import asyncio import functools import io import re import shutil import sys from dataclasses import dataclass, field from pathlib import Path from typing import Any, DefaultDict, Dict, Optional from urllib.parse import urlparse import aiofiles from PIL import Image as PILImage import nio from .backend import Backend from .utils import Size if sys.version_info < (3, 8): import pyfastcopy # noqa CryptDict = Optional[Dict[str, Any]] CONCURRENT_DOWNLOADS_LIMIT = asyncio.BoundedSemaphore(8) ACCESS_LOCKS: DefaultDict[str, asyncio.Lock] = DefaultDict(asyncio.Lock) @dataclass class Media: cache: "MediaCache" = field() mxc: str = field() crypt_dict: CryptDict = field(repr=False) def __post_init__(self) -> None: self.mxc = re.sub(r"#auto$", "", self.mxc) if not re.match(r"^mxc://.+/.+", self.mxc): raise ValueError(f"Invalid mxc URI: {self.mxc}") @property def local_path(self) -> Path: parsed = urlparse(self.mxc) name = parsed.path.lstrip("/") return self.cache.downloads_dir / parsed.netloc / name async def get(self) -> Path: async with ACCESS_LOCKS[self.mxc]: try: return await self._get_local_existing_file() except FileNotFoundError: return await self.create() async def _get_local_existing_file(self) -> Path: if not self.local_path.exists(): raise FileNotFoundError() return self.local_path async def create(self) -> Path: async with CONCURRENT_DOWNLOADS_LIMIT: data = await self._get_remote_data() self.local_path.parent.mkdir(parents=True, exist_ok=True) async with aiofiles.open(self.local_path, "wb") as file: await file.write(data) return self.local_path async def _get_remote_data(self) -> bytes: parsed = urlparse(self.mxc) resp = await self.cache.backend.download( server_name = parsed.netloc, media_id = parsed.path.lstrip("/"), ) return await self._decrypt(resp.body) async def _decrypt(self, data: bytes) -> bytes: if not self.crypt_dict: return data func = functools.partial( nio.crypto.attachments.decrypt_attachment, data, self.crypt_dict["key"]["k"], self.crypt_dict["hashes"]["sha256"], self.crypt_dict["iv"], ) # Run in a separate thread return await asyncio.get_event_loop().run_in_executor(None, func) @classmethod async def from_existing_file( cls, cache: "MediaCache", mxc: str, existing: Path, overwrite: bool = False, **kwargs, ) -> "Media": media = cls(cache, mxc, {}, **kwargs) # type: ignore media.local_path.parent.mkdir(parents=True, exist_ok=True) if not media.local_path.exists() or overwrite: func = functools.partial(shutil.copy, existing, media.local_path) await asyncio.get_event_loop().run_in_executor(None, func) return media @classmethod async def from_bytes( cls, cache: "MediaCache", mxc: str, data: bytes, overwrite: bool = False, **kwargs, ) -> "Media": media = cls(cache, mxc, {}, **kwargs) # type: ignore media.local_path.parent.mkdir(parents=True, exist_ok=True) if not media.local_path.exists() or overwrite: async with aiofiles.open(media.local_path, "wb") as file: await file.write(data) return media @dataclass class Thumbnail(Media): cache: "MediaCache" = field() mxc: str = field() crypt_dict: CryptDict = field(repr=False) wanted_size: Size = field() server_size: Optional[Size] = field(init=False, repr=False, default=None) @staticmethod def normalize_size(size: Size) -> Size: # https://matrix.org/docs/spec/client_server/latest#thumbnails if size[0] > 640 or size[1] > 480: return (800, 600) if size[0] > 320 or size[1] > 240: return (640, 480) if size[0] > 96 or size[1] > 96: return (320, 240) if size[0] > 32 or size[1] > 32: return (96, 96) return (32, 32) @property def local_path(self) -> Path: # example: thumbnails/matrix.org/32x32/ parsed = urlparse(self.mxc) size = self.normalize_size(self.server_size or self.wanted_size) name = "%dx%d/%s" % (size[0], size[1], parsed.path.lstrip("/")) return self.cache.thumbs_dir / parsed.netloc / name async def _get_local_existing_file(self) -> Path: if self.local_path.exists(): return self.local_path # If we have a bigger size thumbnail than the wanted_size for this pic, # return it instead of asking the server for a smaller thumbnail. try_sizes = ((32, 32), (96, 96), (320, 240), (640, 480), (800, 600)) parts = list(self.local_path.parts) size = self.normalize_size(self.server_size or self.wanted_size) for width, height in try_sizes: if width < size[0] or height < size[1]: continue parts[-2] = f"{width}x{height}" path = Path("/".join(parts)) if path.exists(): return path raise FileNotFoundError() async def _get_remote_data(self) -> bytes: parsed = urlparse(self.mxc) if self.crypt_dict: # Matrix makes encrypted thumbs only available through the download # end-point, not the thumbnail one resp = await self.cache.backend.download( server_name = parsed.netloc, media_id = parsed.path.lstrip("/"), ) else: resp = await self.cache.backend.thumbnail( server_name = parsed.netloc, media_id = parsed.path.lstrip("/"), width = self.wanted_size[0], height = self.wanted_size[1], ) decrypted = await self._decrypt(resp.body) with io.BytesIO(decrypted) as img: # The server may return a thumbnail bigger than what we asked for self.server_size = PILImage.open(img).size return decrypted @dataclass class MediaCache: backend: Backend = field() base_dir: Path = field() def __post_init__(self) -> None: self.thumbs_dir = self.base_dir / "thumbnails" self.downloads_dir = self.base_dir / "downloads" self.thumbs_dir.mkdir(parents=True, exist_ok=True) self.downloads_dir.mkdir(parents=True, exist_ok=True) # These methods are for conveniant usage from QML async def get_media(self, mxc: str, crypt_dict: CryptDict = None) -> Path: return await Media(self, mxc, crypt_dict).get() async def get_thumbnail( self, mxc: str, width: int, height: int, crypt_dict: CryptDict = None, ) -> Path: thumb = Thumbnail( # QML sometimes pass float sizes, which matrix API doesn't like. self, mxc, crypt_dict, (round(width), round(height)), ) return await thumb.get()