lib.rs

//! Cast
//!
//! TODO
use chrono::NaiveDateTime;
use ethers_core::{
    abi::{
        token::{LenientTokenizer, Tokenizer},
        Abi, AbiParser, Token,
    },
    types::{Chain, *},
    utils::{self, keccak256},
};

use ethers_etherscan::Client;
use ethers_providers::{Middleware, PendingTransaction};
use eyre::{Context, Result};
use rustc_hex::{FromHexIter, ToHex};
use std::str::FromStr;

use foundry_utils::{encode_args, get_func, get_func_etherscan, to_table};

// TODO: CastContract with common contract initializers? Same for CastProviders?

pub struct Cast<M> {
    provider: M,
}

impl<M: Middleware> Cast<M>
where
    M::Error: 'static,
{
    /// Converts ASCII text input to hex
    ///
    /// ```
    /// use cast::Cast;
    /// use ethers_providers::{Provider, Http};
    /// use std::convert::TryFrom;
    ///
    /// # async fn foo() -> eyre::Result<()> {
    /// let provider = Provider::<Http>::try_from("http://localhost:8545")?;
    /// let cast = Cast::new(provider);
    /// # Ok(())
    /// # }
    /// ```
    pub fn new(provider: M) -> Self {
        Self { provider }
    }

    /// Makes a read-only call to the specified address
    ///
    /// ```no_run
    /// 
    /// use cast::Cast;
    /// use ethers_core::types::{Address, Chain};
    /// use ethers_providers::{Provider, Http};
    /// use std::{str::FromStr, convert::TryFrom};
    ///
    /// # async fn foo() -> eyre::Result<()> {
    /// let provider = Provider::<Http>::try_from("http://localhost:8545")?;
    /// let cast = Cast::new(provider);
    /// let to = Address::from_str("0xB3C95ff08316fb2F2e3E52Ee82F8e7b605Aa1304")?;
    /// let sig = "function greeting(uint256 i) public returns (string)";
    /// let args = vec!["5".to_owned()];
    /// let data = cast.call(Address::zero(), to, (sig, args), Chain::Mainnet, None).await?;
    /// println!("{}", data);
    /// # Ok(())
    /// # }
    /// ```
    pub async fn call<F: Into<NameOrAddress>, T: Into<NameOrAddress>>(
        &self,
        from: F,
        to: T,
        args: (&str, Vec<String>),
        chain: Chain,
        etherscan_api_key: Option<String>,
    ) -> Result<String> {
        let (tx, func) = self.build_tx(from, to, Some(args), chain, etherscan_api_key).await?;
        let tx = tx.into();
        let res = self.provider.call(&tx, None).await?;

        // decode args into tokens
        let func = func.expect("no valid function signature was provided.");
        let decoded = func.decode_output(res.as_ref()).wrap_err(
            "could not decode output. did you specify the wrong function return data type perhaps?",
        )?;
        // handle case when return type is not specified
        Ok(if decoded.is_empty() {
            format!("{}\n", res)
        } else {
            // seth compatible user-friendly return type conversions
            let out = decoded
                .iter()
                .map(|item| {
                    match item {
                        Token::Address(inner) => format!("{:?}", inner),
                        // add 0x
                        Token::Bytes(inner) => format!("0x{}", hex::encode(inner)),
                        Token::FixedBytes(inner) => format!("0x{}", hex::encode(inner)),
                        // print as decimal
                        Token::Uint(inner) | Token::Int(inner) => inner.to_string(),
                        _ => format!("{}", item),
                    }
                })
                .collect::<Vec<_>>();

            out.join("\n")
        })
    }

    pub async fn balance<T: Into<NameOrAddress> + Send + Sync>(
        &self,
        who: T,
        block: Option<BlockId>,
    ) -> Result<U256> {
        Ok(self.provider.get_balance(who, block).await?)
    }

    /// Sends a transaction to the specified address
    ///
    /// ```no_run
    /// use cast::Cast;
    /// use ethers_core::types::{Address, Chain};
    /// use ethers_providers::{Provider, Http};
    /// use std::{str::FromStr, convert::TryFrom};
    ///
    /// # async fn foo() -> eyre::Result<()> {
    /// let provider = Provider::<Http>::try_from("http://localhost:8545")?;
    /// let cast = Cast::new(provider);
    /// let from = "vitalik.eth";
    /// let to = Address::from_str("0xB3C95ff08316fb2F2e3E52Ee82F8e7b605Aa1304")?;
    /// let sig = "greet(string)()";
    /// let args = vec!["hello".to_owned()];
    /// let data = cast.send(from, to, Some((sig, args)), Chain::Mainnet, None).await?;
    /// println!("{}", *data);
    /// # Ok(())
    /// # }
    /// ```
    pub async fn send<F: Into<NameOrAddress>, T: Into<NameOrAddress>>(
        &self,
        from: F,
        to: T,
        args: Option<(&str, Vec<String>)>,
        chain: Chain,
        etherscan_api_key: Option<String>,
    ) -> Result<PendingTransaction<'_, M::Provider>> {
        let (tx, _) = self.build_tx(from, to, args, chain, etherscan_api_key).await?;
        let res = self.provider.send_transaction(tx, None).await?;

        Ok::<_, eyre::Error>(res)
    }

    /// Publishes a raw transaction to the network
    ///
    /// ```no_run
    /// use cast::Cast;
    /// use ethers_providers::{Provider, Http};
    ///
    /// # async fn foo() -> eyre::Result<()> {
    /// let provider = Provider::<Http>::try_from("http://localhost:8545")?;
    /// let cast = Cast::new(provider);
    /// let res = cast.publish("0x1234".to_string()).await?;
    /// println!("{:?}", res);
    /// # Ok(())
    /// # }
    /// ```
    pub async fn publish(&self, mut raw_tx: String) -> Result<PendingTransaction<'_, M::Provider>> {
        raw_tx = match raw_tx.strip_prefix("0x") {
            Some(s) => s.to_string(),
            None => raw_tx,
        };
        let tx = Bytes::from(hex::decode(raw_tx)?);
        let res = self.provider.send_raw_transaction(tx).await?;

        Ok::<_, eyre::Error>(res)
    }

    /// Estimates the gas cost of a transaction
    ///
    /// ```no_run
    /// use cast::Cast;
    /// use ethers_core::types::{Address, Chain};
    /// use ethers_providers::{Provider, Http};
    /// use std::{str::FromStr, convert::TryFrom};
    ///
    /// # async fn foo() -> eyre::Result<()> {
    /// let provider = Provider::<Http>::try_from("http://localhost:8545")?;
    /// let cast = Cast::new(provider);
    /// let from = "vitalik.eth";
    /// let to = Address::from_str("0xB3C95ff08316fb2F2e3E52Ee82F8e7b605Aa1304")?;
    /// let sig = "greet(string)()";
    /// let args = vec!["5".to_owned()];
    /// let data = cast.estimate(from, to, Some((sig, args)), Chain::Mainnet, None).await?;
    /// println!("{}", data);
    /// # Ok(())
    /// # }
    /// ```
    pub async fn estimate<F: Into<NameOrAddress>, T: Into<NameOrAddress>>(
        &self,
        from: F,
        to: T,
        args: Option<(&str, Vec<String>)>,
        chain: Chain,
        etherscan_api_key: Option<String>,
    ) -> Result<U256> {
        let (tx, _) = self.build_tx(from, to, args, chain, etherscan_api_key).await?;
        let tx = tx.into();
        let res = self.provider.estimate_gas(&tx).await?;

        Ok::<_, eyre::Error>(res)
    }

    async fn build_tx<F: Into<NameOrAddress>, T: Into<NameOrAddress>>(
        &self,
        from: F,
        to: T,
        args: Option<(&str, Vec<String>)>,
        chain: Chain,
        etherscan_api_key: Option<String>,
    ) -> Result<(Eip1559TransactionRequest, Option<ethers_core::abi::Function>)> {
        let from = match from.into() {
            NameOrAddress::Name(ref ens_name) => self.provider.resolve_name(ens_name).await?,
            NameOrAddress::Address(addr) => addr,
        };

        // Queries the addressbook for the address if present.
        let to = foundry_utils::resolve_addr(to, chain)?;

        let to = match to {
            NameOrAddress::Name(ref ens_name) => self.provider.resolve_name(ens_name).await?,
            NameOrAddress::Address(addr) => addr,
        };

        // make the call
        let mut tx = Eip1559TransactionRequest::new().from(from).to(to);

        let func = if let Some((sig, args)) = args {
            let func = if sig.contains('(') {
                get_func(sig)?
            } else {
                get_func_etherscan(
                    sig,
                    to,
                    args.clone(),
                    chain,
                    etherscan_api_key.expect("Must set ETHERSCAN_API_KEY"),
                )
                .await?
            };
            let data = encode_args(&func, &args)?;
            tx = tx.data(data);
            Some(func)
        } else {
            None
        };

        Ok((tx, func))
    }

    /// ```no_run
    /// use cast::Cast;
    /// use ethers_providers::{Provider, Http};
    /// use std::convert::TryFrom;
    ///
    /// # async fn foo() -> eyre::Result<()> {
    /// let provider = Provider::<Http>::try_from("http://localhost:8545")?;
    /// let cast = Cast::new(provider);
    /// let block = cast.block(5, true, None, false).await?;
    /// println!("{}", block);
    /// # Ok(())
    /// # }
    /// ```
    pub async fn block<T: Into<BlockId>>(
        &self,
        block: T,
        full: bool,
        field: Option<String>,
        to_json: bool,
    ) -> Result<String> {
        let block = block.into();
        let block = if full {
            let block = self
                .provider
                .get_block_with_txs(block)
                .await?
                .ok_or_else(|| eyre::eyre!("block {:?} not found", block))?;
            if let Some(ref field) = field {
                // TODO: Use custom serializer to serialize
                // u256s as decimals
                serde_json::to_value(&block)?
                    .get(field)
                    .cloned()
                    .ok_or_else(|| eyre::eyre!("field {} not found", field))?
            } else {
                serde_json::to_value(&block)?
            }
        } else {
            let block = self
                .provider
                .get_block(block)
                .await?
                .ok_or_else(|| eyre::eyre!("block {:?} not found", block))?;
            if let Some(ref field) = field {
                serde_json::to_value(block)?
                    .get(field)
                    .cloned()
                    .ok_or_else(|| eyre::eyre!("field {} not found", field))?
            } else {
                serde_json::to_value(&block)?
            }
        };

        let block = if to_json { serde_json::to_string(&block)? } else { to_table(block) };

        Ok(block)
    }

    async fn block_field_as_num<T: Into<BlockId>>(&self, block: T, field: String) -> Result<U256> {
        let block = block.into();
        let block_field = Cast::block(
            self,
            block,
            false,
            // Select only select field
            Some(field),
            false,
        )
        .await?;
        Ok(U256::from_str_radix(strip_0x(&block_field), 16)
            .expect("Unable to convert hexadecimal to U256"))
    }

    pub async fn base_fee<T: Into<BlockId>>(&self, block: T) -> Result<U256> {
        Ok(Cast::block_field_as_num(self, block, String::from("baseFeePerGas")).await?)
    }

    pub async fn age<T: Into<BlockId>>(&self, block: T) -> Result<String> {
        let timestamp_str =
            Cast::block_field_as_num(self, block, String::from("timestamp")).await?.to_string();
        let datetime = NaiveDateTime::from_timestamp(timestamp_str.parse::<i64>().unwrap(), 0);
        Ok(datetime.format("%a %b %e %H:%M:%S %Y").to_string())
    }

    pub async fn chain(&self) -> Result<&str> {
        let genesis_hash = Cast::block(
            self,
            0,
            false,
            // Select only block hash
            Some(String::from("hash")),
            false,
        )
        .await?;

        Ok(match &genesis_hash[..] {
            "0xd4e56740f876aef8c010b86a40d5f56745a118d0906a34e69aec8c0db1cb8fa3" => {
                match &(Cast::block(self, 1920000, false, Some(String::from("hash")), false)
                    .await?)[..]
                {
                    "0x94365e3a8c0b35089c1d1195081fe7489b528a84b22199c916180db8b28ade7f" => {
                        "etclive"
                    }
                    _ => "ethlive",
                }
            }
            "0xa3c565fc15c7478862d50ccd6561e3c06b24cc509bf388941c25ea985ce32cb9" => "kovan",
            "0x41941023680923e0fe4d74a34bdac8141f2540e3ae90623718e47d66d1ca4a2d" => "ropsten",
            "0x7ca38a1916c42007829c55e69d3e9a73265554b586a499015373241b8a3fa48b" => {
                "optimism-mainnet"
            }
            "0x02adc9b449ff5f2467b8c674ece7ff9b21319d76c4ad62a67a70d552655927e5" => {
                "optimism-kovan"
            }
            "0x7ee576b35482195fc49205cec9af72ce14f003b9ae69f6ba0faef4514be8b442" => {
                "arbitrum-mainnet"
            }
            "0x0cd786a2425d16f152c658316c423e6ce1181e15c3295826d7c9904cba9ce303" => "morden",
            "0x6341fd3daf94b748c72ced5a5b26028f2474f5f00d824504e4fa37a75767e177" => "rinkeby",
            "0xbf7e331f7f7c1dd2e05159666b3bf8bc7a8a3a9eb1d518969eab529dd9b88c1a" => "goerli",
            "0x14c2283285a88fe5fce9bf5c573ab03d6616695d717b12a127188bcacfc743c4" => "kotti",
            "0xa9c28ce2141b56c474f1dc504bee9b01eb1bd7d1a507580d5519d4437a97de1b" => "polygon",
            "0x7b66506a9ebdbf30d32b43c5f15a3b1216269a1ec3a75aa3182b86176a2b1ca7" => {
                "polygon-mumbai"
            }
            "0x6d3c66c5357ec91d5c43af47e234a939b22557cbb552dc45bebbceeed90fbe34" => "bsctest",
            "0x0d21840abff46b96c84b2ac9e10e4f5cdaeb5693cb665db62a2f3b02d2d57b5b" => "bsc",
            "0x31ced5b9beb7f8782b014660da0cb18cc409f121f408186886e1ca3e8eeca96b" => {
                match &(Cast::block(self, 1, false, Some(String::from("hash")), false).await?)[..] {
                    "0x738639479dc82d199365626f90caa82f7eafcfe9ed354b456fb3d294597ceb53" => {
                        "avalanche-fuji"
                    }
                    _ => "avalanche",
                }
            }
            _ => "unknown",
        })
    }

    pub async fn chain_id(&self) -> Result<U256> {
        Ok(self.provider.get_chainid().await?)
    }

    pub async fn block_number(&self) -> Result<U64> {
        Ok(self.provider.get_block_number().await?)
    }

    pub async fn gas_price(&self) -> Result<U256> {
        Ok(self.provider.get_gas_price().await?)
    }

    /// ```no_run
    /// use cast::Cast;
    /// use ethers_providers::{Provider, Http};
    /// use ethers_core::types::Address;
    /// use std::{str::FromStr, convert::TryFrom};
    ///
    /// # async fn foo() -> eyre::Result<()> {
    /// let provider = Provider::<Http>::try_from("http://localhost:8545")?;
    /// let cast = Cast::new(provider);
    /// let addr = Address::from_str("0x7eD52863829AB99354F3a0503A622e82AcD5F7d3")?;
    /// let nonce = cast.nonce(addr, None).await?;
    /// println!("{}", nonce);
    /// # Ok(())
    /// # }
    /// ```
    pub async fn nonce<T: Into<NameOrAddress> + Send + Sync>(
        &self,
        who: T,
        block: Option<BlockId>,
    ) -> Result<U256> {
        Ok(self.provider.get_transaction_count(who, block).await?)
    }

    /// ```no_run
    /// use cast::Cast;
    /// use ethers_providers::{Provider, Http};
    /// use ethers_core::types::Address;
    /// use std::{str::FromStr, convert::TryFrom};
    ///
    /// # async fn foo() -> eyre::Result<()> {
    /// let provider = Provider::<Http>::try_from("http://localhost:8545")?;
    /// let cast = Cast::new(provider);
    /// let addr = Address::from_str("0x00000000219ab540356cbb839cbe05303d7705fa")?;
    /// let code = cast.code(addr, None).await?;
    /// println!("{}", code);
    /// # Ok(())
    /// # }
    /// ```
    pub async fn code<T: Into<NameOrAddress> + Send + Sync>(
        &self,
        who: T,
        block: Option<BlockId>,
    ) -> Result<String> {
        Ok(format!("{}", self.provider.get_code(who, block).await?))
    }

    /// ```no_run
    /// use cast::Cast;
    /// use ethers_providers::{Provider, Http};
    /// use std::convert::TryFrom;
    ///
    /// # async fn foo() -> eyre::Result<()> {
    /// let provider = Provider::<Http>::try_from("http://localhost:8545")?;
    /// let cast = Cast::new(provider);
    /// let tx_hash = "0xf8d1713ea15a81482958fb7ddf884baee8d3bcc478c5f2f604e008dc788ee4fc";
    /// let tx = cast.transaction(tx_hash.to_string(), None, false).await?;
    /// println!("{}", tx);
    /// # Ok(())
    /// # }
    /// ```
    pub async fn transaction(
        &self,
        tx_hash: String,
        field: Option<String>,
        to_json: bool,
    ) -> Result<String> {
        let transaction_result = self
            .provider
            .get_transaction(H256::from_str(&tx_hash)?)
            .await?
            .ok_or_else(|| eyre::eyre!("transaction {:?} not found", tx_hash))?;

        let transaction = if let Some(ref field) = field {
            serde_json::to_value(&transaction_result)?
                .get(field)
                .cloned()
                .ok_or_else(|| eyre::eyre!("field {} not found", field))?
        } else {
            serde_json::to_value(&transaction_result)?
        };

        let transaction =
            if to_json { serde_json::to_string(&transaction)? } else { to_table(transaction) };
        Ok(transaction)
    }
}

pub struct InterfaceSource {
    pub name: String,
    pub source: String,
}

pub enum InterfacePath {
    Local(String),
    Etherscan { address: Address, chain: Chain, api_key: String },
}

pub struct SimpleCast;
impl SimpleCast {
    /// Converts UTF-8 text input to hex
    ///
    /// ```
    /// use cast::SimpleCast as Cast;
    ///
    /// let bin = Cast::from_utf8("yo");
    /// assert_eq!(bin, "0x796f")
    /// ```
    pub fn from_utf8(s: &str) -> String {
        let s: String = s.as_bytes().to_hex();
        format!("0x{}", s)
    }
    /// Generates an interface in solidity from either a local file ABI or a verified contract on
    /// Etherscan. It returns a vector of [`InterfaceSource`] structs that contain the source of the
    /// interface and their name.
    /// ```no_run
    /// use cast::SimpleCast as Cast;
    /// use cast::InterfacePath;
    /// # async fn foo() -> eyre::Result<()> {
    /// let path = InterfacePath::Local("utils/testdata/interfaceTestABI.json".to_owned());
    /// let interfaces= Cast::generate_interface(path).await?;
    /// println!("interface {} {{\n {}\n}}", interfaces[0].name, interfaces[0].source);
    /// # Ok(())
    /// # }
    /// ```
    pub async fn generate_interface(
        address_or_path: InterfacePath,
    ) -> Result<Vec<InterfaceSource>> {
        let (contract_abis, contract_names): (Vec<Abi>, Vec<String>) = match address_or_path {
            InterfacePath::Local(path) => {
                let file = std::fs::read_to_string(&path).wrap_err("unable to read abi file")?;
                (
                    vec![serde_json::from_str(&file)
                        .wrap_err("unable to parse json ABI from file")?],
                    vec!["Interface".to_owned()],
                )
            }
            InterfacePath::Etherscan { address, chain, api_key } => {
                let client = Client::new(chain, api_key)?;

                // get the source
                let contract_source = match client.contract_source_code(address).await {
                    Ok(src) => src,
                    Err(err) => {
                        let msg = err.to_string();
                        if msg.contains("Invalid API Key") {
                            eyre::bail!("Invalid Etherscan API key. Did you set it correctly? You may be using an API key for another Etherscan API chain (e.g. Ethereum API key for Polygonscan).")
                        } else {
                            eyre::bail!(err)
                        }
                    }
                };

                if contract_source
                    .items
                    .iter()
                    .any(|item| item.abi == "Contract source code not verified")
                {
                    eyre::bail!("Contract source code at {:?} on {} not verified. Maybe you have selected the wrong chain?", address, chain)
                }

                let contract_source_names = contract_source
                    .items
                    .iter()
                    .map(|item| item.contract_name.clone())
                    .collect::<Vec<String>>();
                (contract_source.abis()?, contract_source_names)
            }
        };
        contract_abis
            .iter()
            .zip(&contract_names)
            .map(|(contract_abi, contract_name)| {
                let interface_source = foundry_utils::abi_to_solidity(contract_abi, contract_name)?;
                Ok(InterfaceSource { name: contract_name.to_owned(), source: interface_source })
            })
            .collect::<Result<Vec<InterfaceSource>>>()
    }
    /// Converts hex data into text data
    /// ```
    /// use cast::SimpleCast as Cast;
    ///
    /// fn main() -> eyre::Result<()> {
    ///     assert_eq!("Hello, World!", Cast::ascii("48656c6c6f2c20576f726c6421")?);
    ///     assert_eq!("TurboDappTools", Cast::ascii("0x547572626f44617070546f6f6c73")?);
    ///
    ///     Ok(())
    /// }
    /// ```
    pub fn ascii(hex: &str) -> Result<String> {
        let hex_trimmed = hex.trim_start_matches("0x");
        let iter = FromHexIter::new(hex_trimmed);
        let mut ascii = String::new();
        for letter in iter.collect::<Vec<_>>() {
            ascii.push(letter.unwrap() as char);
        }
        Ok(ascii)
    }

    /// Converts hex input to decimal
    ///
    /// ```
    /// use cast::SimpleCast as Cast;
    /// use ethers_core::types::U256;
    ///
    /// fn main() -> eyre::Result<()> {
    ///     assert_eq!(U256::from_dec_str("424242")?, Cast::to_dec("0x67932")?);
    ///     assert_eq!(U256::from_dec_str("1234")?, Cast::to_dec("0x4d2")?);
    ///
    ///     Ok(())
    /// }
    pub fn to_dec(hex: &str) -> Result<U256> {
        Ok(U256::from_str(hex)?)
    }

    /// Returns maximum I256 value
    ///
    /// ```
    /// use cast::SimpleCast as Cast;
    /// use ethers_core::types::I256;
    ///
    /// fn main() -> eyre::Result<()> {
    ///     assert_eq!(I256::MAX, Cast::max_int()?);
    ///
    ///     Ok(())
    /// }
    /// ```
    pub fn max_int() -> Result<I256> {
        Ok(I256::MAX)
    }

    /// Returns minimum I256 value
    ///
    /// ```
    /// use cast::SimpleCast as Cast;
    /// use ethers_core::types::I256;
    ///
    /// fn main() -> eyre::Result<()> {
    ///     assert_eq!(I256::MIN, Cast::min_int()?);
    ///
    ///     Ok(())
    /// }
    /// ```
    pub fn min_int() -> Result<I256> {
        Ok(I256::MIN)
    }
    /// Returns maximum U256 value
    ///
    /// ```
    /// use cast::SimpleCast as Cast;
    /// use ethers_core::types::U256;
    ///
    /// fn main() -> eyre::Result<()> {
    ///     assert_eq!(U256::MAX, Cast::max_uint()?);
    ///
    ///     Ok(())
    /// }
    /// ```
    pub fn max_uint() -> Result<U256> {
        Ok(U256::MAX)
    }

    /// Converts integers with specified decimals into fixed point numbers
    ///
    /// ```
    /// use cast::SimpleCast as Cast;
    /// use ethers_core::types::U256;
    ///
    /// fn main() -> eyre::Result<()> {
    ///     assert_eq!(Cast::to_fix(0, 10.into())?, "10.");
    ///     assert_eq!(Cast::to_fix(1, 10.into())?, "1.0");
    ///     assert_eq!(Cast::to_fix(2, 10.into())?, "0.10");
    ///     assert_eq!(Cast::to_fix(3, 10.into())?, "0.010");
    ///
    ///     Ok(())
    /// }
    /// ```
    pub fn to_fix(decimals: u128, value: U256) -> Result<String> {
        let mut value: String = value.to_string();
        let decimals = decimals as usize;

        if decimals >= value.len() {
            // {0}.{0 * (number_of_decimals - value.len())}{value}
            Ok(format!("0.{:0>1$}", value, decimals))
        } else {
            // Insert decimal at -idx (i.e 1 => decimal idx = -1)
            value.insert(value.len() - decimals, '.');
            Ok(value)
        }
    }
    /// Decodes abi-encoded hex input or output
    ///
    /// ```
    /// use cast::SimpleCast as Cast;
    ///
    /// fn main() -> eyre::Result<()> {
    ///     // Passing `input = false` will decode the data as the output type.
    ///     // The input data types and the full function sig are ignored, i.e.
    ///     // you could also pass `balanceOf()(uint256)` and it'd still work.
    ///     let data = "0x0000000000000000000000000000000000000000000000000000000000000001";
    ///     let sig = "balanceOf(address, uint256)(uint256)";
    ///     let decoded = Cast::abi_decode(sig, data, false)?[0].to_string();
    ///     assert_eq!(decoded, "1");
    ///
    ///     // Passing `input = true` will decode the data with the input function signature.
    ///     let data = "0xf242432a0000000000000000000000008dbd1b711dc621e1404633da156fcc779e1c6f3e000000000000000000000000d9f3c9cc99548bf3b44a43e0a2d07399eb918adc000000000000000000000000000000000000000000000000000000000000002a000000000000000000000000000000000000000000000000000000000000000100000000000000000000000000000000000000000000000000000000000000a00000000000000000000000000000000000000000000000000000000000000000";
    ///     let sig = "safeTransferFrom(address, address, uint256, uint256, bytes)";
    ///     let decoded = Cast::abi_decode(sig, data, true)?;
    ///     let decoded = decoded.iter().map(ToString::to_string).collect::<Vec<_>>();
    ///     assert_eq!(
    ///         decoded,
    ///         vec!["8dbd1b711dc621e1404633da156fcc779e1c6f3e", "d9f3c9cc99548bf3b44a43e0a2d07399eb918adc", "2a", "1", ""]
    ///     );
    ///
    ///
    ///     # Ok(())
    /// }
    /// ```
    pub fn abi_decode(sig: &str, calldata: &str, input: bool) -> Result<Vec<Token>> {
        foundry_utils::abi_decode(sig, calldata, input)
    }

    /// Performs ABI encoding based off of the function signature. Does not include
    /// the function selector in the result.
    ///
    /// ```
    /// # use cast::SimpleCast as Cast;
    ///
    /// # fn main() -> eyre::Result<()> {
    ///     assert_eq!(
    ///         "0x0000000000000000000000000000000000000000000000000000000000000001",
    ///         Cast::abi_encode("f(uint a)", &["1"]).unwrap().as_str()
    ///     );
    /// #    Ok(())
    /// # }
    /// ```
    pub fn abi_encode(sig: &str, args: &[impl AsRef<str>]) -> Result<String> {
        let func = AbiParser::default().parse_function(sig.as_ref())?;
        let calldata = encode_args(&func, args)?.to_hex::<String>();
        let encoded = &calldata[8..];
        Ok(format!("0x{}", encoded))
    }

    /// Converts decimal input to hex
    ///
    /// ```
    /// use cast::SimpleCast as Cast;
    /// use ethers_core::types::U256;
    ///
    /// fn main() -> eyre::Result<()> {
    ///     assert_eq!(Cast::hex(U256::from_dec_str("424242")?), "0x67932");
    ///     assert_eq!(Cast::hex(U256::from_dec_str("1234")?), "0x4d2");
    ///     assert_eq!(Cast::hex(U256::from_dec_str("115792089237316195423570985008687907853269984665640564039457584007913129639935")?), "0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff");
    ///
    ///     Ok(())
    /// }
    /// ```
    pub fn hex(u: U256) -> String {
        format!("{:#x}", u)
    }

    /// Converts a number into uint256 hex string with 0x prefix
    ///
    /// ```
    /// use cast::SimpleCast as Cast;
    ///
    /// fn main() -> eyre::Result<()> {
    ///     assert_eq!(Cast::to_uint256("100")?, "0x0000000000000000000000000000000000000000000000000000000000000064");
    ///     assert_eq!(Cast::to_uint256("192038293923")?, "0x0000000000000000000000000000000000000000000000000000002cb65fd1a3");
    ///     assert_eq!(
    ///         Cast::to_uint256("115792089237316195423570985008687907853269984665640564039457584007913129639935")?,
    ///         "0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff"
    ///     );
    ///
    ///     Ok(())
    /// }
    /// ```
    pub fn to_uint256(value: &str) -> Result<String> {
        let num_u256 = U256::from_str_radix(value, 10)?;
        let num_hex = format!("{:x}", num_u256);
        Ok(format!("0x{}{}", "0".repeat(64 - num_hex.len()), num_hex))
    }

    /// Converts an eth amount into a specified unit
    ///
    /// ```
    /// use cast::SimpleCast as Cast;
    ///
    /// fn main() -> eyre::Result<()> {
    ///     assert_eq!(Cast::to_unit("1 wei".to_string(), "wei".to_string())?, "1");
    ///     assert_eq!(Cast::to_unit("1".to_string(), "wei".to_string())?, "1");
    ///     assert_eq!(Cast::to_unit("1ether".to_string(), "wei".to_string())?, "1000000000000000000");
    ///     assert_eq!(Cast::to_unit("100 gwei".to_string(), "gwei".to_string())?, "100");
    ///
    ///     Ok(())
    /// }
    /// ```
    pub fn to_unit(value: String, unit: String) -> Result<String> {
        let value = U256::from(LenientTokenizer::tokenize_uint(&value)?);

        Ok(match &unit[..] {
            "ether" => ethers_core::utils::format_units(value, 18)?
                .trim_end_matches(".000000000000000000")
                .to_string(),
            "gwei" | "nano" | "nanoether" => ethers_core::utils::format_units(value, 9)?
                .trim_end_matches(".000000000")
                .to_string(),
            "wei" => ethers_core::utils::format_units(value, 0)?.trim_end_matches(".0").to_string(),
            _ => return Err(eyre::eyre!("invalid unit")),
        })
    }

    /// Converts an eth amount into wei
    ///
    /// ```
    /// use cast::SimpleCast as Cast;
    ///
    /// fn main() -> eyre::Result<()> {
    ///     assert_eq!(Cast::to_wei(1.into(), "".to_string())?, "1000000000000000000");
    ///     assert_eq!(Cast::to_wei(100.into(), "gwei".to_string())?, "100000000000");
    ///     assert_eq!(Cast::to_wei(100.into(), "eth".to_string())?, "100000000000000000000");
    ///     assert_eq!(Cast::to_wei(1000.into(), "ether".to_string())?, "1000000000000000000000");
    ///
    ///     Ok(())
    /// }
    /// ```
    pub fn to_wei(value: f64, unit: String) -> Result<String> {
        let value = value.to_string();
        Ok(match &unit[..] {
            "gwei" => ethers_core::utils::parse_units(value, 9),
            "eth" | "ether" => ethers_core::utils::parse_units(value, 18),
            _ => ethers_core::utils::parse_units(value, 18),
        }?
        .to_string())
    }

    /// Converts wei into an eth amount
    ///
    /// ```
    /// use cast::SimpleCast as Cast;
    ///
    /// fn main() -> eyre::Result<()> {
    ///     assert_eq!(Cast::from_wei(1.into(), "gwei".to_string())?, "0.000000001");
    ///     assert_eq!(Cast::from_wei(12340000005u64.into(), "gwei".to_string())?, "12.340000005");
    ///     assert_eq!(Cast::from_wei(10.into(), "ether".to_string())?, "0.000000000000000010");
    ///     assert_eq!(Cast::from_wei(100.into(), "eth".to_string())?, "0.000000000000000100");
    ///     assert_eq!(Cast::from_wei(17.into(), "".to_string())?, "0.000000000000000017");
    ///
    ///     Ok(())
    /// }
    /// ```
    pub fn from_wei(value: U256, unit: String) -> Result<String> {
        Ok(match &unit[..] {
            "gwei" => ethers_core::utils::format_units(value, 9),
            "eth" | "ether" => ethers_core::utils::format_units(value, 18),
            _ => ethers_core::utils::format_units(value, 18),
        }?)
    }

    /// Converts an Ethereum address to its checksum format
    /// according to [EIP-55](https://github.com/ethereum/EIPs/blob/master/EIPS/eip-55.md)
    ///
    /// ```
    /// use cast::SimpleCast as Cast;
    /// use ethers_core::types::Address;
    /// use std::str::FromStr;
    ///
    /// # fn main() -> eyre::Result<()> {
    /// let addr = Address::from_str("0xb7e390864a90b7b923c9f9310c6f98aafe43f707")?;
    /// let addr = Cast::checksum_address(&addr)?;
    /// assert_eq!(addr, "0xB7e390864a90b7b923C9f9310C6F98aafE43F707");
    ///
    /// # Ok(())
    /// # }
    /// ```
    pub fn checksum_address(address: &Address) -> Result<String> {
        Ok(utils::to_checksum(address, None))
    }

    /// Converts hexdata into bytes32 value
    /// ```
    /// use cast::SimpleCast as Cast;
    ///
    /// # fn main() -> eyre::Result<()> {
    /// let bytes = Cast::bytes32("1234")?;
    /// assert_eq!(bytes, "0x1234000000000000000000000000000000000000000000000000000000000000");
    ///
    /// let bytes = Cast::bytes32("0x1234")?;
    /// assert_eq!(bytes, "0x1234000000000000000000000000000000000000000000000000000000000000");
    ///
    /// let err = Cast::bytes32("0x123400000000000000000000000000000000000000000000000000000000000011").unwrap_err();
    /// assert_eq!(err.to_string(), "string >32 bytes");
    ///
    /// # Ok(())
    /// # }
    pub fn bytes32(s: &str) -> Result<String> {
        let s = strip_0x(s);
        if s.len() > 64 {
            eyre::bail!("string >32 bytes");
        }

        let padded = format!("{:0<64}", s);
        // need to use the Debug implementation
        Ok(format!("{:?}", H256::from_str(&padded)?))
    }

    /// Keccak-256 hashes arbitrary data
    ///
    /// ```
    /// use cast::SimpleCast as Cast;
    ///
    /// fn main() -> eyre::Result<()> {
    ///     assert_eq!(Cast::keccak("foo")?, "0x41b1a0649752af1b28b3dc29a1556eee781e4a4c3a1f7f53f90fa834de098c4d");
    ///     assert_eq!(Cast::keccak("123abc")?, "0xb1f1c74a1ba56f07a892ea1110a39349d40f66ca01d245e704621033cb7046a4");
    ///
    ///     Ok(())
    /// }
    /// ```
    pub fn keccak(data: &str) -> Result<String> {
        let hash: String = keccak256(data.as_bytes()).to_hex();
        Ok(format!("0x{}", hash))
    }

    /// Converts ENS names to their namehash representation
    /// [Namehash reference](https://docs.ens.domains/contract-api-reference/name-processing#hashing-names)
    /// [namehash-rust reference](https://github.com/InstateDev/namehash-rust/blob/master/src/lib.rs)
    ///
    /// ```
    /// use cast::SimpleCast as Cast;
    ///
    /// fn main() -> eyre::Result<()> {
    ///     assert_eq!(Cast::namehash("")?, "0x0000000000000000000000000000000000000000000000000000000000000000");
    ///     assert_eq!(Cast::namehash("eth")?, "0x93cdeb708b7545dc668eb9280176169d1c33cfd8ed6f04690a0bcc88a93fc4ae");
    ///     assert_eq!(Cast::namehash("foo.eth")?, "0xde9b09fd7c5f901e23a3f19fecc54828e9c848539801e86591bd9801b019f84f");
    ///     assert_eq!(Cast::namehash("sub.foo.eth")?, "0x500d86f9e663479e5aaa6e99276e55fc139c597211ee47d17e1e92da16a83402");
    ///
    ///     Ok(())
    /// }
    /// ```
    pub fn namehash(ens: &str) -> Result<String> {
        let mut node = vec![0u8; 32];

        if !ens.is_empty() {
            let ens_lower = ens.to_lowercase();
            let mut labels: Vec<&str> = ens_lower.split('.').collect();
            labels.reverse();

            for label in labels {
                let mut label_hash = keccak256(label.as_bytes());
                node.append(&mut label_hash.to_vec());

                label_hash = keccak256(node.as_slice());
                node = label_hash.to_vec();
            }
        }

        let namehash: String = node.to_hex();
        Ok(format!("0x{}", namehash))
    }

    /// Performs ABI encoding to produce the hexadecimal calldata with the given arguments.
    ///
    /// ```
    /// # use cast::SimpleCast as Cast;
    ///
    /// # fn main() -> eyre::Result<()> {
    ///     assert_eq!(
    ///         "0xb3de648b0000000000000000000000000000000000000000000000000000000000000001",
    ///         Cast::calldata("f(uint a)", &["1"]).unwrap().as_str()
    ///     );
    /// #    Ok(())
    /// # }
    /// ```
    pub fn calldata(sig: impl AsRef<str>, args: &[impl AsRef<str>]) -> Result<String> {
        let func = AbiParser::default().parse_function(sig.as_ref())?;
        let calldata = encode_args(&func, args)?;
        Ok(format!("0x{}", calldata.to_hex::<String>()))
    }

    /// Fetches source code of verified contracts from etherscan.
    ///
    /// ```
    /// # use cast::SimpleCast as Cast;
    /// # use ethers_core::types::Chain;
    ///
    /// # async fn foo() -> eyre::Result<()> {
    ///     assert_eq!(
    ///             "/*
    ///             - Bytecode Verification performed was compared on second iteration -
    ///             This file is part of the DAO.....",
    ///         Cast::etherscan_source(Chain::Mainnet, "0xBB9bc244D798123fDe783fCc1C72d3Bb8C189413".to_string(), "<etherscan_api_key>".to_string()).await.unwrap().as_str()
    ///     );
    /// #    Ok(())
    /// # }
    /// ```
    pub async fn etherscan_source(
        chain: Chain,
        contract_address: String,
        etherscan_api_key: String,
    ) -> Result<String> {
        let client = Client::new(chain, etherscan_api_key)?;
        let meta = client.contract_source_code(contract_address.parse()?).await?;
        let code = meta.source_code();

        if code.is_empty() {
            return Err(eyre::eyre!("unverified contract"))
        }

        Ok(code)
    }
}

fn strip_0x(s: &str) -> &str {
    s.strip_prefix("0x").unwrap_or(s)
}

#[cfg(test)]
mod tests {
    use super::SimpleCast as Cast;

    #[test]
    fn calldata_uint() {
        assert_eq!(
            "0xb3de648b0000000000000000000000000000000000000000000000000000000000000001",
            Cast::calldata("f(uint a)", &["1"]).unwrap().as_str()
        );
    }

    #[test]
    fn calldata_bool() {
        assert_eq!(
            "0x6fae94120000000000000000000000000000000000000000000000000000000000000000",
            Cast::calldata("bar(bool)", &["false"]).unwrap().as_str()
        );
    }
}