#pragma once

#include <arpa/inet.h>

#include <cstdint>
#include <cstdio>
#include <cstdlib>
#include <sstream>
#include <stdexcept>
#include <string>

#include <nlohmann/json.hpp>

extern "C" {
#include <mtl/mtl_api.h>
#include <mtl/st20_api.h>
#include <mtl/st_pipeline_api.h>
}

#include <mxl/flow.h>

#include "FlowDef.hpp"
#include "NodeBase.hpp"

namespace dmf {

struct ST2110ReceiverConfig {
    std::string flow_id;
    std::string ifname;
    std::string local_ip;
    std::string source_ip;
    std::string mcast_ip;
    uint16_t udp_port = 0;
    uint8_t payload_type = 96;
    int width = 1920;
    int height = 1080;
    int depth = 8;
    int fps_num = 25;
    int fps_den = 1;
    int framebuff_cnt = 3;
    int mxl_latency_frames = 2;
    std::string mxl_index_mode = "rtp";

    bool direct_v210() const { return depth == 10; }
    enum st20_fmt transport_fmt() const {
        return direct_v210() ? ST20_FMT_YUV_422_10BIT : ST20_FMT_YUV_422_8BIT;
    }
    enum st_frame_fmt output_fmt() const {
        return direct_v210() ? ST_FRAME_FMT_V210 : ST_FRAME_FMT_UYVY;
    }
};

inline std::string st2110_trim(std::string s) {
    const auto first = s.find_first_not_of(" \t\r\n");
    if (first == std::string::npos) return {};
    const auto last = s.find_last_not_of(" \t\r\n");
    return s.substr(first, last - first + 1);
}

inline bool st2110_parse_int(const std::string& text, int* out) {
    char* end = nullptr;
    const long value = std::strtol(text.c_str(), &end, 10);
    if (!end || *end != '\0') return false;
    *out = static_cast<int>(value);
    return true;
}

inline void st2110_parse_exactframerate(const std::string& value,
                                        ST2110ReceiverConfig& cfg) {
    const auto slash = value.find('/');
    if (slash == std::string::npos) {
        if (!st2110_parse_int(value, &cfg.fps_num)) {
            throw std::runtime_error("invalid SDP exactframerate: " + value);
        }
        cfg.fps_den = 1;
        return;
    }

    const std::string num = value.substr(0, slash);
    const std::string den = value.substr(slash + 1);
    if (!st2110_parse_int(num, &cfg.fps_num) || !st2110_parse_int(den, &cfg.fps_den)) {
        throw std::runtime_error("invalid SDP exactframerate: " + value);
    }
}

inline void st2110_apply_fmtp_param(const std::string& key, const std::string& value,
                                    ST2110ReceiverConfig& cfg, std::string& sampling) {
    if (key == "width") {
        if (!st2110_parse_int(value, &cfg.width)) {
            throw std::runtime_error("invalid SDP width: " + value);
        }
    } else if (key == "height") {
        if (!st2110_parse_int(value, &cfg.height)) {
            throw std::runtime_error("invalid SDP height: " + value);
        }
    } else if (key == "depth") {
        if (!st2110_parse_int(value, &cfg.depth)) {
            throw std::runtime_error("invalid SDP depth: " + value);
        }
    } else if (key == "sampling") {
        sampling = value;
    } else if (key == "exactframerate") {
        st2110_parse_exactframerate(value, cfg);
    }
}

inline void st2110_parse_fmtp(const std::string& line, ST2110ReceiverConfig& cfg,
                              std::string& sampling) {
    const auto space = line.find(' ');
    if (space == std::string::npos) return;

    std::stringstream params(line.substr(space + 1));
    std::string item;
    while (std::getline(params, item, ';')) {
        item = st2110_trim(item);
        if (item.empty()) continue;

        const auto eq = item.find('=');
        if (eq == std::string::npos) continue;
        const std::string key = st2110_trim(item.substr(0, eq));
        const std::string value = st2110_trim(item.substr(eq + 1));
        st2110_apply_fmtp_param(key, value, cfg, sampling);
    }
}

inline void st2110_apply_sdp(const std::string& sdp, ST2110ReceiverConfig& cfg) {
    std::stringstream lines(sdp);
    std::string line;
    std::string sampling = "YCbCr-4:2:2";

    while (std::getline(lines, line)) {
        line = st2110_trim(line);
        if (line.rfind("m=video ", 0) == 0) {
            std::stringstream media(line.substr(8));
            int port = 0;
            std::string proto;
            int payload = 0;
            if (media >> port >> proto >> payload) {
                if (port < 0 || port > 65535 || payload < 0 || payload > 255) {
                    throw std::runtime_error("SDP m=video port or payload out of range");
                }
                cfg.udp_port = static_cast<uint16_t>(port);
                cfg.payload_type = static_cast<uint8_t>(payload);
            }
        } else if (line.rfind("c=IN IP4 ", 0) == 0) {
            std::string addr = line.substr(9);
            const auto slash = addr.find('/');
            if (slash != std::string::npos) addr.resize(slash);
            cfg.mcast_ip = st2110_trim(addr);
        } else if (line.rfind("a=source-filter:incl IN IP4 ", 0) == 0) {
            std::stringstream filter(line.substr(28));
            std::string group;
            std::string source;
            if (filter >> group >> source) {
                cfg.source_ip = source;
            }
        } else if (line.rfind("a=fmtp:", 0) == 0) {
            st2110_parse_fmtp(line.substr(7), cfg, sampling);
        }
    }

    if (sampling != "YCbCr-4:2:2" || (cfg.depth != 8 && cfg.depth != 10)) {
        throw std::runtime_error("only SDP YCbCr-4:2:2 depth=8 or depth=10 is supported currently");
    }
}

inline void st2110_set_ip(uint8_t dst[MTL_IP_ADDR_LEN], const std::string& ip) {
    if (inet_pton(AF_INET, ip.c_str(), dst) != 1) {
        throw std::runtime_error("invalid IP address: " + ip);
    }
}

inline uint16_t st2110_checked_u16(const nlohmann::json& j, const char* key) {
    const int value = j.at(key).get<int>();
    if (value < 0 || value > 65535) {
        throw std::runtime_error(std::string(key) + " out of uint16 range");
    }
    return static_cast<uint16_t>(value);
}

inline uint8_t st2110_checked_u8(const nlohmann::json& j, const char* key, int fallback) {
    const int value = j.value(key, fallback);
    if (value < 0 || value > 255) {
        throw std::runtime_error(std::string(key) + " out of uint8 range");
    }
    return static_cast<uint8_t>(value);
}

inline enum st_fps st2110_to_st_fps(int fps_num, int fps_den) {
    if (fps_den == 1) {
        switch (fps_num) {
            case 24: return ST_FPS_P24;
            case 25: return ST_FPS_P25;
            case 30: return ST_FPS_P30;
            case 50: return ST_FPS_P50;
            case 60: return ST_FPS_P60;
            case 100: return ST_FPS_P100;
            case 120: return ST_FPS_P120;
            default: break;
        }
    }
    if (fps_num == 24000 && fps_den == 1001) return ST_FPS_P23_98;
    if (fps_num == 30000 && fps_den == 1001) return ST_FPS_P29_97;
    if (fps_num == 60000 && fps_den == 1001) return ST_FPS_P59_94;
    if (fps_num == 120000 && fps_den == 1001) return ST_FPS_P119_88;
    throw std::runtime_error("unsupported ST 2110 frame rate");
}

inline ST2110ReceiverConfig parse_st2110_receiver_config(const nlohmann::json& cfg) {
    if (!cfg.contains("video_flow_id")) {
        throw std::runtime_error("no video output connected");
    }

    ST2110ReceiverConfig out;
    out.flow_id = cfg.at("video_flow_id").at("id").get<std::string>();
    out.ifname = cfg.at("interface").get<std::string>();
    out.local_ip = cfg.at("local_ip").get<std::string>();

    if (cfg.contains("sdp")) {
        st2110_apply_sdp(cfg.at("sdp").get<std::string>(), out);
    }

    if (cfg.contains("source_ip")) out.source_ip = cfg.at("source_ip").get<std::string>();
    if (cfg.contains("mcast_ip")) out.mcast_ip = cfg.at("mcast_ip").get<std::string>();
    if (cfg.contains("udp_port")) out.udp_port = st2110_checked_u16(cfg, "udp_port");
    out.payload_type = st2110_checked_u8(cfg, "payload_type", out.payload_type);
    out.width = cfg.value("width", out.width);
    out.height = cfg.value("height", out.height);
    out.depth = cfg.value("depth", out.depth);
    out.fps_num = cfg.value("fps_num", out.fps_num);
    out.fps_den = cfg.value("fps_den", out.fps_den);
    out.framebuff_cnt = cfg.value("framebuff_cnt", out.framebuff_cnt);
    out.mxl_latency_frames = cfg.value("mxl_latency_frames", out.mxl_latency_frames);
    out.mxl_index_mode = cfg.value("mxl_index_mode", out.mxl_index_mode);

    if (out.width <= 0 || out.height <= 0) {
        throw std::runtime_error("width and height must be positive");
    }
    if (out.depth != 8 && out.depth != 10) {
        throw std::runtime_error("only depth=8 and depth=10 are supported currently");
    }
    if (out.source_ip.empty() || out.mcast_ip.empty() || out.udp_port == 0) {
        throw std::runtime_error("source_ip, mcast_ip and udp_port are required unless provided by sdp");
    }
    if (out.width % 6 != 0) {
        throw std::runtime_error("width must be divisible by 6 for v210 output");
    }
    if (out.fps_num <= 0 || out.fps_den <= 0) {
        throw std::runtime_error("fps_num and fps_den must be positive");
    }
    if (out.framebuff_cnt < 2 || out.framebuff_cnt > ST20_FB_MAX_COUNT) {
        throw std::runtime_error("framebuff_cnt must be in [2, ST20_FB_MAX_COUNT]");
    }
    if (out.mxl_latency_frames < 1 || out.mxl_latency_frames > 30) {
        throw std::runtime_error("mxl_latency_frames must be in [1, 30]");
    }
    if (out.mxl_index_mode != "rtp" && out.mxl_index_mode != "live") {
        throw std::runtime_error("mxl_index_mode must be 'rtp' or 'live'");
    }

    return out;
}

class MTLContext {
public:
    explicit MTLContext(const ST2110ReceiverConfig& cfg) {
        mtl_init_params params{};
        params.num_ports = 1;

        port_name_ = "kernel:" + cfg.ifname;
        std::snprintf(params.port[MTL_PORT_P], sizeof(params.port[MTL_PORT_P]), "%s",
                      port_name_.c_str());

        params.pmd[MTL_PORT_P] = MTL_PMD_KERNEL_SOCKET;
        params.net_proto[MTL_PORT_P] = MTL_PROTO_STATIC;
        params.rx_queues_cnt[MTL_PORT_P] = 1;
        params.tx_queues_cnt[MTL_PORT_P] = 0;
        params.log_level = MTL_LOG_LEVEL_INFO;
        params.flags = MTL_FLAG_DEV_AUTO_START_STOP;
        st2110_set_ip(params.sip_addr[MTL_PORT_P], cfg.local_ip);

        handle_ = mtl_init(&params);
        if (!handle_) {
            throw std::runtime_error("mtl_init failed");
        }
    }

    ~MTLContext() {
        if (handle_) {
            mtl_uninit(handle_);
        }
    }

    MTLContext(const MTLContext&) = delete;
    MTLContext& operator=(const MTLContext&) = delete;

    mtl_handle get() const { return handle_; }
    const std::string& port_name() const { return port_name_; }

private:
    mtl_handle handle_{nullptr};
    std::string port_name_;
};

class ST20RxSession {
public:
    ST20RxSession(mtl_handle mt, const std::string& port_name,
                  const ST2110ReceiverConfig& cfg) {
        st20p_rx_ops ops{};
        ops.name = "dmf-st2110in-video";
        ops.port.num_port = 1;
        ops.port.udp_port[MTL_SESSION_PORT_P] = cfg.udp_port;
        ops.port.payload_type = cfg.payload_type;
        std::snprintf(ops.port.port[MTL_SESSION_PORT_P],
                      sizeof(ops.port.port[MTL_SESSION_PORT_P]), "%s", port_name.c_str());
        st2110_set_ip(ops.port.ip_addr[MTL_SESSION_PORT_P], cfg.mcast_ip);
        st2110_set_ip(ops.port.mcast_sip_addr[MTL_SESSION_PORT_P], cfg.source_ip);

        ops.width = static_cast<uint32_t>(cfg.width);
        ops.height = static_cast<uint32_t>(cfg.height);
        ops.fps = st2110_to_st_fps(cfg.fps_num, cfg.fps_den);
        ops.interlaced = false;
        ops.transport_fmt = cfg.transport_fmt();
        ops.output_fmt = cfg.output_fmt();
        ops.device = ST_PLUGIN_DEVICE_AUTO;
        ops.framebuff_cnt = static_cast<uint16_t>(cfg.framebuff_cnt);
        ops.flags = ST20P_RX_FLAG_BLOCK_GET;

        handle_ = st20p_rx_create(mt, &ops);
        if (!handle_) {
            throw std::runtime_error("st20p_rx_create failed");
        }
        st20p_rx_set_block_timeout(handle_, 100'000'000);
    }

    ~ST20RxSession() {
        if (handle_) {
            st20p_rx_wake_block(handle_);
            st20p_rx_free(handle_);
        }
    }

    ST20RxSession(const ST20RxSession&) = delete;
    ST20RxSession& operator=(const ST20RxSession&) = delete;

    st20p_rx_handle get() const { return handle_; }

private:
    st20p_rx_handle handle_{nullptr};
};

class MXLVideoWriter {
public:
    MXLVideoWriter(mxlInstance instance, const ST2110ReceiverConfig& cfg,
                   const std::string& node_id)
        : instance_(instance) {
        bool created = false;
        const std::string flow_def =
            make_video_flow_def(cfg.flow_id, node_id, cfg.width, cfg.height, cfg.fps_num,
                                cfg.fps_den);
        const mxlStatus st =
            mxlCreateFlowWriter(instance_, flow_def.c_str(), "", &writer_, &config_, &created);
        if (st != MXL_STATUS_OK) {
            throw std::runtime_error(std::string("mxlCreateFlowWriter failed: ") +
                                     mxl_status_str(st));
        }
    }

    ~MXLVideoWriter() {
        if (writer_) {
            mxlReleaseFlowWriter(instance_, writer_);
        }
    }

    MXLVideoWriter(const MXLVideoWriter&) = delete;
    MXLVideoWriter& operator=(const MXLVideoWriter&) = delete;

    mxlFlowWriter get() const { return writer_; }
    const mxlFlowConfigInfo& config() const { return config_; }

private:
    mxlInstance instance_{nullptr};
    mxlFlowWriter writer_{nullptr};
    mxlFlowConfigInfo config_{};
};

} // namespace dmf