wip: schema addition and structure for delegation

src/delegation.rs

@@ -0,0 +1,72 @@
+//! Event parsing and validation
+//use crate::error::Error::*;
+//use crate::error::Result;
+//use crate::utils::unix_time;
+//use bitcoin_hashes::{sha256, Hash};
+//use lazy_static::lazy_static;
+//use secp256k1::{schnorr, Secp256k1, VerifyOnly, XOnlyPublicKey};
+use serde::{Deserialize, Serialize};
+//use serde_json::value::Value;
+//use serde_json::Number;
+//use std::collections::HashMap;
+//use std::collections::HashSet;
+//use std::str::FromStr;
+//use tracing::{debug, info};
+
+// This handles everything related to delegation, in particular the
+// condition/rune parsing and logic.
+
+// Conditions are poorly specified, so we will implement the minimum
+// necessary for now.
+
+// fields MUST be either "kind" or "created_at".
+// operators supported are ">", "<", "=", "!".
+// no operations on 'content' are supported.
+
+// this allows constraints for:
+// valid date ranges (valid from X->Y dates).
+// specific kinds (publish kind=1,5)
+// kind ranges (publish ephemeral events, kind>19999&kind<30001)
+
+// for more complex scenarios (allow delegatee to publish ephemeral
+// AND replacement events), it may be necessary to generate and use
+// different condition strings, since we do not support grouping or
+// "OR" logic.
+
+#[derive(Serialize, Deserialize, PartialEq, Eq, Debug, Clone)]
+pub enum Field {
+    Kind,
+    CreatedAt,
+}
+
+#[derive(Serialize, Deserialize, PartialEq, Eq, Debug, Clone)]
+pub enum Operator {
+    LessThan,
+    GreaterThan,
+    Equals,
+    NotEquals,
+}
+
+#[derive(Serialize, Deserialize, PartialEq, Eq, Debug, Clone)]
+pub enum Value {
+    Number(u64),
+    List(Vec<Value>),
+}
+
+/// Parsed delegation statement
+#[derive(Serialize, Deserialize, PartialEq, Eq, Debug, Clone)]
+pub struct Delegation {
+    pub(crate) pubkey: String,
+    pub(crate) conditions: Vec<Condition>,
+    pub(crate) signature: String,
+}
+
+/// Parsed delegation condition
+/// see https://github.com/nostr-protocol/nips/pull/28#pullrequestreview-1084903800
+/// An example complex condition would be:  kind=1,2,3&created_at<1665265999
+#[derive(Serialize, Deserialize, PartialEq, Eq, Debug, Clone)]
+pub struct Condition {
+    pub(crate) field: Field,
+    pub(crate) operator: Operator,
+    pub(crate) value: Value,
+}

src/event.rs

@@ -110,6 +110,16 @@ impl Event {
         None
     }
 
+    // is this event delegated (properly)?
+    // does the signature match, and are conditions valid?
+    pub fn is_delegated(&self) -> bool {
+        // is there a delegation tag?
+        let _delegation_tag = self.tag_values_by_name("delegation");
+        // delegation tags should have exactly 3 elements after the name (pubkey, condition, sig)
+        // try to construct a delegation object (
+        todo!();
+    }
+
     /// Build an event tag index
     fn build_index(&mut self) {
         // if there are no tags; just leave the index as None
@@ -388,6 +398,32 @@ mod tests {
         assert_eq!(v, vec!["foo", "bar", "baz"]);
     }
 
+    #[test]
+    fn event_no_tag_select() {
+        let e = Event {
+            id: "999".to_owned(),
+            pubkey: "012345".to_owned(),
+            created_at: 501234,
+            kind: 1,
+            tags: vec![
+                vec!["j".to_owned(), "abc".to_owned()],
+                vec!["e".to_owned(), "foo".to_owned()],
+                vec!["e".to_owned(), "baz".to_owned()],
+                vec![
+                    "p".to_owned(),
+                    "aaaa".to_owned(),
+                    "ws://example.com".to_owned(),
+                ],
+            ],
+            content: "this is a test".to_owned(),
+            sig: "abcde".to_owned(),
+            tagidx: None,
+        };
+        let v = e.tag_values_by_name("x");
+        // asking for tags that don't exist just returns zero-length vector
+        assert_eq!(v.len(), 0);
+    }
+
     #[test]
     fn event_canonical_with_tags() {
         let e = Event {

src/lib.rs

@@ -2,6 +2,7 @@ pub mod close;
 pub mod config;
 pub mod conn;
 pub mod db;
+pub mod delegation;
 pub mod error;
 pub mod event;
 pub mod hexrange;

src/schema.rs

@@ -20,7 +20,7 @@ pragma mmap_size = 536870912; -- 512MB of mmap
 "##;
 
 /// Latest database version
-pub const DB_VERSION: usize = 6;
+pub const DB_VERSION: usize = 7;
 
 /// Schema definition
 const INIT_SQL: &str = formatcp!(
@@ -40,6 +40,7 @@ event_hash BLOB NOT NULL, -- 4-byte hash
 first_seen INTEGER NOT NULL, -- when the event was first seen (not authored!) (seconds since 1970)
 created_at INTEGER NOT NULL, -- when the event was authored
 author BLOB NOT NULL, -- author pubkey
+delegator BLOB, -- delegator pubkey (NIP-26)
 kind INTEGER NOT NULL, -- event kind
 hidden INTEGER, -- relevant for queries
 content TEXT NOT NULL -- serialized json of event object
@@ -152,6 +153,9 @@ pub fn upgrade_db(conn: &mut PooledConnection) -> Result<()> {
             if curr_version == 5 {
                 curr_version = mig_5_to_6(conn)?;
             }
+            if curr_version == 6 {
+                curr_version = mig_6_to_7(conn)?;
+            }
             if curr_version == DB_VERSION {
                 info!(
                     "All migration scripts completed successfully.  Welcome to v{}.",
@@ -348,3 +352,22 @@ fn mig_5_to_6(conn: &mut PooledConnection) -> Result<usize> {
     info!("vacuumed DB after tags rebuild in {:?}", start.elapsed());
     Ok(6)
 }
+
+fn mig_6_to_7(conn: &mut PooledConnection) -> Result<usize> {
+    info!("database schema needs update from 6->7");
+    // only change is adding a hidden column to events.
+    let upgrade_sql = r##"
+ALTER TABLE event ADD delegator BLOB;
+PRAGMA user_version = 7;
+"##;
+    match conn.execute_batch(upgrade_sql) {
+        Ok(()) => {
+            info!("database schema upgraded v6 -> v7");
+        }
+        Err(err) => {
+            error!("update failed: {}", err);
+            panic!("database could not be upgraded");
+        }
+    }
+    Ok(7)
+}