feat: add 'burn_status' view (#51)

contract/src/burn/api.rs

@@ -1,9 +1,9 @@
 use claim_model::{
     api::BurnApi,
     event::{emit, BurnData, EventKind},
-    TokensAmount, UnixTimestamp,
+    BurnStatus, TokensAmount, UnixTimestamp,
 };
-use near_sdk::{json_types::U128, near_bindgen, require, PromiseOrValue};
+use near_sdk::{env::panic_str, json_types::U128, near_bindgen, require, AccountId, PromiseOrValue};
 
 use crate::{
     common::{now_seconds, UnixTimestampExtension},
@@ -38,6 +38,27 @@ impl BurnApi for Contract {
             PromiseOrValue::Value(U128(0))
         }
     }
+
+    fn get_burn_status(&self, account_id: AccountId) -> BurnStatus {
+        let now = now_seconds();
+        let account = self
+            .accounts
+            .get(&account_id)
+            .unwrap_or_else(|| panic_str(format!("Account {account_id} not found").as_str()));
+        let min_claimable_ts: Option<UnixTimestamp> = account
+            .accruals
+            .iter()
+            .map(|(timestamp, _)| timestamp)
+            .filter(|timestamp| timestamp.is_within_period(now, self.burn_period))
+            .min()
+            .cloned();
+
+        BurnStatus {
+            min_claimable_ts,
+            claim_period_refreshed_at: account.claim_period_refreshed_at,
+            burn_period: self.burn_period,
+        }
+    }
 }
 
 impl Contract {

model/src/api.rs

@@ -1,11 +1,10 @@
 #[cfg(feature = "release-api")]
 use near_sdk::AccountId;
 use near_sdk::{json_types::U128, PromiseOrValue};
-#[cfg(feature = "integration-api")]
-use nitka::AccountId;
+// #[cfg(feature = "integration-api")]
 use nitka_proc::make_integration_version;
 
-use crate::{ClaimAvailabilityView, ClaimResultView, Duration};
+use crate::{BurnStatus, ClaimAvailabilityView, ClaimResultView, Duration};
 
 #[cfg(feature = "integration-test")]
 pub struct ClaimContract<'a> {
@@ -138,6 +137,8 @@ pub trait BurnApi {
     ///
     /// Panics if another service call is running.
     fn burn(&mut self) -> PromiseOrValue<U128>;
+
+    fn get_burn_status(&self, account_id: AccountId) -> BurnStatus;
 }
 
 /// An API for recording (updating) user balances in the smart contract.

model/src/lib.rs

@@ -35,3 +35,11 @@ impl ClaimResultView {
         Self { total: U128(total) }
     }
 }
+
+#[derive(Serialize, Deserialize, Debug, PartialEq)]
+#[serde(crate = "near_sdk::serde")]
+pub struct BurnStatus {
+    pub min_claimable_ts: Option<UnixTimestamp>,
+    pub claim_period_refreshed_at: UnixTimestamp,
+    pub burn_period: Duration,
+}