You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: main.rs
    path of file: ./repos/risc0/bonsai/examples/governance/relay/src
    
    the code of the file until where you have to start completion: // Copyright 2024 RISC Zero, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

use std::io::Write;

use anyhow::Context;
use bonsai_ethereum_relay::{tokenize_snark_receipt, EthersClientConfig, Relayer};
use bonsai_ethereum_relay_cli::{resolve_guest_entry, resolve_image_output, Output};
use bonsai_sdk::alpha_async::{get_client_from_parts, upload_img};
use clap::{Args, Parser, Subcommand};
use ethers::{
    abi::{Hash, Token, Tokenizable},
    types::Address,
};
use methods::GUEST_LIST;
use risc0_zkvm::sha::Digest;

/// Index 0 private key generated by default in Anvil.
const ANVIL_DEFAULT_KEY: &'static str =
    "ac0974bec39a17e36ba4a6b4d238ff944bacb478cbed5efcae784d7bf4f2ff80";

/// Interval between connection attempts in case of connection loss.
const CONNECTION_RETRY_INTERVAL: std::time::Duration = std::time::Duration::from_secs(5);

/// Number of connection attempts.
const CONNECTION_RETRY_ATTEMPTS: u64 = 60;

#[derive(Subcommand)]
enum Command {
    /// Runs the RISC-V ELF binary.
    Query {
        /// The name of the guest binary
        guest_binary: String,

        /// The input to provide to the guest binary
        input: Option<String>,
    },
    /// Upload the RISC-V ELF binary to Bonsai.
    Upload {
        /// The name of the guest binary
        /// If not provided, all defined guests will be uploaded.
        guest_binary: Option<String>,
    },
    /// Upload the RISC-V ELF binary to Bonsai.
    Run {
        /// Bonsai Relay contract address on Ethereum
        #[arg(long, env)]
        relay_address: Address,

        /// Ethereum Node endpoint.
        #[arg(long, env, default_value = "ws://localhost:8545")]
        eth_node: String,

        /// Ethereum chain ID
        #[arg(long, default_value_t = 31337)]
        eth_chain_id: u64,

        /// Wallet Key Identifier.
        /// Can be a private key as a hex string, or an AWS KMS key identifier.
        /// Defaults to the first private key of a deafult Anvil instance.
        #[arg(
            short,
            long,
            env,
  
    
async fn main() -> anyhow::Result<()> {
    let args = App::parse();
    let dev_mode = args.global_opts.risc0_dev_mode;

    match args.command {
        Command::Query {
            guest_binary,
            input,
        } => {
            // Search list for requested binary name
            let guest_entry = resolve_guest_entry(GUEST_LIST, &guest_binary)
                .context("failed to resolve guest entry")?;

            // Execute or return image id
            let output_tokens = match &input {
                // Input provided. Return the Ethereum ABI encoded journal and
                Some(input) => {
                    let output = resolve_image_output(input, &guest_entry, dev_mode)
                        .await
                        .context("failed to resolve image output")?;
                    match (dev_mode, output) {
                        (true, Output::Execution { journal }) => {
                            vec![Token::Bytes(journal)]
                        }
                        (false, Output::Bonsai { snark_receipt }) => {
                            vec![
                                Token::Bytes(snark_receipt.journal),
                                Token::FixedBytes(snark_receipt.post_state_digest),
                                Token::Bytes(ethers::abi::encode(&[tokenize_snark_receipt(
                                    &snark_receipt.snark,
                                )?])),
                            ]
                        }
                        _ => {
                            anyhow::bail!("invalid dev mode and output combination: {:?}", dev_mode)
                        }
                    }
                }
                // No input. Return the Ethereum ABI encoded bytes32 image ID.
                None => vec![
                    Hash::from(bytemuck::cast::<_, [u8; 32]>(guest_entry.image_id)).into_token(),
                ],
            };

            let output = hex::encode(ethers::abi::encode(&output_tokens));
            print!("{output}");
            std::io::stdout()
                .flush()
                .context("failed to flush stdout buffer")?;
        }
        Command::Upload { guest_binary } => {
            let image_ids = upload_images(
                guest_binary,
                &args.global_opts.bonsai_api_url,
                &args.global_opts.bonsai_api_key,
            )
            .await?;

            let output = hex::encode(ethers::abi::encode(&[Token::Array(
                image_ids
                    .into_iter()
                    .map(|image_id| {
                        Hash::from(bytemuck::cast::<_, [u8; 32]>(image_id)).into_token()
                    })
                    .collect(),
            )]));
            print!("{output}");
            std::io::stdout()
                .flush()
                .context("failed to flush stdout buffer")?;
        }
        Command::Run {
            relay_address,
            eth_node,
            eth_chain_id,
            private_key,
            connection_retry_attempts,
            connection_retry_interval,
        } => {
            let relayer = Relayer {
                rest_api: true,
                dev_mode: dev_mode,
                rest_api_port: "8080".to_string(),
                bonsai_api_url: args.global_opts.bonsai_api_url.clone(),
                bonsai_api_key: args.global_opts.bonsai_api_key.clone(),
                relay_contract_address: relay_address,
            };
            let client_config = EthersClientConfig::new(
                eth_node,
                eth_chain_id,
                private_key.try_into()?,
                connection_retry_attempts,
                connection_retry_interval.into(),
            );
            let server_handle = tokio::spawn(relayer.run(client_config));

            // HACK: Wait 1 second to give local Bonsai a chance to start.
            std::thread::sleep(std::time::Duration::from_secs(1));

            // Upload all locally defined images.
            upload_images(
                None,
                &args.global_opts.bonsai_api_url,
                &args.global_opts.bonsai_api_key,
            )
            .await?;

            // Wait for the server to exit.
            let _ = server_handle.await;
        }
    }
    Ok(())
}