chore: adding CLI interface

Cargo.toml

@@ -14,6 +14,7 @@ license-file = "LICENSE"
 
 [workspace.dependencies]
 pretty_assertions = "1.2.1"
+clap = { version = "4.5.4", features = ["cargo", "derive"] }
 
 [workspace.lints.rust]
 warnings = "deny"

crates/committer_cli/Cargo.toml

@@ -11,3 +11,6 @@ workspace = true
 
 [dev-dependencies]
 pretty_assertions.workspace = true
+
+[dependencies]
+clap.workspace = true

crates/committer_cli/src/main.rs

@@ -1,20 +1,65 @@
-use std::env;
+use clap::{Args, Parser, Subcommand};
 use std::path::Path;
 
+/// Committer CLI.
+#[derive(Debug, Parser)]
+#[clap(name = "committer-cli", version)]
+pub struct CommitterCliArgs {
+    #[clap(flatten)]
+    global_opts: GlobalOpts,
+
+    #[clap(subcommand)]
+    command: Command,
+}
+
+#[derive(Debug, Subcommand)]
+enum Command {
+    /// Given previous state tree skeleton and a state diff, computes the new commitment.
+    Commit {
+        /// File path to input.
+        #[clap(long, short = 'i', default_value = "stdin")]
+        input_path: String,
+
+        /// File path to output.
+        #[clap(long, short = 'o', default_value = "stdout")]
+        output_path: String,
+
+        /// The version of the class hash, as a string (before conversion to raw bytes).
+        #[clap(long)]
+        class_hash_version: String,
+
+        /// The version of the contract state hash, as a string (before conversion to raw bytes).
+        #[clap(long)]
+        contract_state_hash_version: String,
+    },
+}
+
+#[derive(Debug, Args)]
+struct GlobalOpts {}
+
 /// Main entry point of the committer CLI.
 fn main() {
-    // Open the input file.
-    let args: Vec<String> = env::args().collect();
-    let input_file_name = Path::new(&args[1]);
-    let output_file_name = Path::new(&args[2]);
-    assert!(
-        input_file_name.is_absolute() && output_file_name.is_absolute(),
-        "Given paths must be absolute"
-    );
-
-    // Business logic to be implemented here.
-    let output = std::fs::read(input_file_name).unwrap();
-
-    // Output to file.
-    std::fs::write(output_file_name, output).expect("Failed to write output");
+    let args = CommitterCliArgs::parse();
+
+    match args.command {
+        Command::Commit {
+            input_path,
+            output_path,
+            class_hash_version: _,
+            contract_state_hash_version: _,
+        } => {
+            let input_file_name = Path::new(&input_path);
+            let output_file_name = Path::new(&output_path);
+            assert!(
+                input_file_name.is_absolute() && output_file_name.is_absolute(),
+                "Given paths must be absolute."
+            );
+
+            // Business logic to be implemented here.
+            let output = std::fs::read(input_file_name).unwrap();
+
+            // Output to file.
+            std::fs::write(output_file_name, output).expect("Failed to write output");
+        }
+    }
 }