feat(NIP-33): parameterized replaceable events

src/event.rs

@@ -130,6 +130,33 @@ impl Event {
         self.kind == 0 || self.kind == 3 || self.kind == 41 || (self.kind >= 10000 && self.kind < 20000)
     }
 
+    /// Should this event be replaced with newer timestamps from same author, for distinct `d` tag values?
+    #[must_use] pub fn is_param_replaceable(&self) -> bool {
+        self.kind >= 30000 && self.kind < 40000
+    }
+
+    /// What is the replaceable `d` tag value?
+
+    /// Should this event be replaced with newer timestamps from same author, for distinct `d` tag values?
+    #[must_use] pub fn distinct_param(&self) -> Option<String> {
+        if self.is_param_replaceable() {
+            let default = "".to_string();
+            let dvals:Vec<&String> = self.tags
+                .iter()
+                .filter(|x| x.len() >= 1)
+                .filter(|x| x.get(0).unwrap() == "d")
+                .map(|x| x.get(1).unwrap_or_else(|| &default)).take(1)
+                .collect();
+            let dval_first = dvals.get(0);
+            match dval_first {
+                Some(_) => {dval_first.map(|x| x.to_string())},
+                None => Some(default)
+            }
+        } else {
+            None
+        }
+    }
+
     /// Pull a NIP-05 Name out of the event, if one exists
     #[must_use] pub fn get_nip05_addr(&self) -> Option<nip05::Nip05Name> {
         if self.is_kind_metadata() {
@@ -509,6 +536,19 @@ mod tests {
         assert_eq!(c, expected);
     }
 
+    #[test]
+    fn ephemeral_event() {
+        let mut event = Event::simple_event();
+        event.kind=20000;
+        assert!(event.is_ephemeral());
+        event.kind=29999;
+        assert!(event.is_ephemeral());
+        event.kind=30000;
+        assert!(!event.is_ephemeral());
+        event.kind=19999;
+        assert!(!event.is_ephemeral());
+    }
+
     #[test]
     fn replaceable_event() {
         let mut event = Event::simple_event();
@@ -516,9 +556,102 @@ mod tests {
         assert!(event.is_replaceable());
         event.kind=3;
         assert!(event.is_replaceable());
-        event.kind=12000;
+        event.kind=10000;
         assert!(event.is_replaceable());
+        event.kind=19999;
+        assert!(event.is_replaceable());
+        event.kind=20000;
+        assert!(!event.is_replaceable());
+    }
 
+    #[test]
+    fn param_replaceable_event() {
+        let mut event = Event::simple_event();
+        event.kind = 30000;
+        assert!(event.is_param_replaceable());
+        event.kind = 39999;
+        assert!(event.is_param_replaceable());
+        event.kind = 29999;
+        assert!(!event.is_param_replaceable());
+        event.kind = 40000;
+        assert!(!event.is_param_replaceable());
+    }
+
+    #[test]
+    fn param_replaceable_value_case_1() {
+        // NIP case #1: "tags":[["d",""]]
+        let mut event = Event::simple_event();
+        event.kind = 30000;
+        event.tags = vec![
+            vec!["d".to_owned(), "".to_owned()]];
+        assert_eq!(event.distinct_param(), Some("".to_string()));
+    }
+
+    #[test]
+    fn param_replaceable_value_case_2() {
+        // NIP case #2: "tags":[]: implicit d tag with empty value
+        let mut event = Event::simple_event();
+        event.kind = 30000;
+        assert_eq!(event.distinct_param(), Some("".to_string()));
+    }
+
+    #[test]
+    fn param_replaceable_value_case_3() {
+        // NIP case #3: "tags":[["d"]]: implicit empty value ""
+        let mut event = Event::simple_event();
+        event.kind = 30000;
+        event.tags = vec![
+            vec!["d".to_owned()]];
+        assert_eq!(event.distinct_param(), Some("".to_string()));
+    }
+
+    #[test]
+    fn param_replaceable_value_case_4() {
+        // NIP case #4: "tags":[["d",""],["d","not empty"]]: only first d tag is considered
+        let mut event = Event::simple_event();
+        event.kind = 30000;
+        event.tags = vec![
+            vec!["d".to_owned(), "".to_string()],
+            vec!["d".to_owned(), "not empty".to_string()]
+        ];
+        assert_eq!(event.distinct_param(), Some("".to_string()));
+    }
+
+    #[test]
+    fn param_replaceable_value_case_4b() {
+        // Variation of #4 with
+        // NIP case #4: "tags":[["d","not empty"],["d",""]]: only first d tag is considered
+        let mut event = Event::simple_event();
+        event.kind = 30000;
+        event.tags = vec![
+            vec!["d".to_owned(), "not empty".to_string()],
+            vec!["d".to_owned(), "".to_string()]
+        ];
+        assert_eq!(event.distinct_param(), Some("not empty".to_string()));
+    }
+
+    #[test]
+    fn param_replaceable_value_case_5() {
+        // NIP case #5: "tags":[["d"],["d","some value"]]: only first d tag is considered
+        let mut event = Event::simple_event();
+        event.kind = 30000;
+        event.tags = vec![
+            vec!["d".to_owned()],
+            vec!["d".to_owned(), "second value".to_string()],
+            vec!["d".to_owned(), "third value".to_string()]
+        ];
+        assert_eq!(event.distinct_param(), Some("".to_string()));
+    }
+
+    #[test]
+    fn param_replaceable_value_case_6() {
+        // NIP case #6: "tags":[["e"]]: same as no tags
+        let mut event = Event::simple_event();
+        event.kind = 30000;
+        event.tags = vec![
+            vec!["e".to_owned()],
+        ];
+        assert_eq!(event.distinct_param(), Some("".to_string()));
     }
 
 }

src/repo/sqlite.rs

@@ -115,6 +115,25 @@ impl SqliteRepo {
                 return Ok(0);
             }
         }
+        // check for parameterized replaceable events that would be hidden; don't insert these either.
+        if let Some(d_tag) = e.distinct_param() {
+            let repl_count;
+            if is_lower_hex(&d_tag) && (d_tag.len() % 2 == 0) {
+                repl_count = tx.query_row(
+                    "SELECT e.id FROM event e LEFT JOIN tag t ON e.id=t.event_id WHERE e.author=? AND e.kind=? AND t.name='d' AND t.value_hex=? AND e.created_at >= ? LIMIT 1;",
+                    params![pubkey_blob, e.kind, hex::decode(d_tag).ok(), e.created_at],|row| row.get::<usize, usize>(0));
+            } else {
+                repl_count = tx.query_row(
+                    "SELECT e.id FROM event e LEFT JOIN tag t ON e.id=t.event_id WHERE e.author=? AND e.kind=? AND t.name='d' AND t.value=? AND e.created_at >= ? LIMIT 1;",
+                    params![pubkey_blob, e.kind, d_tag, e.created_at],|row| row.get::<usize, usize>(0));
+            }
+            // if any rows were returned, then some newer event with
+            // the same author/kind/tag value exist, and we can ignore
+            // this event.
+            if repl_count.ok().is_some() {
+                return Ok(0)
+            }
+        }
         // ignore if the event hash is a duplicate.
         let mut ins_count = tx.execute(
             "INSERT OR IGNORE INTO event (event_hash, created_at, kind, author, delegated_by, content, first_seen, hidden) VALUES (?1, ?2, ?3, ?4, ?5, ?6, strftime('%s','now'), FALSE);",
@@ -174,6 +193,27 @@ impl SqliteRepo {
                 );
             }
         }
+        // if this event is parameterized replaceable, remove other events.
+        if let Some(d_tag) = e.distinct_param() {
+            let update_count;
+            if is_lower_hex(&d_tag) && (d_tag.len() % 2 == 0) {
+                update_count = tx.execute(
+                    "DELETE FROM event WHERE kind=? AND author=? AND id NOT IN (SELECT e.id FROM event e LEFT JOIN tag t ON e.id=t.event_id WHERE e.kind=? AND e.author=? AND t.name='d' AND t.value_hex=? ORDER BY created_at DESC LIMIT 1);",
+                    params![e.kind, pubkey_blob, e.kind, pubkey_blob, hex::decode(d_tag).ok()])?;
+            } else {
+                update_count = tx.execute(
+                    "DELETE FROM event WHERE kind=? AND author=? AND id NOT IN (SELECT e.id FROM event e LEFT JOIN tag t ON e.id=t.event_id WHERE e.kind=? AND e.author=? AND t.name='d' AND t.value=? ORDER BY created_at DESC LIMIT 1);",
+                    params![e.kind, pubkey_blob, e.kind, pubkey_blob, d_tag])?;
+            }
+            if update_count > 0 {
+                info!(
+                    "removed {} older parameterized replaceable kind {} events for author: {:?}",
+                    update_count,
+                    e.kind,
+                    e.get_author_prefix()
+                );
+            }
+        }
         // if this event is a deletion, hide the referenced events from the same author.
         if e.kind == 5 {
             let event_candidates = e.tag_values_by_name("e");