From 1f79c15ff5bf6f71a1bfaf58fef5387ab835e9f9 Mon Sep 17 00:00:00 2001
From: Dmitry Novikov <novikov.dm.al@gmail.com>
Date: Mon, 4 Dec 2023 17:22:39 +0100
Subject: [PATCH 1/8] Remove `PaymentVoucher` trait

---
 common/src/lib.rs                        | 16 ----------------
 pallets/gear-voucher/src/benchmarking.rs |  4 ++--
 pallets/gear-voucher/src/lib.rs          | 15 ++-------------
 pallets/gear-voucher/src/tests.rs        |  8 ++++----
 pallets/gear/src/lib.rs                  | 17 +++++------------
 pallets/gear/src/mock.rs                 |  2 +-
 pallets/gear/src/pallet_tests.rs         |  7 -------
 pallets/gear/src/tests.rs                |  4 ++--
 pallets/payment/src/mock.rs              |  5 ++---
 pallets/payment/src/tests.rs             |  2 +-
 runtime/vara/src/lib.rs                  |  8 +++-----
 11 files changed, 22 insertions(+), 66 deletions(-)

diff --git a/common/src/lib.rs b/common/src/lib.rs
index e8fdff55497..e243e05b206 100644
--- a/common/src/lib.rs
+++ b/common/src/lib.rs
@@ -347,19 +347,3 @@ where
         self.function.clone()
     }
 }
-
-pub trait PaymentVoucher<AccountId, ProgramId, Balance> {
-    type VoucherId;
-    type Error;
-
-    fn voucher_id(who: AccountId, program: ProgramId) -> Self::VoucherId;
-}
-
-impl<AccountId: Default, ProgramId, Balance> PaymentVoucher<AccountId, ProgramId, Balance> for () {
-    type VoucherId = AccountId;
-    type Error = &'static str;
-
-    fn voucher_id(_who: AccountId, _program: ProgramId) -> Self::VoucherId {
-        unimplemented!()
-    }
-}
diff --git a/pallets/gear-voucher/src/benchmarking.rs b/pallets/gear-voucher/src/benchmarking.rs
index 38aac81bf34..0f02593f473 100644
--- a/pallets/gear-voucher/src/benchmarking.rs
+++ b/pallets/gear-voucher/src/benchmarking.rs
@@ -48,9 +48,9 @@ benchmarks! {
         let holder_lookup = T::Lookup::unlookup(holder.clone());
     }: _(RawOrigin::Signed(issuer), holder_lookup, program_id, 10_000_000_000_000_u128.unique_saturated_into())
     verify {
-        let voucher_account_id = GearVoucher::<T>::voucher_account_id(&holder, &program_id);
+        let voucher_id = GearVoucher::<T>::voucher_id(&holder, &program_id);
         assert_eq!(
-            CurrencyOf::<T>::free_balance(&voucher_account_id),
+            CurrencyOf::<T>::free_balance(&voucher_id),
             10_000_000_000_000_u128.unique_saturated_into(),
         );
     }
diff --git a/pallets/gear-voucher/src/lib.rs b/pallets/gear-voucher/src/lib.rs
index c3257765888..f4d90f930d4 100644
--- a/pallets/gear-voucher/src/lib.rs
+++ b/pallets/gear-voucher/src/lib.rs
@@ -57,7 +57,6 @@ mod mock;
 #[cfg(test)]
 mod tests;
 
-use common::PaymentVoucher;
 use frame_support::{
     pallet_prelude::*,
     traits::{Currency, ExistenceRequirement, ReservableCurrency, StorageVersion},
@@ -158,7 +157,7 @@ pub mod pallet {
             let to = T::Lookup::lookup(to)?;
 
             // Generate unique account id corresponding to the pair (user, program)
-            let voucher_id = Self::voucher_account_id(&to, &program);
+            let voucher_id = Self::voucher_id(&to, &program);
 
             // Transfer funds to the keyless account
             T::Currency::transfer(&who, &voucher_id, value, ExistenceRequirement::KeepAlive)
@@ -192,23 +191,13 @@ pub mod pallet {
 
 impl<T: Config> Pallet<T> {
     /// Derive a synthesized account ID from an account ID and a program ID.
-    pub fn voucher_account_id(who: &T::AccountId, program_id: &ProgramId) -> T::AccountId {
+    pub fn voucher_id(who: &T::AccountId, program_id: &ProgramId) -> T::AccountId {
         let entropy = (b"modlpy/voucher__", who, program_id).using_encoded(blake2_256);
         Decode::decode(&mut TrailingZeroInput::new(entropy.as_ref()))
             .expect("infinite length input; no invalid inputs for type; qed")
     }
 }
 
-impl<T: Config> PaymentVoucher<T::AccountId, ProgramId, BalanceOf<T>> for Pallet<T> {
-    type VoucherId = T::AccountId;
-    type Error = DispatchError;
-
-    #[inline]
-    fn voucher_id(who: T::AccountId, program: ProgramId) -> Self::VoucherId {
-        Self::voucher_account_id(&who, &program)
-    }
-}
-
 #[derive(Debug, Clone, Encode, Decode, TypeInfo, PartialEq, Eq, PartialOrd, Ord)]
 pub enum PrepaidCall<Balance> {
     SendMessage {
diff --git a/pallets/gear-voucher/src/tests.rs b/pallets/gear-voucher/src/tests.rs
index a46cfe97ac4..fd2701f0902 100644
--- a/pallets/gear-voucher/src/tests.rs
+++ b/pallets/gear-voucher/src/tests.rs
@@ -26,7 +26,7 @@ use primitive_types::H256;
 fn voucher_issue_works() {
     new_test_ext().execute_with(|| {
         let program_id = ProgramId::from_origin(H256::from(b"some//quasy//random//program//id"));
-        let synthesized = Voucher::voucher_account_id(&BOB, &program_id);
+        let synthesized = Voucher::voucher_id(&BOB, &program_id);
 
         assert_ok!(Voucher::issue(
             RuntimeOrigin::signed(ALICE),
@@ -56,7 +56,7 @@ fn voucher_issue_works() {
 fn voucher_redemption_works() {
     new_test_ext().execute_with(|| {
         let program_id = ProgramId::from_origin(H256::from(b"some//quasy//random//program//id"));
-        let synthesized = Voucher::voucher_account_id(&BOB, &program_id);
+        let synthesized = Voucher::voucher_id(&BOB, &program_id);
 
         assert_ok!(Voucher::issue(
             RuntimeOrigin::signed(ALICE),
@@ -69,13 +69,13 @@ fn voucher_redemption_works() {
 
         // Redemption ok
         assert_ok!(Balances::reserve(
-            &Voucher::voucher_id(BOB, program_id),
+            &Voucher::voucher_id(&BOB, &program_id),
             2_000
         ));
 
         // Redemption fails
         assert_noop!(
-            Balances::reserve(&Voucher::voucher_id(BOB, program_id), 100_000_000),
+            Balances::reserve(&Voucher::voucher_id(&BOB, &program_id), 100_000_000),
             pallet_balances::Error::<Test>::InsufficientBalance
         );
     });
diff --git a/pallets/gear/src/lib.rs b/pallets/gear/src/lib.rs
index 28ede177994..64edea70fb7 100644
--- a/pallets/gear/src/lib.rs
+++ b/pallets/gear/src/lib.rs
@@ -54,7 +54,7 @@ use alloc::{format, string::String};
 use common::{
     self, event::*, gas_provider::GasNodeId, paused_program_storage::SessionId, scheduler::*,
     storage::*, BlockLimiter, CodeMetadata, CodeStorage, GasProvider, GasTree, Origin,
-    PausedProgramStorage, PaymentVoucher, Program, ProgramState, ProgramStorage, QueueRunner,
+    PausedProgramStorage, Program, ProgramState, ProgramStorage, QueueRunner,
 };
 use core::marker::PhantomData;
 use core_processor::{
@@ -119,7 +119,6 @@ pub type RentFreePeriodOf<T> = <T as Config>::ProgramRentFreePeriod;
 pub type RentCostPerBlockOf<T> = <T as Config>::ProgramRentCostPerBlock;
 pub type ResumeMinimalPeriodOf<T> = <T as Config>::ProgramResumeMinimalRentPeriod;
 pub type ResumeSessionDurationOf<T> = <T as Config>::ProgramResumeSessionDuration;
-pub(crate) type VoucherOf<T> = <T as Config>::Voucher;
 pub(crate) type GearBank<T> = pallet_gear_bank::Pallet<T>;
 
 /// The current storage version.
@@ -240,14 +239,6 @@ pub mod pallet {
         /// Message Queue processing routing provider.
         type QueueRunner: QueueRunner<Gas = GasBalanceOf<Self>>;
 
-        /// Type that allows to check caller's eligibility for using voucher for payment.
-        type Voucher: PaymentVoucher<
-            Self::AccountId,
-            ProgramId,
-            BalanceOf<Self>,
-            VoucherId = Self::AccountId,
-        >;
-
         /// The free of charge period of rent.
         #[pallet::constant]
         type ProgramRentFreePeriod: Get<BlockNumberFor<Self>>;
@@ -1862,7 +1853,8 @@ pub mod pallet {
                 let external_node = if prepaid {
                     // If voucher is used, we attempt to reserve funds on the respective account.
                     // If no such voucher exists, the call is invalidated.
-                    let voucher_id = VoucherOf::<T>::voucher_id(who.clone(), destination);
+                    // TODO (breathx): replace.
+                    let voucher_id = AccountIdOf::<T>::from_origin(0.into_origin());
 
                     GearBank::<T>::deposit_gas(&voucher_id, gas_limit, keep_alive).map_err(|e| {
                         log::debug!(
@@ -1964,7 +1956,8 @@ pub mod pallet {
             let external_node = if prepaid {
                 // If voucher is used, we attempt to reserve funds on the respective account.
                 // If no such voucher exists, the call is invalidated.
-                let voucher_id = VoucherOf::<T>::voucher_id(origin.clone(), destination);
+                // TODO (breathx): replace.
+                let voucher_id = AccountIdOf::<T>::from_origin(0.into_origin());
 
                 GearBank::<T>::deposit_gas(&voucher_id, gas_limit, keep_alive).map_err(|e| {
                     log::debug!(
diff --git a/pallets/gear/src/mock.rs b/pallets/gear/src/mock.rs
index 84d3a630975..bb4b9aa6b2d 100644
--- a/pallets/gear/src/mock.rs
+++ b/pallets/gear/src/mock.rs
@@ -93,7 +93,7 @@ pallet_gear_program::impl_config!(Test);
 pallet_gear_messenger::impl_config!(Test, CurrentBlockNumber = Gear);
 pallet_gear_scheduler::impl_config!(Test);
 pallet_gear_bank::impl_config!(Test);
-pallet_gear::impl_config!(Test, Schedule = DynamicSchedule, Voucher = GearVoucher);
+pallet_gear::impl_config!(Test, Schedule = DynamicSchedule);
 pallet_gear_gas::impl_config!(Test);
 common::impl_pallet_balances!(Test);
 common::impl_pallet_authorship!(Test);
diff --git a/pallets/gear/src/pallet_tests.rs b/pallets/gear/src/pallet_tests.rs
index 7cd98cb72c7..ccc6d78ece6 100644
--- a/pallets/gear/src/pallet_tests.rs
+++ b/pallets/gear/src/pallet_tests.rs
@@ -56,7 +56,6 @@ macro_rules! impl_config_inner {
             type BlockLimiter = GearGas;
             type Scheduler = GearScheduler;
             type QueueRunner = Gear;
-            type Voucher = GearConfigVoucher;
             type ProgramRentFreePeriod = RentFreePeriod;
             type ProgramResumeMinimalRentPeriod = ResumeMinimalPeriod;
             type ProgramRentCostPerBlock = RentCostPerBlock;
@@ -72,12 +71,6 @@ macro_rules! impl_config_inner {
         $crate::impl_config_inner!($runtime, $($( $rest )*)?);
     };
 
-    ($runtime:ty, Voucher = $voucher:ty $(, $( $rest:tt )*)?) => {
-        type GearConfigVoucher = $voucher;
-
-        $crate::impl_config_inner!($runtime, $($( $rest )*)?);
-    };
-
     ($runtime:ty, DebugInfo = $debug_info:ty $(, $( $rest:tt )*)?) => {
         type GearConfigDebugInfo = $debug_info;
 
diff --git a/pallets/gear/src/tests.rs b/pallets/gear/src/tests.rs
index 63cfa56dfc9..367c54f657d 100644
--- a/pallets/gear/src/tests.rs
+++ b/pallets/gear/src/tests.rs
@@ -14335,7 +14335,7 @@ fn send_gasless_message_works() {
 
         // Balance check
         // Voucher has been issued, but not used yet, so funds should be still in the respective account
-        let voucher_id = GearVoucher::voucher_account_id(&USER_2, &program_id);
+        let voucher_id = GearVoucher::voucher_id(&USER_2, &program_id);
         assert_eq!(
             Balances::free_balance(voucher_id),
             gas_price(DEFAULT_GAS_LIMIT)
@@ -14417,7 +14417,7 @@ fn send_gasless_reply_works() {
             prog_id,
             gas_price(DEFAULT_GAS_LIMIT),
         ));
-        let voucher_id = GearVoucher::voucher_account_id(&USER_1, &prog_id);
+        let voucher_id = GearVoucher::voucher_id(&USER_1, &prog_id);
 
         run_to_block(3, None);
 
diff --git a/pallets/payment/src/mock.rs b/pallets/payment/src/mock.rs
index b989c655a8d..393a9c18004 100644
--- a/pallets/payment/src/mock.rs
+++ b/pallets/payment/src/mock.rs
@@ -166,9 +166,8 @@ impl DelegateFee<RuntimeCall, AccountId> for DelegateFeeAccountBuilder {
             }) => Some(FEE_PAYER),
             RuntimeCall::GearVoucher(pallet_gear_voucher::Call::call {
                 call: pallet_gear_voucher::PrepaidCall::SendReply { reply_to_id, .. },
-            }) => <MailboxOf<Test> as common::storage::Mailbox>::peek(who, reply_to_id).map(
-                |stored_message| GearVoucher::voucher_account_id(who, &stored_message.source()),
-            ),
+            }) => <MailboxOf<Test> as common::storage::Mailbox>::peek(who, reply_to_id)
+                .map(|stored_message| GearVoucher::voucher_id(who, &stored_message.source())),
             _ => None,
         }
     }
diff --git a/pallets/payment/src/tests.rs b/pallets/payment/src/tests.rs
index 067c4db71a4..a1343dc50ce 100644
--- a/pallets/payment/src/tests.rs
+++ b/pallets/payment/src/tests.rs
@@ -648,7 +648,7 @@ fn reply_with_voucher_pays_fee_from_voucher_ok() {
             program_id,
             200_000_000,
         ));
-        let voucher_id = GearVoucher::voucher_account_id(&BOB, &program_id);
+        let voucher_id = GearVoucher::voucher_id(&BOB, &program_id);
 
         run_to_block(2);
 
diff --git a/runtime/vara/src/lib.rs b/runtime/vara/src/lib.rs
index 784f3a7b435..e6408f6d923 100644
--- a/runtime/vara/src/lib.rs
+++ b/runtime/vara/src/lib.rs
@@ -994,7 +994,6 @@ impl pallet_gear::Config for Runtime {
     type BlockLimiter = GearGas;
     type Scheduler = GearScheduler;
     type QueueRunner = Gear;
-    type Voucher = GearVoucher;
     type ProgramRentFreePeriod = ConstU32<{ MONTHS * RENT_FREE_PERIOD_MONTH_FACTOR }>;
     type ProgramResumeMinimalRentPeriod = ConstU32<{ WEEKS * RENT_RESUME_WEEK_FACTOR }>;
     type ProgramRentCostPerBlock = ConstU128<RENT_COST_PER_BLOCK>;
@@ -1060,12 +1059,11 @@ impl DelegateFee<RuntimeCall, AccountId> for DelegateFeeAccountBuilder {
         match call {
             RuntimeCall::GearVoucher(pallet_gear_voucher::Call::call {
                 call: pallet_gear_voucher::PrepaidCall::SendMessage { destination, .. },
-            }) => Some(GearVoucher::voucher_account_id(who, destination)),
+            }) => Some(GearVoucher::voucher_id(who, destination)),
             RuntimeCall::GearVoucher(pallet_gear_voucher::Call::call {
                 call: pallet_gear_voucher::PrepaidCall::SendReply { reply_to_id, .. },
-            }) => <<GearMessenger as Messenger>::Mailbox as Mailbox>::peek(who, reply_to_id).map(
-                |stored_message| GearVoucher::voucher_account_id(who, &stored_message.source()),
-            ),
+            }) => <<GearMessenger as Messenger>::Mailbox as Mailbox>::peek(who, reply_to_id)
+                .map(|stored_message| GearVoucher::voucher_id(who, &stored_message.source())),
             _ => None,
         }
     }

From 43d85b9221acb462b49c2bab1c9393f0d8717146 Mon Sep 17 00:00:00 2001
From: Dmitry Novikov <novikov.dm.al@gmail.com>
Date: Mon, 4 Dec 2023 18:26:16 +0100
Subject: [PATCH 2/8] Refactor inner gear calls impls

---
 pallets/gear/src/lib.rs   | 69 +++++++++------------------------------
 pallets/gear/src/tests.rs | 27 +++++++--------
 2 files changed, 30 insertions(+), 66 deletions(-)

diff --git a/pallets/gear/src/lib.rs b/pallets/gear/src/lib.rs
index 64edea70fb7..911abcb5658 100644
--- a/pallets/gear/src/lib.rs
+++ b/pallets/gear/src/lib.rs
@@ -441,8 +441,6 @@ pub mod pallet {
         ResumePeriodLessThanMinimal,
         /// Program with the specified id is not found.
         ProgramNotFound,
-        /// Voucher can't be redeemed
-        FailureRedeemingVoucher,
         /// Gear::run() already included in current block.
         GearRunAlreadyInBlock,
         /// The program rent logic is disabled.
@@ -1481,8 +1479,8 @@ pub mod pallet {
                 payload,
                 gas_limit,
                 value,
-                false,
                 keep_alive,
+                None,
             )
         }
 
@@ -1518,8 +1516,8 @@ pub mod pallet {
                 payload,
                 gas_limit,
                 value,
-                false,
                 keep_alive,
+                None,
             )
         }
 
@@ -1818,8 +1816,8 @@ pub mod pallet {
             payload: Vec<u8>,
             gas_limit: u64,
             value: BalanceOf<T>,
-            prepaid: bool,
             keep_alive: bool,
+            gas_sponsor: Option<AccountIdOf<T>>,
         ) -> DispatchResultWithPostInfo {
             let payload = payload
                 .try_into()
@@ -1850,28 +1848,11 @@ pub mod pallet {
                 // a voucher exists. The latter can only be used to pay for gas or transaction fee.
                 GearBank::<T>::deposit_value(&who, value, keep_alive)?;
 
-                let external_node = if prepaid {
-                    // If voucher is used, we attempt to reserve funds on the respective account.
-                    // If no such voucher exists, the call is invalidated.
-                    // TODO (breathx): replace.
-                    let voucher_id = AccountIdOf::<T>::from_origin(0.into_origin());
-
-                    GearBank::<T>::deposit_gas(&voucher_id, gas_limit, keep_alive).map_err(|e| {
-                        log::debug!(
-                            "Failed to redeem voucher for user {who:?} and program {destination:?}: {e:?}"
-                        );
-                        Error::<T>::FailureRedeemingVoucher
-                    })?;
-
-                    voucher_id
-                } else {
-                    // If voucher is not used, we reserve gas limit on the user's account.
-                    GearBank::<T>::deposit_gas(&who, gas_limit, keep_alive)?;
-
-                    who.clone()
-                };
-
-                Self::create(external_node, message.id(), gas_limit, false);
+                // If voucher or any other prepaid mechanism is not used,
+                // gas limit is taken from user's account.
+                let gas_sponsor = gas_sponsor.unwrap_or_else(|| who.clone());
+                GearBank::<T>::deposit_gas(&gas_sponsor, gas_limit, keep_alive)?;
+                Self::create(gas_sponsor, message.id(), gas_limit, false);
 
                 let message = message.into_stored_dispatch(ProgramId::from_origin(origin));
 
@@ -1921,8 +1902,8 @@ pub mod pallet {
             payload: Vec<u8>,
             gas_limit: u64,
             value: BalanceOf<T>,
-            prepaid: bool,
             keep_alive: bool,
+            gas_sponsor: Option<AccountIdOf<T>>,
         ) -> DispatchResultWithPostInfo {
             let payload = payload
                 .try_into()
@@ -1953,29 +1934,11 @@ pub mod pallet {
 
             GearBank::<T>::deposit_value(&origin, value, keep_alive)?;
 
-            let external_node = if prepaid {
-                // If voucher is used, we attempt to reserve funds on the respective account.
-                // If no such voucher exists, the call is invalidated.
-                // TODO (breathx): replace.
-                let voucher_id = AccountIdOf::<T>::from_origin(0.into_origin());
-
-                GearBank::<T>::deposit_gas(&voucher_id, gas_limit, keep_alive).map_err(|e| {
-                    log::debug!(
-                        "Failed to redeem voucher for user {origin:?} and program {destination:?}: {e:?}"
-                    );
-                    Error::<T>::FailureRedeemingVoucher
-                })?;
-
-                voucher_id
-            } else {
-                // If voucher is not used, we reserve gas limit on the user's account.
-                GearBank::<T>::deposit_gas(&origin, gas_limit, keep_alive)?;
-
-                origin.clone()
-            };
-
-            // Following up with a gas node creation.
-            Self::create(external_node, reply_id, gas_limit, true);
+            // If voucher or any other prepaid mechanism is not used,
+            // gas limit is taken from user's account.
+            let gas_sponsor = gas_sponsor.unwrap_or_else(|| origin.clone());
+            GearBank::<T>::deposit_gas(&gas_sponsor, gas_limit, keep_alive)?;
+            Self::create(gas_sponsor, reply_id, gas_limit, true);
 
             // Creating reply message.
             let message = ReplyMessage::from_packet(
@@ -2044,8 +2007,8 @@ pub mod pallet {
                     payload,
                     gas_limit,
                     value,
-                    true,
                     keep_alive,
+                    None, // TODO (breathx): replace.
                 ),
                 PrepaidCall::SendReply {
                     reply_to_id,
@@ -2059,8 +2022,8 @@ pub mod pallet {
                     payload,
                     gas_limit,
                     value,
-                    true,
                     keep_alive,
+                    None, // TODO (breathx): replace.
                 ),
             }
         }
diff --git a/pallets/gear/src/tests.rs b/pallets/gear/src/tests.rs
index 367c54f657d..887e16a8109 100644
--- a/pallets/gear/src/tests.rs
+++ b/pallets/gear/src/tests.rs
@@ -14300,19 +14300,20 @@ fn send_gasless_message_works() {
 
         // Test 1: USER_2 sends a gasless message to the program (intending to use a voucher).
         // Expect failure because USER_2 has no voucher.
-        assert_noop!(
-            GearVoucher::call(
-                RuntimeOrigin::signed(USER_2),
-                PrepaidCall::SendMessage {
-                    destination: program_id,
-                    payload: EMPTY_PAYLOAD.to_vec(),
-                    gas_limit: DEFAULT_GAS_LIMIT,
-                    value: 0,
-                    keep_alive: false,
-                }
-            ),
-            Error::<Test>::FailureRedeemingVoucher
-        );
+        // TODO (breathx): replace.
+        // assert_noop!(
+        //     GearVoucher::call(
+        //         RuntimeOrigin::signed(USER_2),
+        //         PrepaidCall::SendMessage {
+        //             destination: program_id,
+        //             payload: EMPTY_PAYLOAD.to_vec(),
+        //             gas_limit: DEFAULT_GAS_LIMIT,
+        //             value: 0,
+        //             keep_alive: false,
+        //         }
+        //     ),
+        //     Error::<Test>::FailureRedeemingVoucher
+        // );
 
         // USER_1 as the program owner issues a voucher for USER_2 enough to send a message
         assert_ok!(GearVoucher::issue(

From 130f1c558d4a785cd395f44256ca9ace42452e6f Mon Sep 17 00:00:00 2001
From: Dmitry Novikov <novikov.dm.al@gmail.com>
Date: Wed, 13 Dec 2023 17:38:57 +0400
Subject: [PATCH 3/8] Add `sponsor_id` to dispatcher trait

---
 pallets/gear-voucher/src/lib.rs  | 27 +++++++++++++++++++--------
 pallets/gear-voucher/src/mock.rs |  1 +
 pallets/gear/src/lib.rs          |  5 +++--
 3 files changed, 23 insertions(+), 10 deletions(-)

diff --git a/pallets/gear-voucher/src/lib.rs b/pallets/gear-voucher/src/lib.rs
index f4d90f930d4..a986ba1e9f8 100644
--- a/pallets/gear-voucher/src/lib.rs
+++ b/pallets/gear-voucher/src/lib.rs
@@ -184,17 +184,27 @@ pub mod pallet {
         ) -> DispatchResultWithPostInfo {
             let origin = ensure_signed(origin)?;
 
-            T::CallsDispatcher::dispatch(origin, call)
+            let sponsor = Self::sponsor_of(&origin, &call);
+
+            T::CallsDispatcher::dispatch(origin, sponsor, call)
         }
     }
-}
 
-impl<T: Config> Pallet<T> {
-    /// Derive a synthesized account ID from an account ID and a program ID.
-    pub fn voucher_id(who: &T::AccountId, program_id: &ProgramId) -> T::AccountId {
-        let entropy = (b"modlpy/voucher__", who, program_id).using_encoded(blake2_256);
-        Decode::decode(&mut TrailingZeroInput::new(entropy.as_ref()))
-            .expect("infinite length input; no invalid inputs for type; qed")
+    impl<T: Config> Pallet<T> {
+        /// Derive a synthesized account ID from an account ID and a program ID.
+        pub fn voucher_id(who: &T::AccountId, program_id: &ProgramId) -> T::AccountId {
+            let entropy = (b"modlpy/voucher__", who, program_id).using_encoded(blake2_256);
+            Decode::decode(&mut TrailingZeroInput::new(entropy.as_ref()))
+                .expect("infinite length input; no invalid inputs for type; qed")
+        }
+
+        /// Return synthesized account ID based on call data.
+        pub fn sponsor_of(who: &T::AccountId, call: &PrepaidCall<BalanceOf<T>>) -> T::AccountId {
+            match call {
+                PrepaidCall::SendMessage { destination, .. } => Self::voucher_id(who, destination),
+                PrepaidCall::SendReply { .. } => todo!("TODO (breathx): extract mailbox here"),
+            }
+        }
     }
 }
 
@@ -224,6 +234,7 @@ pub trait PrepaidCallsDispatcher {
 
     fn dispatch(
         account_id: Self::AccountId,
+        sponsor_id: Self::AccountId,
         call: PrepaidCall<Self::Balance>,
     ) -> DispatchResultWithPostInfo;
 }
diff --git a/pallets/gear-voucher/src/mock.rs b/pallets/gear-voucher/src/mock.rs
index 418dedc28bc..c8d6f6dfc2f 100644
--- a/pallets/gear-voucher/src/mock.rs
+++ b/pallets/gear-voucher/src/mock.rs
@@ -71,6 +71,7 @@ impl crate::PrepaidCallsDispatcher for () {
     }
     fn dispatch(
         _account_id: Self::AccountId,
+        _sponsor_id: Self::AccountId,
         _call: pallet_gear_voucher::PrepaidCall<Balance>,
     ) -> frame_support::pallet_prelude::DispatchResultWithPostInfo {
         unimplemented!()
diff --git a/pallets/gear/src/lib.rs b/pallets/gear/src/lib.rs
index 911abcb5658..b69659d8420 100644
--- a/pallets/gear/src/lib.rs
+++ b/pallets/gear/src/lib.rs
@@ -1992,6 +1992,7 @@ pub mod pallet {
 
         fn dispatch(
             account_id: Self::AccountId,
+            sponsor_id: Self::AccountId,
             call: PrepaidCall<Self::Balance>,
         ) -> DispatchResultWithPostInfo {
             match call {
@@ -2008,7 +2009,7 @@ pub mod pallet {
                     gas_limit,
                     value,
                     keep_alive,
-                    None, // TODO (breathx): replace.
+                    Some(sponsor_id),
                 ),
                 PrepaidCall::SendReply {
                     reply_to_id,
@@ -2023,7 +2024,7 @@ pub mod pallet {
                     gas_limit,
                     value,
                     keep_alive,
-                    None, // TODO (breathx): replace.
+                    Some(sponsor_id),
                 ),
             }
         }

From b61bc0448bec2b3f3979d645c52974963bf40c3e Mon Sep 17 00:00:00 2001
From: Dmitry Novikov <novikov.dm.al@gmail.com>
Date: Wed, 13 Dec 2023 18:02:56 +0400
Subject: [PATCH 4/8] Replace error expected in test

---
 pallets/gear/src/tests.rs | 27 +++++++++++++--------------
 1 file changed, 13 insertions(+), 14 deletions(-)

diff --git a/pallets/gear/src/tests.rs b/pallets/gear/src/tests.rs
index 8be7661fecd..9ceea5eac7f 100644
--- a/pallets/gear/src/tests.rs
+++ b/pallets/gear/src/tests.rs
@@ -14284,20 +14284,19 @@ fn send_gasless_message_works() {
 
         // Test 1: USER_2 sends a gasless message to the program (intending to use a voucher).
         // Expect failure because USER_2 has no voucher.
-        // TODO (breathx): replace.
-        // assert_noop!(
-        //     GearVoucher::call(
-        //         RuntimeOrigin::signed(USER_2),
-        //         PrepaidCall::SendMessage {
-        //             destination: program_id,
-        //             payload: EMPTY_PAYLOAD.to_vec(),
-        //             gas_limit: DEFAULT_GAS_LIMIT,
-        //             value: 0,
-        //             keep_alive: false,
-        //         }
-        //     ),
-        //     Error::<Test>::FailureRedeemingVoucher
-        // );
+        assert_noop!(
+            GearVoucher::call(
+                RuntimeOrigin::signed(USER_2),
+                PrepaidCall::SendMessage {
+                    destination: program_id,
+                    payload: EMPTY_PAYLOAD.to_vec(),
+                    gas_limit: DEFAULT_GAS_LIMIT,
+                    value: 0,
+                    keep_alive: false,
+                }
+            ),
+            pallet_gear_bank::Error::<Test>::InsufficientBalance
+        );
 
         // USER_1 as the program owner issues a voucher for USER_2 enough to send a message
         assert_ok!(GearVoucher::issue(

From 4e719c1fa8606f62b6396c9779ac9ccaf1652730 Mon Sep 17 00:00:00 2001
From: Dmitry Novikov <novikov.dm.al@gmail.com>
Date: Wed, 13 Dec 2023 18:08:44 +0400
Subject: [PATCH 5/8] Make `sponsor_of` optional

---
 pallets/gear-voucher/src/lib.rs   | 17 +++++++++++------
 pallets/gear-voucher/src/tests.rs |  2 +-
 2 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/pallets/gear-voucher/src/lib.rs b/pallets/gear-voucher/src/lib.rs
index a986ba1e9f8..4ce86957214 100644
--- a/pallets/gear-voucher/src/lib.rs
+++ b/pallets/gear-voucher/src/lib.rs
@@ -123,8 +123,8 @@ pub mod pallet {
     // Gas pallet error.
     #[pallet::error]
     pub enum Error<T> {
-        FailureToCreateVoucher,
-        FailureToRedeemVoucher,
+        InsufficientBalance,
+        InvalidVoucher,
     }
 
     #[pallet::hooks]
@@ -163,7 +163,7 @@ pub mod pallet {
             T::Currency::transfer(&who, &voucher_id, value, ExistenceRequirement::KeepAlive)
                 .map_err(|e| {
                     log::debug!("Failed to transfer funds to the voucher account: {:?}", e);
-                    Error::<T>::FailureToCreateVoucher
+                    Error::<T>::InsufficientBalance
                 })?;
 
             Self::deposit_event(Event::VoucherIssued {
@@ -184,7 +184,7 @@ pub mod pallet {
         ) -> DispatchResultWithPostInfo {
             let origin = ensure_signed(origin)?;
 
-            let sponsor = Self::sponsor_of(&origin, &call);
+            let sponsor = Self::sponsor_of(&origin, &call).ok_or(Error::<T>::InvalidVoucher)?;
 
             T::CallsDispatcher::dispatch(origin, sponsor, call)
         }
@@ -199,9 +199,14 @@ pub mod pallet {
         }
 
         /// Return synthesized account ID based on call data.
-        pub fn sponsor_of(who: &T::AccountId, call: &PrepaidCall<BalanceOf<T>>) -> T::AccountId {
+        pub fn sponsor_of(
+            who: &T::AccountId,
+            call: &PrepaidCall<BalanceOf<T>>,
+        ) -> Option<T::AccountId> {
             match call {
-                PrepaidCall::SendMessage { destination, .. } => Self::voucher_id(who, destination),
+                PrepaidCall::SendMessage { destination, .. } => {
+                    Some(Self::voucher_id(who, destination))
+                }
                 PrepaidCall::SendReply { .. } => todo!("TODO (breathx): extract mailbox here"),
             }
         }
diff --git a/pallets/gear-voucher/src/tests.rs b/pallets/gear-voucher/src/tests.rs
index 41674d54ed5..5d16c90ab5e 100644
--- a/pallets/gear-voucher/src/tests.rs
+++ b/pallets/gear-voucher/src/tests.rs
@@ -47,7 +47,7 @@ fn voucher_issue_works() {
         // Insufficient funds
         assert_noop!(
             Voucher::issue(RuntimeOrigin::signed(ALICE), BOB, program_id, 100_000_000,),
-            Error::<Test>::FailureToCreateVoucher
+            Error::<Test>::InsufficientBalance
         );
     });
 }

From 9baedba0d40e39411490a159304a0207b6d1fdc4 Mon Sep 17 00:00:00 2001
From: Dmitry Novikov <novikov.dm.al@gmail.com>
Date: Wed, 13 Dec 2023 18:24:43 +0400
Subject: [PATCH 6/8] Add associated type representing mailbox to vouchers

---
 common/src/storage/complex/mailbox.rs |  5 ++++
 pallets/gear-voucher/src/lib.rs       |  4 ++++
 pallets/gear-voucher/src/mock.rs      | 33 +++++++++++++++++++++++++++
 pallets/gear/src/mock.rs              |  1 +
 pallets/payment/src/mock.rs           |  1 +
 runtime/vara/src/lib.rs               |  1 +
 6 files changed, 45 insertions(+)

diff --git a/common/src/storage/complex/mailbox.rs b/common/src/storage/complex/mailbox.rs
index 0dd98ac590e..da73ebdba30 100644
--- a/common/src/storage/complex/mailbox.rs
+++ b/common/src/storage/complex/mailbox.rs
@@ -99,6 +99,11 @@ pub trait MailboxError {
     fn element_not_found() -> Self;
 }
 
+impl MailboxError for () {
+    fn duplicate_key() -> Self {}
+    fn element_not_found() -> Self {}
+}
+
 /// `Mailbox` implementation based on `DoubleMapStorage`.
 ///
 /// Generic parameter `Error` requires `MailboxError` implementation.
diff --git a/pallets/gear-voucher/src/lib.rs b/pallets/gear-voucher/src/lib.rs
index 4ce86957214..34ed574687c 100644
--- a/pallets/gear-voucher/src/lib.rs
+++ b/pallets/gear-voucher/src/lib.rs
@@ -81,7 +81,9 @@ const STORAGE_VERSION: StorageVersion = StorageVersion::new(0);
 #[frame_support::pallet]
 pub mod pallet {
     use super::*;
+    use common::storage::Mailbox;
     use frame_system::pallet_prelude::*;
+    use gear_core::message::UserStoredMessage;
 
     #[pallet::config]
     pub trait Config: frame_system::Config {
@@ -102,6 +104,8 @@ pub mod pallet {
             AccountId = Self::AccountId,
             Balance = BalanceOf<Self>,
         >;
+
+        type Mailbox: Mailbox<Key1 = Self::AccountId, Key2 = MessageId, Value = UserStoredMessage>;
     }
 
     #[pallet::pallet]
diff --git a/pallets/gear-voucher/src/mock.rs b/pallets/gear-voucher/src/mock.rs
index c8d6f6dfc2f..8224c66199d 100644
--- a/pallets/gear-voucher/src/mock.rs
+++ b/pallets/gear-voucher/src/mock.rs
@@ -17,10 +17,12 @@
 // along with this program. If not, see <https://www.gnu.org/licenses/>.
 
 use crate as pallet_gear_voucher;
+use common::storage::{Interval, Mailbox};
 use frame_support::{
     construct_runtime, parameter_types, weights::constants::RocksDbWeight, PalletId,
 };
 use frame_system as system;
+use gear_core::{ids::MessageId, message::UserStoredMessage};
 use primitive_types::H256;
 use sp_runtime::{
     generic,
@@ -78,12 +80,43 @@ impl crate::PrepaidCallsDispatcher for () {
     }
 }
 
+pub struct MailboxMock;
+
+impl Mailbox for MailboxMock {
+    type BlockNumber = ();
+    type Error = ();
+    type Key1 = AccountId;
+    type Key2 = MessageId;
+    type Value = UserStoredMessage;
+    type OutputError = ();
+
+    fn clear() {
+        unimplemented!()
+    }
+    fn contains(_key1: &Self::Key1, _key2: &Self::Key2) -> bool {
+        unimplemented!()
+    }
+    fn insert(_value: Self::Value, _bn: Self::BlockNumber) -> Result<(), Self::OutputError> {
+        unimplemented!()
+    }
+    fn peek(_key1: &Self::Key1, _key2: &Self::Key2) -> Option<Self::Value> {
+        unimplemented!()
+    }
+    fn remove(
+        _key1: Self::Key1,
+        _key2: Self::Key2,
+    ) -> Result<(Self::Value, Interval<Self::BlockNumber>), Self::OutputError> {
+        unimplemented!()
+    }
+}
+
 impl pallet_gear_voucher::Config for Test {
     type RuntimeEvent = RuntimeEvent;
     type Currency = Balances;
     type PalletId = VoucherPalletId;
     type WeightInfo = ();
     type CallsDispatcher = ();
+    type Mailbox = MailboxMock;
 }
 
 // Build genesis storage according to the mock runtime.
diff --git a/pallets/gear/src/mock.rs b/pallets/gear/src/mock.rs
index 5932b85898c..107358b2c0c 100644
--- a/pallets/gear/src/mock.rs
+++ b/pallets/gear/src/mock.rs
@@ -174,6 +174,7 @@ impl pallet_gear_voucher::Config for Test {
     type PalletId = VoucherPalletId;
     type WeightInfo = ();
     type CallsDispatcher = Gear;
+    type Mailbox = MailboxOf<Self>;
 }
 
 // Build genesis storage according to the mock runtime.
diff --git a/pallets/payment/src/mock.rs b/pallets/payment/src/mock.rs
index 393a9c18004..6e5e71ca7e8 100644
--- a/pallets/payment/src/mock.rs
+++ b/pallets/payment/src/mock.rs
@@ -189,6 +189,7 @@ impl pallet_gear_voucher::Config for Test {
     type PalletId = VoucherPalletId;
     type WeightInfo = ();
     type CallsDispatcher = Gear;
+    type Mailbox = MailboxOf<Self>;
 }
 
 // Build genesis storage according to the mock runtime.
diff --git a/runtime/vara/src/lib.rs b/runtime/vara/src/lib.rs
index e6408f6d923..6e91e358501 100644
--- a/runtime/vara/src/lib.rs
+++ b/runtime/vara/src/lib.rs
@@ -1085,6 +1085,7 @@ impl pallet_gear_voucher::Config for Runtime {
     type PalletId = VoucherPalletId;
     type WeightInfo = weights::pallet_gear_voucher::SubstrateWeight<Runtime>;
     type CallsDispatcher = Gear;
+    type Mailbox = <GearMessenger as Messenger>::Mailbox;
 }
 
 impl<C> frame_system::offchain::SendTransactionTypes<C> for Runtime

From 0e355c44fb212f97e773f278e0b44d74f9b5968b Mon Sep 17 00:00:00 2001
From: Dmitry Novikov <novikov.dm.al@gmail.com>
Date: Wed, 13 Dec 2023 18:36:05 +0400
Subject: [PATCH 7/8] Remove explicit mailbox dependency

---
 pallets/gear-voucher/src/lib.rs |  3 ++-
 pallets/payment/src/mock.rs     |  7 +++----
 runtime/vara/src/lib.rs         | 12 ++++--------
 3 files changed, 9 insertions(+), 13 deletions(-)

diff --git a/pallets/gear-voucher/src/lib.rs b/pallets/gear-voucher/src/lib.rs
index 34ed574687c..e7e7d0a2980 100644
--- a/pallets/gear-voucher/src/lib.rs
+++ b/pallets/gear-voucher/src/lib.rs
@@ -211,7 +211,8 @@ pub mod pallet {
                 PrepaidCall::SendMessage { destination, .. } => {
                     Some(Self::voucher_id(who, destination))
                 }
-                PrepaidCall::SendReply { .. } => todo!("TODO (breathx): extract mailbox here"),
+                PrepaidCall::SendReply { reply_to_id, .. } => T::Mailbox::peek(who, reply_to_id)
+                    .map(|stored_message| Self::voucher_id(who, &stored_message.source())),
             }
         }
     }
diff --git a/pallets/payment/src/mock.rs b/pallets/payment/src/mock.rs
index 6e5e71ca7e8..7cf4809e880 100644
--- a/pallets/payment/src/mock.rs
+++ b/pallets/payment/src/mock.rs
@@ -164,10 +164,9 @@ impl DelegateFee<RuntimeCall, AccountId> for DelegateFeeAccountBuilder {
             RuntimeCall::GearVoucher(pallet_gear_voucher::Call::call {
                 call: pallet_gear_voucher::PrepaidCall::SendMessage { .. },
             }) => Some(FEE_PAYER),
-            RuntimeCall::GearVoucher(pallet_gear_voucher::Call::call {
-                call: pallet_gear_voucher::PrepaidCall::SendReply { reply_to_id, .. },
-            }) => <MailboxOf<Test> as common::storage::Mailbox>::peek(who, reply_to_id)
-                .map(|stored_message| GearVoucher::voucher_id(who, &stored_message.source())),
+            RuntimeCall::GearVoucher(pallet_gear_voucher::Call::call { call }) => {
+                GearVoucher::sponsor_of(who, call)
+            }
             _ => None,
         }
     }
diff --git a/runtime/vara/src/lib.rs b/runtime/vara/src/lib.rs
index 6e91e358501..8b01682a855 100644
--- a/runtime/vara/src/lib.rs
+++ b/runtime/vara/src/lib.rs
@@ -24,7 +24,7 @@
 #[cfg(all(feature = "std", not(feature = "fuzz")))]
 include!(concat!(env!("OUT_DIR"), "/wasm_binary.rs"));
 
-use common::storage::{Mailbox, Messenger};
+use common::storage::Messenger;
 use frame_election_provider_support::{
     onchain, ElectionDataProvider, NposSolution, SequentialPhragmen, VoteWeight,
 };
@@ -1057,13 +1057,9 @@ pub struct DelegateFeeAccountBuilder;
 impl DelegateFee<RuntimeCall, AccountId> for DelegateFeeAccountBuilder {
     fn delegate_fee(call: &RuntimeCall, who: &AccountId) -> Option<AccountId> {
         match call {
-            RuntimeCall::GearVoucher(pallet_gear_voucher::Call::call {
-                call: pallet_gear_voucher::PrepaidCall::SendMessage { destination, .. },
-            }) => Some(GearVoucher::voucher_id(who, destination)),
-            RuntimeCall::GearVoucher(pallet_gear_voucher::Call::call {
-                call: pallet_gear_voucher::PrepaidCall::SendReply { reply_to_id, .. },
-            }) => <<GearMessenger as Messenger>::Mailbox as Mailbox>::peek(who, reply_to_id)
-                .map(|stored_message| GearVoucher::voucher_id(who, &stored_message.source())),
+            RuntimeCall::GearVoucher(pallet_gear_voucher::Call::call { call }) => {
+                GearVoucher::sponsor_of(who, call)
+            }
             _ => None,
         }
     }

From 1b3c7ba282b449c18d224f26c866beda00eff98b Mon Sep 17 00:00:00 2001
From: Dmitry Novikov <novikov.dm.al@gmail.com>
Date: Wed, 13 Dec 2023 18:54:31 +0400
Subject: [PATCH 8/8] Update `gsdk` metadata

---
 gsdk/src/metadata/generated.rs | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/gsdk/src/metadata/generated.rs b/gsdk/src/metadata/generated.rs
index b64cac4330e..007041e2882 100644
--- a/gsdk/src/metadata/generated.rs
+++ b/gsdk/src/metadata/generated.rs
@@ -2667,12 +2667,9 @@ pub mod runtime_types {
                     #[doc = "Program with the specified id is not found."]
                     ProgramNotFound,
                     #[codec(index = 14)]
-                    #[doc = "Voucher can't be redeemed"]
-                    FailureRedeemingVoucher,
-                    #[codec(index = 15)]
                     #[doc = "Gear::run() already included in current block."]
                     GearRunAlreadyInBlock,
-                    #[codec(index = 16)]
+                    #[codec(index = 15)]
                     #[doc = "The program rent logic is disabled."]
                     ProgramRentDisabled,
                 }
@@ -3339,9 +3336,9 @@ pub mod runtime_types {
                 #[doc = "\n\t\t\tCustom [dispatch errors](https://docs.substrate.io/main-docs/build/events-errors/)\n\t\t\tof this pallet.\n\t\t\t"]
                 pub enum Error {
                     #[codec(index = 0)]
-                    FailureToCreateVoucher,
+                    InsufficientBalance,
                     #[codec(index = 1)]
-                    FailureToRedeemVoucher,
+                    InvalidVoucher,
                 }
                 #[derive(Debug, crate::gp::Decode, crate::gp::DecodeAsType, crate::gp::Encode)]
                 #[doc = "\n\t\t\tThe [event](https://docs.substrate.io/main-docs/build/events-errors/) emitted\n\t\t\tby this pallet.\n\t\t\t"]