From 915a109c18615395194b95ed21ca08b312db8520 Mon Sep 17 00:00:00 2001
From: Ava Howell <ava@avahowell.me>
Date: Wed, 18 Sep 2024 17:44:10 -0700
Subject: [PATCH] wip: total supply indexer

---
 crates/bin/pindexer/src/lib.rs    |   1 +
 crates/bin/pindexer/src/supply.rs | 129 ++++++++++++++++++++++++++++++
 2 files changed, 130 insertions(+)
 create mode 100644 crates/bin/pindexer/src/supply.rs

diff --git a/crates/bin/pindexer/src/lib.rs b/crates/bin/pindexer/src/lib.rs
index 5cf2d8bd14..2e17584475 100644
--- a/crates/bin/pindexer/src/lib.rs
+++ b/crates/bin/pindexer/src/lib.rs
@@ -7,5 +7,6 @@ pub mod dex;
 pub mod shielded_pool;
 mod sql;
 pub mod stake;
+pub mod supply;
 
 pub mod governance;
diff --git a/crates/bin/pindexer/src/supply.rs b/crates/bin/pindexer/src/supply.rs
new file mode 100644
index 0000000000..5ba50c8073
--- /dev/null
+++ b/crates/bin/pindexer/src/supply.rs
@@ -0,0 +1,129 @@
+use std::collections::HashSet;
+
+use anyhow::{anyhow, Context, Result};
+use cometindex::{async_trait, sqlx, AppView, ContextualizedEvent, PgTransaction};
+use penumbra_app::genesis::AppState;
+use penumbra_num::Amount;
+use penumbra_proto::{core::component::sct::v1 as pb, event::ProtoEvent};
+use penumbra_stake::IdentityKey;
+use sqlx::{types::chrono::DateTime, PgPool, Postgres, Transaction};
+
+/// Supply-relevant events.
+/// The supply of the native staking token can change:
+/// - When notes are minted (e.g., during initial genesis, or as a result of
+/// IBC, though in the case of IBC the circuit breaker should never allow more
+/// inbound UM to be minted than outbound um were originally sent.)
+/// - As a result of claiming delegation tokens that have increased in
+/// underlying UM value due to accumulating the staking rate.
+/// - As a result of burning UM which can happen due to arbs, fees, and slashing.
+#[derive(Clone, Debug)]
+enum Event {
+    /// A parsed version of [pb::EventUndelegate]
+    Undelegate {
+        identity_key: IdentityKey,
+        unbonded_amount: Amount,
+    },
+    /// A parsed version of [pb::EventDelegate]
+    Delegate {
+        identity_key: IdentityKey,
+        amount: Amount,
+    }, // TKTK....
+}
+
+impl Event {
+    const NAMES: [&'static str; 2] = [
+        "penumbra.core.component.stake.v1.EventUndelegate",
+        "penumbra.core.component.stake.v1.EventDelegate",
+    ];
+
+    async fn index<'d>(&self, dbtx: &mut Transaction<'d, Postgres>) -> anyhow::Result<()> {
+        match self {
+            Event::Delegate {
+                identity_key: _,
+                amount: _,
+            } => Ok(()),
+            Event::Undelegate {
+                identity_key: _,
+                unbonded_amount: _,
+            } => Ok(()),
+        }
+    }
+}
+
+async fn add_genesis_native_token_allocation_supply<'a>(
+    dbtx: &mut PgTransaction<'a>,
+    app_state: &AppState,
+) -> Result<()> {
+    let content = app_state
+        .content()
+        .ok_or_else(|| anyhow::anyhow!("cannot initialized indexer from checkpoint genesis"))?;
+
+    let mut native_token_sum: Amount = Amount::zero();
+    for allo in &content.shielded_pool_content.allocations {
+        if allo.denom().base_denom().denom == "upenumbra" {
+            let value = allo.value();
+            native_token_sum = native_token_sum.checked_add(&value.amount).unwrap();
+        }
+    }
+
+    sqlx::query("INSERT INTO supply_initial_genesis (value) VALUES ($1)")
+        .bind(native_token_sum.value() as i64)
+        .execute(dbtx.as_mut())
+        .await?;
+
+    Ok(())
+}
+
+#[derive(Debug)]
+pub struct Supply {
+    event_strings: HashSet<&'static str>,
+}
+
+impl Supply {
+    pub fn new() -> Self {
+        let event_strings = Event::NAMES.into_iter().collect();
+        Self { event_strings }
+    }
+}
+
+#[async_trait]
+impl AppView for Supply {
+    async fn init_chain(
+        &self,
+        dbtx: &mut PgTransaction,
+        app_state: &serde_json::Value,
+    ) -> Result<(), anyhow::Error> {
+        sqlx::query(
+            // table name is module path + struct name
+            "
+CREATE TABLE IF NOT EXISTS supply_initial_genesiis (
+    value BIGINT PRIMARY KEY,
+);
+",
+        )
+        .execute(dbtx.as_mut())
+        .await?;
+
+        // decode the initial supply from the genesis
+        // initial app state is not recomputed from events, because events are not emitted in init_chain.
+        // instead, the indexer directly parses the genesis.
+        let app_state: penumbra_app::genesis::AppState =
+            serde_json::from_value(app_state.clone()).context("error decoding app_state json")?;
+        add_genesis_native_token_allocation_supply(dbtx, &app_state).await?;
+
+        Ok(())
+    }
+
+    fn is_relevant(&self, type_str: &str) -> bool {
+        self.event_strings.contains(type_str)
+    }
+
+    async fn index_event(
+        &self,
+        dbtx: &mut PgTransaction,
+        event: &ContextualizedEvent,
+        _src_db: &PgPool,
+    ) -> Result<(), anyhow::Error> {
+        Event::try_from(event)?.index(dbtx).await
+    }
+}