Introduce CLI command (#5)

This is first step towards CLI command of state reconstruction tool.

Cargo.toml

@@ -6,6 +6,7 @@ edition = "2021"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+clap = { version = "4.4.0", features = ["string"] }
 ethers = "2.0.10"
 eyre = "0.6.8"
 serde_json = "1.0.107"

src/main.rs

@@ -0,0 +1,58 @@
+use clap::{arg, value_parser, Command};
+
+fn cli() -> Command {
+    Command::new("state-reconstruct")
+        .about("zkSync state reconstruction tool")
+        .subcommand_required(true)
+        .arg_required_else_help(false)
+        .subcommand(
+            Command::new("reconstruct")
+                .about("Reconstruct L2 state")
+                .subcommand_required(true)
+                .subcommand(
+                    Command::new("l1")
+                        .about("Read state from Ethereum L1")
+                        .arg(
+                            arg!(--"start-block" <START_BLOCK>)
+                                .help("Ethereum block number to start state import from")
+                                .default_value(state_reconstruct::GENESIS_BLOCK.to_string())
+                                .value_parser(value_parser!(u64)),
+                        )
+                        .arg(
+                            arg!(--"block-step" <BLOCK_STEP>)
+                                .help("Number of blocks to filter & process in one step")
+                                .default_value(state_reconstruct::BLOCK_STEP.to_string())
+                                .value_parser(value_parser!(u64)),
+                        ),
+                )
+                .subcommand(
+                    Command::new("file")
+                        .about("Read state from file")
+                        .arg(arg!(<FILE> "File to import state from"))
+                        .arg_required_else_help(true),
+                ),
+        )
+}
+
+fn main() {
+    let matches = cli().get_matches();
+
+    match matches.subcommand() {
+        Some(("reconstruct", sub_matches)) => {
+            match sub_matches.subcommand() {
+                Some(("l1", args)) => {
+                    let start_block = args.get_one::<u64>("start-block").expect("required");
+                    let block_step = args.get_one::<u64>("block-step").expect("required");
+                    println!("reconstruct from L1, starting from block number {}, processing {} blocks at a time", start_block, block_step);
+                    // TODO(tuommaki): Implement block fetch logic.
+                }
+                Some(("file", args)) => {
+                    let input_file = args.get_one::<String>("FILE").expect("required");
+                    println!("reconstruct from file (path: \"{}\")", input_file);
+                }
+                _ => unreachable!(),
+            }
+        }
+        _ => unreachable!(),
+    }
+}