import logging
import os
import tempfile
import asyncio

from typing import Optional, List

import settings
from db import collection
from sync.data import request
from sync.models import Model
from utils.hash import md5
from utils.image import image_magick_resize

logger = logging.getLogger(settings.name + '.Image')

store = collection(settings.collection_images)


def get_upload_url(url):
    return os.path.join(settings.image_url_upload, os.path.basename(url))


def default_url_factory(file, size, ext):
    url = settings.image_url_base + '{}-{}{}'
    return url.format(md5(file), size, ext)


class Image(Model):
    @staticmethod
    async def find_one(query):
        document = store.find_one(query)
        return document

    @staticmethod
    async def new(provider, file, sizes, url_factory=None):
        url_factory = url_factory if url_factory else default_url_factory

        img = Image(provider, file, data=None, url_factory=url_factory)
        changed = await img.is_changed()
        if changed:
            await img.build(sizes=sizes)
            await img.upload()
            await img.save()
        else:
            doc = await Image.find_one({'file': file})
            img = Image(provider, file, doc['data'], url_factory)
            img.__set_id(doc['_id'])

        return img

    def __init__(self, provider, file, data, url_factory):
        self.data = data
        self.url_factory = url_factory

        super().__init__(provider, store, file)

    def init(self):
        self.hash = self.__get_hash()

    async def is_changed(self):
        i = await Image.find_one({'file': self.file})
        return self._is_changed_hash(i)

    async def build(self, sizes):
        logger.info('Building Image {}'.format(self.provider.get_abs(self.file)))

        img_in = self.provider.get_abs(self.file)
        img_out = tempfile.mkdtemp()

        images = await create_image(img_in, sizes, self.url_factory, img_out)
        if not images:
            raise Exception('Failed to create Image {}'.format(img_in))
        data = {}
        for i in images:
            if i:
                size_name = i['size']
                data[size_name] = {
                    **i,
                }
        self.data = data

    async def upload(self):
        if self.data:
            async def fn(i):
                url = get_upload_url(i['url'])
                file = i['file']

                logger.info('Uploading to {}'.format(url))
                await request.upload(url, file)

            await asyncio.wait([fn(i) for i in self.data.values()])

    async def save(self):
        c = sync_image(self.bake())
        self.__set_id(c['_id'])

    def bake(self):
        return {
            'file': self.file,
            'hash': self.hash,
            'data': self.data,
        }

    def get_size(self, size):
        if size in self.data:
            return self.data[size]
        return None

    def __filename(self):
        return os.path.basename(self.file)

    def __set_id(self, value):
        self.id = value

    def __get_hash(self):
        return self.provider.hash(self.file)

    def __str__(self):
        return '<Image hash={} file={}>'.format(self.hash, self.file)


def sync_image(record):
    from db import db

    q = {'hash': record['hash']}
    try:
        db().images.update_one(q, {'$set': record}, upsert=True)
        i = db().images.find_one({'hash': record['hash']})
        return i
    except ValueError:
        pass

    return None


async def create_image(file: str, sizes: [()], url_fn, output_dir: str) -> Optional[List[dict]]:
    """

    :param file: Image path to process
    :param sizes: list of sizes to generate image (<size_name>, <width>, <height>)
    :param url_fn: function (size_name, ext) for creating image url
    :param output_dir: path to local folder for thumbs storing
    :return:
    """
    if not os.path.exists(file):
        return None

    _, ext = os.path.splitext(file)
    images = []

    async def fn(size):
        size_name, width, height = size

        image_url = url_fn(file, size_name, ext)
        image_filename = os.path.basename(image_url)
        local_image_path = os.path.join(output_dir, image_filename)

        # if settings.image_processing_enabled:
        image = await process_image(file, local_image_path, size)
        if not image:
            logger.warning('Failed to process image {}'.format(file))
            return None
        width, height = image.size

        images.append({
            'file': local_image_path,
            'url': image_url,
            'size': size_name,
            'width': width,
            'height': height
        })

    await asyncio.wait([fn(s) for s in sizes])

    return images


async def process_image(input_file, output_file, size):
    size_name, width, height = size

    if size_name == 'original':
        return await optimize(input_file, output_file, quality=90)
    else:
        image = await read_image(input_file)
        if not image:
            return None
        image_width, image_height = image.size
        if image_height > image_width:
            width, height = height, width
        return await thumbnail(input_file, output_file, (width, height), quality=90)


async def read_image(src):
    import aiofiles
    from PIL import Image
    import io

    async with aiofiles.open(src, mode='rb') as f:
        image_data = await f.read()
        image = Image.open(io.BytesIO(image_data))
        return image


async def thumbnail(src, dest, size, quality):
    await image_magick_resize(src, dest, size, quality)
    return await read_image(dest)


async def optimize(src, dest, quality):
    image = await read_image(src)
    image.save(dest, quality=quality)
    return image