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

#define BUFFER_SIZE 100
#define FILE_HEADER_STRING "__info2_image_file_format__"

// Funktionen müssen noch auf Teilfunktionen 
// übersichtlich aufgeteilt werden!

// TODO Implementieren Sie geeignete Hilfsfunktionen für das Lesen der Bildserie aus einer Datei
//void setupMemory();
unsigned int readStatusInfo(FILE *source, char *const headerString, unsigned int *const imageCount, unsigned int *const imageWidth, unsigned int *const imageHeight, int const amountToRead);
void readImagedata(FILE *source, unsigned char *const imageBuffer, unsigned char *const labelBuffer,int const imageCount ,int const amountToRead);


// TODO Vervollständigen Sie die Funktion readImages unter Benutzung Ihrer Hilfsfunktionen
GrayScaleImageSeries *readImages(const char *path)
{
    GrayScaleImageSeries *series = NULL;

    // selbst geschriebene Variablen
    FILE                    *readSource;
    unsigned int            numberOfBytesToRead         = 0;
    const unsigned int      amountOfStatusInfoToRead    = 1;
    char                    headerString[sizeof("__info2_image_file_format__\0")] = "";

    //speicher allocaten weil *series auf null zeigt !!!!!!!!

    readSource = fopen(path, "rb");

    if (readSource != NULL)
    {

        series          = calloc(sizeof(GrayScaleImageSeries),  amountOfStatusInfoToRead);
        series->images  = calloc(sizeof(GrayScaleImage),        amountOfStatusInfoToRead);
        
        numberOfBytesToRead = readStatusInfo(readSource, headerString, &(series->count), &(series->images->width), &(series->images->height), amountOfStatusInfoToRead);
        
        series->images->buffer  = calloc((series->count) * numberOfBytesToRead, sizeof(GrayScalePixelType));
        series->labels          = calloc((series->count),                       sizeof(&(series->labels)));

        readImagedata(readSource, series->images->buffer, series->labels, series->count, numberOfBytesToRead);
    }

    fclose(readSource);
    

    return series;
}

// TODO Vervollständigen Sie die Funktion clearSeries, welche eine Bildserie vollständig aus dem Speicher freigibt
void clearSeries(GrayScaleImageSeries *series)
{
    int i = 0;


    // Write NULL into all memory spaces
    for (i = 0; i < ((series->count) * (series->images->width) * (series->images->height)); i++)
    {
        *(series->images->buffer + i * (series->images->width) * (series->images->height)) = '\0';
    }
    for (i = 0; i < (series->count); i++)
    {
        *(series->labels + i) = '\0';
    }
    series->count           = 0;
    series->images->width   = 0;
    series->images->height  = 0;

    // Closse all allocated memory
    // AND write NULL into every pointer
    // so they can't be accessed
    free(series->images->buffer);
    free(series->labels);
    series->images->buffer  = NULL;
    series->images          = NULL;
    series->labels          = NULL;
    free(series);
    series                  = NULL;

}


//  reads string, pictureCount, pictureWidth, pictureHight
unsigned int readStatusInfo(FILE *source, char *const headerString, unsigned int *const imageCount, unsigned int *const imageWidth, unsigned int *const imageHeight, int const amountToRead)
{
    unsigned int bytesToRead = 0;
    
    fread(headerString, sizeof("__info2_image_file_format__\0"),  amountToRead, source);
    fread(imageCount,   sizeof(int),      1, source);
    fread(imageWidth,   sizeof(int),     amountToRead, source);
    fread(imageHeight,  sizeof(int),    amountToRead, source);
    
    bytesToRead = (*imageWidth) * (*imageHeight);
    // state of debugging: 
    //      stopped here,
    //      read width and height 
    //      return nonsensical numbers
    //      is the sizeof() command correct??
    printf("hier\n");
    printf("stringsize: %lld\n", sizeof(headerString));
    printf("string: %send\n", headerString);
    printf("count: %u\n", *imageCount);
    printf("width: %u\n", *imageWidth);
    printf("height %u\n", *imageHeight);
    printf("bytes to read = %u\n", bytesToRead);
    return bytesToRead;
}

//  reads the imagebytes and the label of all images
void readImagedata(FILE *source, unsigned char *const imageBuffer, unsigned char *const labelBuffer,int const imageCount ,  int const amountOfBytes)
{
    int i = 0;

    for (i = 0; i <= imageCount; i++)
    {
    fread((imageBuffer + i * amountOfBytes),    sizeof(&(imageBuffer)), amountOfBytes,  source);
    fread((labelBuffer + i),                    sizeof(&(labelBuffer)), 1,              source);
    }
}