#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: Fehlerfälle prüfen, prüfen auf 0-werten etc.

static int openAndCheck(FILE **fd, const char *path)
{
    int status = 0;
    const size_t headerLen = sizeof(FILE_HEADER_STRING);
    char *headerRead = calloc(1, headerLen);
    if (!(*fd = fopen(path, "rb")))
    {
        // fprintf(stderr, "Error: could not open file %s\n", path);
        status = 2;
        goto ending_openAndCheck;
    }

    if (!fread(headerRead, headerLen-1, 1, *fd))
    {
        // fprintf(stderr, "Error: could not read file %s\n", path);
        status = 1;
        goto ending_openAndCheck;
    }

    if (strcmp(headerRead, FILE_HEADER_STRING)) // 0 = Keine Abweichung!
    {
        // fprintf(stderr, "Error: %s header mismatch\n", path);
        status = 1;
        goto ending_openAndCheck;
    }
ending_openAndCheck:
    free(headerRead);
    return status;
}

static int getUShort(FILE **fd, unsigned short *bilderAnzahl)
{
    if (!fread(bilderAnzahl, (size_t)sizeof(unsigned short), 1, *fd))
        return 1;
    return 0;
}

static int getUChar(FILE **fd, unsigned char *dest)
{
    // unsigned short lab = '0';
    if (!fread(dest, sizeof(*dest), 1, *fd))
        return 1;
    // printf("Read Label: %d\n", *dest);
    return 0;
}

static int getPixelData(FILE **fd, const size_t bufSize, GrayScalePixelType *pixelData)
{
    if (!fread((char *)pixelData, bufSize, 1, *fd))
        return 1;
    return 0;
}

static GrayScaleImageSeries *getImageReihe(const char *path, int *status)
{
    FILE *fd = NULL;

    // printf("Opening %s\n", path);

    *status = openAndCheck(&fd, path);
    if (*status)
    {
        if (*status != 2)
            fclose(fd);
        ;
        return NULL;
    }
    // fd is at head of file, read dimensions:
    unsigned short bilderAnzahl;
    unsigned short width;
    unsigned short height;

    if (getUShort(&fd, &bilderAnzahl))
    {
        *status = 1;
        fclose(fd);
        return NULL;
    }

    if (getUShort(&fd, &width))
    {
        *status = 1;
        fclose(fd);
        return NULL;
    }

    if (getUShort(&fd, &height))
    {
        *status = 1;
        fclose(fd);
        return NULL;
    }

    // fd is at head of data, read calculated size:
    // fprintf(stderr, "Anzahl: %d, Width: %d, Height: %d\n", bilderAnzahl, width, height);
    GrayScaleImageSeries *series = (GrayScaleImageSeries *)calloc(bilderAnzahl, sizeof(GrayScaleImageSeries));
    GrayScaleImage *images = (GrayScaleImage *)calloc(bilderAnzahl, sizeof(GrayScaleImage));
    unsigned char *imageLabels = (unsigned char *)calloc(bilderAnzahl, sizeof(unsigned char));
    // unsigned char buf;
    // int count = 0;

    // while(!getUChar(&fd, &buf) && buf != 15) {
    //     fprintf(stderr, "Label: %d; Count: %d\n", buf, count);
    //     count++;
    // }

    // fprintf(stderr, "Label: %d; Count: %d\n", buf, count);

    // read each image - pixelWerte dann Klasse
    for (unsigned short i = 0; i < bilderAnzahl; ++i)
    {
        images[i].height = height;
        images[i].width = width;
        size_t bufSize = sizeof(GrayScalePixelType) * (width * height);
        images[i].buffer = (GrayScalePixelType *)calloc(1, bufSize);
        // fprintf(stderr, "Reading %lu Bytes\n", bufSize);
        if (getPixelData(&fd, bufSize, images[i].buffer))
        {
            *status = 1;
            fclose(fd);
            fprintf(stderr, "Error reading pixel data\n");
            return NULL;
        }

        if (getUChar(&fd, &imageLabels[i]))
        {
            *status = 1;
            fclose(fd);
            fprintf(stderr, "Error reading image label\n");
            return NULL;
        }
    }

    series->images = images;
    series->count = bilderAnzahl;
    series->labels = imageLabels;

    fclose(fd);
    return series;
}

GrayScaleImageSeries *readImages(const char *path)
{
    GrayScaleImageSeries *series = NULL;
    int status = 0;
    series = getImageReihe(path, &status);

    return series;
}

void clearSeries(GrayScaleImageSeries *series)
{
    // GrayScalePixelType* pixelData = (GrayScalePixelType*)calloc(bilderAnzahl, sizeof(GrayScalePixelType) * width * height);
    for (unsigned short i = 0; i < series->count; ++i)
    {
        free(series->images[i].buffer);
    }
    free(series->images);
    // unsigned char* imageLabels = (unsigned char*)calloc(bilderAnzahl, sizeof(unsigned char));
    free(series->labels);

    // free(series->images[0].buffer);
    // GrayScaleImageSeries* series = (GrayScaleImageSeries*)calloc(bilderAnzahl, sizeof(GrayScaleImageSeries));
    free(series);
}