#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 int checkHeader (FILE *file)
{
    char header [strlen (FILE_HEADER_STRING) +1]; //Ermittle die Länge des Strings, +1 wegen Null

    size_t gelesen = fread (header, sizeof(char), strlen(FILE_HEADER_STRING), file);
    if (gelesen == NULL)
        return -1;
    
    header [strlen (FILE_HEADER_STRING)] = '\0';

    if (strcmp (header, FILE_HEADER_STRING) == 0) //Headerlänge Vergleich 
    {
        return 1;
    } else 
    {
        return -1;
    }   

}

static unsigned int readUnit (FILE *file)
{
    unsigned int value = 0;
    size_t gelesen = fread (&value, sizeof(unsigned int), 1, file); //liest genau 4 Bytes ein
    if (gelesen == NULL)
        return -1;
    
    return value;

}

static GrayScaleImage readSingleImage (FILE *file)
{
    GrayScaleImage img = NULL;

    //Breite und Höhe einlesen
    size_t gelesenWidth = fread (&img.width, sizeof(unsigned int), 1, file);
    size_t gelesenHeight = fread (&img.height, sizeof(unsigned int), 1, file);
        if (gelesenWidth == NULL || gelesenHeight == NULL)
            return -1;
    
    //Speicher für Pixel reservieren
    size_t pixelCount = img.width * img.height;
    img.buffer = malloc(pixelCount * sizeof(GrayScalePixelType));
        if (img.buffer == NULL)
            return -1;

    //Pixel einlesen
    size_t gelesenPixels = fread (img.buffer, sizeof(GrayScalePixelType), pixelCount, file);
    if (gelesenPixels != pixelCount)
        return -1;

    return img;
}

static unsigned char readLabel (FILE *file)
{
    unsigned char label = NULL;
    
    size_t gelesen = fread (&label, sizeof(unsigned char), 1, file);
        if (gelesen == NULL)
        return -1;

    return label;
}

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

    FILE *file = fopen(path, "rb"); 
    if (path == NULL) {
        return -1; 
    }

    if (checkHeader(file) != 1) {
        return -1;
    }

    count = readUnit (file); 

    series = malloc (sizeof(GrayScaleImageSeries));
    series ->count = count;
    series ->images = malloc (count * sizeof(GrayScaleImage));
    series ->labels = malloc (count * sizeof(unsigned char));

    for (unsigned int i = 0; i < count; i++)
    {
        series ->images[i] = readSingleImage(file);
        series ->labels[i] = readLabel(file);
    }

    fclose (file); 
    return series; //series ist das array das ein Bild besitzt
}
*/
// TODO Implementieren Sie geeignete Hilfsfunktionen für das Lesen der Bildserie aus einer Datei neue Version16.11. 11:40 3/6 Tests

static int checkHeader (FILE *file)
{
    char header [strlen (FILE_HEADER_STRING) +1]; //Ermittle die Länge des Strings, +1 wegen Null

    size_t gelesen = fread (header, sizeof(char), strlen(FILE_HEADER_STRING), file);
    if (gelesen == 0)
        return -1;
    
    header [strlen (FILE_HEADER_STRING)] = '\0';

    if (strcmp (header, FILE_HEADER_STRING) == 0) //Headerlänge Vergleich 
    {
        return 1;
    } else 
    {
        return -1;
    }   

}

static unsigned int readUnit (FILE *file)
{
    unsigned int value = 0;
    size_t gelesen = fread (&value, sizeof(unsigned int), 1, file); //liest genau 4 Bytes ein
    if (gelesen == 0)
        return -1;
    
    return value;

}

static GrayScaleImage readSingleImage (FILE *file)
{
    GrayScaleImage img;
    img.buffer = NULL;
    img.width = 0;
    img.height = 0;

    //Breite und Höhe einlesen
    size_t gelesenWidth = fread (&img.width, sizeof(unsigned int), 1, file);
    size_t gelesenHeight = fread (&img.height, sizeof(unsigned int), 1, file);
        if (gelesenWidth == 0 || gelesenHeight == 0)
            return img;
    
    //Speicher für Pixel reservieren
    size_t pixelCount = img.width * img.height;
    img.buffer = malloc(pixelCount * sizeof(GrayScalePixelType));
        if (img.buffer == NULL){
            img.width = 0;
            img.height = 0;
            return img;
        }

    //Pixel einlesen
    size_t gelesenPixels = fread (img.buffer, sizeof(GrayScalePixelType), pixelCount, file);
    if (gelesenPixels != pixelCount) {
        img.buffer = NULL;
        img.width = 0;
        img.height = 0;
        return img;
    }

    return img;
}

static unsigned char readLabel (FILE *file)
{
    unsigned char label = 0;
    
    size_t gelesen = fread (&label, sizeof(unsigned char), 1, file);
        if (gelesen == 0)
        return 0;

    return label;
}

// TODO Vervollständigen Sie die Funktion readImages unter Benutzung Ihrer Hilfsfunktionen
GrayScaleImageSeries *readImages(const char *path)
{
    GrayScaleImageSeries *series = NULL;
    unsigned int count = 0;

    FILE *file = fopen(path, "rb"); 
    if (path == 0) {
        return NULL; 
    }

    if (checkHeader(file) != 1) {
        return NULL;
    }

    count = readUnit (file); 

    series = malloc (sizeof(GrayScaleImageSeries));
    series->count = count;
    series->images = malloc (count * sizeof(GrayScaleImage));
    series->labels = malloc (count * sizeof(unsigned char));

    for (unsigned int i = 0; i < count; i++)
    {
        series->images[i] = readSingleImage(file);
        if (series->images[i].buffer == NULL){
            
        }
        series->labels[i] = readLabel(file);
    }

    fclose (file); 
    return series; //series ist das array das ein Bild besitzt
}



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