// systemd_activated_fd(): the LISTEN_PID/LISTEN_FDS contract, without a real systemd.

#include <unistd.h>

#include <cstdlib>
#include <string>

#include "check.hpp"
#include "rpc/systemd_activation.hpp"

using namespace velox::daemon::rpc;

namespace {
void set_env(const char* k, const std::string& v) { ::setenv(k, v.c_str(), 1); }
}  // namespace

void run() {
    // Not activated: neither var set.
    ::unsetenv("LISTEN_PID");
    ::unsetenv("LISTEN_FDS");
    CHECK_EQ(systemd_activated_fd(), -1);

    // LISTEN_PID for a different process: not us, so not activated.
    set_env("LISTEN_PID", std::to_string(::getpid() + 1));
    set_env("LISTEN_FDS", "1");
    CHECK_EQ(systemd_activated_fd(), -1);
    // Consumed regardless of the outcome — a stale value from some other process's
    // exec chain must not leak into what veloxd checks next time.
    CHECK(::getenv("LISTEN_PID") == nullptr);
    CHECK(::getenv("LISTEN_FDS") == nullptr);

    // Our own pid, LISTEN_FDS=1: activated, fd 3 (SD_LISTEN_FDS_START).
    set_env("LISTEN_PID", std::to_string(::getpid()));
    set_env("LISTEN_FDS", "1");
    CHECK_EQ(systemd_activated_fd(), 3);
    CHECK(::getenv("LISTEN_PID") == nullptr);

    // Our own pid but LISTEN_FDS=2: a unit file mismatch (veloxd only ever asks for one
    // socket) — refuse rather than guess which of two fds is the right one.
    set_env("LISTEN_PID", std::to_string(::getpid()));
    set_env("LISTEN_FDS", "2");
    CHECK_EQ(systemd_activated_fd(), -1);

    // Garbage LISTEN_FDS: not activated, not a crash.
    set_env("LISTEN_PID", std::to_string(::getpid()));
    set_env("LISTEN_FDS", "not-a-number");
    CHECK_EQ(systemd_activated_fd(), -1);

    ::unsetenv("LISTEN_PID");
    ::unsetenv("LISTEN_FDS");
}

TEST_MAIN()