#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "imageInput.h"

#define BUFFER_SIZE 100
#define FILE_HEADER_STRING "__info2_image_file_format__"

// TODO Implementieren Sie geeignete Hilfsfunktionen für das Lesen der Bildserie aus einer Datei

static GrayScaleImage *readIndividualImage(unsigned int width, unsigned int height, FILE *file){

    char *buf = calloc(width * height, sizeof(char));
    if(!buf){
        fprintf(stderr, "calloc failed!\n");
        return NULL;
    }
    if(fread(buf, sizeof(char), width * height,file) != (width* height)){
        fprintf(stderr, "imageline not in the rigth format!\n");
        free(buf);
        return NULL;
    }

    GrayScaleImage *gimage = calloc(sizeof(GrayScaleImage, 1));
    if(gimage == NULL){
        fprintf(stderr, "calloc failed!\n");
        free(buf);
        return NULL;
    }
    
    gimage->buffer = buf;
    gimage->width = width;
    gimage->height = height;

    return gimage;
}

// TODO Vervollständigen Sie die Funktion readImages unter Benutzung Ihrer Hilfsfunktionen
GrayScaleImageSeries *readImages(const char *path)
{
    GrayScaleImageSeries *series = NULL;
    
    series = calloc(1, sizeof(GrayScaleImageSeries));
    if(series == NULL){
        fprintf(stderr, "Couldn't allocate enough space!\n");
        return NULL;
    }

    FILE *file = fopen(path, "rb");
    if(file == NULL){
        fprintf(stderr, "%s could not be opened!\n", path);
        clearSeries(series);
        return NULL;
    }

    //Schaue ob die erste Zeile der richtige Header ist.
    char buffer[32];
    size_t bytes = fread(buffer, sizeof(char), strlen(FILE_HEADER_STRING), file);
    if(!strncmp(buffer, FILE_HEADER_STRING, strlen(FILE_HEADER_STRING))){
        fprintf(stderr, "__info2_image_file_format__ not found!\n");
        clearSeries(series);
        return NULL;
    }

    if(bytes = fread(buffer, sizeof(short), 3, file) != (3*szieof(short))){
        fprintf(stderr, "Couldn't read number of images/sizes of Images!\n");
        clearSeries(series);
        return NULL;
    }

    series->count = (short)buffer[0];
    unsigned int width = (short)buffer[1];
    unsigned int height = (short)buffer[2];

    series->labels = calloc(count, sizeof(char));
    if(series->labels == NULL){
        fprintf(stderr, "calloc failed!\n");
        clearSeries(series);
        return NULL;
    }

    for (int i = 0; i < count; i++){
        if(series->images[i] = readIndividualImage(width, heigth, file) == NULL){
            clearSeries(series);
            return NULL;
        }
        fread(series->labels[i], sizeof(char), 1, file);
    }

    return series;
}

// TODO Vervollständigen Sie die Funktion clearSeries, welche eine Bildserie vollständig aus dem Speicher freigibt
void clearSeries(GrayScaleImageSeries *series)
{
    for(int i = 0; i < series->count; i++){
        free(series->GrayScaleImage[i]);
    }
    free(series);
}