#include <iostream>
#include <iomanip>
#include <fstream>
#include <cstdint>
#include <sstream>
using namespace std;

typedef uint32_t u32;
typedef uint8_t u8;

#define BLOCKS_PER_MEGABYTE 1024*1024/0x10

struct ctrCommand {
    u32 ctr[4];
    u32 keyY[4];
    u32 megabytes;
    wchar_t filename[32];
};
struct ctrCommandsList {
    int count;
    ctrCommand* items;
};

string padHex(u32 n) {
    stringstream s;
    s << setfill('0') << setw(8) << hex << n;
    return s.str();
}
string itos(int n) {
    stringstream s;
    s << n;
    return s.str();
}


void add_ctr(void* ctr, u32 carry)
{
    u32 counter[4];
    u8 *outctr = (u8 *) ctr;
    u32 sum;
    int i;

    for(i=0; i<4; i++){
        counter[i] = (outctr[i*4+0]<<24) | (outctr[i*4+1]<<16) | (outctr[i*4+2]<<8) | (outctr[i*4+3]<<0);}

    for(i=3; i>=0; i--)
    {
        sum = counter[i] + carry;
        if (sum < counter[i]){
            carry = 1;}
        else{
            carry = 0;}
        counter[i] = sum;
    }

    for(i=0; i<4; i++)
    {
        outctr[i*4+0] = counter[i]>>24;
        outctr[i*4+1] = counter[i]>>16;
        outctr[i*4+2] = counter[i]>>8;
        outctr[i*4+3] = counter[i]>>0;
    }
}


void showCommandInfo(ctrCommand* command) {
    cout << "counter:"
            << " " << padHex(command->ctr[3])
            << " " << padHex(command->ctr[2])
            << " " << padHex(command->ctr[1])
            << " " << padHex(command->ctr[0])
            << endl;
    cout << "keyY:   "
            << " " << padHex(command->keyY[3])
            << " " << padHex(command->keyY[2])
            << " " << padHex(command->keyY[1])
            << " " << padHex(command->keyY[0])
            << endl;
    cout << "length: " << command->megabytes << " MiB" << endl;
    wcout << "filename: " << command->filename << endl;
}

ctrCommandsList splitCommand(ctrCommand* command, int chunkSize) {

    ctrCommandsList list;

    list.count = (command->megabytes+chunkSize-1)/chunkSize;
    list.items = new ctrCommand[list.count];

    for (int i=0; i<list.count; i++) {
        list.items[i] = *command;
        list.items[i].megabytes = chunkSize;

        char c1 = itos(i/10).c_str()[0];
        char c2 = itos(i%10).c_str()[0];

        int length = wcslen(list.items[i].filename);

        list.items[i].filename[length] = '.';
        list.items[i].filename[length+1] = (wchar_t)c1;
        list.items[i].filename[length+2] = (wchar_t)c2;

        add_ctr(command->ctr, chunkSize*BLOCKS_PER_MEGABYTE);
    }

    if (command->megabytes % chunkSize != 0) {
        list.items[list.count-1].megabytes = command->megabytes % chunkSize;
    }

    return list;
}

int main() {

    u32 entries;
    string filename = "D:\\3ds\\ncchinfo.bin";
    ifstream input;
    ofstream output;
    ctrCommand* command = new ctrCommand;

    input.open(filename, ifstream::in | ifstream::binary);

    input.read((char*)&entries, 4);

    cout << "This file has " << entries << " entries." << endl << endl;

    for (int i=0; i<entries; i++) {
        input.read((char*)command, sizeof(ctrCommand));

        cout << "Entry #" << i << ":" << endl;
        showCommandInfo(command);
        ctrCommandsList list = splitCommand(command, 256);

        for (int j=0; j<list.count; j++) {
            string newFilename = filename+"."+itos(i)+"."+itos(j);
            cout << "Writing entry " << i << ", chunk " << j << " to " << newFilename << endl;
            output.open(newFilename, ios::binary | ios::out);

            u32 one = 1;
            output.write((char*)&one, 4);
            output.write((char*)&(list.items[j]), sizeof(ctrCommand));

            output.close();
        }

        cout << endl;

    }

    input.close();
    cin.sync();
    cin.get();
}