core/homeassistant/components/camera/__init__.py

# pylint: disable=too-many-lines
"""
Component to interface with cameras.

For more details about this component, please refer to the documentation at
https://home-assistant.io/components/camera/
"""
import logging
import re
import time

import requests

from homeassistant.helpers.entity import Entity
from homeassistant.helpers.entity_component import EntityComponent
from homeassistant.components import bloomsky
from homeassistant.const import HTTP_OK, HTTP_NOT_FOUND, ATTR_ENTITY_ID
from homeassistant.helpers.config_validation import PLATFORM_SCHEMA  # noqa


DOMAIN = 'camera'
DEPENDENCIES = ['http']
SCAN_INTERVAL = 30
ENTITY_ID_FORMAT = DOMAIN + '.{}'

# Maps discovered services to their platforms
DISCOVERY_PLATFORMS = {
    bloomsky.DISCOVER_CAMERAS: 'bloomsky',
}

STATE_RECORDING = 'recording'
STATE_STREAMING = 'streaming'
STATE_IDLE = 'idle'

ENTITY_IMAGE_URL = '/api/camera_proxy/{0}'

MULTIPART_BOUNDARY = '--jpgboundary'
MJPEG_START_HEADER = 'Content-type: {0}\r\n\r\n'


# pylint: disable=too-many-branches
def setup(hass, config):
    """Setup the camera component."""
    component = EntityComponent(
        logging.getLogger(__name__), DOMAIN, hass, SCAN_INTERVAL,
        DISCOVERY_PLATFORMS)

    component.setup(config)

    def _proxy_camera_image(handler, path_match, data):
        """Serve the camera image via the HA server."""
        entity_id = path_match.group(ATTR_ENTITY_ID)
        camera = component.entities.get(entity_id)

        if camera is None:
            handler.send_response(HTTP_NOT_FOUND)
            handler.end_headers()
            return

        response = camera.camera_image()

        if response is None:
            handler.send_response(HTTP_NOT_FOUND)
            handler.end_headers()
            return

        handler.send_response(HTTP_OK)
        handler.write_content(response)

    hass.http.register_path(
        'GET',
        re.compile(r'/api/camera_proxy/(?P<entity_id>[a-zA-Z\._0-9]+)'),
        _proxy_camera_image)

    def _proxy_camera_mjpeg_stream(handler, path_match, data):
        """Proxy the camera image as an mjpeg stream via the HA server."""
        entity_id = path_match.group(ATTR_ENTITY_ID)
        camera = component.entities.get(entity_id)

        if camera is None:
            handler.send_response(HTTP_NOT_FOUND)
            handler.end_headers()
            return

        try:
            camera.is_streaming = True
            camera.update_ha_state()
            camera.mjpeg_stream(handler)

        except (requests.RequestException, IOError):
            camera.is_streaming = False
            camera.update_ha_state()

    hass.http.register_path(
        'GET',
        re.compile(r'/api/camera_proxy_stream/(?P<entity_id>[a-zA-Z\._0-9]+)'),
        _proxy_camera_mjpeg_stream)

    return True


class Camera(Entity):
    """The base class for camera entities."""

    def __init__(self):
        """Initialize a camera."""
        self.is_streaming = False

    @property
    def should_poll(self):
        """No need to poll cameras."""
        return False

    @property
    def entity_picture(self):
        """Return a link to the camera feed as entity picture."""
        return ENTITY_IMAGE_URL.format(self.entity_id)

    @property
    def is_recording(self):
        """Return true if the device is recording."""
        return False

    @property
    def brand(self):
        """Camera brand."""
        return None

    @property
    def model(self):
        """Camera model."""
        return None

    def camera_image(self):
        """Return bytes of camera image."""
        raise NotImplementedError()

    def mjpeg_stream(self, handler):
        """Generate an HTTP MJPEG stream from camera images."""
        def write_string(text):
            """Helper method to write a string to the stream."""
            handler.request.sendall(bytes(text + '\r\n', 'utf-8'))

        write_string('HTTP/1.1 200 OK')
        write_string('Content-type: multipart/x-mixed-replace; '
                     'boundary={}'.format(MULTIPART_BOUNDARY))
        write_string('')
        write_string(MULTIPART_BOUNDARY)

        while True:
            img_bytes = self.camera_image()

            if img_bytes is None:
                continue

            write_string('Content-length: {}'.format(len(img_bytes)))
            write_string('Content-type: image/jpeg')
            write_string('')
            handler.request.sendall(img_bytes)
            write_string('')
            write_string(MULTIPART_BOUNDARY)

            time.sleep(0.5)

    @property
    def state(self):
        """Camera state."""
        if self.is_recording:
            return STATE_RECORDING
        elif self.is_streaming:
            return STATE_STREAMING
        else:
            return STATE_IDLE

    @property
    def state_attributes(self):
        """Camera state attributes."""
        attr = {}

        if self.model:
            attr['model_name'] = self.model

        if self.brand:
            attr['brand'] = self.brand

        return attr