feat(rpc): add StateMinerInitialPledgeForSector method

CHANGELOG.md

@@ -32,6 +32,9 @@
 - [#5020](https://github.com/ChainSafe/forest/issues/5020) Add support for the
   `Filecoin.EthGetTransactionByBlockNumberAndIndex` RPC method.
 
+- [#4907](https://github.com/ChainSafe/forest/issues/4907) Add support for the
+  `Filecoin.StateMinerInitialPledgeForSector` RPC method.
+
 ### Changed
 
 ### Removed

src/rpc/methods/state.rs

@@ -2800,3 +2800,95 @@ impl TryFrom<&ChainConfig> for ForkUpgradeParams {
         })
     }
 }
+
+pub enum StateMinerInitialPledgeForSector {}
+impl RpcMethod<4> for StateMinerInitialPledgeForSector {
+    const NAME: &'static str = "Filecoin.StateMinerInitialPledgeForSector";
+    const PARAM_NAMES: [&'static str; 4] = [
+        "sector_duration",
+        "sector_size",
+        "verified_size",
+        "tipset_key",
+    ];
+    const API_PATHS: ApiPaths = ApiPaths::V1;
+    const PERMISSION: Permission = Permission::Read;
+
+    type Params = (ChainEpoch, SectorSize, u64, ApiTipsetKey);
+    type Ok = TokenAmount;
+
+    async fn handle(
+        ctx: Ctx<impl Blockstore + Send + Sync + 'static>,
+        (sector_duration, sector_size, verified_size, ApiTipsetKey(tsk)): Self::Params,
+    ) -> Result<Self::Ok, ServerError> {
+        if sector_duration <= 0 {
+            return Err(anyhow::anyhow!("sector duration must be greater than 0").into());
+        }
+
+        if verified_size > sector_size as u64 {
+            return Err(
+                anyhow::anyhow!("verified deal size cannot be larger than sector size").into(),
+            );
+        }
+
+        let ts = ctx.chain_store().load_required_tipset_or_heaviest(&tsk)?;
+
+        let power_state: power::State = ctx.state_manager.get_actor_state(&ts)?;
+        let power_smoothed = power_state.total_power_smoothed();
+        let pledge_collateral = power_state.total_locked();
+
+        let reward_state: reward::State = ctx.state_manager.get_actor_state(&ts)?;
+
+        let genesis_info = GenesisInfo::from_chain_config(ctx.chain_config().clone());
+        let circ_supply = genesis_info.get_vm_circulating_supply_detailed(
+            ts.epoch(),
+            &ctx.store_owned(),
+            ts.parent_state(),
+        )?;
+
+        let deal_weight = BigInt::from(0);
+        let verified_deal_weight = BigInt::from(verified_size) * sector_duration;
+        let sector_weight = qa_power_for_weight(
+            sector_size.into(),
+            sector_duration,
+            &deal_weight,
+            &verified_deal_weight,
+        );
+
+        let (epochs_since_start, duration) = get_pledge_ramp_params(&ctx, ts.epoch(), &ts)?;
+
+        let initial_pledge: TokenAmount = reward_state
+            .initial_pledge_for_power(
+                &sector_weight,
+                pledge_collateral,
+                power_smoothed,
+                &circ_supply.fil_circulating.into(),
+                epochs_since_start,
+                duration,
+            )?
+            .into();
+
+        let (value, _) = (initial_pledge * INITIAL_PLEDGE_NUM).div_rem(INITIAL_PLEDGE_DEN);
+        Ok(value)
+    }
+}
+
+fn get_pledge_ramp_params(
+    ctx: &Ctx<impl Blockstore + Send + Sync + 'static>,
+    height: ChainEpoch,
+    ts: &Tipset,
+) -> Result<(ChainEpoch, u64), anyhow::Error> { 
+    let state_tree = ctx.state_manager.get_state_tree(ts.parent_state())?;
+
+    let power_state: power::State = state_tree
+        .get_actor_state()
+        .map_err(|e| anyhow::anyhow!("loading power actor state: {e}"))?;
+
+    if power_state.ramp_start_epoch() > 0 {
+        Ok((
+            height - power_state.ramp_start_epoch(),
+            power_state.ramp_duration_epochs(),
+        ))
+    } else {
+        Ok((0, 0))
+    }
+}

src/rpc/mod.rs

@@ -217,6 +217,7 @@ macro_rules! for_each_method {
         $callback!(crate::rpc::state::StateVMCirculatingSupplyInternal);
         $callback!(crate::rpc::state::StateWaitMsg);
         $callback!(crate::rpc::state::StateWaitMsgV0);
+        $callback!(crate::rpc::state::StateMinerInitialPledgeForSector);
 
         // sync vertical
         $callback!(crate::rpc::sync::SyncCheckBad);

src/tool/subcommands/api_cmd.rs

@@ -20,6 +20,7 @@ use crate::rpc::types::{ApiTipsetKey, MessageFilter, MessageLookup};
 use crate::rpc::{prelude::*, Permission};
 use crate::shim::actors::market;
 use crate::shim::actors::MarketActorStateLoad as _;
+use crate::shim::sector::SectorSize;
 use crate::shim::{
     address::{Address, Protocol},
     crypto::Signature,
@@ -810,6 +811,12 @@ fn state_tests_with_tipset<DB: Blockstore>(
     let mut tests = vec![
         RpcTest::identity(StateNetworkName::request(())?),
         RpcTest::identity(StateGetNetworkParams::request(())?),
+        RpcTest::identity(StateMinerInitialPledgeForSector::request((
+            1,
+            SectorSize::_2KiB,
+            1024,
+            tipset.key().into(),
+        ))?),
         RpcTest::identity(StateGetActor::request((
             Address::SYSTEM_ACTOR,
             tipset.key().into(),