#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")] = "";

    /*
    char curChar = 0;
    int i = 0;
    

    // dieses print(hier) wird nur einmal aufgerufen,
    // der zweite test schafft es also nicht readImages 
    // korrekt aufzurufen!!!!!
    printf("hier\n");
    */
    readSource = fopen(path, "rb");
    
    if (readSource != NULL)
    {
        /*
            // print entire source char by char
            do
            {
                curChar = fgetc(readSource);
                printf("%x ", curChar);
                if (i >= 9)
                {
                    printf("\n");
                    i = 0;
                }
                i++;
            } while (curChar != EOF);
            // print entire source char by char
        */
        series                  = calloc(sizeof(unsigned int) + 3* sizeof(headerString),  amountOfStatusInfoToRead);
        series->images          = calloc(2*sizeof(unsigned int) + sizeof(headerString),  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);
    series->images->buffer  = NULL;
    free(series->labels);
    series->labels          = NULL;
    free(series->images);
    series->images          = 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;
    /*
    int numred = 0;
    int numred2 = 0;
    int numred3 = 0;
    int numred4 = 0;
    */

    //unsigned int imageCountBuffer = 0;
    fread(headerString, 27,  1, source);
    fread(imageCount,   2,      1, source);
    fread(imageWidth,   2,     1, source);
    fread(imageHeight,  2,    1, source);

    bytesToRead = (*imageWidth) * (*imageHeight);
    /*
    printf("imgCntBuffer: %u\n", imageCountBuffer);
    *imageCount = imageCountBuffer;
    
    printf("numred: %d\n", numred);
    printf("stringsize: %lld\n", sizeof("__info2_image_file_format__"));
    printf("string: %send\n", headerString);
    printf("numred2: %d\n", numred2);
    printf("count: %u\n", *imageCount);
    printf("numred3: %d\n", numred3);
    printf("width: %u\n", *imageWidth);
    printf("numred4: %d\n", numred4);
    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);
    }
}