Update little printer requirements

src/raspberry.py

@@ -1,4 +1,106 @@
-from printer import Printer
+from flask_socketio import SocketIO
+from gpiozero import Button, LED
+from time import sleep
+import io                               # To check if we are on a Raspberry Pi
+import subprocess
 
 class Raspberry(object):
-    pass
+    """
+    This class will manage three things :
+    - Connecting to a USB webcam
+    - Managing a push button
+    - Activating a flash ( or light )
+    - Flash an indicator light
+
+    """
+    def __init__(self, printer, app, socketio, button_gpio_port_number, indicator_gpio_port_number, is_flash_present,):
+        self.printer = printer
+        self.socketio = socketio
+        self.app = app
+
+        self.is_flash_present = is_flash_present
+        self.button_gpio = button_gpio_port_number
+        self.led_gpio = indicator_gpio_port_number
+        self.image_path = self.app.config['UPLOAD_FOLDER'] + '/image.jpg'
+
+    def initialise_gpio(self):
+
+        self.button = Button(self.button_gpio)
+        self.led = LED(self.led_gpio)
+
+        button.when_pressed = self.on_button_pressed()
+
+
+    def is_raspberry_pi(self, raise_on_errors=False):
+        # Check if we are running on a raspberry pi
+        try:
+            with io.open('/proc/cpuinfo', 'r') as cpuinfo:
+                found = False
+                for line in cpuinfo:
+                    if line.startswith('Hardware'):
+                        found = True
+                        label, value = line.strip().split(':', 1)
+                        value = value.strip()
+                        if value not in (
+                            'BCM2708',
+                            'BCM2709',
+                            'BCM2711',
+                            'BCM2835',
+                            'BCM2836'
+                        ):
+                            self.app.logger.debug('This system does not appear to be a Raspberry Pi.')
+                            return False
+
+                if not found:
+                    self.app.logger.error('Couldn\'t get sufficient hardware information from /proc/cpuinfo, Unable to determine if we are on a Raspberry Pi.')
+                    return False
+        except IOError:
+            self.app.logger.error('Unable to open `/proc/cpuinfo`.')
+            return False
+
+        self.app.logger.debug('It seems we are on a Raspberry Pi')
+        return True
+
+    def take_picture(self):
+        # return a path to a picture
+        try:
+            subprocess.run(['fswebcam', '--no-banner', self.image_path])
+        except Exception as e:
+            self.app.logger.error('Unable to take a picture :' + e)
+            raise e
+        return True
+
+    def flash(state):
+        if state:
+            # turn on the flash
+            pass
+        else:
+            # turn off the flash
+            pass
+
+    def flash_indicator(self):
+        # The indicator will flash three times before return true
+        self.led.on()
+        sleep(0.1)
+        self.led.off()
+        sleep(1)
+        self.led.on()
+        sleep(0.1)
+        self.led.off()
+        sleep(1)
+        self.led.on()
+        sleep(0.1)
+        self.led.off()
+
+    def on_button_pressed():
+        self.socketio.emit('button_pressed')  # Notify clients that a button has been pressed on the raspberry pi
+        self.flash_indicator()  # The indicator will flash a countdown LED
+        self.flash(True)
+        try:
+            self.take_picture()
+            self.printer.print_image(self.image_path)
+        except Exception as e:
+            app.logger.error("Could not take a picture after the button press : " + e)
+            self.led.on()
+        self.flash(False)
+        self.socketio.emit('picture_taken')  # Notify clients that a picture has been taken