--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libervia/backend/plugins/plugin_xep_0264.py	Fri Jun 02 11:49:51 2023 +0200
@@ -0,0 +1,207 @@
+#!/usr/bin/env python3
+
+# SàT plugin for managing xep-0264
+# Copyright (C) 2009-2021 Jérôme Poisson (goffi@goffi.org)
+# Copyright (C) 2014 Emmanuel Gil Peyrot (linkmauve@linkmauve.fr)
+
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+from libervia.backend.core.i18n import _
+from libervia.backend.core.constants import Const as C
+from libervia.backend.core.log import getLogger
+
+log = getLogger(__name__)
+from twisted.internet import threads
+from twisted.python.failure import Failure
+
+from zope.interface import implementer
+
+from wokkel import disco, iwokkel
+
+from libervia.backend.core import exceptions
+import hashlib
+
+try:
+    from PIL import Image, ImageOps
+except:
+    raise exceptions.MissingModule(
+        "Missing module pillow, please download/install it from https://python-pillow.github.io"
+    )
+
+#  cf. https://stackoverflow.com/a/23575424
+from PIL import ImageFile
+
+ImageFile.LOAD_TRUNCATED_IMAGES = True
+
+try:
+    from twisted.words.protocols.xmlstream import XMPPHandler
+except ImportError:
+    from wokkel.subprotocols import XMPPHandler
+
+
+MIME_TYPE = "image/jpeg"
+SAVE_FORMAT = "JPEG"  # (cf. Pillow documentation)
+
+NS_THUMBS = "urn:xmpp:thumbs:1"
+
+PLUGIN_INFO = {
+    C.PI_NAME: "XEP-0264",
+    C.PI_IMPORT_NAME: "XEP-0264",
+    C.PI_TYPE: "XEP",
+    C.PI_MODES: C.PLUG_MODE_BOTH,
+    C.PI_PROTOCOLS: ["XEP-0264"],
+    C.PI_DEPENDENCIES: ["XEP-0234"],
+    C.PI_MAIN: "XEP_0264",
+    C.PI_HANDLER: "yes",
+    C.PI_DESCRIPTION: _("""Thumbnails handling"""),
+}
+
+
+class XEP_0264(object):
+    SIZE_SMALL = (320, 320)
+    SIZE_MEDIUM = (640, 640)
+    SIZE_BIG = (1280, 1280)
+    SIZE_FULL_SCREEN = (2560, 2560)
+    # FIXME: SIZE_FULL_SCREEN is currently discarded as the resulting files are too big
+    # for BoB
+    # TODO: use an other mechanism than BoB for bigger files
+    SIZES = (SIZE_SMALL, SIZE_MEDIUM, SIZE_BIG)
+
+    def __init__(self, host):
+        log.info(_("Plugin XEP_0264 initialization"))
+        self.host = host
+        host.trigger.add("XEP-0234_buildFileElement", self._add_file_thumbnails)
+        host.trigger.add("XEP-0234_parseFileElement", self._get_file_thumbnails)
+
+    def get_handler(self, client):
+        return XEP_0264_handler()
+
+    ## triggers ##
+
+    def _add_file_thumbnails(self, client, file_elt, extra_args):
+        try:
+            thumbnails = extra_args["extra"][C.KEY_THUMBNAILS]
+        except KeyError:
+            return
+        for thumbnail in thumbnails:
+            thumbnail_elt = file_elt.addElement((NS_THUMBS, "thumbnail"))
+            thumbnail_elt["uri"] = "cid:" + thumbnail["id"]
+            thumbnail_elt["media-type"] = MIME_TYPE
+            width, height = thumbnail["size"]
+            thumbnail_elt["width"] = str(width)
+            thumbnail_elt["height"] = str(height)
+        return True
+
+    def _get_file_thumbnails(self, client, file_elt, file_data):
+        thumbnails = []
+        for thumbnail_elt in file_elt.elements(NS_THUMBS, "thumbnail"):
+            uri = thumbnail_elt["uri"]
+            if uri.startswith("cid:"):
+                thumbnail = {"id": uri[4:]}
+            width = thumbnail_elt.getAttribute("width")
+            height = thumbnail_elt.getAttribute("height")
+            if width and height:
+                try:
+                    thumbnail["size"] = (int(width), int(height))
+                except ValueError:
+                    pass
+            try:
+                thumbnail["mime_type"] = thumbnail_elt["media-type"]
+            except KeyError:
+                pass
+            thumbnails.append(thumbnail)
+
+        if thumbnails:
+            # we want thumbnails ordered from smallest to biggest
+            thumbnails.sort(key=lambda t: t.get('size', (0, 0)))
+            file_data.setdefault("extra", {})[C.KEY_THUMBNAILS] = thumbnails
+        return True
+
+    ## thumbnails generation ##
+
+    def get_thumb_id(self, image_uid, size):
+        """return an ID unique for image/size combination
+
+        @param image_uid(unicode): unique id of the image
+            can be a hash
+        @param size(tuple(int)): requested size of thumbnail
+        @return (unicode): unique id for this image/size
+        """
+        return hashlib.sha256(repr((image_uid, size)).encode()).hexdigest()
+
+    def _blocking_gen_thumb(
+            self, source_path, size=None, max_age=None, image_uid=None,
+            fix_orientation=True):
+        """Generate a thumbnail for image
+
+        This is a blocking method and must be executed in a thread
+        params are the same as for [generate_thumbnail]
+        """
+        if size is None:
+            size = self.SIZE_SMALL
+        try:
+            img = Image.open(source_path)
+        except IOError:
+            return Failure(exceptions.DataError("Can't open image"))
+
+        img.thumbnail(size)
+        if fix_orientation:
+            img = ImageOps.exif_transpose(img)
+
+        uid = self.get_thumb_id(image_uid or source_path, size)
+
+        with self.host.common_cache.cache_data(
+            PLUGIN_INFO[C.PI_IMPORT_NAME], uid, MIME_TYPE, max_age
+        ) as f:
+            img.save(f, SAVE_FORMAT)
+            if fix_orientation:
+                log.debug(f"fixed orientation for {f.name}")
+
+        return img.size, uid
+
+    def generate_thumbnail(
+        self, source_path, size=None, max_age=None, image_uid=None, fix_orientation=True):
+        """Generate a thumbnail of image
+
+        @param source_path(unicode): absolute path to source image
+        @param size(int, None): max size of the thumbnail
+            can be one of self.SIZE_*
+            None to use default value (i.e. self.SIZE_SMALL)
+        @param max_age(int, None): same as for [memory.cache.Cache.cache_data])
+        @param image_uid(unicode, None): unique ID to identify the image
+            use hash whenever possible
+            if None, source_path will be used
+        @param fix_orientation(bool): if True, fix orientation using EXIF data
+        @return D(tuple[tuple[int,int], unicode]): tuple with:
+            - size of the thumbnail
+            - unique Id of the thumbnail
+        """
+        d = threads.deferToThread(
+            self._blocking_gen_thumb, source_path, size, max_age, image_uid=image_uid,
+            fix_orientation=fix_orientation
+        )
+        d.addErrback(
+            lambda failure_: log.error("thumbnail generation error: {}".format(failure_))
+        )
+        return d
+
+
+@implementer(iwokkel.IDisco)
+class XEP_0264_handler(XMPPHandler):
+
+    def getDiscoInfo(self, requestor, target, nodeIdentifier=""):
+        return [disco.DiscoFeature(NS_THUMBS)]
+
+    def getDiscoItems(self, requestor, target, nodeIdentifier=""):
+        return []