// rtsp_manager.cpp
#include "rtmp_manager.hpp"

#include <arpa/inet.h>
#include <ifaddrs.h>
#include <net/if.h>
#include <netinet/in.h>

#include <chrono>
#include <cstring>
#include <iostream>
#include <string>
#include <thread>

#include "logger.hpp"

static std::string get_ip_address(const std::string &ifname)
{
    struct ifaddrs *ifaddr, *ifa;
    char ip[INET_ADDRSTRLEN] = {0};

    if (getifaddrs(&ifaddr) == -1)
    {
        perror("getifaddrs");
        return "";
    }

    for (ifa = ifaddr; ifa != nullptr; ifa = ifa->ifa_next)
    {
        if (ifa->ifa_addr == nullptr) continue;

        // 只看 IPv4
        if (ifa->ifa_addr->sa_family == AF_INET && ifname == ifa->ifa_name)
        {
            void *addr = &((struct sockaddr_in *)ifa->ifa_addr)->sin_addr;
            if (inet_ntop(AF_INET, addr, ip, sizeof(ip)))
            {
                freeifaddrs(ifaddr);
                return ip;
            }
        }
    }

    freeifaddrs(ifaddr);
    return "";  // 没找到
}

static inline std::string stream_type_suffix(StreamType type) { return (type == StreamType::MAIN) ? "_main" : "_sub"; }

std::unordered_map<std::string, std::unique_ptr<RTMPManager::StreamContext>> RTMPManager::streams;
std::mutex RTMPManager::streams_mutex;
RTMPManager::StreamCallback RTMPManager::status_callback = nullptr;

std::string RTMPManager::make_stream_key(const std::string &cam_name, StreamType type)
{
    return cam_name + stream_type_suffix(type);
}

void RTMPManager::init()
{
    gst_init(nullptr, nullptr);
    LOG_INFO("[RTMP] GStreamer initialized.");
}

void RTMPManager::set_status_callback(StreamCallback cb) { status_callback = std::move(cb); }

void RTMPManager::update_status(const std::string &key, const StreamStatus &status)
{
    {
        std::lock_guard<std::mutex> lock(streams_mutex);
        auto it = streams.find(key);
        if (it != streams.end()) it->second->status = status;
    }
    if (status_callback) status_callback(key, status);
}

GstElement *RTMPManager::create_pipeline(const Camera &cam, StreamType type)
{
    int width = cam.width, height = cam.height, fps = cam.fps, bitrate = cam.bitrate;
    if (type == StreamType::SUB)
    {
        width = std::max(160, width / 2);
        height = std::max(120, height / 2);
        fps = std::max(10, fps / 2);
        bitrate = std::max(300000, bitrate / 2);
    }

    std::string stream_name = cam.name + stream_type_suffix(type);
    std::string pipeline_str = "v4l2src device=" + cam.device +
                               " ! video/x-raw,format=NV12,width=" + std::to_string(width) +
                               ",height=" + std::to_string(height) + ",framerate=" + std::to_string(fps) +
                               "/1 ! queue max-size-buffers=1 leaky=downstream "
                               "! mpph264enc bps=" +
                               std::to_string(bitrate) + " gop=" + std::to_string(fps) +
                               " ! h264parse ! flvmux streamable=true name=mux "
                               "! rtmpsink location=\"rtmp://127.0.0.1/live/" +
                               stream_name + " live=1\" sync=false";

    LOG_INFO("[RTMP] Creating pipeline for '" + stream_name + "': " + pipeline_str);

    GError *error = nullptr;
    GstElement *pipeline = gst_parse_launch(pipeline_str.c_str(), &error);
    if (error)
    {
        LOG_ERROR("[RTMP] Pipeline parse error: " + std::string(error->message));
        g_error_free(error);
        return nullptr;
    }
    return pipeline;
}

int get_camera_index(const std::string &name)
{
    for (size_t i = 0; i < g_app_config.cameras.size(); ++i)
        if (g_app_config.cameras[i].name == name) return static_cast<int>(i);
    return -1;
}

RTMPManager::StreamResultInfo RTMPManager::start_camera(const Camera &cam, StreamType type)
{
    StreamResultInfo res;
    res.loc = get_camera_index(cam.name);
    res.url = get_stream_url(cam.name, type);

    const std::string key = make_stream_key(cam.name, type);

    std::unique_ptr<StreamContext> ctx;
    std::future<StreamStatus> status_future;

    {
        std::lock_guard<std::mutex> lock(streams_mutex);
        auto it = streams.find(key);
        if (it != streams.end() && it->second->running.load())
        {
            res.result = 0;
            res.reason = "Already streaming";
            return res;
        }

        ctx = std::make_unique<StreamContext>();
        ctx->running.store(true);

        // 重要：在把 ctx 放入 map 之前，先从 ctx->start_promise 拿到 future
        status_future = ctx->start_promise.get_future();

        StreamContext *ctx_ptr = ctx.get();
        ctx->thread = std::thread([cam, type, ctx_ptr]() { RTMPManager::stream_loop(cam, type, ctx_ptr); });

        streams.emplace(key, std::move(ctx));
    }

    // 等待首帧或错误，最多 7 秒
    if (status_future.wait_for(std::chrono::seconds(7)) == std::future_status::ready)
    {
        const StreamStatus s = status_future.get();
        res.result = s.running ? 0 : 1;
        res.reason = s.running ? "Started OK" : (s.last_error.empty() ? "Failed to start" : s.last_error);
    }
    else
    {
        res.result = 1;
        res.reason = "Timeout waiting for stream";
    }

    return res;
}

RTMPManager::StreamResultInfo RTMPManager::stop_camera(const std::string &cam_name, StreamType type)
{
    StreamResultInfo res;
    res.loc = get_camera_index(cam_name);
    res.url = get_stream_url(cam_name, type);

    std::unique_ptr<StreamContext> ctx;
    std::string key = make_stream_key(cam_name, type);
    {
        std::lock_guard<std::mutex> lock(streams_mutex);
        auto it = streams.find(key);
        if (it == streams.end())
        {
            res.result = 0;
            res.reason = "Not streaming";
            return res;
        }

        it->second->running.store(false);
        ctx = std::move(it->second);
        streams.erase(it);
    }

    if (ctx->thread.joinable()) ctx->thread.join();

    res.result = 0;
    res.reason = "Stopped manually";
    return res;
}

void RTMPManager::stream_loop(Camera cam, StreamType type, StreamContext *ctx)
{
    const std::string key = make_stream_key(cam.name, type);

    auto try_set_start = [&](const StreamStatus &st)
    {
        bool expected = false;
        if (ctx && ctx->start_promise_set.compare_exchange_strong(expected, true))
        {
            try
            {
                ctx->start_promise.set_value(st);
            }
            catch (...)
            {
            }
        }
    };

    StreamStatus status;
    status.running = false;
    status.last_result = StreamResult::UNKNOWN;
    status.last_error.clear();

    GstElement *pipeline = create_pipeline(cam, type);
    if (!pipeline)
    {
        status.last_result = StreamResult::PIPELINE_ERROR;
        status.last_error = "Failed to create pipeline";
        try_set_start(status);
        return;
    }

    GstBus *bus = gst_element_get_bus(pipeline);
    gst_element_set_state(pipeline, GST_STATE_PLAYING);

    bool first_frame = false;
    const auto t0 = std::chrono::steady_clock::now();

    while (true)
    {
        // 手动停止
        if (!ctx->running.load())
        {
            status.running = false;
            status.last_result = StreamResult::UNKNOWN;
            status.last_error = "Stream stopped manually";
            try_set_start(status);  // 若启动阶段还没返回，这里补一次
            break;
        }

        // 首帧超时（5s）
        if (!first_frame &&
            std::chrono::duration_cast<std::chrono::seconds>(std::chrono::steady_clock::now() - t0).count() > 5)
        {
            status.running = false;
            status.last_result = StreamResult::TIMEOUT;
            status.last_error = "No frames received within timeout";
            try_set_start(status);
            break;
        }

        GstMessage *msg = gst_bus_timed_pop_filtered(
            bus, 100 * GST_MSECOND,
            static_cast<GstMessageType>(GST_MESSAGE_ERROR | GST_MESSAGE_EOS | GST_MESSAGE_STATE_CHANGED));

        if (!msg) continue;

        switch (GST_MESSAGE_TYPE(msg))
        {
            case GST_MESSAGE_STATE_CHANGED:
            {
                GstState old_state, new_state;
                gst_message_parse_state_changed(msg, &old_state, &new_state, nullptr);
                if (GST_MESSAGE_SRC(msg) == GST_OBJECT(pipeline) && new_state == GST_STATE_PLAYING && !first_frame)
                {
                    first_frame = true;
                    status.running = true;
                    status.last_result = StreamResult::OK;
                    status.last_error.clear();
                    try_set_start(status);  // 首帧成功：通知 start_camera
                }
                break;
            }
            case GST_MESSAGE_ERROR:
            {
                GError *err = nullptr;
                gst_message_parse_error(msg, &err, nullptr);
                status.running = false;
                status.last_result = StreamResult::CONNECTION_FAIL;
                status.last_error = err ? err->message : "GStreamer error";
                if (err) g_error_free(err);
                try_set_start(status);
                break;
            }
            case GST_MESSAGE_EOS:
            {
                status.running = false;
                status.last_result = StreamResult::EOS_RECEIVED;
                status.last_error = "EOS received";
                try_set_start(status);
                break;
            }
            default:
                break;
        }

        gst_message_unref(msg);

        // 错误/EOS 后退出循环
        if (status.last_result == StreamResult::CONNECTION_FAIL || status.last_result == StreamResult::EOS_RECEIVED)
        {
            break;
        }
    }

    gst_element_set_state(pipeline, GST_STATE_NULL);
    if (bus) gst_object_unref(bus);
    gst_object_unref(pipeline);

    // 线程收尾：这里不要删 map 里的 ctx，stop_camera 已经负责转移并 join
}

void RTMPManager::stop_all()
{
    std::vector<std::unique_ptr<StreamContext>> ctxs;
    {
        std::lock_guard<std::mutex> lock(streams_mutex);
        for (auto &kv : streams) kv.second->running.store(false);
        for (auto &kv : streams) ctxs.push_back(std::move(kv.second));
        streams.clear();
    }

    for (auto &ctx : ctxs)
        if (ctx->thread.joinable()) ctx->thread.join();

    LOG_INFO("[RTMP] stop_all completed.");
}

bool RTMPManager::is_streaming(const std::string &cam_name, StreamType type)
{
    std::lock_guard<std::mutex> lock(streams_mutex);
    auto it = streams.find(make_stream_key(cam_name, type));
    return it != streams.end() && it->second->running.load();
}

bool RTMPManager::is_any_streaming()
{
    std::lock_guard<std::mutex> lock(streams_mutex);
    for (auto &kv : streams)
        if (kv.second->running.load()) return true;
    return false;
}

std::string RTMPManager::get_stream_url(const std::string &cam_name, StreamType type)
{
    // 获取当前设备 enp1s0 网卡 IP（或者改成你希望的接口）
    std::string ip = get_ip_address("enP2p33s0");
    if (ip.empty()) ip = "127.0.0.1";

    // 构建流名，例如 AHD2_main
    std::string stream_name = make_stream_key(cam_name, type);

    // 最终返回 WebRTC 拉流地址（不加 .flv）
    return "http://" + ip + ":1985/rtc/v1/whep/?app=live&stream=" + stream_name;
}

std::vector<RTMPManager::StreamResultInfo> RTMPManager::process_push_request(const VideoPushRequest &req)
{
    std::vector<StreamResultInfo> results;

    for (const auto &item : req.data)
    {
        StreamType type = (item.streamType == 0) ? StreamType::MAIN : StreamType::SUB;

        for (int ch : item.channels)
        {
            if (ch < 0 || ch >= static_cast<int>(g_app_config.cameras.size())) continue;

            const auto &cam = g_app_config.cameras[ch];
            StreamResultInfo info;

            if (item.switchVal == 0)
            {
                // 开启推流
                info = start_camera(cam, type);
            }
            else
            {
                // 停止推流
                info = stop_camera(cam.name, type);
            }

            results.push_back(info);
        }
    }

    return results;
}