/*
 * test_channel_user_list_abi — M4 channel/user/stream snapshot getters.
 *
 * Covers the new pull-based ABI surface (voicecat.h): vc_list_channels, vc_list_users,
 * vc_list_user_streams, and the new VC_EVENT_JOIN_RESULT feedback for vc_join_channel.
 * Mirrors test_vad_ptt_devices.cpp's approach (real vc_client instances against a real
 * in-process server, not raw sockets).
 *
 *   1. Pre-data: a freshly created (not yet connected) client's getters return VC_OK,
 *      count=0 — never an error just because nothing has arrived yet.
 *   2. After two guests connect and auth: vc_list_channels reflects the server's real
 *      channel config (this is the regression test for the SessionModel field-population
 *      fix — parent_id/password_protected/max_users were silently dropped before);
 *      vc_list_users on either client includes both users with correct nickname/channel_id.
 *   3. After A starts a MIC stream: B's vc_list_user_streams(A's user_id) shows it, with the
 *      same stream_id as A's own VC_EVENT_STREAM_STARTED.
 *   4. vc_list_user_streams with an unknown user_id returns VC_ERR_INVALID_ARG.
 *   5. vc_join_channel's result arrives via VC_EVENT_JOIN_RESULT — success (re-joining the
 *      channel already in) and failure (an unknown channel id).
 *   6. Every vc_free_*_list is idempotent (safe to call twice).
 */
#include <cstdio>

#include <atomic>
#include <chrono>
#include <condition_variable>
#include <cstring>
#include <filesystem>
#include <mutex>
#include <string>
#include <thread>
#include <vector>

#include "voicecat.h"
#include "server.h"

// ── Event tracking ────────────────────────────────────────────────────────────

struct StreamEvent {
    bool     started;
    uint32_t user_id;
    uint32_t stream_id;
};

struct JoinResult {
    bool     ok;
    uint32_t channel_id;
    std::string error;
};

struct EventStore {
    std::mutex              mu;
    std::condition_variable cv;

    bool     auth_ok{false};
    uint32_t self_user_id{0};
    bool     channel_list_received{false};
    std::vector<StreamEvent> stream_events;
    std::vector<JoinResult>  join_results;
    bool     voice_subscribed{false};

    const char* label{nullptr};
    vc_client*  client{nullptr};
};

static void on_event(void* user, const vc_event* ev) {
    auto* s = static_cast<EventStore*>(user);
    std::lock_guard lk(s->mu);
    switch (ev->type) {
        case VC_EVENT_SERVER_IDENTITY:
            vc_confirm_server_identity(s->client, 1);
            break;
        case VC_EVENT_AUTH_RESULT:
            s->auth_ok      = (ev->result == VC_OK);
            s->self_user_id = ev->user_id;
            break;
        case VC_EVENT_CHANNEL_LIST:
            s->channel_list_received = true;
            break;
        case VC_EVENT_VOICE_STATE:
            s->voice_subscribed = (ev->u32a == 1);
            break;
        case VC_EVENT_STREAM_STARTED:
            s->stream_events.push_back({true, ev->user_id, ev->stream_id});
            break;
        case VC_EVENT_STREAM_STOPPED:
            s->stream_events.push_back({false, ev->user_id, ev->stream_id});
            break;
        case VC_EVENT_JOIN_RESULT:
            s->join_results.push_back(
                {ev->result == VC_OK, ev->channel_id, ev->text ? ev->text : ""});
            break;
        default:
            break;
    }
    s->cv.notify_all();
}

template <typename Pred>
static bool wait_for(EventStore& s, Pred pred, int timeout_ms) {
    auto deadline = std::chrono::steady_clock::now() + std::chrono::milliseconds(timeout_ms);
    std::unique_lock lk(s.mu);
    return s.cv.wait_until(lk, deadline, [&] { return pred(s); });
}

// ── Test harness ──────────────────────────────────────────────────────────────

static int g_failures = 0;
#define CHECK(cond)                                                        \
    do {                                                                   \
        if (!(cond)) {                                                     \
            std::printf("FAIL: %s (%s:%d)\n", #cond, __FILE__, __LINE__); \
            ++g_failures;                                                  \
        }                                                                  \
    } while (0)

// ── 1. Pre-data: getters never error just because nothing has arrived yet ──────
static void test_pre_data_empty() {
    vc_config cfg{"test-predata", "0.1", VC_LOG_OFF};
    vc_callbacks cb{};
    vc_client* c = vc_client_create(&cfg, cb);
    CHECK(c != nullptr);

    vc_channel_list cl{};
    CHECK(vc_list_channels(c, &cl) == VC_OK);
    CHECK(cl.count == 0);
    vc_free_channel_list(&cl);
    vc_free_channel_list(&cl);  // idempotent

    vc_user_list ul{};
    CHECK(vc_list_users(c, &ul) == VC_OK);
    CHECK(ul.count == 0);
    vc_free_user_list(&ul);
    vc_free_user_list(&ul);  // idempotent

    // No users known yet — any user_id is "unknown".
    vc_stream_summary_list sl{};
    CHECK(vc_list_user_streams(c, 1, &sl) == VC_ERR_INVALID_ARG);

    vc_client_destroy(c);
    std::printf("test_pre_data_empty: ok\n");
}

// ── 2-6. Real connect/auth/join/stream against a real in-process server ────────
static void test_live_channel_user_list() {
    auto tmp = std::filesystem::temp_directory_path() /
               ("vctest_chanlist_" + std::to_string(
                   std::chrono::steady_clock::now().time_since_epoch().count()));
    std::filesystem::create_directories(tmp);
    std::string data_dir = tmp.string();

    std::atomic<uint16_t> bound_port{0};
    std::mutex              ready_mu;
    std::condition_variable ready_cv;
    bool                    ready{false};

    voicecat::server::Config cfg;
    cfg.data_dir     = data_dir;
    cfg.bind_port    = 0;
    cfg.media_port   = 0;
    cfg.server_name  = "VoiceCat-ChanListTest";
    cfg.allow_guests = true;
    cfg.on_ready = [&](uint16_t p) {
        bound_port.store(p);
        { std::lock_guard lk(ready_mu); ready = true; }
        ready_cv.notify_all();
    };

    voicecat::server::Server server(cfg);
    std::thread server_thread([&] { server.run(); });

    {
        std::unique_lock lk(ready_mu);
        bool ok = ready_cv.wait_for(lk, std::chrono::seconds(10), [&] { return ready; });
        if (!ok) {
            std::printf("FAIL: server did not become ready within 10s\n");
            ++g_failures;
            server.stop();
            server_thread.join();
            std::filesystem::remove_all(tmp);
            return;
        }
    }

    uint16_t port = bound_port.load();
    std::printf("test_live_channel_user_list: server ready on :%u\n", port);

    EventStore evA;
    evA.label = "A";
    vc_callbacks cbA{on_event, nullptr, &evA};
    vc_config cfgA{"test-A", "0.1", VC_LOG_OFF};
    vc_client* clientA = vc_client_create(&cfgA, cbA);
    CHECK(clientA != nullptr);
    evA.client = clientA;
    CHECK(vc_connect(clientA, "127.0.0.1", port) == VC_OK);
    CHECK(vc_authenticate_guest(clientA, "CL-A") == VC_OK);
    CHECK(wait_for(evA, [](EventStore& s) { return s.auth_ok; }, 8000));
    CHECK(wait_for(evA, [](EventStore& s) { return s.channel_list_received; }, 3000));

    CHECK(vc_join_voice(clientA) == VC_OK);
    CHECK(wait_for(evA, [](EventStore& s) { return s.voice_subscribed; }, 5000));

    EventStore evB;
    evB.label = "B";
    vc_callbacks cbB{on_event, nullptr, &evB};
    vc_config cfgB{"test-B", "0.1", VC_LOG_OFF};
    vc_client* clientB = vc_client_create(&cfgB, cbB);
    CHECK(clientB != nullptr);
    evB.client = clientB;
    CHECK(vc_connect(clientB, "127.0.0.1", port) == VC_OK);
    CHECK(vc_authenticate_guest(clientB, "CL-B") == VC_OK);
    CHECK(wait_for(evB, [](EventStore& s) { return s.auth_ok; }, 8000));
    CHECK(wait_for(evB, [](EventStore& s) { return s.channel_list_received; }, 3000));

    CHECK(vc_join_voice(clientB) == VC_OK);
    CHECK(wait_for(evB, [](EventStore& s) { return s.voice_subscribed; }, 5000));

    uint32_t a_uid = 0, b_uid = 0;
    { std::lock_guard lk(evA.mu); a_uid = evA.self_user_id; }
    { std::lock_guard lk(evB.mu); b_uid = evB.self_user_id; }

    // ── 2a. vc_list_channels reflects the real server config (regression test for the
    // SessionModel field-population fix — parent_id/password_protected/max_users). ──────────
    {
        vc_channel_list cl{};
        CHECK(vc_list_channels(clientA, &cl) == VC_OK);
        CHECK(cl.count == 2);  // Lobby (1) + Music Room (2), per session_registry.cpp
        bool found_lobby = false;
        for (size_t i = 0; i < cl.count; ++i) {
            CHECK(cl.items[i].name != nullptr);
            if (cl.items[i].id == 1) {
                found_lobby = true;
                CHECK(std::strcmp(cl.items[i].name, "Lobby") == 0);
                CHECK(cl.items[i].parent_id == 0);
                CHECK(cl.items[i].password_protected == 0);
                CHECK(cl.items[i].max_users == 20);  // non-default — proves the fix
            }
        }
        CHECK(found_lobby);
        vc_free_channel_list(&cl);
        vc_free_channel_list(&cl);  // idempotent
    }

    // ── 2b. vc_list_users includes both A and B with correct nickname/channel_id ─────────────
    {
        vc_user_list ul{};
        CHECK(vc_list_users(clientB, &ul) == VC_OK);
        CHECK(ul.count == 2);
        bool found_a = false, found_b = false;
        for (size_t i = 0; i < ul.count; ++i) {
            CHECK(ul.items[i].nickname != nullptr);
            CHECK(ul.items[i].channel_id == 1);  // both default into Lobby on auth
            if (ul.items[i].id == a_uid) { found_a = true; CHECK(std::strcmp(ul.items[i].nickname, "CL-A") == 0); }
            if (ul.items[i].id == b_uid) { found_b = true; CHECK(std::strcmp(ul.items[i].nickname, "CL-B") == 0); }
        }
        CHECK(found_a);
        CHECK(found_b);
        vc_free_user_list(&ul);
        vc_free_user_list(&ul);  // idempotent
    }

    // ── 3. vc_list_user_streams reflects a real stream, cross-checked against the
    // STREAM_STARTED event's stream_id. ──────────────────────────────────────────────────────
    vc_stream_desc mic_desc{};
    mic_desc.kind  = VC_STREAM_MIC;
    mic_desc.label = "mic";
    uint32_t mic_sid = 0;
    CHECK(vc_stream_start(clientA, &mic_desc, &mic_sid) == VC_OK);
    CHECK(wait_for(evB, [](EventStore& s) { return !s.stream_events.empty(); }, 5000));

    {
        vc_stream_summary_list sl{};
        CHECK(vc_list_user_streams(clientB, a_uid, &sl) == VC_OK);
        CHECK(sl.count == 1);
        if (sl.count == 1) {
            CHECK(sl.items[0].stream_id == mic_sid);
            CHECK(sl.items[0].kind == VC_STREAM_MIC);
            CHECK(sl.items[0].label != nullptr);
        }
        vc_free_stream_summary_list(&sl);
        vc_free_stream_summary_list(&sl);  // idempotent
    }

    // ── 4. Unknown user_id ───────────────────────────────────────────────────────────────────
    {
        vc_stream_summary_list sl{};
        CHECK(vc_list_user_streams(clientB, 0xDEADBEEF, &sl) == VC_ERR_INVALID_ARG);
    }

    // ── 5. VC_EVENT_JOIN_RESULT — success (re-join the channel already in) and failure
    // (unknown channel id). ─────────────────────────────────────────────────────────────────
    CHECK(vc_join_channel(clientA, 1, nullptr) == VC_OK);
    CHECK(wait_for(evA, [](EventStore& s) { return !s.join_results.empty(); }, 3000));
    {
        std::lock_guard lk(evA.mu);
        CHECK(evA.join_results.back().ok);
        CHECK(evA.join_results.back().channel_id == 1);
    }

    size_t mark;
    { std::lock_guard lk(evA.mu); mark = evA.join_results.size(); }
    CHECK(vc_join_channel(clientA, 999999, nullptr) == VC_OK);
    CHECK(wait_for(evA, [&](EventStore& s) { return s.join_results.size() > mark; }, 3000));
    {
        std::lock_guard lk(evA.mu);
        CHECK(!evA.join_results.back().ok);
        CHECK(!evA.join_results.back().error.empty());
    }

    vc_stream_stop(clientA, mic_sid);
    vc_disconnect(clientA);
    vc_disconnect(clientB);
    vc_client_destroy(clientA);
    vc_client_destroy(clientB);

    server.stop();
    server_thread.join();
    std::filesystem::remove_all(tmp);

    std::printf("test_live_channel_user_list: done\n");
}

int main() {
    test_pre_data_empty();
    test_live_channel_user_list();

    if (g_failures == 0) {
        std::printf("channel_user_list_abi: all checks passed\n");
        return 0;
    }
    std::printf("channel_user_list_abi: %d failure(s)\n", g_failures);
    return 1;
}