sliding down borrow limit and 1 percent close factor (#91)

* sliding down borrow limit and 1 percent close factor

* fix tests

* final dates set

token-lending/program/src/processor.rs

@@ -28,7 +28,11 @@ use solana_program::{
 };
 use spl_token::solana_program::instruction::AccountMeta;
 use spl_token::state::{Account, Mint};
-use std::{convert::TryInto, result::Result};
+use std::{
+    cmp::{max, min},
+    convert::TryInto,
+    result::Result,
+};
 use switchboard_program::{
     get_aggregator, get_aggregator_result, AggregatorState, RoundResult, SwitchboardAccountType,
 };
@@ -897,8 +901,34 @@ fn process_refresh_obligation(program_id: &Pubkey, accounts: &[AccountInfo]) ->
 
     obligation.deposited_value = deposited_value;
     obligation.borrowed_value = borrowed_value;
-    obligation.allowed_borrow_value = allowed_borrow_value;
-    obligation.unhealthy_borrow_value = unhealthy_borrow_value;
+
+    // Wednesday, June 22, 2022 12:00:00 PM GMT
+    let start_timestamp = 1655899200u64;
+    // Wednesday, June 28, 2022 8:00:00 AM GMT
+    let end_timestamp = 1656403200u64;
+    let current_timestamp = clock.unix_timestamp as u64;
+    let current_timestamp_in_range = min(max(start_timestamp, current_timestamp), end_timestamp);
+    let numerator = end_timestamp
+        .checked_sub(current_timestamp_in_range)
+        .ok_or(LendingError::MathOverflow)?;
+    let denominator = end_timestamp
+        .checked_sub(start_timestamp)
+        .ok_or(LendingError::MathOverflow)?;
+
+    let start_global_unhealthy_borrow_value = Decimal::from(120000000u64);
+    let end_global_unhealthy_borrow_value = Decimal::from(50000000u64);
+
+    let global_unhealthy_borrow_value = end_global_unhealthy_borrow_value.try_add(
+        start_global_unhealthy_borrow_value
+            .try_sub(end_global_unhealthy_borrow_value)?
+            .try_mul(numerator)?
+            .try_div(denominator)?,
+    )?;
+    let global_allowed_borrow_value =
+        global_unhealthy_borrow_value.try_sub(Decimal::from(5000000u64))?;
+
+    obligation.allowed_borrow_value = min(allowed_borrow_value, global_allowed_borrow_value);
+    obligation.unhealthy_borrow_value = min(unhealthy_borrow_value, global_unhealthy_borrow_value);
 
     obligation.last_update.update_slot(clock.slot);
     Obligation::pack(obligation, &mut obligation_info.data.borrow_mut())?;

token-lending/program/src/state/reserve.rs

@@ -18,7 +18,7 @@ use std::{
 };
 
 /// Percentage of an obligation that can be repaid during each liquidation call
-pub const LIQUIDATION_CLOSE_FACTOR: u8 = 20;
+pub const LIQUIDATION_CLOSE_FACTOR: u8 = 1;
 
 /// Obligation borrow amount that is small enough to close out
 pub const LIQUIDATION_CLOSE_AMOUNT: u64 = 2;

token-lending/program/tests/liquidate_obligation.rs

@@ -12,7 +12,7 @@ use solana_sdk::{
 use solend_program::{
     instruction::{liquidate_obligation, refresh_obligation},
     processor::process_instruction,
-    state::INITIAL_COLLATERAL_RATIO,
+    state::{INITIAL_COLLATERAL_RATIO, LIQUIDATION_CLOSE_FACTOR},
 };
 use spl_token::instruction::approve;
 
@@ -32,10 +32,11 @@ async fn test_success() {
     // 100 SOL * 80% LTV -> 80 SOL * 20 USDC -> 1600 USDC borrow
     const USDC_BORROW_AMOUNT_FRACTIONAL: u64 = 1_600 * FRACTIONAL_TO_USDC;
     // 1600 USDC * 20% -> 320 USDC liquidation
-    const USDC_LIQUIDATION_AMOUNT_FRACTIONAL: u64 = USDC_BORROW_AMOUNT_FRACTIONAL / 5;
+    const USDC_LIQUIDATION_AMOUNT_FRACTIONAL: u64 =
+        USDC_BORROW_AMOUNT_FRACTIONAL * (LIQUIDATION_CLOSE_FACTOR as u64) / 100;
     // 320 USDC / 20 USDC per SOL -> 16 SOL + 10% bonus -> 17.6 SOL (88/5)
     const SOL_LIQUIDATION_AMOUNT_LAMPORTS: u64 =
-        LAMPORTS_TO_SOL * INITIAL_COLLATERAL_RATIO * 88 / 5;
+        LAMPORTS_TO_SOL * INITIAL_COLLATERAL_RATIO * 88 * (LIQUIDATION_CLOSE_FACTOR as u64) / 100;
 
     const SOL_RESERVE_COLLATERAL_LAMPORTS: u64 = 2 * SOL_DEPOSIT_AMOUNT_LAMPORTS;
     const USDC_RESERVE_LIQUIDITY_FRACTIONAL: u64 = 2 * USDC_BORROW_AMOUNT_FRACTIONAL;

token-lending/program/tests/liquidate_obligation_and_redeem_collateral.rs

@@ -12,7 +12,7 @@ use solana_sdk::{
 use solend_program::{
     instruction::{liquidate_obligation_and_redeem_reserve_collateral, refresh_obligation},
     processor::process_instruction,
-    state::INITIAL_COLLATERAL_RATIO,
+    state::{INITIAL_COLLATERAL_RATIO, LIQUIDATION_CLOSE_FACTOR},
 };
 use std::cmp::max;
 
@@ -32,10 +32,11 @@ async fn test_success() {
     // 100 SOL * 80% LTV -> 80 SOL * 20 USDC -> 1600 USDC borrow
     const USDC_BORROW_AMOUNT_FRACTIONAL: u64 = 1_600 * FRACTIONAL_TO_USDC;
     // 1600 USDC * 20% -> 320 USDC liquidation
-    const USDC_LIQUIDATION_AMOUNT_FRACTIONAL: u64 = USDC_BORROW_AMOUNT_FRACTIONAL / 5;
+    const USDC_LIQUIDATION_AMOUNT_FRACTIONAL: u64 =
+        USDC_BORROW_AMOUNT_FRACTIONAL * (LIQUIDATION_CLOSE_FACTOR as u64) / 100;
     // 320 USDC / 20 USDC per SOL -> 16 SOL + 10% bonus -> 17.6 SOL (88/5)
     const SOL_LIQUIDATION_AMOUNT_LAMPORTS: u64 =
-        LAMPORTS_TO_SOL * INITIAL_COLLATERAL_RATIO * 88 / 5;
+        LAMPORTS_TO_SOL * INITIAL_COLLATERAL_RATIO * 88 * (LIQUIDATION_CLOSE_FACTOR as u64) / 100;
 
     const SOL_RESERVE_COLLATERAL_LAMPORTS: u64 = 2 * SOL_DEPOSIT_AMOUNT_LAMPORTS;
     const USDC_RESERVE_LIQUIDITY_FRACTIONAL: u64 = 2 * USDC_BORROW_AMOUNT_FRACTIONAL;