Add missing file

src/images.rs

@@ -0,0 +1,97 @@
+/*
+ * Copyright (C) 2023  Valentin Lorentz
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License version 3,
+ * as published by the Free Software Foundation.
+ *
+ * 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 <https://www.gnu.org/licenses/>.
+ */
+
+use std::io::Cursor;
+use std::sync::Arc;
+
+use matrix_sdk::ruma::events::room::message::ImageMessageEventContent;
+use matrix_sdk::ruma::{OwnedEventId, OwnedRoomId, RoomId};
+use matrix_sdk::Client;
+
+use crate::buffers::room::OwnedBufferItemContent;
+use crate::config::Config;
+use crate::html::{escape_html, format_html};
+
+pub(crate) async fn decode_image(
+  client: &Client,
+  config: &Config,
+  event_id: Option<OwnedEventId>,
+  sender: &str,
+  content: &ImageMessageEventContent,
+) -> OwnedBufferItemContent {
+  // Like `format!()` but returns OwnedBufferItemContent::Text, with is_message=true
+  macro_rules! msg {
+    ($prefix: expr, $($tokens:tt)*) => {
+      OwnedBufferItemContent::Text {
+        event_id,
+        is_message: true,
+        text: format_html(&config, $prefix, &format!($($tokens)*))
+      }
+    }
+  }
+
+  let ImageMessageEventContent { body, info, .. } = content;
+  match client.media().get_file(content, /* use_cache */ true).await {
+    Ok(Some(file)) => {
+      let mut reader = match info
+        .as_ref()
+        .and_then(|info| info.mimetype.as_ref())
+        .and_then(|mimetype| image::ImageFormat::from_mime_type(mimetype))
+      {
+        Some(format) => {
+          // Known format provided by the sender
+          image::io::Reader::with_format(Cursor::new(file), format)
+        },
+        None => {
+          // Unknown format or not provided by the sender, try guessing it
+          let reader = image::io::Reader::new(Cursor::new(file));
+          match reader.with_guessed_format() {
+            Ok(reader) => reader,
+            Err(e) => {
+              log::warn!("Could not guess image format: {:?}", e);
+              return msg!("   ", "&lt;{}> {}", sender, escape_html(body));
+            },
+          }
+        },
+      };
+
+      // Arbitrary values to avoid DoS. TODO: make them configurable
+      let mut limits = image::io::Limits::default();
+      limits.max_image_width = Some(10 * 1024);
+      limits.max_image_height = Some(10 * 1024);
+      limits.max_alloc = Some(100 * 1024 * 1024);
+      reader.limits(limits);
+
+      let image = match reader.decode() {
+        Ok(image) => image,
+        Err(e) => {
+          log::warn!("Could not decode image: {:?}", e);
+          return msg!("   ", "&lt;{}> {}", sender, escape_html(body));
+        },
+      };
+      OwnedBufferItemContent::Image {
+        event_id,
+        is_message: true,
+        image,
+      }
+    },
+    Ok(None) => msg!("   ", "&lt;{}> {}", sender, escape_html(body)),
+    Err(e) => {
+      log::error!("Could not get image file: {:?}", e);
+      msg!("   ", "&lt;{}> {}", sender, escape_html(body))
+    },
+  }
+}