from flask import Blueprint, render_template, Response

import io
import logging
from threading import Condition

from picamera2 import Picamera2
from picamera2.encoders import JpegEncoder
from picamera2.outputs import FileOutput

views = Blueprint('views', __name__)
streaming = Blueprint('streaming', __name__)

class StreamingOutput(io.BufferedIOBase):
    def __init__(self):
        self.frame = None
        self.condition = Condition()

    def write(self, buf):
        with self.condition:
            self.frame = buf
            self.condition.notify_all()

output = StreamingOutput()
picam2 = None

def start_streaming():
    global picam2
    if picam2 is None:
        picam2 = Picamera2()
        picam2.configure(picam2.create_video_configuration(main={"size": (640, 480)}))
        picam2.start_recording(JpegEncoder(), FileOutput(output))

def stop_streaming():
    global picam2
    if picam2 is not None:
        picam2.stop_recording()
        picam2 = None

def generate():
    try:
        while True:
            with output.condition:
                output.condition.wait()
                frame = output.frame
            yield (b'--FRAME\r\n'
                   b'Content-Type: image/jpeg\r\n\r\n' + frame + b'\r\n')
    except Exception as e:
        logging.warning('Removed streaming client: %s', str(e))

@streaming.route('/stream')
def stream():
    start_streaming()
    return Response(generate(), mimetype='multipart/x-mixed-replace; boundary=FRAME')

@views.route('/')
@views.route('/index.html')
def home():
    stop_streaming()
    return render_template("home.html")

@views.route('/live')
def live():
    start_streaming()
    return render_template("live.html")

views.register_blueprint(streaming, url_prefix='/stream')