PatchExtractor/source/extractor.cpp

#include "extractor.hpp"

#include <cstdio>
#include <cstring>
#include <sys/stat.h>

#ifdef __SWITCH__
#include <switch.h>
#endif

static constexpr size_t READ_BUF_SIZE = 8192;

int PatchExtractor::mkdirs(const char* path) {
    char tmp[512];
    snprintf(tmp, sizeof(tmp), "%s", path);
    size_t len = strlen(tmp);
    if (len == 0) return 0;
    if (tmp[len - 1] == '/') tmp[len - 1] = '\0';

    for (char* p = tmp + 1; *p; p++) {
        if (*p == '/') {
            *p = '\0';
            mkdir(tmp, 0755);
            *p = '/';
        }
    }
    return mkdir(tmp, 0755);
}

bool PatchExtractor::open() {
    zip = unzOpen(PATCHES_ZIP);
    if (!zip) return false;

    unz_global_info gi{};
    if (unzGetGlobalInfo(zip, &gi) != UNZ_OK) {
        close();
        return false;
    }

    total     = gi.number_entry;
    extracted = 0;
    skipped   = 0;
    finished  = false;
    err       = unzGoToFirstFile(zip);
    return true;
}

void PatchExtractor::close() {
    if (zip) {
        unzClose(zip);
        zip = nullptr;
    }
}

int PatchExtractor::getProgressPercent() const {
    if (total == 0) return 100;
    return static_cast<int>((extracted * 100) / total);
}

bool PatchExtractor::step() {
    if (!zip || finished) return false;

    if (err != UNZ_OK) {
        finished = true;
        return false;
    }

    char filename[512];
    char fullpath[1024];
    unz_file_info fi{};

    unzGetCurrentFileInfo(zip, &fi, filename, sizeof(filename), nullptr, 0, nullptr, 0);
    snprintf(fullpath, sizeof(fullpath), "%s%s", EXTRACT_DIR, filename);
    currentFile = filename;

    size_t flen = strlen(filename);
    if (flen > 0 && filename[flen - 1] == '/') {
        mkdirs(fullpath);
    } else {
        char dirpart[1024];
        snprintf(dirpart, sizeof(dirpart), "%s", fullpath);
        char* last_slash = strrchr(dirpart, '/');
        if (last_slash) {
            *last_slash = '\0';
            mkdirs(dirpart);
        }

        if (unzOpenCurrentFile(zip) == UNZ_OK) {
            FILE* out = fopen(fullpath, "wb");
            if (out) {
                unsigned char buf[READ_BUF_SIZE];
                int bytes;
                while ((bytes = unzReadCurrentFile(zip, buf, READ_BUF_SIZE)) > 0) {
                    fwrite(buf, 1, static_cast<size_t>(bytes), out);
                }
                fclose(out);
            } else {
                skipped++;
            }
            unzCloseCurrentFile(zip);
        } else {
            skipped++;
        }
    }

    extracted++;
    err = unzGoToNextFile(zip);
    if (err != UNZ_OK) finished = true;

    return !finished;
}

bool PatchExtractor::cleanup() {
    cleanupOk_ = true;

    if (remove(PATCHES_ZIP) != 0)
        cleanupOk_ = false;

    // Cannot delete our own NRO while the app is still running; try anyway for edge cases.
    remove(SELF_NRO);

    remove("sdmc:/switch/.PatchExtractor.nro.star");
    remove("sdmc:/switch/.packages/boot_package.ini");

    return cleanupOk_;
}

void PatchExtractor::tryDeleteSelfOnExit() {
#ifdef __SWITCH__
    // Embedded ROMFS keeps the .nro open on SD; unmount before unlink (console build had no ROMFS).
    romfsExit();
#endif
    remove(SELF_NRO);
}