#include "utilsTargetLocation.h"
#include <QDebug>
#include <QImage>
#include "serialCommand.h"
#include "serialResponse.h"

#define USE_OPENCV
//#define USE_FFMPEG

#ifdef USE_OPENCV
#include <opencv2/opencv.hpp>
#endif

#ifdef USE_FFMPEG
extern "C" {
#include <libavcodec/avcodec.h>
#include <libavformat/avformat.h>
#include <libavutil/imgutils.h>
#include <libswscale/swscale.h>
}
#endif

UtilsTargetLocation::UtilsTargetLocation(SerialPort *serial, SerialCommand *command)
    : mSerial(serial)
    , mCommand(command)
{
    // ... Optional: Additional initialization logic here
}

GPSData UtilsTargetLocation::getLocation(float altitude, float latitude, float lognitude, float yaw, float pitch, float roll, float targetTrueSize, uint16_t targetPixelSize)
{
    if (mSerial == nullptr) {
        qWarning() << "Cannot get geo location: Serial connection not available.";
    }

    if (mCommand == nullptr) {
        qWarning() << "Cannot get geo location: Commands not available.";
    }

    // Capture image from rtsp stream
    captureImageFromStream();

    // TODO?
    // Send image to AI for target identification and/or target choosing

    // From the drone and camera
    CameraData cameraData = getCameraData();
    GPSData gpsData = {latitude, lognitude, altitude};
    DroneData droneData = {gpsData, yaw, pitch, roll}; // GPS (latitude, longitude, altitude) and heading

    // Calculate altitude and distance to the target
    float targetDistance = calculateTargetDistance(targetTrueSize, targetPixelSize, cameraData.width, degreesToRadians(cameraData.fow));

    // Calculate the bearing from the drone orientation and camera orientation
    float targetBearing = fmod(droneData.yaw + cameraData.yaw, 360.0f);

    // Calculate the GPS location of the target
    return calculateTargetLocation(droneData, cameraData, targetDistance, targetBearing);
}

CameraData UtilsTargetLocation::getCameraData()
{
    uint16_t height = CAMERA_RESOLUTION_HEIGHT;
    uint16_t width = CAMERA_RESOLUTION_WIDTH;
    float pitch = 0;
    float yaw = 0;
    float fov = CAMERA_FIELD_OF_VIEW_HORIZONTAL;

    QByteArray response;
    QHash<QString, QVariant> responseValues;
    mSerial->sendCommand(mCommand->getCommandByID(COMMAND_ID::ACQUIRE_CURRENT_ZOOM)); // Field of view in degrees
    response = mSerial->readResponse();
    responseValues = SerialResponse::getResponceValues(response);
    SerialResponse::printResponse(response);
    fov = CAMERA_FIELD_OF_VIEW_HORIZONTAL / (responseValues["zoom"].toFloat() == 0.0 ? 1.0 : responseValues["zoom"].toFloat());

    mSerial->sendCommand(mCommand->getCommandByID(COMMAND_ID::ACQUIRE_ATTITUDE_DATA)); // Yaw and pitch in degrees
    response = mSerial->readResponse();
    responseValues = SerialResponse::getResponceValues(response);
    SerialResponse::printResponse(response);
    yaw = responseValues["yaw"].toFloat();
    pitch = responseValues["pitch"].toFloat();

    mSerial->sendCommand(mCommand->getCommandByID(COMMAND_ID::ACQUIRE_CAMERA_CODEC_SPECS)); // Camera resolution in pixels
    response = mSerial->readResponse();
    responseValues = SerialResponse::getResponceValues(response);
    SerialResponse::printResponse(response);
    height = responseValues["height"].toUInt();
    width = responseValues["width"].toUInt();

    return {height, width, pitch, yaw, fov};
}

// Function to calculate distance from pixel size and target size
float UtilsTargetLocation::calculateTargetDistance(float targetTrueSize, uint16_t targetPixelSize, uint16_t imageWidth, float fov)
{
    float focalLength = (imageWidth / 2) / tan(fov / 2);
    return (targetTrueSize * focalLength) / targetPixelSize;
}

// Function to convert degrees to radians
float UtilsTargetLocation::degreesToRadians(float degrees)
{
    return degrees * M_PI / 180.0f;
}

// Function to calculate the new GPS location
GPSData UtilsTargetLocation::calculateTargetLocation(DroneData drone, CameraData camera, float distance, float bearing)
{
    constexpr float R = 6371000.0; // Earth radius in meters

    float bearingRad = degreesToRadians(bearing);
    float latRad = degreesToRadians(drone.gps.latitude);
    float lonRad = degreesToRadians(drone.gps.longitude);

    float newLatRad = asin(sin(latRad) * cos(distance / R) + cos(latRad) * sin(distance / R) * cos(bearingRad));
    float newLonRad = lonRad + atan2(sin(bearingRad) * sin(distance / R) * cos(latRad), cos(distance / R) - sin(latRad) * sin(newLatRad));

    float angleRad = camera.pitch * M_PI / 180.0;
    float horizontalDistance = distance * cos(angleRad);
    float newAltitude = drone.gps.altitude + (horizontalDistance * tan(angleRad));

    GPSData newLocation;
    newLocation.latitude = newLatRad * 180.0f / M_PI;
    newLocation.longitude = newLonRad * 180.0f / M_PI;
    newLocation.altitude = newAltitude;

    return newLocation;
}

void UtilsTargetLocation::captureImageFromStream()
{
#ifdef USE_OPENCV
    cv::VideoCapture cap;
    cap.open(RTSP_ADDRESS);

    if (!cap.isOpened()) {
        qWarning() << "Error: Could not open RTSP stream";
        return;
    }

    // Hack to capture proper image
    // For some reason first frames get corrupted
    uint8_t frameCount = 0;

    while (true) {
        cv::Mat frame;

        if (cap.grab() && cap.retrieve(frame)) {
            if (frame.empty() || frame.total() == 0) {
                qInfo() << "Warning: Invalid frame captured, retrying...";
            } else {
                // Convert the frame to BGR if needed
                if (frame.channels() == 1) {
                    qInfo() << "Captured frame is grayscale, converting to BGR";
                    cv::cvtColor(frame, frame, cv::COLOR_GRAY2BGR);
                } else if (frame.channels() == 4) {
                    qInfo() << "Captured frame is RGBA, converting to BGR";
                    cv::cvtColor(frame, frame, cv::COLOR_RGBA2BGR);
                }

                frameCount++;
                if (frameCount > 10) {
                    // Save the captured frame as an image
                    std::string filename = "output_opencv.jpg";
                    if (cv::imwrite(filename, frame)) {
                        qInfo() << "Image captured and saved as" << QString::fromStdString(filename);
                        break;
                    } else {
                        qInfo() << "Error: Failed to save the captured image";
                    }
                } else if (frameCount > 100) {
                    qInfo() << "Error: Tried 100 times and still fails, giving up";
                    break;
                }
            }
        } else {
            qInfo() << "Warning: Could not grab or retrieve frame, retrying...";
        }
    }

    // Release the video capture object
    cap.release();
#endif

#ifdef USE_FFMPEG
    // Initialize FFmpeg
    avformat_network_init();

    // Open RTSP stream
    AVFormatContext *formatContext = avformat_alloc_context();
    if (avformat_open_input(&formatContext, RTSP_ADDRESS, NULL, NULL) != 0) {
        qDebug() << "Error: Couldn't open RTSP stream";
        return;
    }

    // Find stream info
    if (avformat_find_stream_info(formatContext, NULL) < 0) {
        qDebug() << "Error: Couldn't find stream info";
        return;
    }

    // Find video stream
    int videoStreamIndex = -1;
    for (uint i = 0; i < formatContext->nb_streams; i++) {
        if (formatContext->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) {
            videoStreamIndex = i;
            break;
        }
    }
    if (videoStreamIndex == -1) {
        qDebug() << "Error: Couldn't find video stream";
        return;
    }

    // Initialize video decoder
    AVCodecParameters *codecParameters = formatContext->streams[videoStreamIndex]->codecpar;
    AVCodec *codec = avcodec_find_decoder(codecParameters->codec_id);
    AVCodecContext *codecContext = avcodec_alloc_context3(codec);
    avcodec_parameters_to_context(codecContext, codecParameters);
    avcodec_open2(codecContext, codec, NULL);

    // Allocate frame
    AVFrame *frame = av_frame_alloc();

    bool shouldBreak = false;

    // Read frames
    AVPacket packet;

    while (shouldBreak == false && av_read_frame(formatContext, &packet) >= 0) {
        if (packet.stream_index == videoStreamIndex) {
            if (avcodec_send_packet(codecContext, &packet) >= 0) {
                while (avcodec_receive_frame(codecContext, frame) >= 0) {
                    // Convert frame to RGB if necessary
                    if (codecParameters->format != AV_PIX_FMT_RGB24) {
                        AVFrame *rgbFrame = av_frame_alloc();
                        int numBytes = av_image_get_buffer_size(AV_PIX_FMT_RGB24, codecParameters->width, codecParameters->height, 1);
                        uint8_t *buffer = (uint8_t *) av_malloc(numBytes * sizeof(uint8_t));
                        if (av_image_fill_arrays(rgbFrame->data, rgbFrame->linesize, buffer, AV_PIX_FMT_RGB24, codecParameters->width, codecParameters->height, 1) > 0) {
                            // Convert format to enum AVPixelFormat
                            const AVPixFmtDescriptor *pixDesc = av_pix_fmt_desc_get((AVPixelFormat) codecParameters->format);
                            if (!pixDesc) {
                                qDebug() << "Error: Unsupported pixel format";
                                return;
                            }

                            // Get the AVPixelFormat enum value directly from the
                            descriptor AVPixelFormat pixelFormat = (AVPixelFormat) codecParameters->format;

                            // Create the sws context
                            struct SwsContext *swsContext = sws_getContext(codecParameters->width, codecParameters->height, pixelFormat, codecParameters->width, codecParameters->height, AV_PIX_FMT_RGB24, SWS_BILINEAR, NULL, NULL, NULL);
                            sws_scale(swsContext, frame->data, frame->linesize, 0, codecParameters->height, rgbFrame->data, rgbFrame->linesize);
                            sws_freeContext(swsContext);

                            // Save frame as JPEG
                            QImage image(rgbFrame->data[0], codecParameters->width, codecParameters->height, QImage::Format_RGB888);
                            image.save("output_ffmpeg.jpg");

                            av_free(buffer);
                            av_frame_free(&rgbFrame);
                            shouldBreak = true;
                            break;
                        }
                    } else {
                        // Save frame as JPEG
                        QImage image(frame->data[0], codecParameters->width, codecParameters->height, QImage::Format_RGB888);
                        image.save("output_ffmpeg.jpg");
                        shouldBreak = true;
                        break;
                    }
                }
            }
        }

        av_packet_unref(&packet);
    }

    // Clean up
    avformat_close_input(&formatContext);
    avcodec_free_context(&codecContext);
    av_frame_free(&frame);
#endif
}