#include "rpc/platform/runtime_paths.hpp"

#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>

#include <cerrno>
#include <cstdlib>

namespace velox::daemon::rpc::platform {

namespace {
std::error_code errc(int e) { return std::error_code(e, std::generic_category()); }
}  // namespace

std::error_code runtime_base_dir(std::string& out) {
    if (const char* xdg = ::getenv("XDG_RUNTIME_DIR"); xdg != nullptr && xdg[0] != '\0') {
        out = xdg;
        return {};
    }
    const std::string base = "/run/user/" + std::to_string(::geteuid());
    struct stat st{};
    if (::stat(base.c_str(), &st) != 0 || !S_ISDIR(st.st_mode)) {
        // No XDG_RUNTIME_DIR and no /run/user/<uid>: refuse rather than pick an insecure
        // fallback. The caller surfaces this as "cannot start".
        return errc(ENOENT);
    }
    out = base;
    return {};
}

std::error_code data_base_dir(std::string& out) {
    if (const char* xdg = ::getenv("XDG_DATA_HOME"); xdg != nullptr && xdg[0] != '\0') {
        out = xdg;
        return {};
    }
    if (const char* home = ::getenv("HOME"); home != nullptr && home[0] != '\0') {
        out = std::string(home) + "/.local/share";
        return {};
    }
    return errc(ENOENT);
}

}  // namespace velox::daemon::rpc::platform