import base64
import datetime
import json
import logging
import os
import time
from functools import reduce

import cv2
import gevent
import numpy as np
from flask import (
    Blueprint,
    Flask,
    Response,
    current_app,
    jsonify,
    make_response,
    request,
)
from flask_sockets import Sockets
from peewee import SqliteDatabase, operator, fn, DoesNotExist
from playhouse.shortcuts import model_to_dict

from frigate.const import CLIPS_DIR
from frigate.models import Event
from frigate.stats import stats_snapshot
from frigate.util import calculate_region
from frigate.version import VERSION

logger = logging.getLogger(__name__)

bp = Blueprint("frigate", __name__)
ws = Blueprint("ws", __name__)


class MqttBackend:
    """Interface for registering and updating WebSocket clients."""

    def __init__(self, mqtt_client, topic_prefix):
        self.clients = list()
        self.mqtt_client = mqtt_client
        self.topic_prefix = topic_prefix

    def register(self, client):
        """Register a WebSocket connection for Mqtt updates."""
        self.clients.append(client)

    def publish(self, message):
        try:
            json_message = json.loads(message)
            json_message = {
                "topic": f"{self.topic_prefix}/{json_message['topic']}",
                "payload": json_message.get["payload"],
                "retain": json_message.get("retain", False),
            }
        except:
            logger.warning("Unable to parse websocket message as valid json.")
            return

        logger.debug(
            f"Publishing mqtt message from websockets at {json_message['topic']}."
        )
        self.mqtt_client.publish(
            json_message["topic"],
            json_message["payload"],
            retain=json_message["retain"],
        )

    def run(self):
        def send(client, userdata, message):
            """Sends mqtt messages to clients."""
            try:
                logger.debug(f"Received mqtt message on {message.topic}.")
                ws_message = json.dumps(
                    {
                        "topic": message.topic.replace(f"{self.topic_prefix}/", ""),
                        "payload": message.payload.decode(),
                    }
                )
            except:
                # if the payload can't be decoded don't relay to clients
                logger.debug(
                    f"MQTT payload for {message.topic} wasn't text. Skipping..."
                )
                return

            for client in self.clients:
                try:
                    client.send(ws_message)
                except:
                    logger.debug(
                        "Removing websocket client due to a closed connection."
                    )
                    self.clients.remove(client)

        self.mqtt_client.message_callback_add(f"{self.topic_prefix}/#", send)

    def start(self):
        """Maintains mqtt subscription in the background."""
        gevent.spawn(self.run)


def create_app(
    frigate_config,
    database: SqliteDatabase,
    stats_tracking,
    detected_frames_processor,
    mqtt_client,
):
    app = Flask(__name__)
    sockets = Sockets(app)

    @app.before_request
    def _db_connect():
        database.connect()

    @app.teardown_request
    def _db_close(exc):
        if not database.is_closed():
            database.close()

    app.frigate_config = frigate_config
    app.stats_tracking = stats_tracking
    app.detected_frames_processor = detected_frames_processor

    app.register_blueprint(bp)
    sockets.register_blueprint(ws)

    app.mqtt_backend = MqttBackend(mqtt_client, frigate_config.mqtt.topic_prefix)
    app.mqtt_backend.start()

    return app


@bp.route("/")
def is_healthy():
    return "Frigate is running. Alive and healthy!"


@bp.route("/events/summary")
def events_summary():
    has_clip = request.args.get("has_clip", type=int)
    has_snapshot = request.args.get("has_snapshot", type=int)

    clauses = []

    if not has_clip is None:
        clauses.append((Event.has_clip == has_clip))

    if not has_snapshot is None:
        clauses.append((Event.has_snapshot == has_snapshot))

    if len(clauses) == 0:
        clauses.append((1 == 1))

    groups = (
        Event.select(
            Event.camera,
            Event.label,
            fn.strftime(
                "%Y-%m-%d", fn.datetime(Event.start_time, "unixepoch", "localtime")
            ).alias("day"),
            Event.zones,
            fn.COUNT(Event.id).alias("count"),
        )
        .where(reduce(operator.and_, clauses))
        .group_by(
            Event.camera,
            Event.label,
            fn.strftime(
                "%Y-%m-%d", fn.datetime(Event.start_time, "unixepoch", "localtime")
            ),
            Event.zones,
        )
    )

    return jsonify([e for e in groups.dicts()])


@bp.route("/events/<id>")
def event(id):
    try:
        return model_to_dict(Event.get(Event.id == id))
    except DoesNotExist:
        return "Event not found", 404


@bp.route("/events/<id>/thumbnail.jpg")
def event_thumbnail(id):
    format = request.args.get("format", "ios")
    thumbnail_bytes = None
    try:
        event = Event.get(Event.id == id)
        thumbnail_bytes = base64.b64decode(event.thumbnail)
    except DoesNotExist:
        # see if the object is currently being tracked
        try:
            for (
                camera_state
            ) in current_app.detected_frames_processor.camera_states.values():
                if id in camera_state.tracked_objects:
                    tracked_obj = camera_state.tracked_objects.get(id)
                    if not tracked_obj is None:
                        thumbnail_bytes = tracked_obj.get_thumbnail()
        except:
            return "Event not found", 404

    if thumbnail_bytes is None:
        return "Event not found", 404

    # android notifications prefer a 2:1 ratio
    if format == "android":
        jpg_as_np = np.frombuffer(thumbnail_bytes, dtype=np.uint8)
        img = cv2.imdecode(jpg_as_np, flags=1)
        thumbnail = cv2.copyMakeBorder(
            img,
            0,
            0,
            int(img.shape[1] * 0.5),
            int(img.shape[1] * 0.5),
            cv2.BORDER_CONSTANT,
            (0, 0, 0),
        )
        ret, jpg = cv2.imencode(".jpg", thumbnail, [int(cv2.IMWRITE_JPEG_QUALITY), 70])
        thumbnail_bytes = jpg.tobytes()

    response = make_response(thumbnail_bytes)
    response.headers["Content-Type"] = "image/jpg"
    return response


@bp.route("/events/<id>/snapshot.jpg")
def event_snapshot(id):
    jpg_bytes = None
    try:
        event = Event.get(Event.id == id)
        if not event.has_snapshot:
            return "Snapshot not available", 404
        # read snapshot from disk
        with open(
            os.path.join(CLIPS_DIR, f"{event.camera}-{id}.jpg"), "rb"
        ) as image_file:
            jpg_bytes = image_file.read()
    except DoesNotExist:
        # see if the object is currently being tracked
        try:
            for (
                camera_state
            ) in current_app.detected_frames_processor.camera_states.values():
                if id in camera_state.tracked_objects:
                    tracked_obj = camera_state.tracked_objects.get(id)
                    if not tracked_obj is None:
                        jpg_bytes = tracked_obj.get_jpg_bytes(
                            timestamp=request.args.get("timestamp", type=int),
                            bounding_box=request.args.get("bbox", type=int),
                            crop=request.args.get("crop", type=int),
                            height=request.args.get("h", type=int),
                        )
        except:
            return "Event not found", 404
    except:
        return "Event not found", 404

    response = make_response(jpg_bytes)
    response.headers["Content-Type"] = "image/jpg"
    return response


@bp.route("/events")
def events():
    limit = request.args.get("limit", 100)
    camera = request.args.get("camera")
    label = request.args.get("label")
    zone = request.args.get("zone")
    after = request.args.get("after", type=float)
    before = request.args.get("before", type=float)
    has_clip = request.args.get("has_clip", type=int)
    has_snapshot = request.args.get("has_snapshot", type=int)
    include_thumbnails = request.args.get("include_thumbnails", default=1, type=int)

    clauses = []
    excluded_fields = []

    if camera:
        clauses.append((Event.camera == camera))

    if label:
        clauses.append((Event.label == label))

    if zone:
        clauses.append((Event.zones.cast("text") % f'*"{zone}"*'))

    if after:
        clauses.append((Event.start_time >= after))

    if before:
        clauses.append((Event.start_time <= before))

    if not has_clip is None:
        clauses.append((Event.has_clip == has_clip))

    if not has_snapshot is None:
        clauses.append((Event.has_snapshot == has_snapshot))

    if not include_thumbnails:
        excluded_fields.append(Event.thumbnail)

    if len(clauses) == 0:
        clauses.append((1 == 1))

    events = (
        Event.select()
        .where(reduce(operator.and_, clauses))
        .order_by(Event.start_time.desc())
        .limit(limit)
    )

    return jsonify([model_to_dict(e, exclude=excluded_fields) for e in events])


@bp.route("/config")
def config():
    return jsonify(current_app.frigate_config.to_dict())


@bp.route("/version")
def version():
    return VERSION


@bp.route("/stats")
def stats():
    stats = stats_snapshot(current_app.stats_tracking)
    return jsonify(stats)


@bp.route("/<camera_name>/<label>/best.jpg")
def best(camera_name, label):
    if camera_name in current_app.frigate_config.cameras:
        best_object = current_app.detected_frames_processor.get_best(camera_name, label)
        best_frame = best_object.get("frame")
        if best_frame is None:
            best_frame = np.zeros((720, 1280, 3), np.uint8)
        else:
            best_frame = cv2.cvtColor(best_frame, cv2.COLOR_YUV2BGR_I420)

        crop = bool(request.args.get("crop", 0, type=int))
        if crop:
            box = best_object.get("box", (0, 0, 300, 300))
            region = calculate_region(
                best_frame.shape, box[0], box[1], box[2], box[3], 1.1
            )
            best_frame = best_frame[region[1] : region[3], region[0] : region[2]]

        height = int(request.args.get("h", str(best_frame.shape[0])))
        width = int(height * best_frame.shape[1] / best_frame.shape[0])

        best_frame = cv2.resize(
            best_frame, dsize=(width, height), interpolation=cv2.INTER_AREA
        )
        ret, jpg = cv2.imencode(".jpg", best_frame, [int(cv2.IMWRITE_JPEG_QUALITY), 70])
        response = make_response(jpg.tobytes())
        response.headers["Content-Type"] = "image/jpg"
        return response
    else:
        return "Camera named {} not found".format(camera_name), 404


@bp.route("/<camera_name>")
def mjpeg_feed(camera_name):
    fps = int(request.args.get("fps", "3"))
    height = int(request.args.get("h", "360"))
    draw_options = {
        "bounding_boxes": request.args.get("bbox", type=int),
        "timestamp": request.args.get("timestamp", type=int),
        "zones": request.args.get("zones", type=int),
        "mask": request.args.get("mask", type=int),
        "motion_boxes": request.args.get("motion", type=int),
        "regions": request.args.get("regions", type=int),
    }
    if camera_name in current_app.frigate_config.cameras:
        # return a multipart response
        return Response(
            imagestream(
                current_app.detected_frames_processor,
                camera_name,
                fps,
                height,
                draw_options,
            ),
            mimetype="multipart/x-mixed-replace; boundary=frame",
        )
    else:
        return "Camera named {} not found".format(camera_name), 404


@bp.route("/<camera_name>/latest.jpg")
def latest_frame(camera_name):
    draw_options = {
        "bounding_boxes": request.args.get("bbox", type=int),
        "timestamp": request.args.get("timestamp", type=int),
        "zones": request.args.get("zones", type=int),
        "mask": request.args.get("mask", type=int),
        "motion_boxes": request.args.get("motion", type=int),
        "regions": request.args.get("regions", type=int),
    }
    if camera_name in current_app.frigate_config.cameras:
        # max out at specified FPS
        frame = current_app.detected_frames_processor.get_current_frame(
            camera_name, draw_options
        )
        if frame is None:
            frame = np.zeros((720, 1280, 3), np.uint8)

        height = int(request.args.get("h", str(frame.shape[0])))
        width = int(height * frame.shape[1] / frame.shape[0])

        frame = cv2.resize(frame, dsize=(width, height), interpolation=cv2.INTER_AREA)

        ret, jpg = cv2.imencode(".jpg", frame, [int(cv2.IMWRITE_JPEG_QUALITY), 70])
        response = make_response(jpg.tobytes())
        response.headers["Content-Type"] = "image/jpg"
        return response
    else:
        return "Camera named {} not found".format(camera_name), 404


def imagestream(detected_frames_processor, camera_name, fps, height, draw_options):
    while True:
        # max out at specified FPS
        gevent.sleep(1/fps)
        frame = detected_frames_processor.get_current_frame(camera_name, draw_options)
        if frame is None:
            frame = np.zeros((height, int(height * 16 / 9), 3), np.uint8)

        width = int(height * frame.shape[1] / frame.shape[0])
        frame = cv2.resize(frame, dsize=(width, height), interpolation=cv2.INTER_LINEAR)

        ret, jpg = cv2.imencode(".jpg", frame, [int(cv2.IMWRITE_JPEG_QUALITY), 70])
        yield (
            b"--frame\r\n"
            b"Content-Type: image/jpeg\r\n\r\n" + jpg.tobytes() + b"\r\n\r\n"
        )


@ws.route("/ws")
def echo_socket(socket):
    current_app.mqtt_backend.register(socket)

    while not socket.closed:
        # Sleep to prevent *constant* context-switches.
        gevent.sleep(0.1)

        message = socket.receive()
        if message:
            current_app.mqtt_backend.publish(message)