#include <stdbool.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>

#include "devil1pld.h"
#include "devil1tex.h"
#include "devil1geo.h"


#define TYPE_ID_LENGTH 4





char *loadfile(const char *fname, unsigned int *s) {
    FILE *f           = fopen(fname, "rb");
    unsigned int size = 0; // number of elements to buffer;
    unsigned int rcnt = 0; // number of char's read by fread(...)
    if (f == NULL) {
        perror("Error 1: ");
        return NULL;
    }
    // this method of determining file size works up to 2 GB.
    fseek(f, 0, SEEK_END);
    size = ftell(f);
    rewind(f);
    char *buf = (char*)malloc(sizeof(char) * size);
    if (buf == NULL) {
        perror("Error 2: ");
        free(buf);
        return NULL;
    }
    rcnt = fread(buf, sizeof(char), size, f);
    if (rcnt < size) {
        perror("Error 3: ");
        free(buf);
        return NULL;
    }
    fclose(f);
    *s = rcnt;
    return buf;
}

void write(const char *filename, 
           const char* t, 
           unsigned int size) {
    if (filename == NULL) {
        return;
    }
    unsigned int written = 0;
    FILE *out = fopen(filename, "wb");
    if (out != NULL) {
        written = fwrite(t, sizeof(unsigned char), size, out);
        fclose(out);
        if (written == 0) {
            perror("texture write error");
        }
    }
}

bool unpackpld(const char *filedata,
               unsigned int filesize,
               const char *filename) {
    if (filedata == NULL || filesize <= 0 || filename == NULL) {
        return false;
    } 
    struct PldHeader h;
    getpldh(&h, filedata);
    char *fn       = NULL;
    fn = (char*)malloc(strlen(filename) + 3 + 4);
    int size       = 0;
    unsigned int i = 0;
    char textureid[TYPE_ID_LENGTH] = {'\0', '2', '3', 'T'};
    for (i = 0; i < h.numOffset; i++) {
        const char * currentfile = filedata + h.offsets[i];
        size = sizeofpldstruct(&h, i, filesize);
        if (strncmp( currentfile, textureid, TYPE_ID_LENGTH ) == 0)
          sprintf(fn, "%s_%d.txp", filename, i);
        else
          sprintf(fn, "%s_%d", filename, i);
        write(fn, currentfile, size);
    }
    free(fn);
    return true;
}

void exporttextures(const char *filedata,
                    unsigned int filesize,
                    const char *filename) {
    struct TexturePack *p = NULL;
    struct Texture *t     = NULL;
    struct TextureBatchDescriptor *d = NULL;
    char * fmt            = NULL;
    if (filedata == NULL || filesize == 0) {
        return;
    }
    p = (struct TexturePack*)filedata;
    fmt = (char*)malloc(strlen(filename) + 3 + 4);
    unsigned int i;
    unsigned int j;
    unsigned int id = 0;
    for (i = 0; i < p -> batchNumber; i++) {
        gettexdescriptor(&d, i, filedata, filesize);
        t = (struct Texture*)
                malloc(sizeof(struct Texture) * (d -> texNumber));
        unpacktexbatch(t, i, filedata, filesize);
        for (j = 0; j < d -> texNumber; j++) {
            sprintf(fmt, "%s_%d.dds", filename, id);
            write(fmt, t[j].data, d -> textureSize);
            id++;
        }
        free(t);
    }
    free(fmt);
    return;
}

void extractmeshes(const char *filedata,
                   unsigned int filesize,
                   const char *filename) {
    if (filedata == NULL || filesize <= 0) {
        return;
    }
    struct Header *h = (struct Header*)filedata;
    struct MeshHeader *mh = NULL;
    struct Mesh m;
    m.b = NULL;
    unsigned int i;
    for (i = 0; i < h -> numMesh; i++) {
        getmeshheader(&mh, i, filedata);
        m.b = (struct Batch*)malloc(sizeof(struct Batch) * (mh -> numBatch));
        if (m.b != NULL) {
            getmesh(&m, i, filedata);
            // do something with mesh e.g write to file.
            free(m.b);
        }
    } // end for
}

int main(int argc, char ** argv) {
    char *f = argv[1];
    unsigned int bufsize = 0;
    char *buffer         = loadfile(f, &bufsize);
//    unpackpld(buffer, bufsize, f);
//    exporttextures(buffer, bufsize, f);
    extractmeshes(buffer, bufsize, f);
    free(buffer);
    return 0;
}