1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88

//! # XCM Support Module.
//!
//! ## Overview
//!
//! The XCM support module provides supporting traits, types and
//! implementations, to support cross-chain message(XCM) integration with ORML
//! modules.

#![cfg_attr(not(feature = "std"), no_std)]
#![allow(clippy::unused_unit)]

use frame_support::dispatch::{DispatchError, DispatchResult};
use sp_runtime::traits::{CheckedConversion, Convert};
use sp_std::{marker::PhantomData, prelude::*};

use xcm::latest::prelude::*;
use xcm_executor::traits::{FilterAssetLocation, MatchesFungible};

use orml_traits::{location::Reserve, GetByKey};

pub use currency_adapter::{DepositToAlternative, MultiCurrencyAdapter, OnDepositFail};

mod currency_adapter;

mod tests;

/// A `MatchesFungible` implementation. It matches concrete fungible assets
/// whose `id` could be converted into `CurrencyId`.
pub struct IsNativeConcrete<CurrencyId, CurrencyIdConvert>(PhantomData<(CurrencyId, CurrencyIdConvert)>);
impl<CurrencyId, CurrencyIdConvert, Amount> MatchesFungible<Amount> for IsNativeConcrete<CurrencyId, CurrencyIdConvert>
where
	CurrencyIdConvert: Convert<MultiLocation, Option<CurrencyId>>,
	Amount: TryFrom<u128>,
{
	fn matches_fungible(a: &MultiAsset) -> Option<Amount> {
		if let (Fungible(ref amount), Concrete(ref location)) = (&a.fun, &a.id) {
			if CurrencyIdConvert::convert(location.clone()).is_some() {
				return CheckedConversion::checked_from(*amount);
			}
		}
		None
	}
}

/// A `FilterAssetLocation` implementation. Filters multi native assets whose
/// reserve is same with `origin`.
pub struct MultiNativeAsset<ReserveProvider>(PhantomData<ReserveProvider>);
impl<ReserveProvider> FilterAssetLocation for MultiNativeAsset<ReserveProvider>
where
	ReserveProvider: Reserve,
{
	fn filter_asset_location(asset: &MultiAsset, origin: &MultiLocation) -> bool {
		if let Some(ref reserve) = ReserveProvider::reserve(asset) {
			if reserve == origin {
				return true;
			}
		}
		false
	}
}

/// Handlers unknown asset deposit and withdraw.
pub trait UnknownAsset {
	/// Deposit unknown asset.
	fn deposit(asset: &MultiAsset, to: &MultiLocation) -> DispatchResult;

	/// Withdraw unknown asset.
	fn withdraw(asset: &MultiAsset, from: &MultiLocation) -> DispatchResult;
}

const NO_UNKNOWN_ASSET_IMPL: &str = "NoUnknownAssetImpl";

impl UnknownAsset for () {
	fn deposit(_asset: &MultiAsset, _to: &MultiLocation) -> DispatchResult {
		Err(DispatchError::Other(NO_UNKNOWN_ASSET_IMPL))
	}
	fn withdraw(_asset: &MultiAsset, _from: &MultiLocation) -> DispatchResult {
		Err(DispatchError::Other(NO_UNKNOWN_ASSET_IMPL))
	}
}

// Default implementation for xTokens::MinXcmFee
pub struct DisabledParachainFee;
impl GetByKey<MultiLocation, Option<u128>> for DisabledParachainFee {
	fn get(_key: &MultiLocation) -> Option<u128> {
		None
	}
}