Make delay time in fake wallet configurable (#445)

crates/cdk-mintd/Cargo.toml

@@ -36,6 +36,7 @@ home = "0.5.5"
 url = "2.3"
 utoipa = { version = "4", optional = true }
 utoipa-swagger-ui = { version = "4", features = ["axum"], optional = true }
+rand = "0.8.5"
 
 [features]
 swagger = ["cdk-axum/swagger", "dep:utoipa", "dep:utoipa-swagger-ui"]

crates/cdk-mintd/src/config.rs

@@ -104,6 +104,8 @@ pub struct FakeWallet {
     pub supported_units: Vec<CurrencyUnit>,
     pub fee_percent: f32,
     pub reserve_fee_min: Amount,
+    pub min_delay_time: u64,
+    pub max_delay_time: u64,
 }
 
 impl Default for FakeWallet {
@@ -112,6 +114,8 @@ impl Default for FakeWallet {
             supported_units: vec![CurrencyUnit::Sat],
             fee_percent: 0.02,
             reserve_fee_min: 2.into(),
+            min_delay_time: 1,
+            max_delay_time: 3,
         }
     }
 }

crates/cdk-mintd/src/setup.rs

@@ -5,6 +5,7 @@ use std::{
 
 use anyhow::{anyhow, bail};
 use axum::{async_trait, Router};
+use rand::Rng;
 
 use cdk::{cdk_lightning::MintLightning, mint::FeeReserve, mint_url::MintUrl, nuts::CurrencyUnit};
 use tokio::sync::Mutex;
@@ -217,11 +218,15 @@ impl LnBackendSetup for config::FakeWallet {
             percent_fee_reserve: self.fee_percent,
         };
 
+        // calculate random delay time
+        let mut rng = rand::thread_rng();
+        let delay_time = rng.gen_range(self.min_delay_time..=self.max_delay_time);
+
         let fake_wallet = cdk_fake_wallet::FakeWallet::new(
             fee_reserve,
             HashMap::default(),
             HashSet::default(),
-            3,
+            delay_time,
         );
 
         Ok(fake_wallet)