#include "devil1tex.h"
#include <stdio.h>
#include <string.h>

// get texture pack header
void gettph (struct TexturePack *tp, const char *filedata) {
// Assume the Texture Pack Header is already allocated memory.
    if (tp != NULL && filedata != NULL) {
        memcpy(tp, filedata, sizeof(struct TexturePack));
    }
    return;
}

void printtph (struct TexturePack *tp) {
    if (tp != NULL) { 
        printf("id: \t %c %c %c %c \n", tp -> id[3], 
                                        tp -> id[2], 
                                        tp -> id[1], 
                                        tp -> id[0]);
        printf("batch#: \t %i \n",    tp -> batchNumber);
        printf("1st batch: \t %i \n", tp -> firstBatchOffset);
        printf("unknownA: \t %i\n",   tp -> unknownA);
    }
    return;
}

// get texture pack descriptors
void gettbd (struct TextureBatchDescriptor *tbd,
               struct TexturePack* tph,
               const char *filedata,
               unsigned int filesize) {
    if (tbd == NULL || tph == NULL || filedata == NULL) {
        // any of these being null will cause segmentation fault.
        return;
    }
    // do some checks regarding the header
    if (tph -> firstBatchOffset >= filesize || 
        tph -> firstBatchOffset <= 0) {
        return;
    }
    unsigned int index = tph -> firstBatchOffset;
    // Batch Descriptors are structured one after another.
    // therefore the next one is at
    // current index + sizeof(TextureBatchDescriptor)
    unsigned int i = 0;
    do {
        index += (sizeof(struct TextureBatchDescriptor) * i);
        printf("batch descriptor start: %x\n", index);
        tbd = (struct TextureBatchDescriptor*)(filedata + index);
        // <do something with the batch descriptor found>
    } while(i < (tph -> batchNumber));
    return;
}