gMod/source/gMod_FileLoader.cpp

#include <uMod_Main.h>
#include <filesystem>
#include "gMod_FileLoader.h"
#include "gMod_XorStream.h"

gMod_FileLoader::gMod_FileLoader(const std::string& fileName)
{
    file_name = std::filesystem::absolute(fileName).string();
}

std::vector<TpfEntry> gMod_FileLoader::Load()
{
    if (!loaded) {
        entry_cache = GetContents();
        loaded = true;
    }

    return entry_cache;
}

std::vector<TpfEntry> gMod_FileLoader::GetContents()
{
    return file_name.ends_with(".tpf") ? GetTpfContents() : GetFileContents();
}

std::vector<TpfEntry> gMod_FileLoader::GetTpfContents()
{
    std::vector<TpfEntry> entries;
    try {
        auto istream = std::ifstream(file_name, std::ios::binary);
        auto xorstream = gMod_XorStream(istream);
        const auto buffer = xorstream.ReadToEnd();
        const std::string password(TPF_PASSWORD.begin(), TPF_PASSWORD.end());
        auto zipArchive = libzippp::ZipArchive::fromBuffer(buffer.data(), buffer.size(), false, password);
        zipArchive->setErrorHandlerCallback([](const std::string& message, const std::string& strerror, int zip_error_code, int system_error_code) -> void {
            Message("GetTpfContents: %s %s %d %d\n", message.c_str(), strerror.c_str(), zip_error_code, system_error_code);
            });
        zipArchive->open();
        LoadEntries(*zipArchive, entries);
        zipArchive->close();
        istream.close();
        delete(zipArchive);
    }
    catch (const std::exception& e) {
        throw std::runtime_error("Failed to open zip file: " + file_name + "\n" + e.what());
    }

    return entries;
}

std::vector<TpfEntry> gMod_FileLoader::GetFileContents()
{
    std::vector<TpfEntry> entries;

    try {
        libzippp::ZipArchive zipArchive(file_name);
        zipArchive.open();
        LoadEntries(zipArchive, entries);
        zipArchive.close();
    }
    catch (const std::exception& e) {
        throw std::runtime_error("Failed to open zip file: " + file_name);
    }

    return entries;
}

void ParseSimpleArchive(libzippp::ZipArchive& archive, std::vector<TpfEntry>& entries) {
    for (const auto& entry : archive.getEntries()) {
        if (entry.isFile()) {
            //TODO: #6 - Implement regex search
            const auto dataPtr = entry.readAsBinary();
            const auto size = entry.getSize();
            auto name = entry.getName();

            // Remove the part before the last underscore (if any)
            size_t firstIndex = name.find_last_of('_');
            while (firstIndex != std::string::npos) {
                if (firstIndex >= entry.getName().length() - 1) {
                    name = entry.getName();
                }
                else {
                    name = entry.getName().substr(firstIndex + 1);
                }

                firstIndex = name.find_last_of('_');
            }

            // Remove the file extension (if any)
            size_t lastIndex = name.find_last_of('.');
            if (lastIndex != std::string::npos) {
                name = name.substr(0, lastIndex);
            }

            uint32_t crcHash;
            try {
                crcHash = std::stoul(name, nullptr, 16);
            }
            catch (const std::invalid_argument& e) {
                Message("Failed to parse %s as a hash", name.c_str());
                continue;
            }
            catch (const std::out_of_range& e) {
                Message("Out of range while parsing %s as a hash", name.c_str());
                continue;
            }

            entries.push_back({ name, entry.getName(), crcHash, dataPtr, size });
        }
    }
}

void ParseTexmodArchive(std::vector<std::string>& lines, libzippp::ZipArchive& archive, std::vector<TpfEntry>& entries) {
    for (const auto& line : lines) {
        std::istringstream iss(line);
        std::string part;
        std::vector<std::string> splits;

        // Split the line by '|'
        while (std::getline(iss, part, '|')) {
            splits.push_back(part);
        }

        if (splits.size() != 2) {
            continue;
        }

        std::string addrstr = splits[0];
        std::string path = splits[1];

        // Remove unwanted characters from the beginning of the path
        while (!path.empty() && (path[0] == '.' && (path[1] == '/' || path[1] == '\\')) || path[0] == '/' || path[0] == '\\') {
            path.erase(0, 1);
        }

        // Remove trailing newline and carriage return characters
        size_t endpos = path.find_last_not_of("\r\n");
        if (endpos != std::string::npos) {
            path.erase(endpos + 1);
        }
        else if (!path.empty()) {
            path.clear();
        }

        const auto entry = archive.getEntry(path);
        if (entry.isNull()) {
            continue;
        }

        if (!entry.isFile()) {
            continue;
        }

        const auto dataPtr = entry.readAsBinary();
        const auto size = entry.getSize();
        uint32_t crcHash;
        try {
            crcHash = std::stoul(addrstr, nullptr, 16);
        }
        catch (const std::invalid_argument& e) {
            Message("Failed to parse %s as a hash", addrstr.c_str());
            continue;
        }
        catch (const std::out_of_range& e) {
            Message("Out of range while parsing %s as a hash", addrstr.c_str());
            continue;
        }

        entries.push_back({ addrstr, entry.getName(), crcHash, dataPtr, size });
    }
}

void gMod_FileLoader::LoadEntries(libzippp::ZipArchive& archive, std::vector<TpfEntry>& entries)
{
    // Iterate over the files in the zip archive
    auto maybeDefiniton = archive.getEntry("texmod.def");
    if (maybeDefiniton.isNull() || !maybeDefiniton.isFile()) {
        ParseSimpleArchive(archive, entries);
    }
    else {
        const auto def = maybeDefiniton.readAsText();
        std::istringstream iss(def);
        std::vector<std::string> lines;
        std::string line;

        while (std::getline(iss, line)) {
            lines.push_back(line);
        }

        ParseTexmodArchive(lines, archive, entries);
    }
}