#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "compressor.h"
#define BUFSIZE 1024


int ByteRLEEncode(char* bufferIn, int size, char* bufferOut) {
    int posIn = 0, count = 1, posOut = 0;
    char byteCurrent, byteRLE = bufferIn[posIn++];

    while (posIn != size) {
        byteCurrent = bufferIn[posIn++];

        if (byteCurrent == byteRLE) {
            count++;

            if (count == 256) {
                bufferOut[posOut++] = byteRLE;
                bufferOut[posOut++] = 255;

                count = 1;
            }
        } else {
            bufferOut[posOut++] = byteRLE;
            bufferOut[posOut++] = count;

            byteRLE = byteCurrent;
            count = 1;
        }
    }

    bufferOut[posOut++] = byteRLE;
    bufferOut[posOut++] = count;

    return posOut;
}

int mycompress(char* bufferIn, int size, char* bufferOut){
    return ByteRLEEncode(bufferIn, size, bufferOut);;
}


void compress(FILE *infile, FILE *outfile){
    char buffer[BUFSIZE];
    memset(buffer,0,BUFSIZE);
    while(1){
        int insize = fread(buffer,sizeof(char),BUFSIZE,infile);
        if (insize == 0){
            if (feof(infile)){
                // end of file
                break;
            }
            assert(!ferror(infile));
        }
        char outbuf[BUFSIZE*2];
        // Doplnte implementaciu kompresie. 
        int outsize = mycompress(buffer,insize,outbuf);
        if (outsize   > 0){
            fwrite(outbuf,sizeof(char),outsize,outfile);
        }
    }
}


void decompress(FILE *infile, FILE *outfile){
    unsigned char RLEMetadata[2];
    char RLEData[255];

    while (fread(RLEMetadata, 2, 1, infile)) {
        printf("%c %d\n", RLEMetadata[0], RLEMetadata[1]);

        for (int i = 0; i < RLEMetadata[1]; i++) {
            RLEData[i] = RLEMetadata[0];
        }

        fwrite(RLEData, RLEMetadata[1], 1, outfile);
    }
}