use crate::{
    codecs::{
        postcard::PostcardCodec,
        NetworkCodec,
    },
    config::Config,
    discovery,
    gossipsub::{
        config::build_gossipsub_behaviour,
        topics::GossipTopic,
    },
    heartbeat,
    peer_report,
    request_response::messages::{
        RequestMessage,
        ResponseMessage,
    },
};
use fuel_core_types::fuel_types::BlockHeight;
use libp2p::{
    allow_block_list,
    gossipsub::{
        self,
        MessageAcceptance,
        MessageId,
        PublishError,
    },
    identify,
    request_response::{
        self,
        OutboundRequestId,
        ProtocolSupport,
        ResponseChannel,
    },
    swarm::NetworkBehaviour,
    Multiaddr,
    PeerId,
};

/// Handles all p2p protocols needed for Fuel.
#[derive(NetworkBehaviour)]
pub struct FuelBehaviour {
    /// **WARNING**: The order of the behaviours is important and fragile, at least for the tests.

    /// The Behaviour to manage connections to blocked peers.
    blocked_peer: allow_block_list::Behaviour<allow_block_list::BlockedPeers>,

    /// Message propagation for p2p
    gossipsub: gossipsub::Behaviour,

    /// Handles regular heartbeats from peers
    heartbeat: heartbeat::Behaviour,

    /// The Behaviour to identify peers.
    identify: identify::Behaviour,

    /// Identifies and periodically requests `BlockHeight` from connected nodes
    peer_report: peer_report::Behaviour,

    /// Node discovery
    discovery: discovery::Behaviour,

    /// RequestResponse protocol
    request_response: request_response::Behaviour<PostcardCodec>,
}

impl FuelBehaviour {
    pub(crate) fn new(p2p_config: &Config, codec: PostcardCodec) -> Self {
        let local_public_key = p2p_config.keypair.public();
        let local_peer_id = PeerId::from_public_key(&local_public_key);

        let discovery_config = {
            let mut discovery_config =
                discovery::Config::new(local_peer_id, p2p_config.network_name.clone());

            discovery_config
                .enable_mdns(p2p_config.enable_mdns)
                .max_peers_connected(p2p_config.max_peers_connected as usize)
                .with_bootstrap_nodes(p2p_config.bootstrap_nodes.clone())
                .with_reserved_nodes(p2p_config.reserved_nodes.clone())
                .enable_reserved_nodes_only_mode(p2p_config.reserved_nodes_only_mode);

            if let Some(random_walk) = p2p_config.random_walk {
                discovery_config.with_random_walk(random_walk);
            }

            if let Some(duration) = p2p_config.connection_idle_timeout {
                discovery_config.set_connection_idle_timeout(duration);
            }

            discovery_config
        };

        let gossipsub = build_gossipsub_behaviour(p2p_config);

        let peer_report = peer_report::Behaviour::new(p2p_config);

        let identify = {
            let identify_config = identify::Config::new(
                "/fuel/1.0".to_string(),
                p2p_config.keypair.public(),
            );
            if let Some(interval) = p2p_config.identify_interval {
                identify::Behaviour::new(identify_config.with_interval(interval))
            } else {
                identify::Behaviour::new(identify_config)
            }
        };

        let heartbeat = heartbeat::Behaviour::new(
            p2p_config.heartbeat_config.clone(),
            BlockHeight::default(),
        );

        let req_res_protocol =
            core::iter::once((codec.get_req_res_protocol(), ProtocolSupport::Full));

        let req_res_config = request_response::Config::default()
            .with_request_timeout(p2p_config.set_request_timeout)
            .with_max_concurrent_streams(p2p_config.max_concurrent_streams);

        let request_response = request_response::Behaviour::with_codec(
            codec,
            req_res_protocol,
            req_res_config,
        );

        Self {
            discovery: discovery_config.finish(),
            gossipsub,
            peer_report,
            request_response,
            blocked_peer: Default::default(),
            identify,
            heartbeat,
        }
    }

    pub fn add_addresses_to_discovery(
        &mut self,
        peer_id: &PeerId,
        addresses: Vec<Multiaddr>,
    ) {
        for address in addresses {
            self.discovery.add_address(peer_id, address.clone());
        }
    }

    pub fn publish_message(
        &mut self,
        topic: GossipTopic,
        encoded_data: Vec<u8>,
    ) -> Result<MessageId, PublishError> {
        self.gossipsub.publish(topic, encoded_data)
    }

    pub fn send_request_msg(
        &mut self,
        message_request: RequestMessage,
        peer_id: &PeerId,
    ) -> OutboundRequestId {
        self.request_response.send_request(peer_id, message_request)
    }

    pub fn send_response_msg(
        &mut self,
        channel: ResponseChannel<ResponseMessage>,
        message: ResponseMessage,
    ) -> Result<(), ResponseMessage> {
        self.request_response.send_response(channel, message)
    }

    pub fn report_message_validation_result(
        &mut self,
        msg_id: &MessageId,
        propagation_source: &PeerId,
        acceptance: MessageAcceptance,
    ) -> Option<f64> {
        let should_check_score = matches!(acceptance, MessageAcceptance::Reject);

        match self.gossipsub.report_message_validation_result(
            msg_id,
            propagation_source,
            acceptance,
        ) {
            Ok(true) => {
                tracing::debug!(target: "fuel-p2p", "Sent a report for MessageId: {} from PeerId: {}", msg_id, propagation_source);
                if should_check_score {
                    return self.gossipsub.peer_score(propagation_source);
                }
            }
            Ok(false) => {
                tracing::warn!(target: "fuel-p2p", "Message with MessageId: {} not found in the Gossipsub Message Cache", msg_id);
            }
            Err(e) => {
                tracing::error!(target: "fuel-p2p", "Failed to report Message with MessageId: {} with Error: {:?}", msg_id, e);
            }
        }

        None
    }

    pub fn update_block_height(&mut self, block_height: BlockHeight) {
        self.heartbeat.update_block_height(block_height);
    }

    #[cfg(test)]
    pub fn get_peer_score(&self, peer_id: &PeerId) -> Option<f64> {
        self.gossipsub.peer_score(peer_id)
    }

    pub fn block_peer(&mut self, peer_id: PeerId) {
        self.blocked_peer.block_peer(peer_id)
    }
}