)) work_buf[0]=a[0]; //jak cyfra albo du¿a litera to ok
    else if (a[0]>=97 && a[0]<=122) work_buf[0]=a[0]-32; //jak ma³a to zamieñ na du¿¹
    else {send_response("ERROR", 5); return;}

    ///pozosta³e znaki
    for (i=1; i<=length-1; i++){

        //if(a[i]<=0) i=length+3;

        if((work_buf[i-1-op]==a[i]) || (work_buf[i-1-op]>=65 && work_buf[i-1-op]<=90 && work_buf[i-1-op]==a[i]-32) || (work_buf[i-1-op]>=97 && work_buf[i-1-op]<=122 && work_buf[i-1-op]==a[i]+32)) op++; //jeœli znak siê powtarza, to go ignorujemy

        if((a[i]>=97 && a[i]<=122) || (a[i]>=48 && a[i]<=57) || a[i]==32) work_buf[i-op]=a[i]; //jak ma³a, spacja albo cyfra to ok

        else if (a[i]>=65 && a[i]<=90) work_buf[i-op]=a[i]+32; //jak du¿a to zmieñ na ma³¹

        else if (a[i] == 46 || a[i] == 33 || a[i] == 63 || a[i] == 44){ //jeœli jest to kropka, znak zapytania, przecinek albo wykrzyknik, to musi byæ on po literze albo cyfrze

            if ((work_buf[i-1-op]>=65 && work_buf[i-1-op]<=90) || (work_buf[i-1-op]>=97 && work_buf[i-1-op]<=122)||(work_buf[i-1-op]>=48 && work_buf[i-1-op]<=57)) {
            	work_buf[i-op]=a[i]; //po literze albo cyfrze jest ok
                    if(a[i]!=44) i=length+30; //jesli nie przecinek to koniec zdania
            }

            else if(work_buf[i-1-op]==32){ //jeœli znak jest po spacji, usuwamy spacjê
            	work_buf[i-1-op]=a[i];
                    op++;
                    if(a[i]!=44) i=length+30;
            }
        }

        else {send_response("ERROR", 5); return;}
    }

    if (work_buf[0]>=97 && work_buf[0]<=122) work_buf[0]=work_buf[0]-32; //jak by³y powtórki na pocz¹tku to zmienia³o na ma³¹ wiêc idê na ³atwiznê i zmieniam to pod koniec
    while(work_buf[k] != 0) k++;
    send_response(work_buf, k);
}

void send_response(unsigned char tab[], int length) {
	int i = 0;
	b = 0;
	for (; i<length; ++i) exit_buf[i] = tab[i];
    exit_buf[i] = '\n';
    exit_buf[i+1] = '\r';
    exit_buf[i+2] = '?';
    DMA0SZ = i+3;
    DMA0CTL |= DMAIE;
    DMA0CTL |= DMAEN;
	U0TXBUF = '>'; //to zainicjuje DMA
	ME1 |= URXE0; //wlacz receivera

}