// vfs_cat -- print one file from a layered VFS to stdout (for byte-equality
// checks against `unzip -p`, and as a tiny inspection tool).
//
//   vfs_cat [--registration] (--zip ARCHIVE | --native DIR)... REL
//   vfs_cat --list (--zip ARCHIVE | --native DIR)... [PREFIX]
#include <cstdio>
#include <cstring>
#include <string>

#include "mars/vfs/vfs.h"

using namespace mars::vfs;

int main(int argc, char** argv) {
    Order order = Order::NativeFirst;
    bool list = false;
    std::string rel;
    std::vector<std::pair<bool, std::string>> mounts;   // (is_zip, path)
    for (int i = 1; i < argc; ++i) {
        std::string a = argv[i];
        if (a == "--registration") order = Order::Registration;
        else if (a == "--list") list = true;
        else if ((a == "--zip" || a == "--native") && i + 1 < argc) mounts.emplace_back(a == "--zip", argv[++i]);
        else rel = a;
    }
    if (mounts.empty() || (!list && rel.empty())) {
        std::fprintf(stderr, "usage: vfs_cat [--registration] (--zip A | --native D)... REL\n"
                             "       vfs_cat --list (--zip A | --native D)... [PREFIX]\n");
        return 2;
    }
    Vfs v(order);
    for (const auto& [is_zip, path] : mounts) {
        auto r = is_zip ? v.mount_zip(path) : v.mount_native(path);
        if (!r) {
            std::fprintf(stderr, "mount %s: %s\n", path.c_str(), r.error().message.c_str());
            return 1;
        }
    }
    if (list) {
        for (const auto& e : v.list(rel)) std::printf("%10llu  m%d  %s\n", static_cast<unsigned long long>(e.size), e.mount, e.name.c_str());
        return 0;
    }
    auto bytes = v.read(rel);
    if (!bytes) {
        std::fprintf(stderr, "%s: %s\n", rel.c_str(), bytes.error().message.c_str());
        return 1;
    }
    std::fwrite(bytes->data(), 1, bytes->size(), stdout);
    return 0;
}