pcli: add balance migration command

crates/bin/pcli/src/command.rs

@@ -1,5 +1,6 @@
 pub use debug::DebugCmd;
 pub use init::InitCmd;
+pub use migrate::MigrateCmd;
 pub use query::QueryCmd;
 pub use threshold::ThresholdCmd;
 pub use tx::TxCmd;
@@ -11,6 +12,7 @@ use self::{ceremony::CeremonyCmd, tx::TxCmdWithOptions};
 mod ceremony;
 mod debug;
 mod init;
+mod migrate;
 mod query;
 mod threshold;
 mod tx;
@@ -53,18 +55,21 @@ pub enum Command {
     /// Create and broadcast a transaction.
     #[clap(display_order = 400, visible_alias = "tx")]
     Transaction(TxCmdWithOptions),
+    /// Follow the threshold signing protocol.
+    #[clap(subcommand, display_order = 500)]
+    Threshold(ThresholdCmd),
+    /// Migrate your balance to another wallet.
+    #[clap(subcommand, display_order = 600)]
+    Migrate(MigrateCmd),
     /// Manage a validator.
     #[clap(subcommand, display_order = 900)]
     Validator(ValidatorCmd),
-    /// Display information related to diagnosing problems running Penumbra
-    #[clap(subcommand, display_order = 999)]
-    Debug(DebugCmd),
     /// Contribute to the summoning ceremony.
     #[clap(subcommand, display_order = 990)]
     Ceremony(CeremonyCmd),
-    /// Follow the threshold signing protocol.
-    #[clap(subcommand, display_order = 500)]
-    Threshold(ThresholdCmd),
+    /// Display information related to diagnosing problems running Penumbra
+    #[clap(subcommand, display_order = 999)]
+    Debug(DebugCmd),
 }
 
 impl Command {
@@ -79,6 +84,7 @@ impl Command {
             Command::Debug(cmd) => cmd.offline(),
             Command::Ceremony(_) => false,
             Command::Threshold(cmd) => cmd.offline(),
+            Command::Migrate(_) => false,
         }
     }
 }

crates/bin/pcli/src/command/migrate.rs

@@ -0,0 +1,143 @@
+use crate::App;
+use anyhow::{Context, Result};
+use penumbra_fee::FeeTier;
+use penumbra_fee::GasPrices;
+use penumbra_keys::{keys::AddressIndex, FullViewingKey};
+use penumbra_proto::view::v1::GasPricesRequest;
+use penumbra_view::ViewClient;
+use penumbra_wallet::plan::Planner;
+use rand_core::OsRng;
+use std::str::FromStr;
+
+#[derive(Debug, clap::Parser)]
+pub enum MigrateCmd {
+    /// Migrate your entire balance to the wallet of the provided FullViewingKey
+    #[clap(name = "balance")]
+    Balance {
+        /// The FullViewingKey associated with the destination wallet.
+        #[clap(long)]
+        to: String,
+    },
+}
+
+impl MigrateCmd {
+    #[tracing::instrument(skip(self, app))]
+    pub async fn exec(&self, app: &mut App) -> Result<()> {
+        let gas_prices: GasPrices = app
+            .view
+            .as_mut()
+            .context("view service must be initialized")?
+            .gas_prices(GasPricesRequest {})
+            .await?
+            .into_inner()
+            .gas_prices
+            .expect("gas prices must be available")
+            .try_into()?;
+
+        match self {
+            MigrateCmd::Balance { to } => {
+                let source_fvk = app.config.full_viewing_key.clone();
+
+                let dest_fvk = to.parse::<FullViewingKey>().map_err(|_| {
+                    anyhow::anyhow!("The provided string is not a valid FullViewingKey.")
+                })?;
+
+                let mut planner = Planner::new(OsRng);
+
+                let memo = format!("Migrating balance from {} to {}", source_fvk, dest_fvk);
+
+                let (source_address, _) =
+                    FullViewingKey::payment_address(&source_fvk, AddressIndex::new(0));
+
+                let (dest_address, _) = FullViewingKey::payment_address(
+                    &FullViewingKey::from_str(&to[..])?,
+                    AddressIndex::new(0),
+                );
+
+                planner
+                    .set_gas_prices(gas_prices)
+                    .set_fee_tier(FeeTier::default());
+
+                // Return all unspent notes from the view service
+                let notes = app
+                    .view
+                    .as_mut()
+                    .context("view service must be initialized")?
+                    .unspent_notes_by_account_and_asset()
+                    .await?;
+
+                // Get all remaining note values after filtering out notes already spent by the planner
+                let note_values = notes.iter().flat_map(|(_, notes_by_asset)| {
+                    notes_by_asset.iter().map(|(asset, notes)| {
+                        let sum: u128 = notes
+                            .iter()
+                            .map(|record| u128::from(record.note.amount()))
+                            .sum();
+
+                        asset.value(sum.into())
+                    })
+                });
+
+                // Add all note values to the planner
+                note_values.clone().for_each(|value| {
+                    planner.output(value, dest_address.clone());
+                });
+
+                let fee =
+                    planner.compute_fee_estimate(&gas_prices, &FeeTier::default(), &source_address);
+
+                println!("Estimated fee for sending total balance: {:?}", fee);
+
+                // Update relevant note values to be less the estimated fee
+
+                let mut note_values_2 = Vec::new();
+
+                note_values.for_each(|value| {
+                    if value.asset_id == fee.0.asset_id {
+                        note_values_2.push(penumbra_asset::Value {
+                            asset_id: value.asset_id,
+                            amount: value.amount - fee.0.amount,
+                        });
+                    } else {
+                        note_values_2.push(penumbra_asset::Value {
+                            asset_id: value.asset_id,
+                            amount: value.amount,
+                        });
+                    }
+                });
+
+                let mut planner_2 = Planner::new(OsRng);
+
+                planner_2
+                    .set_gas_prices(gas_prices)
+                    .set_fee_tier(FeeTier::default());
+
+                // Add all note values to the second planner
+                note_values_2.clone().into_iter().for_each(|value| {
+                    planner_2.output(value, dest_address.clone());
+                });
+
+                // defaulting to index 0 (the default account) here means that this operation
+                // will fail if the default account has insufficient funds for fees
+                // a more general solution could be finding the first/lowest-indexed account with sufficient funds
+                // and spending fees from that account
+                let address_index = AddressIndex::new(0);
+
+                let plan = planner_2
+                    .memo(memo)
+                    .plan(
+                        app.view
+                            .as_mut()
+                            .context("view service must be initialized")?,
+                        address_index,
+                    )
+                    .await
+                    .context("can't build send transaction")?;
+
+                app.build_and_submit_transaction(plan).await?;
+
+                Result::Ok(())
+            }
+        }
+    }
+}

crates/bin/pcli/src/main.rs

@@ -65,6 +65,7 @@ async fn main() -> Result<()> {
         Command::Query(cmd) => cmd.exec(&mut app).await?,
         Command::Ceremony(cmd) => cmd.exec(&mut app).await?,
         Command::Threshold(cmd) => cmd.exec(&mut app).await?,
+        Command::Migrate(cmd) => cmd.exec(&mut app).await?,
     }
 
     Ok(())

crates/core/transaction/src/action_list.rs

@@ -29,6 +29,10 @@ pub struct ActionList {
 }
 
 impl ActionList {
+    /// Returns the transaction fee as currently estimated.
+    pub fn fee(&self) -> Fee {
+        self.fee
+    }
     /// Returns true if the resulting transaction would require a memo.
     pub fn requires_memo(&self) -> bool {
         let has_change_outputs = !self.change_outputs.is_empty();
@@ -124,7 +128,7 @@ impl ActionList {
     /// While the gas cost can be computed exactly, the base fee can only be
     /// estimated, because the actual base fee paid by the transaction will
     /// depend on the gas prices at the time it's accepted on-chain.
-    fn compute_fee_estimate(&self, gas_prices: &GasPrices, fee_tier: &FeeTier) -> Fee {
+    pub fn compute_fee_estimate(&self, gas_prices: &GasPrices, fee_tier: &FeeTier) -> Fee {
         let base_fee = gas_prices.fee(&self.gas_cost());
         base_fee.apply_tier(*fee_tier)
     }

crates/view/src/planner.rs

@@ -96,6 +96,25 @@ impl<R: RngCore + CryptoRng> Planner<R> {
         }
     }
 
+    /// Compute a fee estimate for the transaction.
+
+    pub fn compute_fee_estimate(
+        &mut self,
+        gas_prices: &GasPrices,
+        fee_tier: &FeeTier,
+        change_address: &Address,
+    ) -> Fee {
+
+        self.action_list.refresh_fee_and_change(
+            &mut self.rng,
+            gas_prices,
+            fee_tier,
+            change_address,
+        );
+
+        self.action_list.fee()
+    }
+
     /// Add an arbitrary action to the planner.
     pub fn action<A: Into<ActionPlan>>(&mut self, action: A) -> &mut Self {
         self.action_list.push(action);