feat: allow setting bounds for avg tft price (#427)

Author: DylanVerstraete

substrate-node/node/src/chain_spec.rs

@@ -117,6 +117,10 @@ pub fn development_config() -> Result<ChainSpec, String> {
 			get_account_id_from_seed::<sr25519::Public>("Ferdie"),
 			// TFT price pallet allow account
 			get_account_id_from_seed::<sr25519::Public>("Alice"),
+            // TFT price pallet min price
+            10,
+            // TFT price pallet max price
+            1000,
 		)
         },
         // Bootnodes
@@ -201,6 +205,10 @@ pub fn local_testnet_config() -> Result<ChainSpec, String> {
 			get_account_id_from_seed::<sr25519::Public>("Ferdie"),
 			// TFT price pallet allow account
 			get_account_id_from_seed::<sr25519::Public>("Alice"),
+            // TFT price pallet min price
+            10,
+            // TFT price pallet max price
+            1000,
 		)
         },
         // Bootnodes
@@ -229,6 +237,8 @@ fn testnet_genesis(
     bridge_validator_accounts: Vec<AccountId>,
     bridge_fee_account: AccountId,
     tft_price_allowed_account: AccountId,
+    min_tft_price: u32,
+    max_tft_price: u32,
 ) -> GenesisConfig {
     GenesisConfig {
         system: SystemConfig {
@@ -316,6 +326,8 @@ fn testnet_genesis(
         // just some default for development
         tft_price_module: TFTPriceModuleConfig {
             allowed_origin: Some(tft_price_allowed_account),
+            min_tft_price,
+            max_tft_price,
         },
     }
 }

substrate-node/pallets/pallet-smart-contract/src/cost.rs

@@ -4,7 +4,7 @@ use crate::pallet::Error;
 use crate::types;
 use crate::types::{Contract, ContractBillingInformation};
 use crate::Config;
-use frame_support::{dispatch::DispatchErrorWithPostInfo, ensure};
+use frame_support::dispatch::DispatchErrorWithPostInfo;
 use pallet_tfgrid::types as pallet_tfgrid_types;
 use sp_runtime::Percent;
 use sp_runtime::SaturatedConversion;
@@ -244,10 +244,17 @@ pub fn calculate_cost_in_tft_from_musd<T: Config>(
     total_cost: u64,
 ) -> Result<u64, DispatchErrorWithPostInfo> {
     let avg_tft_price = pallet_tft_price::AverageTftPrice::<T>::get();
-    ensure!(avg_tft_price > 0, Error::<T>::TFTPriceValueError);
+
+    // Guaranty tft price will never be lower than min tft price
+    let min_tft_price = pallet_tft_price::MinTftPrice::<T>::get();
+    let mut tft_price = avg_tft_price.max(min_tft_price);
+
+    // Guaranty tft price will never be higher than max tft price
+    let max_tft_price = pallet_tft_price::MaxTftPrice::<T>::get();
+    tft_price = tft_price.min(max_tft_price);
 
     // TFT Price is in musd
-    let tft_price_musd = U64F64::from_num(avg_tft_price);
+    let tft_price_musd = U64F64::from_num(tft_price);
 
     // Cost is expressed in units USD, divide by 10000 to get the price in musd
     let total_cost_musd = U64F64::from_num(total_cost) / 10000;

substrate-node/pallets/pallet-smart-contract/src/mock.rs

@@ -302,6 +302,8 @@ pub fn new_test_ext() -> sp_io::TestExternalities {
 
     let genesis = pallet_tft_price::GenesisConfig::<TestRuntime> {
         allowed_origin: Some(bob()),
+        min_tft_price: 10,
+        max_tft_price: 1000,
     };
     genesis.assimilate_storage(&mut t).unwrap();
 

substrate-node/pallets/pallet-tft-price/src/lib.rs

@@ -5,7 +5,6 @@
 /// https://substrate.dev/docs/en/knowledgebase/runtime/frame
 use frame_support::{dispatch::DispatchResultWithPostInfo, weights::Pays};
 use frame_system::offchain::{SendSignedTransaction, Signer};
-use lite_json::json::JsonValue;
 use log;
 use sp_runtime::offchain::{http, Duration};
 use sp_runtime::traits::SaturatedConversion;
@@ -26,6 +25,9 @@ const DST_ISSUER: &str = "GBOVQKJYHXRR3DX6NOX2RRYFRCUMSADGDESTDNBDS6CDVLGVESRTAC
 const DST_CODE: &str = "TFT";
 const DST_AMOUNT: u32 = 100;
 
+#[cfg(test)]
+mod mock;
+
 #[cfg(test)]
 mod tests;
 
@@ -91,6 +93,8 @@ pub mod pallet {
         PriceStored(u32),
         OffchainWorkerExecuted(T::AccountId),
         AveragePriceStored(u32),
+        AveragePriceIsAboveMaxPrice(u32, u32),
+        AveragePriceIsBelowMinPrice(u32, u32),
     }
 
     #[pallet::error]
@@ -99,6 +103,8 @@ pub mod pallet {
         OffchainSignedTxError,
         NoLocalAcctForSigning,
         AccountUnauthorizedToSetPrice,
+        MaxPriceBelowMinPriceError,
+        MinPriceAboveMaxPriceError,
     }
 
     #[pallet::pallet]
@@ -130,6 +136,14 @@ pub mod pallet {
     #[pallet::getter(fn allowed_origin)]
     pub type AllowedOrigin<T: Config> = StorageValue<_, T::AccountId, OptionQuery>;
 
+    #[pallet::storage]
+    #[pallet::getter(fn min_tft_price)]
+    pub type MinTftPrice<T> = StorageValue<_, u32, ValueQuery>;
+
+    #[pallet::storage]
+    #[pallet::getter(fn max_tft_price)]
+    pub type MaxTftPrice<T> = StorageValue<_, u32, ValueQuery>;
+
     #[pallet::call]
     impl<T: Config> Pallet<T> {
         #[pallet::weight(100_000_000 + T::DbWeight::get().writes(1) + T::DbWeight::get().reads(1))]
@@ -158,6 +172,28 @@ pub mod pallet {
             AllowedOrigin::<T>::set(Some(target));
             Ok(().into())
         }
+
+        #[pallet::weight(100_000_000 + T::DbWeight::get().writes(1) + T::DbWeight::get().reads(1))]
+        pub fn set_min_tft_price(origin: OriginFor<T>, price: u32) -> DispatchResultWithPostInfo {
+            T::RestrictedOrigin::ensure_origin(origin)?;
+            ensure!(
+                price < MaxTftPrice::<T>::get(),
+                Error::<T>::MinPriceAboveMaxPriceError
+            );
+            MinTftPrice::<T>::put(price);
+            Ok(().into())
+        }
+
+        #[pallet::weight(100_000_000 + T::DbWeight::get().writes(1) + T::DbWeight::get().reads(1))]
+        pub fn set_max_tft_price(origin: OriginFor<T>, price: u32) -> DispatchResultWithPostInfo {
+            T::RestrictedOrigin::ensure_origin(origin)?;
+            ensure!(
+                price > MinTftPrice::<T>::get(),
+                Error::<T>::MaxPriceBelowMinPriceError
+            );
+            MaxTftPrice::<T>::put(price);
+            Ok(().into())
+        }
     }
 
     #[pallet::hooks]
@@ -173,13 +209,17 @@ pub mod pallet {
     #[pallet::genesis_config]
     pub struct GenesisConfig<T: Config> {
         pub allowed_origin: Option<T::AccountId>,
+        pub min_tft_price: u32,
+        pub max_tft_price: u32,
     }
 
     #[cfg(feature = "std")]
     impl<T: Config> Default for GenesisConfig<T> {
         fn default() -> Self {
             Self {
                 allowed_origin: None,
+                min_tft_price: 10,
+                max_tft_price: 1000,
             }
         }
     }
@@ -188,6 +228,8 @@ pub mod pallet {
     impl<T: Config> GenesisBuild<T> for GenesisConfig<T> {
         fn build(&self) {
             AllowedOrigin::<T>::set(self.allowed_origin.clone());
+            MinTftPrice::<T>::put(self.min_tft_price);
+            MaxTftPrice::<T>::put(self.max_tft_price);
         }
     }
 }
@@ -212,6 +254,18 @@ impl<T: Config> Pallet<T> {
         AverageTftPrice::<T>::put(average);
         Self::deposit_event(Event::AveragePriceStored(average));
 
+        let min = Self::min_tft_price();
+        if average < min {
+            log::info!("average price {:?} is below min price {:?} !", average, min);
+            Self::deposit_event(Event::AveragePriceIsBelowMinPrice(average, min));
+        }
+
+        let max = Self::max_tft_price();
+        if average > max {
+            log::info!("average price {:?} is above max price {:?} !", average, max);
+            Self::deposit_event(Event::AveragePriceIsAboveMaxPrice(average, max));
+        }
+
         Ok(Pays::No.into())
     }
 
@@ -305,28 +359,6 @@ impl<T: Config> Pallet<T> {
         return Err(<Error<T>>::OffchainSignedTxError);
     }
 
-    /// Parse the price from the given JSON string using `lite-json`.
-    ///
-    /// Returns `None` when parsing failed or `Some(price in mUSD)` when parsing is successful.
-    pub fn parse_price(price_str: &str) -> Option<u32> {
-        let val = lite_json::parse_json(price_str);
-        let price = match val.ok()? {
-            JsonValue::Object(obj) => {
-                let (_, v) = obj
-                    .into_iter()
-                    .find(|(k, _)| k.iter().copied().eq("USD".chars()))?;
-                match v {
-                    JsonValue::Number(number) => number,
-                    _ => return None,
-                }
-            }
-            _ => return None,
-        };
-
-        let exp = price.fraction_length.saturating_sub(3);
-        Some(price.integer as u32 * 1000 + (price.fraction / 10_u64.pow(exp)) as u32)
-    }
-
     /// Parse the lowest price from the given JSON string using `serde_json`.
     ///
     /// Returns `None` when parsing failed or `Some(price in mUSD)` when parsing is successful.
@@ -366,8 +398,9 @@ impl<T: Config> Pallet<T> {
     }
 
     fn calc_avg() -> u32 {
-        let queue = Self::queue_transient();
-        let items = queue.get_all_values();
+        let items: Vec<u32> = TftPriceHistory::<T>::iter_values()
+            .filter(|val| val > &0_u32)
+            .collect();
         items.iter().fold(0_u32, |a, b| a.saturating_add(*b)) / items.len() as u32
     }
 }