api!:jsonrpc: sort reactions in descending order (#4388)

convert `JSONRPCReactions.reactions` to a `Vec<JSONRPCReaction>` with unique reactions and their count, sorted in descending order.
---------

Co-authored-by: link2xt <link2xt@testrun.org>

CHANGELOG.md

@@ -10,6 +10,7 @@
 - BREAKING: jsonrpc:
   - `get_chatlist_items_by_entries` now takes only chatids instead of `ChatListEntries`
   - `get_chatlist_entries` now returns `Vec<u32>` of chatids instead of `ChatListEntries`
+  - `JSONRPCReactions.reactions` is now a `Vec<JSONRPCReaction>` with unique reactions and their count, sorted in descending order.
   - `Event`: `context_id` property is now called `contextId`
 - jsonrpc: expand `MessageSearchResult`:
   - always include `chat_name`(not an option anymore)

deltachat-jsonrpc/src/api/types/reactions.rs

@@ -1,23 +1,37 @@
 use std::collections::BTreeMap;
 
+use deltachat::contact::ContactId;
 use deltachat::reaction::Reactions;
 use serde::Serialize;
 use typescript_type_def::TypeDef;
 
+/// A single reaction emoji.
+#[derive(Serialize, TypeDef)]
+#[serde(rename = "Reaction", rename_all = "camelCase")]
+pub struct JSONRPCReaction {
+    /// Emoji.
+    emoji: String,
+
+    /// Emoji frequency.
+    count: usize,
+
+    /// True if we reacted with this emoji.
+    is_from_self: bool,
+}
+
 /// Structure representing all reactions to a particular message.
 #[derive(Serialize, TypeDef)]
 #[serde(rename = "Reactions", rename_all = "camelCase")]
 pub struct JSONRPCReactions {
     /// Map from a contact to it's reaction to message.
     reactions_by_contact: BTreeMap<u32, Vec<String>>,
-    /// Unique reactions and their count
-    reactions: BTreeMap<String, u32>,
+    /// Unique reactions and their count, sorted in descending order.
+    reactions: Vec<JSONRPCReaction>,
 }
 
 impl From<Reactions> for JSONRPCReactions {
     fn from(reactions: Reactions) -> Self {
         let mut reactions_by_contact: BTreeMap<u32, Vec<String>> = BTreeMap::new();
-        let mut unique_reactions: BTreeMap<String, u32> = BTreeMap::new();
 
         for contact_id in reactions.contacts() {
             let reaction = reactions.get(contact_id);
@@ -30,18 +44,29 @@ impl From<Reactions> for JSONRPCReactions {
                 .map(|emoji| emoji.to_owned())
                 .collect();
             reactions_by_contact.insert(contact_id.to_u32(), emojis.clone());
-            for emoji in emojis {
-                if let Some(x) = unique_reactions.get_mut(&emoji) {
-                    *x += 1;
-                } else {
-                    unique_reactions.insert(emoji, 1);
-                }
-            }
+        }
+
+        let self_reactions = reactions_by_contact.get(&ContactId::SELF.to_u32());
+
+        let mut reactions_v = Vec::new();
+        for (emoji, count) in reactions.emoji_sorted_by_frequency() {
+            let is_from_self = if let Some(self_reactions) = self_reactions {
+                self_reactions.contains(&emoji)
+            } else {
+                false
+            };
+
+            let reaction = JSONRPCReaction {
+                emoji,
+                count,
+                is_from_self,
+            };
+            reactions_v.push(reaction)
         }
 
         JSONRPCReactions {
             reactions_by_contact,
-            reactions: unique_reactions,
+            reactions: reactions_v,
         }
     }
 }

src/reaction.rs

@@ -14,6 +14,7 @@
 //! possible to remove all reactions by sending an empty string as a reaction,
 //! even though RFC 9078 requires at least one emoji to be sent.
 
+use std::cmp::Ordering;
 use std::collections::BTreeMap;
 use std::fmt;
 
@@ -116,10 +117,9 @@ impl Reactions {
     pub fn is_empty(&self) -> bool {
         self.reactions.is_empty()
     }
-}
 
-impl fmt::Display for Reactions {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+    /// Returns a map from emojis to their frequencies.
+    pub fn emoji_frequencies(&self) -> BTreeMap<String, usize> {
         let mut emoji_frequencies: BTreeMap<String, usize> = BTreeMap::new();
         for reaction in self.reactions.values() {
             for emoji in reaction.emojis() {
@@ -129,6 +129,30 @@ impl fmt::Display for Reactions {
                     .or_insert(1);
             }
         }
+        emoji_frequencies
+    }
+
+    /// Returns a vector of emojis
+    /// sorted in descending order of frequencies.
+    ///
+    /// This function can be used to display the reactions in
+    /// the message bubble in the UIs.
+    pub fn emoji_sorted_by_frequency(&self) -> Vec<(String, usize)> {
+        let mut emoji_frequencies: Vec<(String, usize)> =
+            self.emoji_frequencies().into_iter().collect();
+        emoji_frequencies.sort_by(|(a, a_count), (b, b_count)| {
+            match a_count.cmp(b_count).reverse() {
+                Ordering::Equal => a.cmp(b),
+                other => other,
+            }
+        });
+        emoji_frequencies
+    }
+}
+
+impl fmt::Display for Reactions {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let emoji_frequencies = self.emoji_sorted_by_frequency();
         let mut first = true;
         for (emoji, frequency) in emoji_frequencies {
             if !first {
@@ -481,6 +505,11 @@ Content-Disposition: reaction\n\
         let reactions = get_msg_reactions(&alice, alice_msg.sender_msg_id).await?;
         assert_eq!(reactions.to_string(), "👍2 😀1");
 
+        assert_eq!(
+            reactions.emoji_sorted_by_frequency(),
+            vec![("👍".to_string(), 2), ("😀".to_string(), 1)]
+        );
+
         Ok(())
     }