#include <string>
#include <iostream>
#include <fstream>
#include <filesystem>
#include <vector>
#include <string.h>

using namespace std;
namespace fs = std::filesystem;

struct file_t
{
    string      path;
    uint32_t    size;
    uint32_t    offset;
};

vector<file_t> toc;

void printHelp()
{
    cout << "Usage: respak2 <command>" << endl;
    cout << endl << "Valid commands:" << endl;
    cout << "-p: Pack all files and folders within the 'data' folder into a file named 'data.jf2'." << endl;
    cout << "-u: Unpack all files inside the file 'data.jf2' into the 'data' folder." << endl;
    cout << "-l: List the contents of the 'data.jf2' file." << endl;
    exit(1);
}

void printErrorAndExit(string errorMsg) {
    cout << errorMsg << endl;
    exit(1);
}

bool createDirectories(const string& dirName)
{
    fs::path path(dirName);

    std::error_code err;
    if (!fs::create_directories(path.remove_filename(), err))
    {
        if (fs::exists(path.remove_filename()))
        {
            return true;    // the folder probably already existed
        }

        printf("createDirectories: FAILED to create [%s], err:%s\n", dirName.c_str(), err.message().c_str());
        return false;
    }
    return true;
}

void printDirectory(string path, int tabs=0)
{
    for (const auto & entry : fs::directory_iterator(path))
    {
        for(int i=0;i<tabs;++i) cout << '\t';
        cout << entry.path().string() << endl;
        if (entry.is_directory()) printDirectory(entry.path().string(),tabs+1);
    }
}


void packDirectory(string path, ofstream& fo, uint32_t& num_files, uint32_t& offset)
{
    for (const auto & entry : fs::directory_iterator(path))
    {
        if (entry.is_directory())
            packDirectory(entry.path().string(), fo, num_files, offset);
        else
        {
            const string filename = entry.path().string();
            ifstream fi(filename, ios::binary |ios::ate);
            if (!fi.is_open()) printErrorAndExit("ERROR: Error al obrir l'arxiu '"+filename+"'.");
            const uint32_t size = fi.tellg();
            fi.seekg(0);
            fo << fi.rdbuf();
            fi.close();
            toc.push_back({filename.substr(filename.find_first_of('/')+1), size, offset});
            cout << filename << ":" << size << ":" << offset << endl;
            num_files++;
            offset+=size;
        }
    }
}

void doPack()
{
    //printDirectory("data");

    uint32_t num_files = 0;
    uint32_t toc_offset = 12;

    ofstream fo ("data.jf2", ios::binary);
    if (!fo.is_open()) printErrorAndExit("ERROR: No s'ha pogut obrir l'arxiu 'data.jf2'.");
    fo.write("PK2",4);
    fo.write( (char*)&num_files, 4 );
    fo.write( (char*)&toc_offset, 4 );

    packDirectory("data", fo, num_files, toc_offset);

    for (auto file : toc)
    {
        fo.write( (char*)&file.offset, 4 );
        fo.write( (char*)&file.size, 4 );
        const uint8_t path_size = file.path.size();
        fo.write( (char*)&path_size, 1 );
        // We use this preliminar step to replace '\' with '/', as respak2 in windows generates backslashes, which break everything
        char replace[256];
        strcpy(replace, file.path.c_str());
        for (int i=0; i<path_size; ++i) if (replace[i] == '\\') replace[i] = '/';
        fo.write( replace, path_size );
    }

    fo.seekp(4);
    fo.write( (char*)&num_files, 4 );
    fo.write( (char*)&toc_offset, 4 );

    fo.close();
}

void doUnpack()
{
    ifstream fi ("data.jf2", ios::binary);
    if (!fi.is_open()) printErrorAndExit("ERROR: No s'ha pogut obrir l'arxiu 'data.jf2'.");
    char header[4];
    fi.read(header, 4);
    uint32_t num_files, toc_offset;
    fi.read((char*)&num_files, 4);
    fi.read((char*)&toc_offset, 4);
    fi.seekg(toc_offset);

    for (int i=0; i<num_files; ++i) 
    {
        uint32_t file_offset, file_size;
        fi.read( (char*)&file_offset, 4 );
        fi.read( (char*)&file_size, 4 );
        uint8_t path_size;
        fi.read( (char*)&path_size, 1 );
        char file_name[path_size+1];
        fi.read( file_name, path_size );
        file_name[path_size] = 0;
        string filename = file_name;
        // cout << filename << " : " << file_size << " : " << file_offset << endl;
        toc.push_back({filename, file_size, file_offset});
    }

    for (auto file : toc)
    {
        fi.seekg(file.offset);
        if (!createDirectories(file.path)) printErrorAndExit("ERROR: No s'ha pogut crear la ruta '"+file.path+"'.");
        ofstream fo (file.path, ios::binary);
        if (!fo.is_open()) printErrorAndExit("ERROR: No s'ha pogut obrir l'arxiu '"+file.path+"'.");
        char* buffer = (char*)malloc(file.size);
        fi.read(buffer, file.size);
        fo.write(buffer, file.size);
        fo.close();
    }

    fi.close();
}

void doList()
{
    ifstream fi ("data.jf2", ios::binary);
    if (!fi.is_open()) printErrorAndExit("ERROR: No s'ha pogut obrir l'arxiu 'data.jf2'.");
    char header[4];
    fi.read(header, 4);
    uint32_t num_files, toc_offset;
    fi.read((char*)&num_files, 4);
    fi.read((char*)&toc_offset, 4);
    fi.seekg(toc_offset);

    for (int i=0; i<num_files; ++i) 
    {
        uint32_t file_offset, file_size;
        fi.read( (char*)&file_offset, 4 );
        fi.read( (char*)&file_size, 4 );
        uint8_t path_size;
        fi.read( (char*)&path_size, 1 );
        char file_name[path_size+1];
        fi.read( file_name, path_size );
        file_name[path_size] = 0;
        string filename = file_name;
        cout << filename << " : " << file_size << " : " << file_offset << endl;
        toc.push_back({filename, file_size, file_offset});
    }
    fi.close();
}

int main(int argc, char *argv[])
{
    if (argc<2) printHelp();

    string command = argv[1];

    if ( command == "-p" )
        doPack();
    else if ( command == "-u" )
        doUnpack();
    else if ( command == "-l" )
        doList();
    else
        printHelp();

    return 0;
}