#include "pch.h"
#include <fstream>
#include <cassert>
#include <cstdio>

static int readuint32(std::ifstream& file) {
    unsigned char buffer[4];
    file.read((char *)&buffer,  4);
    int num = buffer[3] | buffer[2] << 8 | buffer[1] << 16 | buffer[0] << 24;
    return num;
}

static int printHeaderInfo(std::ifstream& file)
{
    std::printf("Size of DIR file: %d kilobytes...\n", readuint32(file)); // to not use local variable when not needed
    int structNum = readuint32(file); // read
    std::printf("Number of DIR structs: %d\n\n", structNum);
    return structNum; // return
}

static std::string readFileNames(int mockStrLen, std::ifstream& file)
{
    std::string temp(mockStrLen, 0); // create temp string the size of mockstrlen
    file.read(&temp[0], mockStrLen); // set the pointer to the start of the string and read mockstrlen amount of bytes
    return temp;
}

static std::string dirToArcFileName(std::string dirFile)
{
    if (dirFile.size() <= 3) {
        perror("filename is less than or equal to 3 chars!!!");
    }
    else
        return (dirFile.substr(0, dirFile.size() - 3)).append("arc");
}

int main(int argc, char** argv)
{
    if (argc <= 1) {
        std::printf("ARC+DIR file reader,\nUsage: drag and drop .dir file onto program.\nBy Ambrosia, 2019");
        return 1;
    }
    std::ifstream dirFile;

    dirFile.open(argv[1], std::ios::binary | std::ios::in);
    if (dirFile.is_open()) {
        int structNum, offset, size, mockStrLen;
        std::string fileName, arcFile;

        std::printf("arc file : %s \n", dirToArcFileName(argv[1]).c_str());
        structNum = printHeaderInfo(dirFile); // get header info

        for (int i = 0; i < structNum; i++) { // loop
            offset = readuint32(dirFile); // read uint
            size = readuint32(dirFile); //  read uint
            mockStrLen = readuint32(dirFile); // read uint
            fileName = readFileNames(mockStrLen, dirFile);

            std::printf("%d: filename : %s \n", i, fileName.c_str());
        }

    }
    else {
        perror(argv[1]);
        return 1;
    }
    dirFile.close();
    getchar();
    return 0;
}