sim-cli: source simulation file from data directory

Adds a simln data-dir cli param, but maintains the default value to cwd
Sources the simulation file from this data dir
Prompts the user to select a simulatin file if the default/configured
file is not found

Author: okjodom

.gitignore

@@ -5,4 +5,4 @@ sim.json
 package-lock.json
 activity-generator/releases/*
 .DS_Store
-*simulation_*.csv
+/results

Cargo.lock

@@ -11,6 +11,7 @@ Instantly simulate real-world Lightning network activity
 [dependencies]
 anyhow = { version = "1.0.69", features = ["backtrace"] }
 clap = { version = "4.1.6", features = ["derive", "env", "std", "help", "usage", "error-context", "suggestions"], default-features = false }
+dialoguer = "0.11.0"
 log = "0.4.20"
 serde = "1.0.183"
 serde_json = "1.0.104"

sim-cli/Cargo.toml

@@ -10,10 +10,16 @@ use clap::Parser;
 use log::LevelFilter;
 use sim_lib::{
     cln::ClnNode, lnd::LndNode, ActivityDefinition, LightningError, LightningNode, NodeConnection,
-    NodeId, SimParams, Simulation,
+    NodeId, SimParams, Simulation, WriteResults,
 };
 use simple_logger::SimpleLogger;
 
+/// The default directory where the simulation files are stored and where the results will be written to.
+pub const DEFAULT_DATA_DIR: &str = ".";
+
+/// The default simulation file to be used by the simulator.
+pub const DEFAULT_SIM_FILE: &str = "sim.json";
+
 /// The default expected payment amount for the simulation, around ~$10 at the time of writing.
 pub const EXPECTED_PAYMENT_AMOUNT: u64 = 3_800_000;
 
@@ -42,8 +48,12 @@ fn deserialize_f64_greater_than_zero(x: String) -> Result<f64, String> {
 #[derive(Parser)]
 #[command(version, about)]
 struct Cli {
+    /// Path to a directory containing simulation files, and where simulation results will be stored
+    #[clap(long, short, default_value = DEFAULT_DATA_DIR)]
+    data_dir: PathBuf,
     /// Path to the simulation file to be used by the simulator
-    #[clap(index = 1)]
+    /// This can either be an absolute path, or relative path with respect to data_dir
+    #[clap(long, short, default_value = DEFAULT_SIM_FILE)]
     sim_file: PathBuf,
     /// Total time the simulator will be running
     #[clap(long, short)]
@@ -77,8 +87,9 @@ async fn main() -> anyhow::Result<()> {
         .init()
         .unwrap();
 
+    let sim_path = read_sim_path(cli.data_dir.clone(), cli.sim_file).await?;
     let SimParams { nodes, activity } =
-        serde_json::from_str(&std::fs::read_to_string(cli.sim_file)?)
+        serde_json::from_str(&std::fs::read_to_string(sim_path)?)
             .map_err(|e| anyhow!("Could not deserialize node connection data or activity description from simulation file (line {}, col {}).", e.line(), e.column()))?;
 
     let mut clients: HashMap<PublicKey, Arc<Mutex<dyn LightningNode + Send>>> = HashMap::new();
@@ -179,14 +190,22 @@ async fn main() -> anyhow::Result<()> {
         });
     }
 
+    let write_results = if !cli.no_results {
+        Some(WriteResults {
+            results_dir: mkdir(cli.data_dir.join("results")).await?,
+            batch_size: cli.print_batch_size,
+        })
+    } else {
+        None
+    };
+
     let sim = Simulation::new(
         clients,
         validated_activities,
         cli.total_time,
-        cli.print_batch_size,
         cli.expected_pmt_amt,
         cli.capacity_multiplier,
-        cli.no_results,
+        write_results,
     );
     let sim2 = sim.clone();
 
@@ -199,3 +218,55 @@ async fn main() -> anyhow::Result<()> {
 
     Ok(())
 }
+
+async fn read_sim_path(data_dir: PathBuf, sim_file: PathBuf) -> anyhow::Result<PathBuf> {
+    let sim_path = if sim_file.is_relative() {
+        data_dir.join(sim_file)
+    } else {
+        sim_file
+    };
+
+    if sim_path.exists() {
+        Ok(sim_path)
+    } else {
+        log::info!("Simulation file '{}' does not exist.", sim_path.display());
+        select_sim_file(data_dir).await
+    }
+}
+
+async fn select_sim_file(data_dir: PathBuf) -> anyhow::Result<PathBuf> {
+    let sim_files = std::fs::read_dir(data_dir.clone())?
+        .filter_map(|f| {
+            f.ok().and_then(|f| {
+                if f.path().extension()?.to_str()? == "json" {
+                    f.file_name().into_string().ok()
+                } else {
+                    None
+                }
+            })
+        })
+        .collect::<Vec<_>>();
+
+    if sim_files.is_empty() {
+        anyhow::bail!(
+            "no simulation files found in {}",
+            data_dir.canonicalize()?.display()
+        );
+    }
+
+    let selection = dialoguer::Select::new()
+        .with_prompt(format!(
+            "Select a simulation file. Found these in {}",
+            data_dir.canonicalize()?.display()
+        ))
+        .items(&sim_files)
+        .default(0)
+        .interact()?;
+
+    Ok(data_dir.join(sim_files[selection].clone()))
+}
+
+async fn mkdir(dir: PathBuf) -> anyhow::Result<PathBuf> {
+    tokio::fs::create_dir_all(&dir).await?;
+    Ok(dir)
+}