// Copyright 2019-2021 Parity Technologies (UK) Ltd.
// This file is part of substrate-subxt.
//
// subxt 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.
//
// subxt 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 substrate-subxt.  If not, see <http://www.gnu.org/licenses/>.

// jsonrpsee subscriptions are interminable.
// Allows `while let status = subscription.next().await {}`
// Related: https://github.com/paritytech/substrate-subxt/issues/66
#![allow(irrefutable_let_patterns)]

use std::sync::Arc;

use codec::{
    Decode,
    Encode,
    Error as CodecError,
};
use core::{
    convert::TryInto,
    marker::PhantomData,
};
use frame_metadata::RuntimeMetadataPrefixed;
use jsonrpsee_http_client::HttpClient;
use jsonrpsee_types::{
    error::Error as RpcError,
    jsonrpc::{
        to_value as to_json_value,
        DeserializeOwned,
        Params,
    },
    traits::{
        Client,
        SubscriptionClient,
    },
};
use jsonrpsee_ws_client::{
    WsClient,
    WsSubscription as Subscription,
};
use serde::{
    Deserialize,
    Serialize,
};
use sp_core::{
    storage::{
        StorageChangeSet,
        StorageData,
        StorageKey,
    },
    Bytes,
};
use sp_rpc::{
    list::ListOrValue,
    number::NumberOrHex,
};
use sp_runtime::{
    generic::{
        Block,
        SignedBlock,
    },
    traits::Hash,
};
use sp_version::RuntimeVersion;

use crate::{
    error::Error,
    events::{
        EventsDecoder,
        RawEvent,
    },
    frame::{
        system::System,
        Event,
    },
    metadata::Metadata,
    runtimes::Runtime,
    subscription::{
        EventStorageSubscription,
        EventSubscription,
        FinalizedEventStorageSubscription,
        SystemEvents,
    },
};

pub type ChainBlock<T> =
    SignedBlock<Block<<T as System>::Header, <T as System>::Extrinsic>>;

/// Wrapper for NumberOrHex to allow custom From impls
#[derive(Serialize)]
pub struct BlockNumber(NumberOrHex);

impl From<NumberOrHex> for BlockNumber {
    fn from(x: NumberOrHex) -> Self {
        BlockNumber(x)
    }
}

impl From<u32> for BlockNumber {
    fn from(x: u32) -> Self {
        NumberOrHex::Number(x.into()).into()
    }
}

/// System properties for a Substrate-based runtime
#[derive(serde::Serialize, Deserialize, Debug, Clone, PartialEq, Eq, Default)]
#[serde(rename_all = "camelCase")]
pub struct SystemProperties {
    /// The address format
    pub ss58_format: u8,
    /// The number of digits after the decimal point in the native token
    pub token_decimals: u8,
    /// The symbol of the native token
    pub token_symbol: String,
}

/// Possible transaction status events.
///
/// # Note
///
/// This is copied from `sp-transaction-pool` to avoid a dependency on that crate. Therefore it
/// must be kept compatible with that type from the target substrate version.
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
#[serde(rename_all = "camelCase")]
pub enum TransactionStatus<Hash, BlockHash> {
    /// Transaction is part of the future queue.
    Future,
    /// Transaction is part of the ready queue.
    Ready,
    /// The transaction has been broadcast to the given peers.
    Broadcast(Vec<String>),
    /// Transaction has been included in block with given hash.
    InBlock(BlockHash),
    /// The block this transaction was included in has been retracted.
    Retracted(BlockHash),
    /// Maximum number of finality watchers has been reached,
    /// old watchers are being removed.
    FinalityTimeout(BlockHash),
    /// Transaction has been finalized by a finality-gadget, e.g GRANDPA
    Finalized(BlockHash),
    /// Transaction has been replaced in the pool, by another transaction
    /// that provides the same tags. (e.g. same (sender, nonce)).
    Usurped(Hash),
    /// Transaction has been dropped from the pool because of the limit.
    Dropped,
    /// Transaction is no longer valid in the current state.
    Invalid,
}

#[cfg(feature = "client")]
use substrate_subxt_client::SubxtClient;

/// Rpc client wrapper.
/// This is workaround because adding generic types causes the macros to fail.
#[derive(Clone)]
pub enum RpcClient {
    /// JSONRPC client WebSocket transport.
    WebSocket(Arc<WsClient>),
    /// JSONRPC client HTTP transport.
    // NOTE: Arc because `HttpClient` is not clone.
    Http(Arc<HttpClient>),
    #[cfg(feature = "client")]
    /// Embedded substrate node.
    Subxt(SubxtClient),
}

impl RpcClient {
    /// Start a JSON-RPC request.
    pub async fn request<T: DeserializeOwned>(
        &self,
        method: &str,
        params: Params,
    ) -> Result<T, Error> {
        match self {
            Self::WebSocket(inner) => {
                inner.request(method, params).await.map_err(Into::into)
            }
            Self::Http(inner) => inner.request(method, params).await.map_err(Into::into),
            #[cfg(feature = "client")]
            Self::Subxt(inner) => inner.request(method, params).await.map_err(Into::into),
        }
    }

    /// Start a JSON-RPC Subscription.
    pub async fn subscribe<T: DeserializeOwned>(
        &self,
        subscribe_method: &str,
        params: Params,
        unsubscribe_method: &str,
    ) -> Result<Subscription<T>, Error> {
        match self {
            Self::WebSocket(inner) => {
                inner
                    .subscribe(subscribe_method, params, unsubscribe_method)
                    .await
                    .map_err(Into::into)
            }
            Self::Http(_) => {
                Err(RpcError::Custom(
                    "Subscriptions not supported on HTTP transport".to_owned(),
                )
                .into())
            }
            #[cfg(feature = "client")]
            Self::Subxt(inner) => {
                inner
                    .subscribe(subscribe_method, params, unsubscribe_method)
                    .await
                    .map_err(Into::into)
            }
        }
    }
}

impl From<WsClient> for RpcClient {
    fn from(client: WsClient) -> Self {
        RpcClient::WebSocket(Arc::new(client))
    }
}

impl From<HttpClient> for RpcClient {
    fn from(client: HttpClient) -> Self {
        RpcClient::Http(Arc::new(client))
    }
}

#[cfg(feature = "client")]
impl From<SubxtClient> for RpcClient {
    fn from(client: SubxtClient) -> Self {
        RpcClient::Subxt(client)
    }
}

/// ReadProof struct returned by the RPC
///
/// # Note
///
/// This is copied from `sc-rpc-api` to avoid a dependency on that crate. Therefore it
/// must be kept compatible with that type from the target substrate version.
#[derive(Debug, PartialEq, Serialize, Deserialize)]
#[serde(rename_all = "camelCase")]
pub struct ReadProof<Hash> {
    /// Block hash used to generate the proof
    pub at: Hash,
    /// A proof used to prove that storage entries are included in the storage trie
    pub proof: Vec<Bytes>,
}

/// Client for substrate rpc interfaces
pub struct Rpc<T: Runtime> {
    client: RpcClient,
    marker: PhantomData<T>,
    accept_weak_inclusion: bool,
}

impl<T: Runtime> Clone for Rpc<T> {
    fn clone(&self) -> Self {
        Self {
            client: self.client.clone(),
            marker: PhantomData,
            accept_weak_inclusion: self.accept_weak_inclusion,
        }
    }
}

impl<T: Runtime> Rpc<T> {
    pub fn new(client: RpcClient) -> Self {
        Self {
            client,
            marker: PhantomData,
            accept_weak_inclusion: false,
        }
    }

    /// Configure the Rpc to accept non-finalized blocks
    /// in `submit_and_watch_extrinsic`
    pub fn accept_weak_inclusion(&mut self) {
        self.accept_weak_inclusion = true;
    }

    /// Fetch a storage key
    pub async fn storage(
        &self,
        key: &StorageKey,
        hash: Option<T::Hash>,
    ) -> Result<Option<StorageData>, Error> {
        let params = Params::Array(vec![to_json_value(key)?, to_json_value(hash)?]);
        let data = self.client.request("state_getStorage", params).await?;
        log::debug!("state_getStorage {:?}", data);
        Ok(data)
    }

    /// Returns the keys with prefix with pagination support.
    /// Up to `count` keys will be returned.
    /// If `start_key` is passed, return next keys in storage in lexicographic order.
    pub async fn storage_keys_paged(
        &self,
        prefix: Option<StorageKey>,
        count: u32,
        start_key: Option<StorageKey>,
        hash: Option<T::Hash>,
    ) -> Result<Vec<StorageKey>, Error> {
        let params = Params::Array(vec![
            to_json_value(prefix)?,
            to_json_value(count)?,
            to_json_value(start_key)?,
            to_json_value(hash)?,
        ]);
        let data = self.client.request("state_getKeysPaged", params).await?;
        log::debug!("state_getKeysPaged {:?}", data);
        Ok(data)
    }

    /// Query historical storage entries
    pub async fn query_storage(
        &self,
        keys: Vec<StorageKey>,
        from: T::Hash,
        to: Option<T::Hash>,
    ) -> Result<Vec<StorageChangeSet<<T as System>::Hash>>, Error> {
        let params = Params::Array(vec![
            to_json_value(keys)?,
            to_json_value(from)?,
            to_json_value(to)?,
        ]);
        self.client
            .request("state_queryStorage", params)
            .await
            .map_err(Into::into)
    }

    /// Query historical storage entries
    pub async fn query_storage_at(
        &self,
        keys: &[StorageKey],
        at: Option<T::Hash>,
    ) -> Result<Vec<StorageChangeSet<<T as System>::Hash>>, Error> {
        let params = Params::Array(vec![to_json_value(keys)?, to_json_value(at)?]);
        self.client
            .request("state_queryStorageAt", params)
            .await
            .map_err(Into::into)
    }

    /// Fetch the genesis hash
    pub async fn genesis_hash(&self) -> Result<T::Hash, Error> {
        let block_zero = Some(ListOrValue::Value(NumberOrHex::Number(0)));
        let params = Params::Array(vec![to_json_value(block_zero)?]);
        let list_or_value: ListOrValue<Option<T::Hash>> =
            self.client.request("chain_getBlockHash", params).await?;
        match list_or_value {
            ListOrValue::Value(genesis_hash) => {
                genesis_hash.ok_or_else(|| "Genesis hash not found".into())
            }
            ListOrValue::List(_) => Err("Expected a Value, got a List".into()),
        }
    }

    /// Fetch the metadata
    pub async fn metadata(&self) -> Result<Metadata, Error> {
        let bytes: Bytes = self
            .client
            .request("state_getMetadata", Params::None)
            .await?;
        let meta: RuntimeMetadataPrefixed = Decode::decode(&mut &bytes[..])?;
        let metadata: Metadata = meta.try_into()?;
        Ok(metadata)
    }

    /// Fetch system properties
    pub async fn system_properties(&self) -> Result<SystemProperties, Error> {
        Ok(self
            .client
            .request("system_properties", Params::None)
            .await?)
    }

    /// Get a header
    pub async fn header(
        &self,
        hash: Option<T::Hash>,
    ) -> Result<Option<T::Header>, Error> {
        let params = Params::Array(vec![to_json_value(hash)?]);
        let header = self.client.request("chain_getHeader", params).await?;
        Ok(header)
    }

    /// Get a block hash, returns hash of latest block by default
    pub async fn block_hash(
        &self,
        block_number: Option<BlockNumber>,
    ) -> Result<Option<T::Hash>, Error> {
        let block_number = block_number.map(ListOrValue::Value);
        let params = Params::Array(vec![to_json_value(block_number)?]);
        let list_or_value = self.client.request("chain_getBlockHash", params).await?;
        match list_or_value {
            ListOrValue::Value(hash) => Ok(hash),
            ListOrValue::List(_) => Err("Expected a Value, got a List".into()),
        }
    }

    /// Get a block hash of the latest finalized block
    pub async fn finalized_head(&self) -> Result<T::Hash, Error> {
        let hash = self
            .client
            .request("chain_getFinalizedHead", Params::None)
            .await?;
        Ok(hash)
    }

    /// Get a Block
    pub async fn block(
        &self,
        hash: Option<T::Hash>,
    ) -> Result<Option<ChainBlock<T>>, Error> {
        let params = Params::Array(vec![to_json_value(hash)?]);
        let block = self.client.request("chain_getBlock", params).await?;
        Ok(block)
    }

    /// Get proof of storage entries at a specific block's state.
    pub async fn read_proof(
        &self,
        keys: Vec<StorageKey>,
        hash: Option<T::Hash>,
    ) -> Result<ReadProof<T::Hash>, Error> {
        let params = Params::Array(vec![to_json_value(keys)?, to_json_value(hash)?]);
        let proof = self.client.request("state_getReadProof", params).await?;
        Ok(proof)
    }

    /// Fetch the runtime version
    pub async fn runtime_version(
        &self,
        at: Option<T::Hash>,
    ) -> Result<RuntimeVersion, Error> {
        let params = Params::Array(vec![to_json_value(at)?]);
        let version = self
            .client
            .request("state_getRuntimeVersion", params)
            .await?;
        Ok(version)
    }

    /// Subscribe to System Events that are imported into blocks.
    ///
    /// *WARNING* these may not be included in the finalized chain, use
    /// `subscribe_finalized_events` to ensure events are finalized.
    pub async fn subscribe_events(&self) -> Result<EventStorageSubscription<T>, Error> {
        let keys = Some(vec![StorageKey::from(SystemEvents::new())]);
        let params = Params::Array(vec![to_json_value(keys)?]);

        let subscription = self
            .client
            .subscribe("state_subscribeStorage", params, "state_unsubscribeStorage")
            .await?;
        Ok(EventStorageSubscription::Imported(subscription))
    }

    /// Subscribe to finalized events.
    pub async fn subscribe_finalized_events(
        &self,
    ) -> Result<EventStorageSubscription<T>, Error> {
        Ok(EventStorageSubscription::Finalized(
            FinalizedEventStorageSubscription::new(
                self.clone(),
                self.subscribe_finalized_blocks().await?,
            ),
        ))
    }

    /// Subscribe to blocks.
    pub async fn subscribe_blocks(&self) -> Result<Subscription<T::Header>, Error> {
        let subscription = self
            .client
            .subscribe(
                "chain_subscribeNewHeads",
                Params::None,
                "chain_unsubscribeNewHeads",
            )
            .await?;

        Ok(subscription)
    }

    /// Subscribe to finalized blocks.
    pub async fn subscribe_finalized_blocks(
        &self,
    ) -> Result<Subscription<T::Header>, Error> {
        let subscription = self
            .client
            .subscribe(
                "chain_subscribeFinalizedHeads",
                Params::None,
                "chain_unsubscribeFinalizedHeads",
            )
            .await?;
        Ok(subscription)
    }

    /// Create and submit an extrinsic and return corresponding Hash if successful
    pub async fn submit_extrinsic<E: Encode>(
        &self,
        extrinsic: E,
    ) -> Result<T::Hash, Error> {
        let bytes: Bytes = extrinsic.encode().into();
        let params = Params::Array(vec![to_json_value(bytes)?]);
        let xt_hash = self
            .client
            .request("author_submitExtrinsic", params)
            .await?;
        Ok(xt_hash)
    }

    pub async fn watch_extrinsic<E: Encode>(
        &self,
        extrinsic: E,
    ) -> Result<Subscription<TransactionStatus<T::Hash, T::Hash>>, Error> {
        let bytes: Bytes = extrinsic.encode().into();
        let params = Params::Array(vec![to_json_value(bytes)?]);
        let subscription = self
            .client
            .subscribe(
                "author_submitAndWatchExtrinsic",
                params,
                "author_unwatchExtrinsic",
            )
            .await?;
        Ok(subscription)
    }

    /// Create and submit an extrinsic and return corresponding Event if successful
    pub async fn submit_and_watch_extrinsic<'a, E: Encode + 'static>(
        &self,
        extrinsic: E,
        decoder: &'a EventsDecoder<T>,
    ) -> Result<ExtrinsicSuccess<T>, Error> {
        let ext_hash = T::Hashing::hash_of(&extrinsic);
        log::info!("Submitting Extrinsic `{:?}`", ext_hash);

        let events_sub = if self.accept_weak_inclusion {
            self.subscribe_events().await
        } else {
            self.subscribe_finalized_events().await
        }?;
        let mut xt_sub = self.watch_extrinsic(extrinsic).await?;

        while let Some(status) = xt_sub.next().await {
            log::info!("received status {:?}", status);
            match status {
                // ignore in progress extrinsic for now
                TransactionStatus::Future
                | TransactionStatus::Ready
                | TransactionStatus::Broadcast(_) => continue,
                TransactionStatus::InBlock(block_hash) => {
                    if self.accept_weak_inclusion {
                        return self
                            .process_block(events_sub, decoder, block_hash, ext_hash)
                            .await
                    }
                    continue
                }
                TransactionStatus::Invalid => return Err("Extrinsic Invalid".into()),
                TransactionStatus::Usurped(_) => return Err("Extrinsic Usurped".into()),
                TransactionStatus::Dropped => return Err("Extrinsic Dropped".into()),
                TransactionStatus::Retracted(_) => {
                    return Err("Extrinsic Retracted".into())
                }
                TransactionStatus::Finalized(block_hash) => {
                    // read finalized blocks by default
                    return self
                        .process_block(events_sub, decoder, block_hash, ext_hash)
                        .await
                }
                TransactionStatus::FinalityTimeout(_) => {
                    return Err("Extrinsic FinalityTimeout".into())
                }
            }
        }
        Err(RpcError::Custom("RPC subscription dropped".into()).into())
    }

    async fn process_block<'a>(
        &self,
        events_sub: EventStorageSubscription<T>,
        decoder: &'a EventsDecoder<T>,
        block_hash: T::Hash,
        ext_hash: T::Hash,
    ) -> Result<ExtrinsicSuccess<T>, Error> {
        log::info!("Fetching block {:?}", block_hash);
        if let Some(signed_block) = self.block(Some(block_hash)).await? {
            log::info!(
                "Found block {:?}, with {} extrinsics",
                block_hash,
                signed_block.block.extrinsics.len()
            );
            let ext_index = signed_block
                .block
                .extrinsics
                .iter()
                .position(|ext| {
                    let hash = T::Hashing::hash_of(ext);
                    hash == ext_hash
                })
                .ok_or_else(|| {
                    Error::Other(format!(
                        "Failed to find Extrinsic with hash {:?}",
                        ext_hash,
                    ))
                })?;
            let mut sub = EventSubscription::new(events_sub, &decoder);
            sub.filter_extrinsic(block_hash, ext_index);
            let mut events = vec![];
            while let Some(event) = sub.next().await {
                events.push(event?);
            }
            Ok(ExtrinsicSuccess {
                block: block_hash,
                extrinsic: ext_hash,
                events,
            })
        } else {
            Err(format!("Failed to find block {:?}", block_hash).into())
        }
    }

    /// Insert a key into the keystore.
    pub async fn insert_key(
        &self,
        key_type: String,
        suri: String,
        public: Bytes,
    ) -> Result<(), Error> {
        let params = Params::Array(vec![
            to_json_value(key_type)?,
            to_json_value(suri)?,
            to_json_value(public)?,
        ]);
        self.client.request("author_insertKey", params).await?;
        Ok(())
    }

    /// Generate new session keys and returns the corresponding public keys.
    pub async fn rotate_keys(&self) -> Result<Bytes, Error> {
        Ok(self
            .client
            .request("author_rotateKeys", Params::None)
            .await?)
    }

    /// Checks if the keystore has private keys for the given session public keys.
    ///
    /// `session_keys` is the SCALE encoded session keys object from the runtime.
    ///
    /// Returns `true` iff all private keys could be found.
    pub async fn has_session_keys(&self, session_keys: Bytes) -> Result<bool, Error> {
        let params = Params::Array(vec![to_json_value(session_keys)?]);
        Ok(self.client.request("author_hasSessionKeys", params).await?)
    }

    /// Checks if the keystore has private keys for the given public key and key type.
    ///
    /// Returns `true` if a private key could be found.
    pub async fn has_key(
        &self,
        public_key: Bytes,
        key_type: String,
    ) -> Result<bool, Error> {
        let params =
            Params::Array(vec![to_json_value(public_key)?, to_json_value(key_type)?]);
        Ok(self.client.request("author_hasKey", params).await?)
    }
}

/// Captures data for when an extrinsic is successfully included in a block
#[derive(Debug)]
pub struct ExtrinsicSuccess<T: System> {
    /// Block hash.
    pub block: T::Hash,
    /// Extrinsic hash.
    pub extrinsic: T::Hash,
    /// Raw runtime events, can be decoded by the caller.
    pub events: Vec<RawEvent>,
}

impl<T: System> ExtrinsicSuccess<T> {
    /// Find the Event for the given module/variant, with raw encoded event data.
    /// Returns `None` if the Event is not found.
    pub fn find_event_raw(&self, module: &str, variant: &str) -> Option<&RawEvent> {
        self.events
            .iter()
            .find(|raw| raw.module == module && raw.variant == variant)
    }

    /// Find the Event for the given module/variant, attempting to decode the event data.
    /// Returns `None` if the Event is not found.
    /// Returns `Err` if the data fails to decode into the supplied type.
    pub fn find_event<E: Event<T>>(&self) -> Result<Option<E>, CodecError> {
        if let Some(event) = self.find_event_raw(E::MODULE, E::EVENT) {
            Ok(Some(E::decode(&mut &event.data[..])?))
        } else {
            Ok(None)
        }
    }
}