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

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

bool writedata(const char *basename, 
               unsigned int id, 
               const char *data,
               unsigned int dsize) {
    bool status = false;
    char *fn    = (char*)malloc(sizeof(char) * strlen(basename) + 4);
    sprintf(fn, "%s_%d", basename, id);
    FILE *out   = fopen(fn, "w");
    if (out != NULL) {
        fwrite(data, sizeof(char), dsize, out);
        fclose(out);
        status = true;
    }
    free(fn);
    return status;
}

void splitpld(const char *filedata,               
              unsigned int filesize, 
              const struct PldHeader *ph, 
              const char *name) {
    char *wbuffer      = NULL; // write buffer that will change.
    unsigned int wsize = 0;    // size of wbuffer.
    unsigned int i;
    unsigned int start = 0;    // ending offset for data
    unsigned int end   = 0;    // ending offset for data
    for (i = 0; (i + 1) < (ph -> numOffset) + 1; i++) {
        start = ph -> offsets[i];
        // the last offset still has some data until the end of file
        end   = (i == (ph -> numOffset) - 1) ? 
                filesize : ph -> offsets[i + 1];
        // copy sector to write buffer
        wsize   = end - start;
        wbuffer = (char*)malloc(sizeof(char) * wsize);
        memcpy(wbuffer, filedata + start, wsize);
        // create a file.
        writedata(name, i, wbuffer, wsize);
        free(wbuffer);
    }
}

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 doesn't work until 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;
}

bool unpackpld (const char *filedata, 
                unsigned int filesize,
                const char *filename) {
    bool status = false;
    printf("fsize is %i\n", filesize);
    if (filedata != NULL && filesize != 0) {
        struct PldHeader *pldh = getpldh(filedata);
        splitpld(filedata, filesize, pldh, filename);
        destroypldh(pldh);
        status = true;
    }
    return status;
}

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");
        }
    }
}

void unpacktextures(const char *filedata, 
                    unsigned int filesize,
                    const char *filename) {
    struct TexturePack *tp        = (struct TexturePack*)filedata;
    struct TextureBatch **batches             = NULL;
    struct TextureBatchDescriptor **descripts = NULL;
    batches   = (struct TextureBatch**)malloc(tp -> batchNumber);
    descripts = (struct TextureBatchDescriptor**)malloc(tp -> batchNumber);
    gettbd(descripts, filedata, filesize);
    // array of pointers - texture data exists in memory in filedata.
    unsigned int texturecount = gettexturebatch(batches, 
                                                descripts, 
                                                filedata, 
                                                filesize);
    unsigned int *tloc = (unsigned int*)
                            malloc(sizeof(unsigned int) * texturecount);
    locatetextures(tloc, tp, descripts);
    // add 3 to buffer for digits, & 4 for file extension
    char *fmt = (char*)malloc(strlen(filename) + 3 + 4);
    unsigned int texsize = 0;
    unsigned int i;
    for (i = 0; i < texturecount; i++) {
        texsize = descripts[i/(tp -> batchNumber)] -> textureSize;
        sprintf(fmt, "%s_%d.dds", filename, i);
        write(fmt, filedata + tloc[i], texsize);
    }
    free(fmt);
    free(tloc);
    free(descripts);
    free(batches);
}

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 (filename == 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;
}

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);
    free(buffer);
    return 0;
}