#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

// TODO Vervollständigen Sie die Funktion readImages unter Benutzung Ihrer Hilfsfunktionen
static int checkFileHeader(FILE *file)
{
    char buffer[BUFFER_SIZE] = {0};

    size_t length = strlen(FILE_HEADER_STRING);

    if (length >= BUFFER_SIZE)
    {
        return 0;
    }

    if (fread(buffer, 1, length, file) != length)
    {
        return 0;
    }

    return strcmp(buffer, FILE_HEADER_STRING) == 0;
}
GrayScaleImageSeries *readImages(const char *path)
{

FILE *file = fopen(path, "rb");

if (file == NULL) {
    return NULL;
}
if (!checkFileHeader(file))
{
    fclose(file);
    return NULL;
}
unsigned short numberOfImages;
unsigned short width;
unsigned short height;
if (fread(&numberOfImages, sizeof(unsigned short), 1, file) != 1 ||
    fread(&width, sizeof(unsigned short), 1, file) != 1 ||
    fread(&height, sizeof(unsigned short), 1, file) != 1)
{
    fclose(file);
    return NULL;
}
if (numberOfImages == 0 || width == 0 || height == 0)
{
    fclose(file);
    return NULL;
}
GrayScaleImageSeries *series =
    calloc(1, sizeof(GrayScaleImageSeries));


if (series == NULL)
{
    fclose(file);
    return NULL;
}

series->count = numberOfImages;
series->images =
    calloc(numberOfImages, sizeof(GrayScaleImage));

series->labels =
    calloc(numberOfImages, sizeof(unsigned char));
    if (series->images == NULL || series->labels == NULL)
{
    clearSeries(series);
    fclose(file);
    return NULL;
}
for (unsigned int i = 0; i < numberOfImages; i++)
{
    GrayScaleImage *image = &series->images[i];

    image->width = width;
    image->height = height;

    image->buffer = malloc(
        (size_t)width * height * sizeof(GrayScalePixelType)
    );

    if (image->buffer == NULL)
    {
        clearSeries(series);
        fclose(file);
        return NULL;
    }

    if (fread(image->buffer,
              sizeof(GrayScalePixelType),
              (size_t)width * height,
              file) != (size_t)width * height)
    {
        clearSeries(series);
        fclose(file);
        return NULL;
    }

    if (fread(&series->labels[i],
              sizeof(unsigned char),
              1,
              file) != 1)
    {
        clearSeries(series);
        fclose(file);
        return NULL;
    }
}
fclose(file);
return series;

}

// TODO Vervollständigen Sie die Funktion clearSeries, welche eine Bildserie vollständig aus dem Speicher freigibt
void clearSeries(GrayScaleImageSeries *series)
{
}