// Source code for the Substrate Telemetry Server.
// Copyright (C) 2021 Parity Technologies (UK) Ltd.
//
// This program 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.
//
// This program 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 this program. If not, see <https://www.gnu.org/licenses/>.

//! The structs and enums defined in this module are largely identical to those
//! we'll use elsewhere internally, but are kept separate so that the JSON structure
//! is defined (almost) from just this file, and we don't have to worry about breaking
//! compatibility with the input data when we make changes to our internal data
//! structures (for example, to support bincode better).
use super::hash::Hash;
use common::node_message as internal;
use common::node_types;
use serde::Deserialize;

/// This struct represents a telemetry message sent from a node as
/// a JSON payload. Since JSON is self describing, we can use attributes
/// like serde(untagged) and serde(flatten) without issue.
///
/// Internally, we want to minimise the amount of data sent from shards to
/// the core node. For that reason, we use a non-self-describing serialization
/// format like bincode, which doesn't support things like `[serde(flatten)]` (which
/// internally wants to serialize to a map of unknown length) or `[serde(tag/untagged)]`
/// (which relies on the data to know which variant to deserialize to.)
///
/// So, this can be converted fairly cheaply into an enum we'll use internally
/// which is compatible with formats like bincode.
#[derive(Deserialize, Debug)]
#[serde(untagged)]
pub enum NodeMessage {
    V1 {
        #[serde(flatten)]
        payload: Payload,
    },
    V2 {
        id: NodeMessageId,
        payload: Payload,
    },
}

impl From<NodeMessage> for internal::NodeMessage {
    fn from(msg: NodeMessage) -> Self {
        match msg {
            NodeMessage::V1 { payload } => internal::NodeMessage::V1 {
                payload: payload.into(),
            },
            NodeMessage::V2 { id, payload } => internal::NodeMessage::V2 {
                id,
                payload: payload.into(),
            },
        }
    }
}

#[derive(Deserialize, Debug)]
#[serde(tag = "msg")]
pub enum Payload {
    #[serde(rename = "system.connected")]
    SystemConnected(SystemConnected),
    #[serde(rename = "system.interval")]
    SystemInterval(SystemInterval),
    #[serde(rename = "block.import")]
    BlockImport(Block),
    #[serde(rename = "notify.finalized")]
    NotifyFinalized(Finalized),
    #[serde(rename = "txpool.import")]
    TxPoolImport,
    #[serde(rename = "afg.finalized")]
    AfgFinalized(AfgFinalized),
    #[serde(rename = "afg.received_precommit")]
    AfgReceivedPrecommit(AfgReceived),
    #[serde(rename = "afg.received_prevote")]
    AfgReceivedPrevote(AfgReceived),
    #[serde(rename = "afg.received_commit")]
    AfgReceivedCommit(AfgReceived),
    #[serde(rename = "afg.authority_set")]
    AfgAuthoritySet(AfgAuthoritySet),
    #[serde(rename = "afg.finalized_blocks_up_to")]
    AfgFinalizedBlocksUpTo,
    #[serde(rename = "aura.pre_sealed_block")]
    AuraPreSealedBlock,
    #[serde(rename = "prepared_block_for_proposing")]
    PreparedBlockForProposing,
}

impl From<Payload> for internal::Payload {
    fn from(msg: Payload) -> Self {
        match msg {
            Payload::SystemConnected(m) => internal::Payload::SystemConnected(m.into()),
            Payload::SystemInterval(m) => internal::Payload::SystemInterval(m.into()),
            Payload::BlockImport(m) => internal::Payload::BlockImport(m.into()),
            Payload::NotifyFinalized(m) => internal::Payload::NotifyFinalized(m.into()),
            Payload::TxPoolImport => internal::Payload::TxPoolImport,
            Payload::AfgFinalized(m) => internal::Payload::AfgFinalized(m.into()),
            Payload::AfgReceivedPrecommit(m) => internal::Payload::AfgReceivedPrecommit(m.into()),
            Payload::AfgReceivedPrevote(m) => internal::Payload::AfgReceivedPrevote(m.into()),
            Payload::AfgReceivedCommit(m) => internal::Payload::AfgReceivedCommit(m.into()),
            Payload::AfgAuthoritySet(m) => internal::Payload::AfgAuthoritySet(m.into()),
            Payload::AfgFinalizedBlocksUpTo => internal::Payload::AfgFinalizedBlocksUpTo,
            Payload::AuraPreSealedBlock => internal::Payload::AuraPreSealedBlock,
            Payload::PreparedBlockForProposing => internal::Payload::PreparedBlockForProposing,
        }
    }
}

#[derive(Deserialize, Debug)]
pub struct SystemConnected {
    pub genesis_hash: Hash,
    #[serde(flatten)]
    pub node: NodeDetails,
}

impl From<SystemConnected> for internal::SystemConnected {
    fn from(msg: SystemConnected) -> Self {
        internal::SystemConnected {
            genesis_hash: msg.genesis_hash.into(),
            node: msg.node.into(),
        }
    }
}

#[derive(Deserialize, Debug)]
pub struct SystemInterval {
    pub peers: Option<u64>,
    pub txcount: Option<u64>,
    pub bandwidth_upload: Option<f64>,
    pub bandwidth_download: Option<f64>,
    pub finalized_height: Option<BlockNumber>,
    pub finalized_hash: Option<Hash>,
    #[serde(flatten)]
    pub block: Option<Block>,
    pub used_state_cache_size: Option<f32>,
}

impl From<SystemInterval> for internal::SystemInterval {
    fn from(msg: SystemInterval) -> Self {
        internal::SystemInterval {
            peers: msg.peers,
            txcount: msg.txcount,
            bandwidth_upload: msg.bandwidth_upload,
            bandwidth_download: msg.bandwidth_download,
            finalized_height: msg.finalized_height,
            finalized_hash: msg.finalized_hash.map(|h| h.into()),
            block: msg.block.map(|b| b.into()),
            used_state_cache_size: msg.used_state_cache_size,
        }
    }
}

#[derive(Deserialize, Debug)]
pub struct Finalized {
    #[serde(rename = "best")]
    pub hash: Hash,
    pub height: Box<str>,
}

impl From<Finalized> for internal::Finalized {
    fn from(msg: Finalized) -> Self {
        internal::Finalized {
            hash: msg.hash.into(),
            height: msg.height,
        }
    }
}

#[derive(Deserialize, Debug)]
pub struct AfgAuthoritySet {
    pub authority_id: Box<str>,
    pub authorities: Box<str>,
    pub authority_set_id: Box<str>,
}

impl From<AfgAuthoritySet> for internal::AfgAuthoritySet {
    fn from(msg: AfgAuthoritySet) -> Self {
        internal::AfgAuthoritySet {
            authority_id: msg.authority_id,
            authorities: msg.authorities,
            authority_set_id: msg.authority_set_id,
        }
    }
}

#[derive(Deserialize, Debug, Clone)]
pub struct AfgFinalized {
    pub finalized_hash: Hash,
    pub finalized_number: Box<str>,
}

impl From<AfgFinalized> for internal::AfgFinalized {
    fn from(msg: AfgFinalized) -> Self {
        internal::AfgFinalized {
            finalized_hash: msg.finalized_hash.into(),
            finalized_number: msg.finalized_number,
        }
    }
}

#[derive(Deserialize, Debug, Clone)]
pub struct AfgReceived {
    pub target_hash: Hash,
    pub target_number: Box<str>,
    pub voter: Option<Box<str>>,
}

impl From<AfgReceived> for internal::AfgReceived {
    fn from(msg: AfgReceived) -> Self {
        internal::AfgReceived {
            target_hash: msg.target_hash.into(),
            target_number: msg.target_number,
            voter: msg.voter,
        }
    }
}

#[derive(Deserialize, Debug, Clone, Copy)]
pub struct Block {
    #[serde(rename = "best")]
    pub hash: Hash,
    pub height: BlockNumber,
}

impl From<Block> for node_types::Block {
    fn from(block: Block) -> Self {
        node_types::Block {
            hash: block.hash.into(),
            height: block.height,
        }
    }
}

#[derive(Deserialize, Debug, Clone)]
pub struct NodeDetails {
    pub chain: Box<str>,
    pub name: Box<str>,
    pub implementation: Box<str>,
    pub version: Box<str>,
    pub validator: Option<Box<str>>,
    pub network_id: node_types::NetworkId,
    pub startup_time: Option<Box<str>>,
}

impl From<NodeDetails> for node_types::NodeDetails {
    fn from(details: NodeDetails) -> Self {
        node_types::NodeDetails {
            chain: details.chain,
            name: details.name,
            implementation: details.implementation,
            version: details.version,
            validator: details.validator,
            network_id: details.network_id,
            startup_time: details.startup_time,
        }
    }
}

type NodeMessageId = u64;
type BlockNumber = u64;

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn message_v1() {
        let json = r#"{
            "msg":"notify.finalized",
            "level":"INFO",
            "ts":"2021-01-13T12:38:25.410794650+01:00",
            "best":"0x031c3521ca2f9c673812d692fc330b9a18e18a2781e3f9976992f861fd3ea0cb",
            "height":"50"
        }"#;
        assert!(
            matches!(
                serde_json::from_str::<NodeMessage>(json).unwrap(),
                NodeMessage::V1 { .. },
            ),
            "message did not match variant V1",
        );
    }

    #[test]
    fn message_v2() {
        let json = r#"{
            "id":1,
            "ts":"2021-01-13T12:22:20.053527101+01:00",
            "payload":{
                "best":"0xcc41708573f2acaded9dd75e07dac2d4163d136ca35b3061c558d7a35a09dd8d",
                "height":"209",
                "msg":"notify.finalized"
            }
        }"#;
        assert!(
            matches!(
                serde_json::from_str::<NodeMessage>(json).unwrap(),
                NodeMessage::V2 { .. },
            ),
            "message did not match variant V2",
        );
    }

    #[test]
    fn message_v2_received_precommit() {
        let json = r#"{
            "id":1,
            "ts":"2021-01-13T12:22:20.053527101+01:00",
            "payload":{
                "target_hash":"0xcc41708573f2acaded9dd75e07dac2d4163d136ca35b3061c558d7a35a09dd8d",
                "target_number":"209",
                "voter":"foo",
                "msg":"afg.received_precommit"
            }
        }"#;
        assert!(
            matches!(
                serde_json::from_str::<NodeMessage>(json).unwrap(),
                NodeMessage::V2 {
                    payload: Payload::AfgReceivedPrecommit(..),
                    ..
                },
            ),
            "message did not match the expected output",
        );
    }

    #[test]
    fn message_v2_tx_pool_import() {
        // We should happily ignore any fields we don't care about.
        let json = r#"{
            "id":1,
            "ts":"2021-01-13T12:22:20.053527101+01:00",
            "payload":{
                "foo":"Something",
                "bar":123,
                "wibble":"wobble",
                "msg":"txpool.import"
            }
        }"#;
        assert!(
            matches!(
                serde_json::from_str::<NodeMessage>(json).unwrap(),
                NodeMessage::V2 {
                    payload: Payload::TxPoolImport,
                    ..
                },
            ),
            "message did not match the expected output",
        );
    }
}