/**
 * @mainpage MPAI CAE-ARP Video Analyser
 * @file main.cpp
 *  MPAI CAE-ARP Video Analyser.
 *
 *	Implements MPAI CAE-ARP Video Analyser Technical Specification.
 *	It identifies Irregularities on the Preservation Audio-Visual File,
 *providing:
 *	- Irregularity Files;
 *	- Irregularity Images.
 *
 * @warning Currently, this program is only compatible with the Studer A810
 *and videos recorded in PAL standard.
 *
 * @todo
 *  - A resize function of the entire video should be implemented if it does not
 *conform to the PAL standard (currently taken for granted).
 *  - Progressive videos, which do not require deinterlacing, should be managed
 *(in the code there are several steps that operate considering this property).
 *
 *  @author Nadir Dalla Pozza <nadir.dallapozza@unipd.it>
 *  @author Matteo Spanio <dev2@audioinnova.com>
 *	@copyright 2023, Audio Innova S.r.l.
 *	@credits Niccolò Pretto, Nadir Dalla Pozza, Sergio Canazza
 *	@license GPL v3.0
 *	@version 1.2
 *	@status Production
 */
#include <stdlib.h>
#include <sys/timeb.h>

#include <boost/program_options.hpp>
#include <boost/uuid/uuid.hpp>
#include <boost/uuid/uuid_generators.hpp>
#include <boost/uuid/uuid_io.hpp>
#include <filesystem>
#include <fstream>
#include <iostream>
#include <nlohmann/json.hpp>
#include <opencv2/core/core.hpp>
#include <opencv2/highgui.hpp>
#include <variant>

#include "forAudioAnalyser.h"
#include "lib/Irregularity.hpp"
#include "lib/IrregularityFile.hpp"
#include "lib/colors.hpp"
#include "lib/core.hpp"
#include "lib/detection.hpp"
#include "lib/files.hpp"
#include "lib/io.hpp"
#include "lib/time.hpp"
#include "utility.hpp"
#define BLACK_PIXEL 0

using namespace std;
using namespace colors;
using json = nlohmann::json;
using videoanalyser::core::Frame;
using videoanalyser::io::pprint;
using videoanalyser::io::print_error_and_exit;
namespace fs = std::filesystem;
namespace po = boost::program_options;
namespace va = videoanalyser;

bool g_end_tape_saved = false;
bool g_first_brand = true;  // The first frame containing brands on tape must be saved
float g_first_instant = 0;
float g_mean_prev_frame_color = 0;  // Average frame color

static fs::path g_output_path{};
static fs::path g_irregularity_images_path{};
static json g_irregularity_file_1{};
static json g_irregularity_file_2{};

struct Args {
    fs::path
        working_path; /**< The working path where all input files are stored and where all output files will be saved */
    string files_name; /**< The name of the preservation files to be considered */
    bool brands;       /**< True if tape presents brands on its surface */
    float speed;       /**< The speed at which the tape was read */

    Args(fs::path working_path, string files_name, bool brands, float speed) {
        if (speed != 7.5 && speed != 15) throw invalid_argument("Speed must be 7.5 or 15");
        this->working_path = working_path;
        this->files_name = files_name;
        this->brands = brands;
        this->speed = speed;
    }
    ~Args() {}

    static Args from_file(fs::path path) {
        ifstream iConfig(path);
        json j;
        iConfig >> j;
        return Args(fs::path(string(j["WorkingPath"])), j["FilesName"], j["Brands"], j["Speed"]);
    }

    static Args from_cli(int argc, char** argv) {
        po::variables_map vm;
        try {
            po::options_description desc(
                "A tool that implements MPAI CAE-ARP Video Analyser Technical "
                "Specification.\n"
                "By default, the configuartion parameters are loaded from "
                "config/config.json file,\n"
                "but, alternately, you can pass command line arguments to "
                "replace them");
            desc.add_options()("help,h", "Display this help message")(
                "working-path,w", po::value<string>()->required(),
                "Specify the Working Path, where all input files are stored")(
                "files-name,f", po::value<string>()->required(),
                "Specify the name of the Preservation files (without "
                "extension)")("brands,b", po::value<bool>()->required(),
                              "Specify if the tape presents brands on its surface")(
                "speed,s", po::value<float>()->required(), "Specify the speed at which the tape was read");
            po::store(po::command_line_parser(argc, argv).options(desc).run(), vm);
            if (vm.count("help")) {
                std::cout << desc << "\n";
                std::exit(EXIT_SUCCESS);
            }
            po::notify(vm);
        } catch (po::invalid_command_line_syntax& e) {
            print_error_and_exit("Invalid command line syntax: " + string(e.what()));
        } catch (po::required_option& e) {
            print_error_and_exit("Missing required option: " + string(e.what()));
        } catch (nlohmann::detail::type_error e) {
            print_error_and_exit("config.json error: " + string(e.what()));
        }

        return Args(fs::path(vm["working-path"].as<string>()), vm["files-name"].as<string>(), vm["brands"].as<bool>(),
                    vm["speed"].as<float>());
    }
};

/**
 * @brief Get the next frame object.
 *
 * Whenever we find an Irregularity, we want to skip a lenght equal to the
 * Studer reading head (3 cm = 1.18 inches).
 *
 * Note the following considerations:
 * - since we are analysing video at 25 fps a frame occurs every 40 ms
 * - at 15 ips we cross 3 cm of tape in 79 ms (2 frames)
 * - at 7.5 ips we cross 3 cm of tape in 157 ms (4 frames)
 *
 * The considered lengths are the widths of the tape areas.
 * The following condition constitutes a valid approach if the tape areas
 * have widths always equal to the reading head
 *
 * @param cap VideoCapture object
 * @param speed tape reading speed
 * @return Frame
 */
Frame get_next_frame(VideoCapture& cap, float speed, bool skip = false) {
    if (skip) {
        int ms_to_skip = speed == 15 ? 79 : 157;
        cap.set(CAP_PROP_POS_MSEC, cap.get(CAP_PROP_POS_MSEC) + ms_to_skip);
    }
    Frame frame;
    cap >> frame;
    return frame;
}

float rotated_rect_area(RotatedRect rect) { return rect.size.width * rect.size.height; }

/**
 * @fn bool find_processing_areas(Frame frame, SceneObject tape, SceneObject capstan)
 * @brief Identifies the Regions Of Interest (ROIs) on the video,
 * which are:
 * - The reading head;
 * - The tape area under the tape head (computed on the basis of the detected
 * reading head);
 * - The capstan.
 *
 *
 *
 * @param frame the frame to be analysed
 * @param tape the tape object
 * @param capstan the capstan object
 * @return true if some areas have been detected;
 * @return false otherwise.
 */
va::Result<pair<va::detection::Roi, va::detection::Roi>> find_processing_areas(Frame frame, SceneObject tape,
                                                                               SceneObject capstan) {
    va::detection::SceneElement tape_element{
        va::detection::ElementType::TAPE,
        tape.minDist,
        {tape.threshold.percentual, tape.threshold.angle, tape.threshold.scale, tape.threshold.pos}};

    auto tape_roi_result = va::detection::find_roi(frame, va::detection::Algorithm::GHT, tape_element);
    if (std::holds_alternative<va::Error>(tape_roi_result))
        return va::Error("Error while finding tape roi: " + std::get<va::Error>(tape_roi_result));
    auto rect_tape = std::get<va::detection::Roi>(tape_roi_result);

    va::detection::SceneElement capstan_element{
        va::detection::ElementType::CAPSTAN,
        capstan.minDist,
        {capstan.threshold.percentual, capstan.threshold.angle, capstan.threshold.scale, capstan.threshold.pos}};
    auto capstan_roi_result = va::detection::find_roi(frame, va::detection::Algorithm::SURF, capstan_element);
    if (std::holds_alternative<va::Error>(capstan_roi_result))
        return va::Error("Error while finding capstan roi: " + std::get<va::Error>(capstan_roi_result));
    auto rect_capstan = std::get<va::detection::Roi>(capstan_roi_result);

    // save detected areas to file
    cv::rectangle(frame, rect_tape.boundingRect(), cv::Scalar(0, 255, 0), 2);
    cv::rectangle(frame, rect_capstan.boundingRect(), cv::Scalar(255, 0, 0), 2);
    cv::imwrite(g_output_path.string() + "/my_tape_areas.jpg", frame);

    return make_pair(rect_tape, rect_capstan);
}

/**
 * @fn RotatedRect check_skew(RotatedRect roi)
 * @brief Check if the region of interest is skewed and correct it
 *
 * @param roi the region of interest
 * @return RotatedRect the corrected region of interest
 */
RotatedRect check_skew(RotatedRect roi) {
    // get angle and size from the bounding box
    // thanks to http://felix.abecassis.me/2011/10/opencv-rotation-deskewing/
    cv::Size rect_size = roi.size;
    float angle = roi.angle;
    if (roi.angle < -45.) {
        angle += 90.0;
        std::swap(rect_size.width, rect_size.height);
    }
    return RotatedRect(roi.center, rect_size, angle);
}

/**
 * @fn Frame get_difference_for_roi(Frame previous, Frame current, RotatedRect
 * roi)
 * @brief Look for differences in two consecutive frames in a specific region of
 * interest
 *
 * @param previous the reference frame
 * @param current the frame to compare with the reference
 * @param roi the region of interest
 * @return Frame the difference matrix between the two frames
 */
Frame get_difference_for_roi(Frame previous, Frame current, RotatedRect roi) {
    cv::Mat rotation_matrix = cv::getRotationMatrix2D(roi.center, roi.angle, 1.0);

    return previous.warp(rotation_matrix)
        .crop(roi.size, roi.center)
        .difference(current.warp(rotation_matrix).crop(roi.size, roi.center));
}

/**
 * @fn bool is_frame_different(cv::Mat prev_frame, cv::Mat current_frame, int
 * ms_to_end, SceneObject capstan, SceneObject tape, Args args, va::detection::Roi rect_tape, va::detection::Roi
 * rect_capstan)
 * @brief Compares two consecutive video frames and establish if there
 * potentially is an Irregularity. The comparison is pixel-wise and based on
 * threshold values set on config.json file.
 *
 * @param prev_frame the frame before the current one;
 * @param current_frame the current frame;
 * @param ms_to_end the number of milliseconds left before the end of the video.
 * Useful for capstan analysis.
 * @param capstan the capstan object;
 * @param tape the tape object;
 * @param args the command line arguments;
 * @param rect_tape the tape area under the tape head;
 * @param rect_capstan the capstan area.
 * @return true if a potential Irregularity has been found;
 * @return false otherwise.
 */
bool is_frame_different(cv::Mat prev_frame, cv::Mat current_frame, int ms_to_end, SceneObject capstan, SceneObject tape,
                        Args args, va::detection::Roi rect_tape, va::detection::Roi rect_capstan) {
    bool result = false;
    int num_different_pixels = 0;

    /*********************** Capstan analysis ************************/

    // In the last minute of the video, check for pinchRoller position for
    // endTape event
    if (!g_end_tape_saved && ms_to_end < 60000) {
        RotatedRect corrected_capstan_roi = check_skew(rect_capstan);
        Frame difference_frame = get_difference_for_roi(Frame(prev_frame), Frame(current_frame), corrected_capstan_roi);

        for (int i = 0; i < difference_frame.rows; i++) {
            for (int j = 0; j < difference_frame.cols; j++) {
                if (difference_frame.at<cv::Vec3b>(i, j)[0] == BLACK_PIXEL) {
                    // There is a black pixel, then there is a difference
                    // between previous and current frames
                    num_different_pixels++;
                }
            }
        }

        float capstan_pixel_threshold = rotated_rect_area(rect_capstan) * capstan.threshold.percentual / 100;
        if (num_different_pixels > capstan_pixel_threshold) {
            g_end_tape_saved = true;  // Never check again for end tape instant
            return true;
        }
    }

    /********************* Tape analysis *********************/

    RotatedRect corrected_tape_roi = check_skew(rect_tape);
    Frame difference_frame = get_difference_for_roi(Frame(prev_frame), Frame(current_frame), corrected_tape_roi);

    /********************** Segment analysis ************************/

    Frame cropped_current_frame =
        Frame(current_frame)
            .warp(cv::getRotationMatrix2D(corrected_tape_roi.center, corrected_tape_roi.angle, 1.0))
            .crop(corrected_tape_roi.size, corrected_tape_roi.center);
    num_different_pixels = 0;
    float mean_current_frame_color;
    int current_frame_color_sum = 0;

    for (int i = 0; i < cropped_current_frame.rows; i++) {
        for (int j = 0; j < cropped_current_frame.cols; j++) {
            current_frame_color_sum += cropped_current_frame.at<cv::Vec3b>(i, j)[0] +
                                       cropped_current_frame.at<cv::Vec3b>(i, j)[1] +
                                       cropped_current_frame.at<cv::Vec3b>(i, j)[2];
            if (difference_frame.at<cv::Vec3b>(i, j)[0] == BLACK_PIXEL) {
                num_different_pixels++;
            }
        }
    }
    float tape_area_pixels_sq = rotated_rect_area(rect_tape);
    mean_current_frame_color = current_frame_color_sum / tape_area_pixels_sq;

    /*********************** Decision stage ************************/

    float tape_pixel_threshold = tape_area_pixels_sq * tape.threshold.percentual / 100;
    if (num_different_pixels > tape_pixel_threshold) {  // The threshold must be passed

        /***** AVERAGE_COLOR-BASED DECISION *****/
        if (g_mean_prev_frame_color > (mean_current_frame_color + 7) ||
            g_mean_prev_frame_color < (mean_current_frame_color - 7)) {  // They are not similar for color average
            result = true;
        }

        /***** BRANDS MANAGEMENT *****/
        // At the beginning of the video, wait at least 5 seconds before the
        // next Irregularity to consider it as a brand. It is not guaranteed
        // that it will be the first brand, but it is generally a safe
        // approach to have a correct image
        if (args.brands && g_first_brand && g_first_instant - ms_to_end > 5000) {
            g_first_brand = false;
            result = true;
        }
    }

    g_mean_prev_frame_color = mean_current_frame_color;

    return result;
}

/**
 * @fn void processing(cv::VideoCapture video_capture, SceneObject capstan,
 * SceneObject tape, Args args, va::detection::Roi rect_tape, va::detection::Roi rect_capstan)
 * @brief video processing phase, where each frame is analysed.
 * It saves the IrregularityImages and updates the IrregularityFiles if an
 * Irregularity is found
 *
 * @note To be able to work with the "old" neural network (by Ilenya),
 * the output images should correspond to the old "whole tape" where, from the
 * frame judged as interesting, an area corresponding to the height of the tape
 * was extracted (so about the height of the current rectangle) and as wide as
 * the original frame (so 720px). This area will then have to be resized to
 * 224x224 as in the past. If instead you decide to use the new neural network,
 * no changes are needed.
 *
 * @param video_capture the input Preservation Audio-Visual File;
 * @param capstan the capstan SceneObject;
 * @param tape the tape SceneObject;
 * @param args the command line arguments.
 * @param rect_tape the tape Roi;
 * @param rect_capstan the capstan Roi.
 */
void processing(cv::VideoCapture video_capture, SceneObject capstan, SceneObject tape, Args args,
                va::detection::Roi rect_tape, va::detection::Roi rect_capstan) {
    const int video_length_ms =
        ((float)video_capture.get(CAP_PROP_FRAME_COUNT) / video_capture.get(CAP_PROP_FPS)) * 1000;
    int video_current_ms = video_capture.get(CAP_PROP_POS_MSEC);
    int num_saved_frames = 0;
    bool irregularity_found = false;

    // The first frame of the video won't be processed
    cv::Mat prev_frame = get_next_frame(video_capture, args.speed, irregularity_found);
    g_first_instant = video_length_ms - video_current_ms;

    while (video_capture.isOpened()) {
        Frame frame = get_next_frame(video_capture, args.speed, irregularity_found);
        video_current_ms = video_capture.get(CAP_PROP_POS_MSEC);

        if (frame.empty()) {
            std::cout << endl << "Empty frame!" << endl;
            video_capture.release();
            return;
        }

        int ms_to_end = video_length_ms - video_current_ms;
        if (video_current_ms == 0)  // With OpenCV library, this happens at the last few frames of
                                    // the video before realising that "frame" is empty.
            return;

        // Display program status
        int sec_to_end = ms_to_end / 1000;
        int min_to_end = (sec_to_end / 60) % 60;
        sec_to_end = sec_to_end % 60;
        string sec_str_to_end = (sec_to_end < 10 ? "0" : "") + to_string(sec_to_end);
        string min_str_to_end = (min_to_end < 10 ? "0" : "") + to_string(min_to_end);

        std::cout << "\rIrregularities: " << num_saved_frames << ".   ";
        std::cout << "Remaining video time [mm:ss]: " << min_str_to_end << ":" << sec_str_to_end << flush;

        irregularity_found =
            is_frame_different(prev_frame, frame, ms_to_end, capstan, tape, args, rect_tape, rect_capstan);
        if (irregularity_found) {
            auto [odd_frame, _] = frame.deinterlace();

            string irregularityImageFilename =
                to_string(num_saved_frames) + "_" + getTimeLabel(video_current_ms, "-") + ".jpg";
            cv::imwrite(g_irregularity_images_path / irregularityImageFilename, odd_frame);

            // Append Irregularity information to JSON
            Irregularity irreg = Irregularity(Source::Video, getTimeLabel(video_current_ms, ":"));
            g_irregularity_file_1["Irregularities"] += irreg.to_JSON();
            g_irregularity_file_2["Irregularities"] +=
                irreg.set_image_URI(g_irregularity_images_path.string() + "/" + irregularityImageFilename).to_JSON();

            num_saved_frames++;
        }
        prev_frame = frame;
    }
}

/**
 * @fn int main(int argc, char** argv)
 * @brief main program, organised as:
 * - Get input from command line or config.json file;
 * - Check input parameters;
 * - Creation of output directories;
 * - Regions Of Interest (ROIs) detection;
 * - Irregularities detection;
 * - Saving of output IrregularityFiles.
 *
 * @todo The main function should be splitted into 2 steps, and each step should be callable from the command line, so
 * that the user can choose to run only the first step, only the second step, or both:
 * - First step: generate irregularity file output 1;
 * - Second step: generate irregularity file output 2.
 *
 * @param argc Command line arguments count;
 * @param argv Command line arguments.
 * @return int program status.
 */
int main(int argc, char** argv) {
    const string CONFIG_FILE = "config/config.json";
    const string A_IRREG_FILE_1 = "AudioAnalyser_IrregularityFileOutput1.json";
    const string V_IRREG_FILE_1 = "VideoAnalyser_IrregularityFileOutput1.json";
    const string V_IRREG_FILE_2 = "VideoAnalyser_IrregularityFileOutput2.json";

    Args args = argc > 1 ? Args::from_cli(argc, argv) : Args::from_file(CONFIG_FILE);
    SceneObject capstan = SceneObject::from_file(CONFIG_FILE, ROI::CAPSTAN);
    SceneObject tape = SceneObject::from_file(CONFIG_FILE, ROI::TAPE);

    const fs::path VIDEO_PATH = args.working_path / "PreservationAudioVisualFile" / args.files_name;
    const auto [FILE_NAME, FILE_FORMAT] = files::get_filename_and_extension(VIDEO_PATH);
    const fs::path AUDIO_IRR_FILE_PATH = args.working_path / "temp" / FILE_NAME / A_IRREG_FILE_1;

    std::cout << "Video to be analysed: " << endl;
    std::cout << "\tFile name:  " << FILE_NAME << endl;
    std::cout << "\tExtension:  " << FILE_FORMAT << endl;

    if (FILE_FORMAT.compare("avi") != 0 && FILE_FORMAT.compare("mp4") != 0 && FILE_FORMAT.compare("mov") != 0)
        print_error_and_exit("Input error: The input file must be an AVI, MP4 or MOV file.");
    ifstream iJSON(AUDIO_IRR_FILE_PATH);
    if (iJSON.fail())
        print_error_and_exit("config.json error" + AUDIO_IRR_FILE_PATH.string() + " cannot be found or opened.");

    json audio_irr_file;
    iJSON >> audio_irr_file;

    // Adjust input paramenters (considering given ones as pertinent to a speed reference = 7.5)
    if (args.speed == 15) {
        tape.threshold.percentual += args.brands ? 6 : 20;
    } else if (!args.brands)
        tape.threshold.percentual += 21;

    g_output_path = args.working_path / "temp" / FILE_NAME;
    fs::create_directory(g_output_path);

    g_irregularity_images_path = g_output_path / "IrregularityImages";
    fs::create_directory(g_irregularity_images_path);

    cv::VideoCapture video_capture(VIDEO_PATH);  // Open video file
    if (!video_capture.isOpened()) print_error_and_exit("Video error: Video file cannot be opened.");

    video_capture.set(CAP_PROP_POS_FRAMES,
                      video_capture.get(CAP_PROP_FRAME_COUNT) / 2);  // Set frame position to half video length
    cv::Mat middle_frame = get_next_frame(video_capture, args.speed);
    video_capture.set(CAP_PROP_POS_FRAMES, 0);  // Reset frame position

    std::cout << "\tResolution: " << middle_frame.cols << "x" << middle_frame.rows << "\n\n";

    auto processing_areas = find_processing_areas(middle_frame, tape, capstan);
    if (std::holds_alternative<va::Error>(processing_areas))
        print_error_and_exit("Processing area not found: Try changing JSON parameters.");
    auto [rect_tape, rect_capstan] = std::get<pair<va::detection::Roi, va::detection::Roi>>(processing_areas);

    pprint("Processing...", CYAN);
    processing(video_capture, capstan, tape, args, rect_tape, rect_capstan);

    files::save_file(g_output_path / V_IRREG_FILE_1, g_irregularity_file_1.dump(4));

    // Irregularities to extract for the AudioAnalyser and to the TapeIrregularityClassifier
    extract_irregularity_images_for_audio(g_output_path, VIDEO_PATH, audio_irr_file, g_irregularity_file_2);
    files::save_file(g_output_path / V_IRREG_FILE_2, g_irregularity_file_2.dump(4));

    return EXIT_SUCCESS;
}