"""Optical character recognition processing of seven segments displays."""
import io
import logging
import os
import subprocess

from PIL import Image
import voluptuous as vol

from homeassistant.components.image_processing import (
    CONF_ENTITY_ID,
    CONF_NAME,
    CONF_SOURCE,
    PLATFORM_SCHEMA,
    ImageProcessingEntity,
)
from homeassistant.core import split_entity_id
import homeassistant.helpers.config_validation as cv

_LOGGER = logging.getLogger(__name__)

CONF_DIGITS = "digits"
CONF_EXTRA_ARGUMENTS = "extra_arguments"
CONF_HEIGHT = "height"
CONF_ROTATE = "rotate"
CONF_SSOCR_BIN = "ssocr_bin"
CONF_THRESHOLD = "threshold"
CONF_WIDTH = "width"
CONF_X_POS = "x_position"
CONF_Y_POS = "y_position"

DEFAULT_BINARY = "ssocr"

PLATFORM_SCHEMA = PLATFORM_SCHEMA.extend(
    {
        vol.Optional(CONF_EXTRA_ARGUMENTS, default=""): cv.string,
        vol.Optional(CONF_DIGITS): cv.positive_int,
        vol.Optional(CONF_HEIGHT, default=0): cv.positive_int,
        vol.Optional(CONF_SSOCR_BIN, default=DEFAULT_BINARY): cv.string,
        vol.Optional(CONF_THRESHOLD, default=0): cv.positive_int,
        vol.Optional(CONF_ROTATE, default=0): cv.positive_int,
        vol.Optional(CONF_WIDTH, default=0): cv.positive_int,
        vol.Optional(CONF_X_POS, default=0): cv.string,
        vol.Optional(CONF_Y_POS, default=0): cv.positive_int,
    }
)


async def async_setup_platform(hass, config, async_add_entities, discovery_info=None):
    """Set up the Seven segments OCR platform."""
    entities = []
    for camera in config[CONF_SOURCE]:
        entities.append(
            ImageProcessingSsocr(
                hass, camera[CONF_ENTITY_ID], config, camera.get(CONF_NAME)
            )
        )

    async_add_entities(entities)


class ImageProcessingSsocr(ImageProcessingEntity):
    """Representation of the seven segments OCR image processing entity."""

    def __init__(self, hass, camera_entity, config, name):
        """Initialize seven segments processing."""
        self.hass = hass
        self._camera_entity = camera_entity
        if name:
            self._name = name
        else:
            self._name = "SevenSegment OCR {0}".format(
                split_entity_id(camera_entity)[1]
            )
        self._state = None

        self.filepath = os.path.join(
            self.hass.config.config_dir,
            "ssocr-{0}.png".format(self._name.replace(" ", "_")),
        )
        crop = [
            "crop",
            str(config[CONF_X_POS]),
            str(config[CONF_Y_POS]),
            str(config[CONF_WIDTH]),
            str(config[CONF_HEIGHT]),
        ]
        digits = ["-d", str(config.get(CONF_DIGITS, -1))]
        rotate = ["rotate", str(config[CONF_ROTATE])]
        threshold = ["-t", str(config[CONF_THRESHOLD])]
        extra_arguments = config[CONF_EXTRA_ARGUMENTS].split(" ")

        self._command = (
            [config[CONF_SSOCR_BIN]]
            + crop
            + digits
            + threshold
            + rotate
            + extra_arguments
        )
        self._command.append(self.filepath)

    @property
    def device_class(self):
        """Return the class of this device, from component DEVICE_CLASSES."""
        return "ocr"

    @property
    def camera_entity(self):
        """Return camera entity id from process pictures."""
        return self._camera_entity

    @property
    def name(self):
        """Return the name of the image processor."""
        return self._name

    @property
    def state(self):
        """Return the state of the entity."""
        return self._state

    def process_image(self, image):
        """Process the image."""
        stream = io.BytesIO(image)
        img = Image.open(stream)
        img.save(self.filepath, "png")

        ocr = subprocess.Popen(
            self._command, stdout=subprocess.PIPE, stderr=subprocess.PIPE
        )
        out = ocr.communicate()
        if out[0] != b"":
            self._state = out[0].strip().decode("utf-8")
        else:
            self._state = None
            _LOGGER.warning(
                "Unable to detect value: %s", out[1].strip().decode("utf-8")
            )
