#include "GStreamerPipeline.h"
#include <iostream>
#include <cstring>
#include <utility>

GStreamerPipeline::GStreamerPipeline(std::string  pipelineDescription)
    : pipeline_(nullptr), appsrc_(nullptr), bus_(nullptr), running_(false),
      pipelineDescription_(std::move(pipelineDescription)), width_(0), height_(0) {
    std::cout << "[DEBUG] Initializing GStreamer..." << std::endl;
    gst_init(nullptr, nullptr);
    std::cout << "[DEBUG] GStreamer initialized successfully" << std::endl;
    if (!pipelineDescription_.empty()) {
        std::cout << "[DEBUG] Pipeline description: " << pipelineDescription_ << std::endl;
    }
}

GStreamerPipeline::~GStreamerPipeline() {
    std::cout << "[DEBUG] Destroying GStreamerPipeline..." << std::endl;
    stop();
    std::cout << "[DEBUG] GStreamerPipeline destroyed" << std::endl;
}

void GStreamerPipeline::setPipelineDescription(const std::string& description) {
    if (!running_) {
        std::cout << "[DEBUG] Setting pipeline description: " << description << std::endl;
        pipelineDescription_ = description;
    } else {
        std::cerr << "[DEBUG] Cannot set pipeline description while running" << std::endl;
    }
}

bool GStreamerPipeline::start() {
    std::cout << "[DEBUG] Starting GStreamer pipeline..." << std::endl;

    if (running_) {
        std::cerr << "[ERROR] GStreamer pipeline already running" << std::endl;
        return false;
    }

    if (pipelineDescription_.empty()) {
        std::cerr << "[ERROR] Pipeline description is empty" << std::endl;
        return false;
    }

    GError* error = nullptr;
    const std::string fullPipeline = "appsrc name=source ! " + pipelineDescription_;
    std::cout << "[DEBUG] Full pipeline string: " << fullPipeline << std::endl;

    std::cout << "[DEBUG] Parsing pipeline..." << std::endl;
    pipeline_ = gst_parse_launch(fullPipeline.c_str(), &error);
    if (error) {
        std::cerr << "[ERROR] Failed to create pipeline: " << error->message << std::endl;
        g_error_free(error);
        return false;
    }
    std::cout << "[DEBUG] Pipeline parsed successfully" << std::endl;

    std::cout << "[DEBUG] Getting appsrc element..." << std::endl;
    appsrc_ = gst_bin_get_by_name(GST_BIN(pipeline_), "source");
    if (!appsrc_) {
        std::cerr << "[ERROR] Failed to get appsrc element" << std::endl;
        gst_object_unref(pipeline_);
        return false;
    }
    std::cout << "[DEBUG] Appsrc element retrieved successfully" << std::endl;

    // Configure appsrc
    std::cout << "[DEBUG] Configuring appsrc properties..." << std::endl;
    g_object_set(G_OBJECT(appsrc_),
                 "stream-type", GST_APP_STREAM_TYPE_STREAM,
                 "format", GST_FORMAT_TIME,
                 "is-live", TRUE,
                 nullptr);

    // Set callbacks
    std::cout << "[DEBUG] Setting appsrc callbacks..." << std::endl;
    GstAppSrcCallbacks callbacks;
    callbacks.need_data = onNeedData;
    callbacks.enough_data = onEnoughData;
    callbacks.seek_data = nullptr;
    gst_app_src_set_callbacks(GST_APP_SRC(appsrc_), &callbacks, this, nullptr);

    // Start the pipeline
    std::cout << "[DEBUG] Setting pipeline state to PLAYING..." << std::endl;
    GstStateChangeReturn ret = gst_element_set_state(pipeline_, GST_STATE_PLAYING);
    if (ret == GST_STATE_CHANGE_FAILURE) {
        std::cerr << "[ERROR] Failed to set pipeline state to PLAYING" << std::endl;
        gst_object_unref(appsrc_);
        gst_object_unref(pipeline_);
        return false;
    }

    std::cout << "[DEBUG] Pipeline state change return: ";
    switch(ret) {
        case GST_STATE_CHANGE_SUCCESS:
            std::cout << "SUCCESS" << std::endl;
            break;
        case GST_STATE_CHANGE_ASYNC:
            std::cout << "ASYNC" << std::endl;
            break;
        case GST_STATE_CHANGE_NO_PREROLL:
            std::cout << "NO_PREROLL" << std::endl;
            break;
        default:
            std::cout << "UNKNOWN" << std::endl;
    }

    bus_ = gst_element_get_bus(pipeline_);
    running_ = true;

    std::cout << "[SUCCESS] GStreamer pipeline started successfully" << std::endl;
    std::cout << "[INFO] Full pipeline: " << fullPipeline << std::endl;
    return true;
}

void GStreamerPipeline::stop() {
    if (!running_) {
        std::cout << "[DEBUG] Pipeline already stopped, nothing to do" << std::endl;
        return;
    }

    std::cout << "[DEBUG] Stopping GStreamer pipeline..." << std::endl;
    running_ = false;

    if (appsrc_) {
        std::cout << "[DEBUG] Sending EOS to appsrc..." << std::endl;
        gst_app_src_end_of_stream(GST_APP_SRC(appsrc_));
    }

    if (pipeline_) {
        std::cout << "[DEBUG] Setting pipeline state to NULL..." << std::endl;
        gst_element_set_state(pipeline_, GST_STATE_NULL);
        std::cout << "[DEBUG] Unreferencing pipeline..." << std::endl;
        gst_object_unref(pipeline_);
        pipeline_ = nullptr;
    }

    if (appsrc_) {
        std::cout << "[DEBUG] Unreferencing appsrc..." << std::endl;
        gst_object_unref(appsrc_);
        appsrc_ = nullptr;
    }

    if (bus_) {
        std::cout << "[DEBUG] Unreferencing bus..." << std::endl;
        gst_object_unref(bus_);
        bus_ = nullptr;
    }

    std::cout << "[SUCCESS] GStreamer pipeline stopped" << std::endl;
}

bool GStreamerPipeline::pushBuffer(const uint8_t* data, const size_t size, const int width, const int height, const std::string& format) {
    if (!running_ || !appsrc_) {
        std::cerr << "[DEBUG] Cannot push buffer: pipeline not running or appsrc is null" << std::endl;
        return false;
    }

    // Update format if changed
    if (width != width_ || height != height_ || format != format_) {
        std::cout << "[DEBUG] Stream format changed - updating caps" << std::endl;
        std::cout << "[DEBUG] Old: " << width_ << "x" << height_ << " (" << format_ << ")" << std::endl;
        std::cout << "[DEBUG] New: " << width << "x" << height << " (" << format << ")" << std::endl;

        width_ = width;
        height_ = height;
        format_ = format;

        // Set caps based on format
        std::string capsStr;
        if (format == "YUY2" || format == "UYVY" || format == "BGR" || format == "RGB") {
            capsStr = "video/x-raw,format=" + format + ",width=" + std::to_string(width) +
                     ",height=" + std::to_string(height) + ",framerate=30/1";
        } else if (format == "MJPG") {
            capsStr = "image/jpeg,width=" + std::to_string(width) +
                     ",height=" + std::to_string(height) + ",framerate=30/1";
        }  else {
            capsStr = "video/x-raw,width=" + std::to_string(width) +
                     ",height=" + std::to_string(height) + ",framerate=30/1";
        }

        std::cout << "[DEBUG] Setting caps: " << capsStr << std::endl;
        GstCaps* caps = gst_caps_from_string(capsStr.c_str());
        gst_app_src_set_caps(GST_APP_SRC(appsrc_), caps);
        gst_caps_unref(caps);
        std::cout << "[DEBUG] Caps set successfully" << std::endl;
    }

    // Create buffer and copy data
    GstBuffer* buffer = gst_buffer_new_allocate(nullptr, size, nullptr);
    GstMapInfo map;
    gst_buffer_map(buffer, &map, GST_MAP_WRITE);
    memcpy(map.data, data, size);
    gst_buffer_unmap(buffer, &map);

    // Push buffer to pipeline
    GstFlowReturn ret = gst_app_src_push_buffer(GST_APP_SRC(appsrc_), buffer);
    if (ret != GST_FLOW_OK) {
        std::cerr << "[ERROR] Failed to push buffer to pipeline, flow return: " << ret << std::endl;
        return false;
    }

    return true;
}

void GStreamerPipeline::onNeedData(GstAppSrc* appsrc, guint unused, gpointer user_data) {
    // Called when pipeline needs more data
    //std::cout << "[DEBUG] Pipeline callback: need_data - pipeline ready for more data" << std::endl;
}

void GStreamerPipeline::onEnoughData(GstAppSrc* appsrc, gpointer user_data) {
    // Called when pipeline has enough data buffered
    // std::cout << "[DEBUG] Pipeline callback: enough_data - pipeline buffer full" << std::endl;
}