#############################################################################
##
## Copyright (C) 2020 The Qt Company Ltd.
## Contact: https://www.qt.io/licensing/
##
## This file is part of the Qt for Python examples of the Qt Toolkit.
##
## $QT_BEGIN_LICENSE:BSD$
## You may use this file under the terms of the BSD license as follows:
##
## "Redistribution and use in source and binary forms, with or without
## modification, are permitted provided that the following conditions are
## met:
##   * Redistributions of source code must retain the above copyright
##     notice, this list of conditions and the following disclaimer.
##   * Redistributions in binary form must reproduce the above copyright
##     notice, this list of conditions and the following disclaimer in
##     the documentation and/or other materials provided with the
##     distribution.
##   * Neither the name of The Qt Company Ltd nor the names of its
##     contributors may be used to endorse or promote products derived
##     from this software without specific prior written permission.
##
##
## THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
## "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
## LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
## A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
## OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
## SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
## LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
## DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
## THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
## (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
## OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
##
## $QT_END_LICENSE$
##
#############################################################################

import os
import sys
import time

import cv2
from PySide6.QtCore import Qt, QThread, Signal, Slot
from PySide6.QtGui import QAction, QImage, QKeySequence, QPixmap
from PySide6.QtWidgets import (QApplication, QComboBox, QGroupBox,
                               QHBoxLayout, QLabel, QMainWindow, QPushButton,
                               QSizePolicy, QVBoxLayout, QWidget)


"""This example uses the video from a  webcam to apply pattern
detection from the OpenCV module. e.g.: face, eyes, body, etc."""


class Thread(QThread):
    updateFrame = Signal(QImage)

    def __init__(self, parent=None):
        QThread.__init__(self, parent)
        self.trained_file = None
        self.status = True
        self.cap = True

    def set_file(self, fname):
        # The data comes with the 'opencv-python' module
        self.trained_file = os.path.join(cv2.data.haarcascades, fname)

    def run(self):
        self.cap = cv2.VideoCapture(0)
        while self.status:
            cascade = cv2.CascadeClassifier(self.trained_file)
            ret, frame = self.cap.read()
            if not ret:
                continue

            # Reading frame in gray scale to process the pattern
            gray_frame = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)

            detections = cascade.detectMultiScale(gray_frame, scaleFactor=1.1,
                                                  minNeighbors=5, minSize=(30, 30))

            # Drawing green rectangle around the pattern
            for (x, y, w, h) in detections:
                pos_ori = (x, y)
                pos_end = (x + w, y + h)
                color = (0, 255, 0)
                cv2.rectangle(frame, pos_ori, pos_end, color, 2)

            # Reading the image in RGB to display it
            color_frame = cv2.cvtColor(frame, cv2.COLOR_BGR2RGB)

            # Creating and scaling QImage
            h, w, ch = color_frame.shape
            img = QImage(color_frame.data, w, h, ch * w, QImage.Format_RGB888)
            scaled_img = img.scaled(640, 480, Qt.KeepAspectRatio)

            # Emit signal
            self.updateFrame.emit(scaled_img)
        sys.exit(-1)


class Window(QMainWindow):
    def __init__(self):
        QMainWindow.__init__(self)
        # Title and dimensions
        self.setWindowTitle("Patterns detection")
        self.setGeometry(0, 0, 800, 500)

        # Main menu bar
        self.menu = self.menuBar()
        self.menu_file = self.menu.addMenu("File")
        exit = QAction("Exit", self, triggered=qApp.quit)
        self.menu_file.addAction(exit)

        self.menu_about = self.menu.addMenu("&About")
        about = QAction("About Qt", self, shortcut=QKeySequence(QKeySequence.HelpContents),
                        triggered=qApp.aboutQt)
        self.menu_about.addAction(about)

        # Create a label for the display camera
        self.label = QLabel(self)
        self.label.setFixedSize(640, 480)

        # Thread in charge of updating the image
        self.th = Thread(self)
        self.th.finished.connect(self.close)
        self.th.updateFrame.connect(self.setImage)

        # Model group
        self.group_model = QGroupBox("Trained model")
        self.group_model.setSizePolicy(QSizePolicy.Preferred, QSizePolicy.Expanding)
        model_layout = QHBoxLayout()

        self.combobox = QComboBox()
        for xml_file in os.listdir(cv2.data.haarcascades):
            if xml_file.endswith(".xml"):
                self.combobox.addItem(xml_file)

        model_layout.addWidget(QLabel("File:"), 10)
        model_layout.addWidget(self.combobox, 90)
        self.group_model.setLayout(model_layout)

        # Buttons layout
        buttons_layout = QHBoxLayout()
        self.button1 = QPushButton("Start")
        self.button2 = QPushButton("Stop/Close")
        self.button1.setSizePolicy(QSizePolicy.Preferred, QSizePolicy.Expanding)
        self.button2.setSizePolicy(QSizePolicy.Preferred, QSizePolicy.Expanding)
        buttons_layout.addWidget(self.button2)
        buttons_layout.addWidget(self.button1)

        right_layout = QHBoxLayout()
        right_layout.addWidget(self.group_model, 1)
        right_layout.addLayout(buttons_layout, 1)

        # Main layout
        layout = QVBoxLayout()
        layout.addWidget(self.label)
        layout.addLayout(right_layout)

        # Central widget
        widget = QWidget(self)
        widget.setLayout(layout)
        self.setCentralWidget(widget)

        # Connections
        self.button1.clicked.connect(self.start)
        self.button2.clicked.connect(self.kill_thread)
        self.button2.setEnabled(False)
        self.combobox.currentTextChanged.connect(self.set_model)

    @Slot()
    def set_model(self, text):
        self.th.set_file(text)

    @Slot()
    def kill_thread(self):
        print("Finishing...")
        self.button2.setEnabled(False)
        self.button1.setEnabled(True)
        self.th.cap.release()
        cv2.destroyAllWindows()
        self.status = False
        self.th.terminate()
        # Give time for the thread to finish
        time.sleep(1)

    @Slot()
    def start(self):
        print("Starting...")
        self.button2.setEnabled(True)
        self.button1.setEnabled(False)
        self.th.set_file(self.combobox.currentText())
        self.th.start()

    @Slot(QImage)
    def setImage(self, image):
        self.label.setPixmap(QPixmap.fromImage(image))


if __name__ == "__main__":
    app = QApplication()
    w = Window()
    w.show()
    sys.exit(app.exec_())
