// Copyright (C) Moondance Labs Ltd.

// This file is part of Tanssi.

// Tanssi is free software: you can redistribute it and/or modify

// it under the terms of the GNU General Public License as published by

// the Free Software Foundation, either version 3 of the License, or

// (at your option) any later version.

// Tanssi is distributed in the hope that it will be useful,

// but WITHOUT ANY WARRANTY; without even the implied warranty of

// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License

// along with Tanssi.  If not, see <http://www.gnu.org/licenses/>

//! Crate containing various traits used by moondance crates allowing to connect pallet

//! with each other or with mocks.

#![cfg_attr(not(feature = "std"), no_std)]

pub mod alias;

pub use {

    alias::*,

    cumulus_primitives_core::{

        relay_chain::{BlockNumber, HeadData, Slot, ValidationCode},

        ParaId,

    },

    dp_chain_state_snapshot::{GenericStateProof, ReadEntryErr},

    dp_container_chain_genesis_data::ContainerChainGenesisDataItem,

};

use {

    core::marker::PhantomData,

    frame_support::{

        dispatch::DispatchErrorWithPostInfo,

        pallet_prelude::{Decode, DispatchResultWithPostInfo, Encode, Get, MaxEncodedLen, Weight},

        BoundedVec,

    },

    scale_info::TypeInfo,

    serde::{Deserialize, Serialize},

    sp_core::H256,

    sp_runtime::{

        app_crypto::sp_core,

        traits::{CheckedAdd, CheckedMul},

        ArithmeticError, DispatchResult, Perbill, RuntimeDebug,

    },

    sp_std::{

        collections::{btree_map::BTreeMap, btree_set::BTreeSet},

        vec::Vec,

    },

};

// Separate import as rustfmt wrongly change it to `sp_std::vec::self`, which is the module instead

// of the macro.

use sp_std::vec;

/// The collator-assignment hook to react to collators being assigned to container chains.

pub trait CollatorAssignmentHook<Balance> {

    /// This hook is called when collators are assigned to a container

    ///

    /// The hook should never panic and is required to return the weight consumed.

    fn on_collators_assigned(

        para_id: ParaId,

        maybe_tip: Option<&Balance>,

        is_parathread: bool,

    ) -> Result<Weight, sp_runtime::DispatchError>;

}

#[impl_trait_for_tuples::impl_for_tuples(5)]

impl<Balance> CollatorAssignmentHook<Balance> for Tuple {

}

/// Container chains collator assignment tip prioritization on congestion.

/// Tips paras are willing to pay for collator assignment in case of collators demand

/// surpasses the offer.

pub trait CollatorAssignmentTip<Balance> {

    fn get_para_tip(a: ParaId) -> Option<Balance>;

}

impl<Balance> CollatorAssignmentTip<Balance> for () {

}

pub struct AuthorNotingInfo<AccountId> {

    pub author: AccountId,

    pub block_number: BlockNumber,

    pub para_id: ParaId,

}

/// The author-noting hook to react to container chains authoring.

pub trait AuthorNotingHook<AccountId> {

    /// This hook is called partway through the `set_latest_author_data` inherent in author-noting.

    ///

    /// The hook should never panic and is required to return the weight consumed.

    fn on_container_authors_noted(info: &[AuthorNotingInfo<AccountId>]) -> Weight;

    #[cfg(feature = "runtime-benchmarks")]

    fn prepare_worst_case_for_bench(author: &AccountId, block_number: BlockNumber, para_id: ParaId);

}

#[impl_trait_for_tuples::impl_for_tuples(5)]

impl<AccountId> AuthorNotingHook<AccountId> for Tuple {

    #[cfg(feature = "runtime-benchmarks")]

    fn prepare_worst_case_for_bench(a: &AccountId, b: BlockNumber, p: ParaId) {

        for_tuples!( #( Tuple::prepare_worst_case_for_bench(a, b, p); )* );

    }

}

pub trait DistributeRewards<AccountId, Imbalance> {

    fn distribute_rewards(rewarded: AccountId, amount: Imbalance) -> DispatchResultWithPostInfo;

}

impl<AccountId, Imbalance> DistributeRewards<AccountId, Imbalance> for () {

}

/// Get the current list of container chains parachain ids.

pub trait GetCurrentContainerChains {

    type MaxContainerChains: Get<u32>;

    fn current_container_chains() -> BoundedVec<ParaId, Self::MaxContainerChains>;

    #[cfg(feature = "runtime-benchmarks")]

    fn set_current_container_chains(container_chains: &[ParaId]);

}

#[derive(Copy, Clone, PartialEq, Eq)]

pub enum ForSession {

    Current,

    Next,

}

/// Get the current list of container chains parachain ids with its assigned collators.

/// It can return a para id with an empty list of collators.

pub trait GetContainerChainsWithCollators<AccountId> {

    fn container_chains_with_collators(for_session: ForSession) -> Vec<(ParaId, Vec<AccountId>)>;

    #[cfg(feature = "runtime-benchmarks")]

    fn set_container_chains_with_collators(

        for_session: ForSession,

        container_chains: &[(ParaId, Vec<AccountId>)],

    );

}

/// How often should a parathread collator propose blocks. The units are "1 out of n slots", where the slot time is the

/// tanssi slot time, 6 seconds.

// TODO: this is currently ignored

#[derive(

    Clone,

    Debug,

    Encode,

    Decode,

    PartialEq,

    Eq,

    Serialize,

    Deserialize,

)]

pub struct SlotFrequency {

    /// The parathread will produce at most 1 block every x slots. min=10 means that collators can produce 1 block

    /// every `x >= 10` slots, but they are not enforced to. If collators produce a block after less than 10

    /// slots, they will not be rewarded by tanssi.

    pub min: u32,

    /// The parathread will produce at least 1 block every x slots. max=10 means that collators are forced to

    /// produce 1 block every `x <= 10` slots. Collators can produce a block sooner than that if the `min` allows it, but

    /// waiting more than 10 slots will make them lose the block reward.

    pub max: u32,

}

impl SlotFrequency {

}

impl Default for SlotFrequency {

}

#[derive(

    Clone,

    Debug,

    Encode,

    Decode,

    PartialEq,

    Eq,

    Serialize,

    Deserialize,

)]

pub struct ParathreadParams {

    pub slot_frequency: SlotFrequency,

}

pub struct SessionContainerChains {

    pub parachains: Vec<ParaId>,

    pub parathreads: Vec<(ParaId, ParathreadParams)>,

}

/// Get the list of container chains parachain ids at given

/// session index.

pub trait GetSessionContainerChains<SessionIndex> {

    fn session_container_chains(session_index: SessionIndex) -> SessionContainerChains;

    #[cfg(feature = "runtime-benchmarks")]

    fn set_session_container_chains(session_index: SessionIndex, container_chains: &[ParaId]);

}

/// Returns author for a parachain id for the given slot.

pub trait GetContainerChainAuthor<AccountId> {

    fn author_for_slot(slot: Slot, para_id: ParaId) -> Option<AccountId>;

    #[cfg(feature = "runtime-benchmarks")]

    fn set_authors_for_para_id(para_id: ParaId, authors: Vec<AccountId>);

}

/// Returns the host configuration composed of the amount of collators assigned

/// to the orchestrator chain, and how many collators are assigned per container chain.

pub trait GetHostConfiguration<SessionIndex> {

    fn max_collators(session_index: SessionIndex) -> u32;

    fn min_collators_for_orchestrator(session_index: SessionIndex) -> u32;

    fn max_collators_for_orchestrator(session_index: SessionIndex) -> u32;

    fn collators_per_container(session_index: SessionIndex) -> u32;

    fn collators_per_parathread(session_index: SessionIndex) -> u32;

    fn target_container_chain_fullness(session_index: SessionIndex) -> Perbill;

    fn max_parachain_cores_percentage(session_index: SessionIndex) -> Option<Perbill>;

    fn full_rotation_mode(session_index: SessionIndex) -> FullRotationModes;

    #[cfg(feature = "runtime-benchmarks")]

    fn set_host_configuration(_session_index: SessionIndex) {}

}

/// Returns current session index.

pub trait GetSessionIndex<SessionIndex> {

    fn session_index() -> SessionIndex;

}

/// Should pallet_collator_assignment trigger a full rotation on this session?

pub trait ShouldRotateAllCollators<SessionIndex> {

    fn should_rotate_all_collators(session_index: SessionIndex) -> bool;

}

impl<SessionIndex> ShouldRotateAllCollators<SessionIndex> for () {

}

/// Helper trait for pallet_collator_assignment to be able to give priority to invulnerables

pub trait RemoveInvulnerables<AccountId> {

    /// Remove the first n invulnerables from the list of collators. The order should be respected.

    fn remove_invulnerables(

        collators: &mut Vec<AccountId>,

        num_invulnerables: usize,

    ) -> Vec<AccountId>;

}

impl<AccountId: Clone> RemoveInvulnerables<AccountId> for () {

}

/// Helper trait for pallet_collator_assignment to be able to not assign collators to container chains with no credits

/// in pallet_services_payment

pub trait ParaIdAssignmentHooks<B, AC> {

    /// Remove para ids with not enough credits. The resulting order will affect priority: the first para id in the list

    /// will be the first one to get collators.

    fn pre_assignment(para_ids: &mut Vec<ParaId>, old_assigned: &BTreeSet<ParaId>);

    fn post_assignment(

        current_assigned: &BTreeSet<ParaId>,

        new_assigned: &mut BTreeMap<ParaId, Vec<AC>>,

        maybe_tip: &Option<B>,

    ) -> Weight;

    /// Make those para ids valid by giving them enough credits, for benchmarking.

    #[cfg(feature = "runtime-benchmarks")]

    fn make_valid_para_ids(para_ids: &[ParaId]);

}

impl<B, AC> ParaIdAssignmentHooks<B, AC> for () {

    #[cfg(feature = "runtime-benchmarks")]

    fn make_valid_para_ids(_para_ids: &[ParaId]) {}

}

pub trait RelayStorageRootProvider {

    fn get_relay_storage_root(relay_block_number: u32) -> Option<H256>;

    #[cfg(feature = "runtime-benchmarks")]

    fn set_relay_storage_root(relay_block_number: u32, storage_root: Option<H256>);

}

impl RelayStorageRootProvider for () {

    #[cfg(feature = "runtime-benchmarks")]

    fn set_relay_storage_root(_relay_block_number: u32, _storage_root: Option<H256>) {}

}

/// Information extracted from the latest container chain header

#[derive(

    Default,

    Clone,

    Encode,

    Decode,

    PartialEq,

    Serialize,

    Deserialize,

)]

pub struct ContainerChainBlockInfo<AccountId> {

    pub block_number: BlockNumber,

    pub author: AccountId,

    pub latest_slot_number: Slot,

}

pub trait LatestAuthorInfoFetcher<AccountId> {

    fn get_latest_author_info(para_id: ParaId) -> Option<ContainerChainBlockInfo<AccountId>>;

}

pub trait StorageDeposit<Data, Balance> {

    fn compute_deposit(data: &Data) -> Result<Balance, DispatchErrorWithPostInfo>;

}

pub struct BytesDeposit<BaseCost, ByteCost>(PhantomData<(BaseCost, ByteCost)>);

impl<Data, Balance, BaseCost, ByteCost> StorageDeposit<Data, Balance>

    for BytesDeposit<BaseCost, ByteCost>

where

    Data: Encode,

    Balance: TryFrom<usize> + CheckedAdd + CheckedMul,

    BaseCost: Get<Balance>,

    ByteCost: Get<Balance>,

{

}

/// Trait to abstract away relay storage proofs, and allow the same logic to work on both parachains and solochains.

/// Parachains should use relay storage proofs, while solochains should read from storage directly.

pub trait GenericStorageReader {

    fn read_entry<T: Decode>(&self, key: &[u8], fallback: Option<T>) -> Result<T, ReadEntryErr>;

}

impl GenericStorageReader for GenericStateProof<cumulus_primitives_core::relay_chain::Block> {

}

/// Solo chain impl, read directly from storage

pub struct NativeStorageReader;

impl GenericStorageReader for NativeStorageReader {

        }

}

/// Trait to handle registrar-related operations in a relay-chain context.

/// Mostly used to wire Tanssi's and Polkadot's registrars, for them to

/// work together in a solo-chain environment.

pub trait RegistrarHandler<AccountId> {

    fn register(

        who: AccountId,

        id: ParaId,

        genesis_storage: &[ContainerChainGenesisDataItem],

        head_data: Option<HeadData>,

    ) -> DispatchResult;

    fn schedule_para_upgrade(id: ParaId) -> DispatchResult;

    fn schedule_para_downgrade(id: ParaId) -> DispatchResult;

    fn deregister(id: ParaId);

    fn deregister_weight() -> Weight;

    #[cfg(feature = "runtime-benchmarks")]

    fn bench_head_data() -> Option<HeadData> {

        None

    }

    #[cfg(feature = "runtime-benchmarks")]

    fn add_trusted_validation_code(_code: Vec<u8>) {}

    #[cfg(feature = "runtime-benchmarks")]

    fn registrar_new_session(_session: u32) {}

    #[cfg(feature = "runtime-benchmarks")]

    fn prepare_chain_registration(_id: ParaId, _who: AccountId) {}

}

impl<AccountId> RegistrarHandler<AccountId> for () {

}

/// Trait to retrieve the orchestrator block author (if any).

/// In a relay-chain context we will return None.

pub trait MaybeSelfChainBlockAuthor<AccountId> {

    fn get_block_author() -> Option<AccountId>;

}

impl<AccountId> MaybeSelfChainBlockAuthor<AccountId> for () {

}

/// Information regarding the active era (era in used in session).

pub struct ActiveEraInfo {

    /// Index of era.

    pub index: EraIndex,

    /// Moment of start expressed as millisecond from `$UNIX_EPOCH`.

    ///

    /// Start can be none if start hasn't been set for the era yet,

    /// Start is set on the first on_finalize of the era to guarantee usage of `Time`.

    pub start: Option<u64>,

}

/// Counter for the number of eras that have passed.

pub type EraIndex = u32;

pub trait EraIndexProvider {

    fn active_era() -> ActiveEraInfo;

    fn era_to_session_start(era_index: EraIndex) -> Option<u32>;

}

pub trait ValidatorProvider<ValidatorId> {

    fn validators() -> Vec<ValidatorId>;

}

pub trait InvulnerablesProvider<ValidatorId> {

    fn invulnerables() -> Vec<ValidatorId>;

}

pub trait OnEraStart {

}

#[impl_trait_for_tuples::impl_for_tuples(5)]

impl OnEraStart for Tuple {

}

pub trait OnEraEnd {

}

#[impl_trait_for_tuples::impl_for_tuples(5)]

impl OnEraEnd for Tuple {

}

/// Strategy to use when rotating collators. Default: rotate all of them. Allows to rotate only a random subset.

#[derive(

    Clone,

    Debug,

    Default,

    Encode,

    PartialEq,

    Eq,

    Serialize,

    Deserialize,

)]

pub enum FullRotationMode {

    RotateAll,

    KeepCollators {

        keep: u32,

    },

    /// If max collators changes, the number of collators kept also changes.

    KeepPerbill {

        percentage: Perbill,

    },

}

/// Allow to set a different [FullRotationMode] for each kind of chain. Default: rotate all.

#[derive(

    Clone,

    Debug,

    Default,

    Encode,

    Decode,

    PartialEq,

    Eq,

    Serialize,

    Deserialize,

)]

pub struct FullRotationModes {

    pub orchestrator: FullRotationMode,

    pub parachain: FullRotationMode,

    pub parathread: FullRotationMode,

}

impl FullRotationModes {

    /// Keep all collators assigned to their current chain if possible. This is equivalent to disabling rotation.

}

// A trait to retrieve the external index provider identifying some set of data

// In starlight, used to retrieve the external index associated to validators

pub trait ExternalIndexProvider {

    fn get_external_index() -> u64;

}