Add more resolvable variables (#120)

* Allow resolution of base fee

* Fix block difficulty resolution

* Allow for the resolution of gas price

crates/format/src/traits.rs

@@ -1,13 +1,22 @@
+use std::collections::HashMap;
+
 use alloy::eips::BlockNumberOrTag;
+use alloy::json_abi::JsonAbi;
 use alloy::primitives::{Address, BlockHash, BlockNumber, BlockTimestamp, ChainId, U256};
+use alloy_primitives::TxHash;
 use anyhow::Result;
 
+use crate::metadata::ContractInstance;
+
 /// A trait of the interface are required to implement to be used by the resolution logic that this
 /// crate implements to go from string calldata and into the bytes calldata.
 pub trait ResolverApi {
     /// Returns the ID of the chain that the node is on.
     fn chain_id(&self) -> impl Future<Output = Result<ChainId>>;
 
+    /// Returns the gas price for the specified transaction.
+    fn transaction_gas_price(&self, tx_hash: &TxHash) -> impl Future<Output = Result<u128>>;
+
     // TODO: This is currently a u128 due to Kitchensink needing more than 64 bits for its gas limit
     // when we implement the changes to the gas we need to adjust this to be a u64.
     /// Returns the gas limit of the specified block.
@@ -19,6 +28,9 @@ pub trait ResolverApi {
     /// Returns the difficulty of the specified block.
     fn block_difficulty(&self, number: BlockNumberOrTag) -> impl Future<Output = Result<U256>>;
 
+    /// Returns the base fee of the specified block.
+    fn block_base_fee(&self, number: BlockNumberOrTag) -> impl Future<Output = Result<u64>>;
+
     /// Returns the hash of the specified block.
     fn block_hash(&self, number: BlockNumberOrTag) -> impl Future<Output = Result<BlockHash>>;
 
@@ -31,3 +43,108 @@ pub trait ResolverApi {
     /// Returns the number of the last block.
     fn last_block_number(&self) -> impl Future<Output = Result<BlockNumber>>;
 }
+
+#[derive(Clone, Copy, Debug, Default)]
+/// Contextual information required by the code that's performing the resolution.
+pub struct ResolutionContext<'a> {
+    /// When provided the contracts provided here will be used for resolutions.
+    deployed_contracts: Option<&'a HashMap<ContractInstance, (Address, JsonAbi)>>,
+
+    /// When provided the variables in here will be used for performing resolutions.
+    variables: Option<&'a HashMap<String, U256>>,
+
+    /// When provided this block number will be treated as the tip of the chain.
+    block_number: Option<&'a BlockNumber>,
+
+    /// When provided the resolver will use this transaction hash for all of its resolutions.
+    transaction_hash: Option<&'a TxHash>,
+}
+
+impl<'a> ResolutionContext<'a> {
+    pub fn new() -> Self {
+        Default::default()
+    }
+
+    pub fn new_from_parts(
+        deployed_contracts: impl Into<Option<&'a HashMap<ContractInstance, (Address, JsonAbi)>>>,
+        variables: impl Into<Option<&'a HashMap<String, U256>>>,
+        block_number: impl Into<Option<&'a BlockNumber>>,
+        transaction_hash: impl Into<Option<&'a TxHash>>,
+    ) -> Self {
+        Self {
+            deployed_contracts: deployed_contracts.into(),
+            variables: variables.into(),
+            block_number: block_number.into(),
+            transaction_hash: transaction_hash.into(),
+        }
+    }
+
+    pub fn with_deployed_contracts(
+        mut self,
+        deployed_contracts: impl Into<Option<&'a HashMap<ContractInstance, (Address, JsonAbi)>>>,
+    ) -> Self {
+        self.deployed_contracts = deployed_contracts.into();
+        self
+    }
+
+    pub fn with_variables(
+        mut self,
+        variables: impl Into<Option<&'a HashMap<String, U256>>>,
+    ) -> Self {
+        self.variables = variables.into();
+        self
+    }
+
+    pub fn with_block_number(mut self, block_number: impl Into<Option<&'a BlockNumber>>) -> Self {
+        self.block_number = block_number.into();
+        self
+    }
+
+    pub fn with_transaction_hash(
+        mut self,
+        transaction_hash: impl Into<Option<&'a TxHash>>,
+    ) -> Self {
+        self.transaction_hash = transaction_hash.into();
+        self
+    }
+
+    pub fn resolve_block_number(&self, number: BlockNumberOrTag) -> BlockNumberOrTag {
+        match self.block_number {
+            Some(block_number) => match number {
+                BlockNumberOrTag::Latest => BlockNumberOrTag::Number(*block_number),
+                n @ (BlockNumberOrTag::Finalized
+                | BlockNumberOrTag::Safe
+                | BlockNumberOrTag::Earliest
+                | BlockNumberOrTag::Pending
+                | BlockNumberOrTag::Number(_)) => n,
+            },
+            None => number,
+        }
+    }
+
+    pub fn deployed_contract(&self, instance: &ContractInstance) -> Option<&(Address, JsonAbi)> {
+        self.deployed_contracts
+            .and_then(|deployed_contracts| deployed_contracts.get(instance))
+    }
+
+    pub fn deployed_contract_address(&self, instance: &ContractInstance) -> Option<&Address> {
+        self.deployed_contract(instance).map(|(a, _)| a)
+    }
+
+    pub fn deployed_contract_abi(&self, instance: &ContractInstance) -> Option<&JsonAbi> {
+        self.deployed_contract(instance).map(|(_, a)| a)
+    }
+
+    pub fn variable(&self, name: impl AsRef<str>) -> Option<&U256> {
+        self.variables
+            .and_then(|variables| variables.get(name.as_ref()))
+    }
+
+    pub fn tip_block_number(&self) -> Option<&'a BlockNumber> {
+        self.block_number
+    }
+
+    pub fn transaction_hash(&self) -> Option<&'a TxHash> {
+        self.transaction_hash
+    }
+}