// This file is part of Substrate.

// Copyright (C) 2018-2020 Parity Technologies (UK) Ltd.
// SPDX-License-Identifier: Apache-2.0

// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// 	http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

pub use frame_metadata::{
	DecodeDifferent, FnEncode, RuntimeMetadata, ModuleMetadata, RuntimeMetadataLastVersion,
	DefaultByteGetter, RuntimeMetadataPrefixed, StorageEntryMetadata, StorageMetadata,
	StorageEntryType, StorageEntryModifier, DefaultByte, StorageHasher, ModuleErrorMetadata,
	ExtrinsicMetadata,
};

/// Implements the metadata support for the given runtime and all its modules.
///
/// Example:
/// ```
///# mod module0 {
///#    pub trait Trait {
///#        type Origin;
///#        type BlockNumber;
///#    }
///#    frame_support::decl_module! {
///#        pub struct Module<T: Trait> for enum Call where origin: T::Origin {}
///#    }
///#
///#    frame_support::decl_storage! {
///#        trait Store for Module<T: Trait> as TestStorage {}
///#    }
///# }
///# use module0 as module1;
///# use module0 as module2;
///# impl module0::Trait for Runtime {
///#     type Origin = u32;
///#     type BlockNumber = u32;
///# }
///#
///# type UncheckedExtrinsic = sp_runtime::generic::UncheckedExtrinsic<(), (), (), ()>;
///
/// struct Runtime;
/// frame_support::impl_runtime_metadata! {
///     for Runtime with modules where Extrinsic = UncheckedExtrinsic
///         module0::Module as Module0 { index 0 } with,
///         module1::Module as Module1 { index 1 } with,
///         module2::Module as Module2 { index 2 } with Storage,
/// };
/// ```
///
/// In this example, just `MODULE3` implements the `Storage` trait.
#[macro_export]
macro_rules! impl_runtime_metadata {
	(
		for $runtime:ident with modules where Extrinsic = $ext:ident
			$( $rest:tt )*
	) => {
		impl $runtime {
			pub fn metadata() -> $crate::metadata::RuntimeMetadataPrefixed {
				$crate::metadata::RuntimeMetadataLastVersion {
						modules: $crate::__runtime_modules_to_metadata!($runtime;; $( $rest )*),
						extrinsic: $crate::metadata::ExtrinsicMetadata {
							version: <$ext as $crate::sp_runtime::traits::ExtrinsicMetadata>::VERSION,
							signed_extensions: <
									<
										$ext as $crate::sp_runtime::traits::ExtrinsicMetadata
									>::SignedExtensions as $crate::sp_runtime::traits::SignedExtension
								>::identifier()
									.into_iter()
									.map($crate::metadata::DecodeDifferent::Encode)
									.collect(),
						},
				}.into()
			}
		}
	}
}

#[macro_export]
#[doc(hidden)]
macro_rules! __runtime_modules_to_metadata {
	(
		$runtime: ident;
		$( $metadata:expr ),*;
		$mod:ident::$module:ident $( < $instance:ident > )? as $name:ident
			{ index $index:tt }
			$(with)+ $($kw:ident)*
		,
		$( $rest:tt )*
	) => {
		$crate::__runtime_modules_to_metadata!(
			$runtime;
			$( $metadata, )* $crate::metadata::ModuleMetadata {
				name: $crate::metadata::DecodeDifferent::Encode(stringify!($name)),
				index: $index,
				storage: $crate::__runtime_modules_to_metadata_calls_storage!(
					$mod, $module $( <$instance> )?, $runtime, $(with $kw)*
				),
				calls: $crate::__runtime_modules_to_metadata_calls_call!(
					$mod, $module $( <$instance> )?, $runtime, $(with $kw)*
				),
				event: $crate::__runtime_modules_to_metadata_calls_event!(
					$mod, $module $( <$instance> )?, $runtime, $(with $kw)*
				),
				constants: $crate::metadata::DecodeDifferent::Encode(
					$crate::metadata::FnEncode(
						$mod::$module::<$runtime $(, $mod::$instance )?>::module_constants_metadata
					)
				),
				errors: $crate::metadata::DecodeDifferent::Encode(
					$crate::metadata::FnEncode(
						<$mod::$module::<$runtime $(, $mod::$instance )?> as $crate::metadata::ModuleErrorMetadata>::metadata
					)
				)
			};
			$( $rest )*
		)
	};
	(
		$runtime:ident;
		$( $metadata:expr ),*;
	) => {
		$crate::metadata::DecodeDifferent::Encode(&[ $( $metadata ),* ])
	};
}

#[macro_export]
#[doc(hidden)]
macro_rules! __runtime_modules_to_metadata_calls_call {
	(
		$mod: ident,
		$module: ident $( <$instance:ident> )?,
		$runtime: ident,
		with Call
		$(with $kws:ident)*
	) => {
		Some($crate::metadata::DecodeDifferent::Encode(
			$crate::metadata::FnEncode(
				$mod::$module::<$runtime $(, $mod::$instance )?>::call_functions
			)
		))
	};
	(
		$mod: ident,
		$module: ident $( <$instance:ident> )?,
		$runtime: ident,
		with $_:ident
		$(with $kws:ident)*
	) => {
		$crate::__runtime_modules_to_metadata_calls_call! {
			$mod, $module $( <$instance> )?, $runtime, $(with $kws)*
		};
	};
	(
		$mod: ident,
		$module: ident $( <$instance:ident> )?,
		$runtime: ident,
	) => {
		None
	};
}


#[macro_export]
#[doc(hidden)]
macro_rules! __runtime_modules_to_metadata_calls_event {
	(
		$mod: ident,
		$module: ident $( <$instance:ident> )?,
		$runtime: ident,
		with Event
		$(with $kws:ident)*
	) => {
		Some($crate::metadata::DecodeDifferent::Encode(
			$crate::metadata::FnEncode(
				$crate::paste::expr!{
					$runtime:: [< __module_events_ $mod $(_ $instance)?>]
				}
			)
		))
	};
	(
		$mod: ident,
		$module: ident $( <$instance:ident> )?,
		$runtime: ident,
		with $_:ident
		$(with $kws:ident)*
	) => {
		$crate::__runtime_modules_to_metadata_calls_event!( $mod, $module $( <$instance> )?, $runtime, $(with $kws)* );
	};
	(
		$mod: ident,
		$module: ident $( <$instance:ident> )?,
		$runtime: ident,
	) => {
		None
	};
}

#[macro_export]
#[doc(hidden)]
macro_rules! __runtime_modules_to_metadata_calls_storage {
	(
		$mod: ident,
		$module: ident $( <$instance:ident> )?,
		$runtime: ident,
		with Storage
		$(with $kws:ident)*
	) => {
		Some($crate::metadata::DecodeDifferent::Encode(
			$crate::metadata::FnEncode(
				$mod::$module::<$runtime $(, $mod::$instance )?>::storage_metadata
			)
		))
	};
	(
		$mod: ident,
		$module: ident $( <$instance:ident> )?,
		$runtime: ident,
		with $_:ident
		$(with $kws:ident)*
	) => {
		$crate::__runtime_modules_to_metadata_calls_storage! {
			$mod, $module $( <$instance> )?, $runtime, $(with $kws)*
		};
	};
	(
		$mod: ident,
		$module: ident $( <$instance:ident> )?,
		$runtime: ident,
	) => {
		None
	};
}


#[cfg(test)]
// Do not complain about unused `dispatch` and `dispatch_aux`.
#[allow(dead_code)]
mod tests {
	use super::*;
	use frame_metadata::{
		EventMetadata, StorageEntryModifier, StorageEntryType, FunctionMetadata, StorageEntryMetadata,
		ModuleMetadata, RuntimeMetadataPrefixed, DefaultByte, ModuleConstantMetadata, DefaultByteGetter,
		ErrorMetadata, ExtrinsicMetadata,
	};
	use codec::{Encode, Decode};
	use crate::traits::Get;
	use sp_runtime::transaction_validity::TransactionValidityError;

	#[derive(Clone, Eq, Debug, PartialEq, Encode, Decode)]
	struct TestExtension;
	impl sp_runtime::traits::SignedExtension for TestExtension {
		type AccountId = u32;
		type Call = ();
		type AdditionalSigned = u32;
		type Pre = ();
		const IDENTIFIER: &'static str = "testextension";
		fn additional_signed(&self) -> Result<Self::AdditionalSigned, TransactionValidityError> {
			Ok(1)
		}
	}

	#[derive(Clone, Eq, Debug, PartialEq, Encode, Decode)]
	struct TestExtension2;
	impl sp_runtime::traits::SignedExtension for TestExtension2 {
		type AccountId = u32;
		type Call = ();
		type AdditionalSigned = u32;
		type Pre = ();
		const IDENTIFIER: &'static str = "testextension2";
		fn additional_signed(&self) -> Result<Self::AdditionalSigned, TransactionValidityError> {
			Ok(1)
		}
	}

	struct TestExtrinsic;

	impl sp_runtime::traits::ExtrinsicMetadata for TestExtrinsic {
		const VERSION: u8 = 1;
		type SignedExtensions = (TestExtension, TestExtension2);
	}

	mod system {
		use super::*;

		pub trait Trait: 'static {
			type BaseCallFilter;
			const ASSOCIATED_CONST: u64 = 500;
			type Origin: Into<Result<RawOrigin<Self::AccountId>, Self::Origin>>
				+ From<RawOrigin<Self::AccountId>>;
			type AccountId: From<u32> + Encode;
			type BlockNumber: From<u32> + Encode;
			type SomeValue: Get<u32>;
			type PalletInfo: crate::traits::PalletInfo;
			type Call;
		}

		decl_module! {
			pub struct Module<T: Trait> for enum Call where origin: T::Origin {
				/// Hi, I am a comment.
				const BlockNumber: T::BlockNumber = 100.into();
				const GetType: T::AccountId = T::SomeValue::get().into();
				const ASSOCIATED_CONST: u64 = T::ASSOCIATED_CONST.into();
			}
		}

		decl_event!(
			pub enum Event {
				SystemEvent,
			}
		);

		#[derive(Clone, PartialEq, Eq, Debug, Encode, Decode)]
		pub enum RawOrigin<AccountId> {
			Root,
			Signed(AccountId),
			None,
		}

		impl<AccountId> From<Option<AccountId>> for RawOrigin<AccountId> {
			fn from(s: Option<AccountId>) -> RawOrigin<AccountId> {
				match s {
					Some(who) => RawOrigin::Signed(who),
					None => RawOrigin::None,
				}
			}
		}

		pub type Origin<T> = RawOrigin<<T as Trait>::AccountId>;
	}

	mod event_module {
		use crate::dispatch::DispatchResult;

		pub trait Trait: super::system::Trait {
			type Balance;
		}

		decl_event!(
			pub enum Event<T> where <T as Trait>::Balance
			{
				/// Hi, I am a comment.
				TestEvent(Balance),
			}
		);

		decl_module! {
			pub struct Module<T: Trait> for enum Call where origin: T::Origin {
				type Error = Error<T>;

				#[weight = 0]
				fn aux_0(_origin) -> DispatchResult { unreachable!() }
			}
		}

		crate::decl_error! {
			pub enum Error for Module<T: Trait> {
				/// Some user input error
				UserInputError,
				/// Something bad happened
				/// this could be due to many reasons
				BadThingHappened,
			}
		}
	}

	mod event_module2 {
		pub trait Trait {
			type Origin;
			type Balance;
			type BlockNumber;
		}

		decl_event!(
			pub enum Event<T> where <T as Trait>::Balance
			{
				TestEvent(Balance),
			}
		);

		decl_module! {
			pub struct Module<T: Trait> for enum Call where origin: T::Origin {}
		}

		crate::decl_storage! {
			trait Store for Module<T: Trait> as TestStorage {
				StorageMethod : Option<u32>;
			}
			add_extra_genesis {
				build(|_| {});
			}
		}
	}

	type EventModule = event_module::Module<TestRuntime>;
	type EventModule2 = event_module2::Module<TestRuntime>;

	#[derive(Debug, Clone, PartialEq, Eq, Encode, Decode)]
	pub struct TestRuntime;

	impl_outer_event! {
		pub enum TestEvent for TestRuntime {
			system,
			event_module<T>,
			event_module2<T>,
		}
	}

	impl_outer_origin! {
		pub enum Origin for TestRuntime where system = system {}
	}

	impl_outer_dispatch! {
		pub enum Call for TestRuntime where origin: Origin {
			event_module::EventModule,
			event_module2::EventModule2,
		}
	}

	impl event_module::Trait for TestRuntime {
		type Balance = u32;
	}

	impl event_module2::Trait for TestRuntime {
		type Origin = Origin;
		type Balance = u32;
		type BlockNumber = u32;
	}

	crate::parameter_types! {
		pub const SystemValue: u32 = 600;
	}

	impl system::Trait for TestRuntime {
		type BaseCallFilter = ();
		type Origin = Origin;
		type AccountId = u32;
		type BlockNumber = u32;
		type SomeValue = SystemValue;
		type PalletInfo = ();
		type Call = Call;
	}

	impl_runtime_metadata!(
		for TestRuntime with modules where Extrinsic = TestExtrinsic
			system::Module as System { index 0 } with Event,
			event_module::Module as Module { index 1 } with Event Call,
			event_module2::Module as Module2 { index 2 } with Event Storage Call,
	);

	struct ConstantBlockNumberByteGetter;
	impl DefaultByte for ConstantBlockNumberByteGetter {
		fn default_byte(&self) -> Vec<u8> {
			100u32.encode()
		}
	}

	struct ConstantGetTypeByteGetter;
	impl DefaultByte for ConstantGetTypeByteGetter {
		fn default_byte(&self) -> Vec<u8> {
			SystemValue::get().encode()
		}
	}

	struct ConstantAssociatedConstByteGetter;
	impl DefaultByte for ConstantAssociatedConstByteGetter {
		fn default_byte(&self) -> Vec<u8> {
			<TestRuntime as system::Trait>::ASSOCIATED_CONST.encode()
		}
	}

	#[test]
	fn runtime_metadata() {
		let expected_metadata: RuntimeMetadataLastVersion = RuntimeMetadataLastVersion {
			modules: DecodeDifferent::Encode(&[
				ModuleMetadata {
					name: DecodeDifferent::Encode("System"),
					index: 0,
					storage: None,
					calls: None,
					event: Some(DecodeDifferent::Encode(
						FnEncode(||&[
							EventMetadata {
								name: DecodeDifferent::Encode("SystemEvent"),
								arguments: DecodeDifferent::Encode(&[]),
								documentation: DecodeDifferent::Encode(&[])
							}
						])
					)),
					constants: DecodeDifferent::Encode(
						FnEncode(|| &[
							ModuleConstantMetadata {
								name: DecodeDifferent::Encode("BlockNumber"),
								ty: DecodeDifferent::Encode("T::BlockNumber"),
								value: DecodeDifferent::Encode(
									DefaultByteGetter(&ConstantBlockNumberByteGetter)
								),
								documentation: DecodeDifferent::Encode(&[" Hi, I am a comment."]),
							},
							ModuleConstantMetadata {
								name: DecodeDifferent::Encode("GetType"),
								ty: DecodeDifferent::Encode("T::AccountId"),
								value: DecodeDifferent::Encode(
									DefaultByteGetter(&ConstantGetTypeByteGetter)
								),
								documentation: DecodeDifferent::Encode(&[]),
							},
							ModuleConstantMetadata {
								name: DecodeDifferent::Encode("ASSOCIATED_CONST"),
								ty: DecodeDifferent::Encode("u64"),
								value: DecodeDifferent::Encode(
									DefaultByteGetter(&ConstantAssociatedConstByteGetter)
								),
								documentation: DecodeDifferent::Encode(&[]),
							}
						])
					),
					errors: DecodeDifferent::Encode(FnEncode(|| &[])),
				},
				ModuleMetadata {
					name: DecodeDifferent::Encode("Module"),
					index: 1,
					storage: None,
					calls: Some(
						DecodeDifferent::Encode(FnEncode(|| &[
							FunctionMetadata {
								name: DecodeDifferent::Encode("aux_0"),
								arguments: DecodeDifferent::Encode(&[]),
								documentation: DecodeDifferent::Encode(&[]),
							}
						]))),
					event: Some(DecodeDifferent::Encode(
						FnEncode(||&[
							EventMetadata {
								name: DecodeDifferent::Encode("TestEvent"),
								arguments: DecodeDifferent::Encode(&["Balance"]),
								documentation: DecodeDifferent::Encode(&[" Hi, I am a comment."])
							}
						])
					)),
					constants: DecodeDifferent::Encode(FnEncode(|| &[])),
					errors: DecodeDifferent::Encode(FnEncode(|| &[
						ErrorMetadata {
							name: DecodeDifferent::Encode("UserInputError"),
							documentation: DecodeDifferent::Encode(&[" Some user input error"]),
						},
						ErrorMetadata {
							name: DecodeDifferent::Encode("BadThingHappened"),
							documentation: DecodeDifferent::Encode(&[
								" Something bad happened",
								" this could be due to many reasons",
							]),
						},
					])),
				},
				ModuleMetadata {
					name: DecodeDifferent::Encode("Module2"),
					index: 2,
					storage: Some(DecodeDifferent::Encode(
						FnEncode(|| StorageMetadata {
							prefix: DecodeDifferent::Encode("TestStorage"),
							entries: DecodeDifferent::Encode(
								&[
									StorageEntryMetadata {
										name: DecodeDifferent::Encode("StorageMethod"),
										modifier: StorageEntryModifier::Optional,
										ty: StorageEntryType::Plain(DecodeDifferent::Encode("u32")),
										default: DecodeDifferent::Encode(
											DefaultByteGetter(
												&event_module2::__GetByteStructStorageMethod(
													std::marker::PhantomData::<TestRuntime>
												)
											)
										),
										documentation: DecodeDifferent::Encode(&[]),
									}
								]
							)
						}),
					)),
					calls: Some(DecodeDifferent::Encode(FnEncode(|| &[]))),
					event: Some(DecodeDifferent::Encode(
						FnEncode(||&[
							EventMetadata {
								name: DecodeDifferent::Encode("TestEvent"),
								arguments: DecodeDifferent::Encode(&["Balance"]),
								documentation: DecodeDifferent::Encode(&[])
							}
						])
					)),
					constants: DecodeDifferent::Encode(FnEncode(|| &[])),
					errors: DecodeDifferent::Encode(FnEncode(|| &[])),
				},
			]),
			extrinsic: ExtrinsicMetadata {
				version: 1,
				signed_extensions: vec![
					DecodeDifferent::Encode("testextension"),
					DecodeDifferent::Encode("testextension2"),
				],
			}
		};

		let metadata_encoded = TestRuntime::metadata().encode();
		let metadata_decoded = RuntimeMetadataPrefixed::decode(&mut &metadata_encoded[..]);
		let expected_metadata: RuntimeMetadataPrefixed = expected_metadata.into();

		pretty_assertions::assert_eq!(expected_metadata, metadata_decoded.unwrap());
	}
}