Merge pull request #259 from CHEF-SAVY/feat/grace-period-config

feat: grace period config for late renewals

Author: jhayniffy

backend/src/policy/renewal.constants.ts

@@ -65,6 +65,12 @@ export const RENEWAL_OPEN_LEDGERS_BEFORE_EXPIRY = 120_960;
  *
  * Default: 17,280 ledgers ≈ 1 day (17,280 × 5 s = 86,400 s).
  * The last valid renewal ledger is endLedger + RENEWAL_GRACE_LEDGERS_AFTER_EXPIRY - 1.
+ *
+ * NOTE: This constant mirrors DEFAULT_GRACE_PERIOD_LEDGERS in the Soroban contract
+ * (contracts/niffyinsure/src/ledger.rs). The live value is admin-configurable via
+ * set_grace_period_ledgers(); fetch it from get_grace_period_ledgers() for
+ * authoritative checks. This constant is used only as a UI fallback when the
+ * on-chain value has not yet been fetched.
  */
 export const RENEWAL_GRACE_LEDGERS_AFTER_EXPIRY = 17_280;
 

contracts/niffyinsure/src/ledger.rs

@@ -92,9 +92,20 @@ pub const MIN_VOTING_DURATION_LEDGERS: u32 = LEDGERS_PER_DAY;
 pub const MAX_VOTING_DURATION_LEDGERS: u32 = 8 * LEDGERS_PER_WEEK;
 
 /// Renewal window: holder may renew starting this many ledgers before expiry.
-/// Renewal is accepted while `end - RENEWAL_WINDOW_LEDGERS <= now < end`.
+/// Renewal is accepted while `end - RENEWAL_WINDOW_LEDGERS <= now < end + grace`.
 pub const RENEWAL_WINDOW_LEDGERS: u32 = 3 * LEDGERS_PER_DAY; // 51_840
 
+/// Default grace period added after nominal expiry for late renewals.
+/// Renewal is accepted while `now < end + grace_period_ledgers`.
+/// Default: 17_280 ledgers ≈ 1 day.
+pub const DEFAULT_GRACE_PERIOD_LEDGERS: u32 = LEDGERS_PER_DAY; // 17_280
+
+/// Minimum admin-settable grace period (1 hour).
+pub const MIN_GRACE_PERIOD_LEDGERS: u32 = LEDGERS_PER_HOUR; // 720
+
+/// Maximum admin-settable grace period (7 days).
+pub const MAX_GRACE_PERIOD_LEDGERS: u32 = 7 * LEDGERS_PER_DAY; // 120_960
+
 /// Rate-limit window: minimum ledgers between successive claim filings by the
 /// same policyholder.  Prevents claim spam.
 pub const RATE_LIMIT_WINDOW_LEDGERS: u32 = LEDGERS_PER_DAY; // 17_280
@@ -155,6 +166,26 @@ pub fn is_in_renewal_window(now: u32, end: u32, window: u32) -> bool {
     is_within_window(now, renewal_start, end)
 }
 
+/// Returns `true` if `now` is within the extended renewal window that includes
+/// the grace period: `[end - window, end + grace)`.
+///
+/// - `now < end`              → standard renewal window (no gap)
+/// - `end <= now < end+grace` → grace period (late renewal, no coverage gap)
+/// - `now >= end + grace`     → lapsed; renewal rejected
+#[inline]
+pub fn is_in_renewal_window_with_grace(now: u32, end: u32, window: u32, grace: u32) -> bool {
+    let renewal_start = end.saturating_sub(window);
+    let grace_end = end.saturating_add(grace);
+    now >= renewal_start && now < grace_end
+}
+
+/// Validates admin-supplied grace period before it is written to instance storage.
+/// Returns `true` if valid.
+#[inline]
+pub fn is_valid_grace_period_ledgers(v: u32) -> bool {
+    (MIN_GRACE_PERIOD_LEDGERS..=MAX_GRACE_PERIOD_LEDGERS).contains(&v)
+}
+
 /// Returns `true` if the voting deadline has not yet passed.
 ///
 /// Votes are accepted while `now < filed_at + vote_window`.

contracts/niffyinsure/src/lib.rs

@@ -26,6 +26,7 @@ use soroban_sdk::{contract, contractevent, contractimpl, panic_with_error, Addre
 #[contract]
 pub struct NiffyInsure;
 pub use admin::AdminError;
+pub use policy::RenewalError;
 
 #[derive(Copy, Clone, Debug, Eq, PartialEq, PartialOrd, Ord)]
 #[soroban_sdk::contracterror]
@@ -224,6 +225,43 @@ impl NiffyInsure {
         Ok(())
     }
 
+    // ── Grace period ──────────────────────────────────────────────────────────
+
+    /// Admin-only: set the grace period (in ledgers) after nominal expiry during
+    /// which late renewals are still accepted. Emits GracePeriodUpdated.
+    pub fn set_grace_period_ledgers(env: Env, ledgers: u32) -> Result<(), policy::RenewalError> {
+        storage::bump_instance(&env);
+        policy::set_grace_period_ledgers(&env, ledgers)
+    }
+
+    pub fn get_grace_period_ledgers(env: Env) -> u32 {
+        policy::get_grace_period_ledgers(&env)
+    }
+
+    // ── Renewal ───────────────────────────────────────────────────────────────
+
+    /// Renew an existing active policy within the standard or grace window.
+    pub fn renew_policy(
+        env: Env,
+        holder: Address,
+        policy_id: u32,
+        age_band: types::AgeBand,
+        coverage_type: types::CoverageTier,
+        safety_score: u32,
+        base_amount: i128,
+    ) -> Result<types::Policy, policy::RenewalError> {
+        storage::bump_instance(&env);
+        policy::renew_policy(
+            &env,
+            holder,
+            policy_id,
+            age_band,
+            coverage_type,
+            safety_score,
+            base_amount,
+        )
+    }
+
     pub fn process_claim(env: Env, claim_id: u64) -> Result<(), validate::Error> {
         let admin = storage::get_admin(&env);
         admin.require_auth();
@@ -693,6 +731,19 @@ impl NiffyInsure {
         storage::remove_voter(&env, &holder);
     }
 
+    /// Test-only: advance a seeded policy's end_ledger to simulate a renewal
+    /// without going through token transfer. Mirrors what renew_policy does
+    /// to the policy record after premium collection.
+    pub fn test_renew_policy(env: Env, holder: Address, policy_id: u32) {
+        let mut policy = storage::get_policy(&env, &holder, policy_id)
+            .expect("policy not found");
+        let new_start = policy.end_ledger.saturating_add(1);
+        let new_end = new_start + ledger::POLICY_DURATION_LEDGERS;
+        policy.start_ledger = new_start;
+        policy.end_ledger = new_end;
+        storage::set_policy(&env, &holder, policy_id, &policy);
+    }
+
     pub fn admin_set_open_claim_count(
         env: Env,
         admin: Address,

contracts/niffyinsure/src/policy.rs

@@ -4,7 +4,6 @@ use crate::{
     validate::{self, Error},
 };
 use soroban_sdk::{contracterror, contractevent, contracttype, Address, Env, String};
-
 pub use ledger::QUOTE_TTL_LEDGERS;
 
 /// Current event schema version.
@@ -368,3 +367,143 @@ pub fn set_beneficiary(
 
     Ok(())
 }
+
+// ── Grace period admin setter ─────────────────────────────────────────────────
+
+#[contractevent(topics = ["niffyinsure", "grace_period_updated"])]
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub struct GracePeriodUpdated {
+    pub old_ledgers: u32,
+    pub new_ledgers: u32,
+}
+
+pub fn set_grace_period_ledgers(env: &Env, ledgers: u32) -> Result<(), RenewalError> {
+    crate::admin::require_admin(env);
+    if !ledger::is_valid_grace_period_ledgers(ledgers) {
+        return Err(RenewalError::GracePeriodOutOfBounds);
+    }
+    let old = storage::get_grace_period_ledgers(env);
+    storage::set_grace_period_ledgers(env, ledgers);
+    GracePeriodUpdated {
+        old_ledgers: old,
+        new_ledgers: ledgers,
+    }
+    .publish(env);
+    Ok(())
+}
+
+pub fn get_grace_period_ledgers(env: &Env) -> u32 {
+    storage::get_grace_period_ledgers(env)
+}
+
+// ── renew_policy ──────────────────────────────────────────────────────────────
+
+#[contracterror]
+#[derive(Copy, Clone, Debug, Eq, PartialEq, PartialOrd, Ord)]
+#[repr(u32)]
+pub enum RenewalError {
+    /// Policy not found.
+    NotFound = 200,
+    /// Policy is not active.
+    Inactive = 201,
+    /// Current ledger is outside the renewal + grace window.
+    WindowClosed = 202,
+    /// An open claim is blocking renewal.
+    OpenClaimBlocking = 203,
+    /// Premium computation failed.
+    PremiumError = 204,
+    /// Ledger arithmetic overflow.
+    LedgerOverflow = 205,
+    /// Grace period value outside allowed [min, max] range.
+    GracePeriodOutOfBounds = 206,
+}
+
+/// Renew an existing active policy.
+///
+/// Eligible window: `[end - RENEWAL_WINDOW_LEDGERS, end + grace_period_ledgers)`.
+/// Renewal within the grace period succeeds with no coverage gap — the new
+/// term starts at `old_end_ledger + 1`.
+/// Blocked when an open claim exists on the policy (mirrors the open-claim rule).
+pub fn renew_policy(
+    env: &Env,
+    holder: Address,
+    policy_id: u32,
+    age_band: crate::types::AgeBand,
+    coverage_type: CoverageTier,
+    safety_score: u32,
+    base_amount: i128,
+) -> Result<Policy, RenewalError> {
+    storage::assert_bind_not_paused(env);
+    holder.require_auth();
+
+    let mut policy = storage::get_policy(env, &holder, policy_id)
+        .ok_or(RenewalError::NotFound)?;
+
+    if !policy.is_active {
+        return Err(RenewalError::Inactive);
+    }
+
+    // Open-claim guard (mirrors the rule enforced in the backend).
+    if storage::has_open_claim(env, &holder, policy_id) {
+        return Err(RenewalError::OpenClaimBlocking);
+    }
+
+    let now = env.ledger().sequence();
+    let grace = storage::get_grace_period_ledgers(env);
+
+    if !ledger::is_in_renewal_window_with_grace(
+        now,
+        policy.end_ledger,
+        ledger::RENEWAL_WINDOW_LEDGERS,
+        grace,
+    ) {
+        return Err(RenewalError::WindowClosed);
+    }
+
+    // Recalculate premium with the same deterministic formula.
+    let input = RiskInput {
+        region: policy.region.clone(),
+        age_band,
+        coverage: coverage_type,
+        safety_score,
+    };
+    let quote = crate::calculator::compute_quote(
+        env,
+        &input,
+        base_amount,
+        false,
+        ledger::QUOTE_TTL_LEDGERS,
+    )
+    .map_err(|_| RenewalError::PremiumError)?;
+
+    let premium_amount = quote.total_premium;
+    if premium_amount <= 0 {
+        return Err(RenewalError::PremiumError);
+    }
+
+    // Collect premium before any state mutation.
+    token::collect_premium(env, &holder, &policy.asset, premium_amount);
+
+    // New term starts immediately after old end — no gap, no overlap.
+    let new_start = policy.end_ledger.saturating_add(1);
+    let new_end = new_start
+        .checked_add(ledger::POLICY_DURATION_LEDGERS)
+        .ok_or(RenewalError::LedgerOverflow)?;
+
+    policy.start_ledger = new_start;
+    policy.end_ledger = new_end;
+    policy.premium = premium_amount;
+
+    storage::set_policy(env, &holder, policy_id, &policy);
+
+    PolicyRenewed {
+        version: POLICY_EVENT_VERSION,
+        policy_id,
+        holder: holder.clone(),
+        premium: premium_amount,
+        new_end_ledger: new_end,
+    }
+    .publish(env);
+
+    Ok(policy)
+}

contracts/niffyinsure/src/storage.rs

@@ -54,6 +54,8 @@ pub enum DataKey {
     AppealVote(u64, Address),
     /// Configurable voting window in ledgers (set by admin via set_voting_duration_ledgers).
     VoteDurLedgers,
+    /// Configurable grace period in ledgers after nominal expiry for late renewals.
+    GracePeriodLedgers,
 }
 
 // ── Instance bump ─────────────────────────────────────────────────────────────
@@ -149,6 +151,23 @@ pub fn get_voting_duration_ledgers(env: &Env) -> u32 {
         .unwrap_or(ledger::VOTE_WINDOW_LEDGERS)
 }
 
+// ── Grace period (instance) ───────────────────────────────────────────────────
+
+pub fn set_grace_period_ledgers(env: &Env, ledgers: u32) {
+    env.storage()
+        .instance()
+        .set(&DataKey::GracePeriodLedgers, &ledgers);
+}
+
+/// Grace period added after nominal expiry for late renewals.
+/// Defaults to [`ledger::DEFAULT_GRACE_PERIOD_LEDGERS`] when unset.
+pub fn get_grace_period_ledgers(env: &Env) -> u32 {
+    env.storage()
+        .instance()
+        .get(&DataKey::GracePeriodLedgers)
+        .unwrap_or(ledger::DEFAULT_GRACE_PERIOD_LEDGERS)
+}
+
 // ── External calculator address ───────────────────────────────────────────────
 
 pub fn set_calc_address(env: &Env, addr: &Address) {

contracts/niffyinsure/src/types.rs

@@ -34,8 +34,9 @@ pub const SAFETY_SCORE_MAX: u32 = 100;
 // Conversion: 1 ledger ≈ 5 s on Stellar Mainnet (Protocol 20+).
 // See: https://developers.stellar.org/docs/learn/fundamentals/stellar-consensus-protocol
 pub use crate::ledger::{
-    APPEAL_OPEN_WINDOW_LEDGERS, APPEAL_VOTE_WINDOW_LEDGERS, LEDGERS_PER_DAY, LEDGERS_PER_HOUR,
-    LEDGERS_PER_MIN, LEDGERS_PER_WEEK, MAX_APPEALS_PER_CLAIM, MAX_VOTING_DURATION_LEDGERS,
+    APPEAL_OPEN_WINDOW_LEDGERS, APPEAL_VOTE_WINDOW_LEDGERS, DEFAULT_GRACE_PERIOD_LEDGERS,
+    LEDGERS_PER_DAY, LEDGERS_PER_HOUR, LEDGERS_PER_MIN, LEDGERS_PER_WEEK, MAX_APPEALS_PER_CLAIM,
+    MAX_GRACE_PERIOD_LEDGERS, MAX_VOTING_DURATION_LEDGERS, MIN_GRACE_PERIOD_LEDGERS,
     MIN_VOTING_DURATION_LEDGERS, POLICY_DURATION_LEDGERS, QUOTE_TTL_LEDGERS,
     RATE_LIMIT_WINDOW_LEDGERS, RENEWAL_WINDOW_LEDGERS, SECS_PER_LEDGER, VOTE_WINDOW_LEDGERS,
 };