//! The `tvu` module implements the Transaction Validation Unit, a
//! 3-stage transaction validation pipeline in software.
//!
//! ```text
//!      .------------------------------------------------.
//!      |                                                |
//!      |           .------------------------------------+------------.
//!      |           |  TVU                               |            |
//!      |           |                                    |            |
//!      |           |                                    |            |  .------------.
//!      |           |                   .----------------+-------------->| Validators |
//!      v           |  .-------.        |                |            |  `------------`
//! .----+---.       |  |       |   .----+-------.   .----+---------.  |
//! | Leader |--------->| Blob  |   | Retransmit |   | Replicate    |  |
//! `--------`       |  | Fetch |-->|   Stage    |-->| Stage /      |  |
//! .------------.   |  | Stage |   |            |   | Vote Stage   |  |
//! | Validators |----->|       |   `------------`   `----+---------`  |
//! `------------`   |  `-------`                         |            |
//!                  |                                    |            |
//!                  |                                    |            |
//!                  |                                    |            |
//!                  `------------------------------------|------------`
//!                                                       |
//!                                                       v
//!                                                    .------.
//!                                                    | Bank |
//!                                                    `------`
//! ```
//!
//! 1. Fetch Stage
//! - Incoming blobs are picked up from the replicate socket and repair socket.
//! 2. SharedWindow Stage
//! - Blobs are windowed until a contiguous chunk is available.  This stage also repairs and
//! retransmits blobs that are in the queue.
//! 3. Replicate Stage
//! - Transactions in blobs are processed and applied to the bank.
//! - TODO We need to verify the signatures in the blobs.

use bank::Bank;
use blob_fetch_stage::BlobFetchStage;
use crdt::Crdt;
use packet::BlobRecycler;
use replicate_stage::ReplicateStage;
use retransmit_stage::RetransmitStage;
use service::Service;
use signature::Keypair;
use std::net::UdpSocket;
use std::sync::atomic::AtomicBool;
use std::sync::{Arc, RwLock};
use std::thread;
use window::SharedWindow;

pub struct Tvu {
    replicate_stage: ReplicateStage,
    fetch_stage: BlobFetchStage,
    retransmit_stage: RetransmitStage,
}

impl Tvu {
    /// This service receives messages from a leader in the network and processes the transactions
    /// on the bank state.
    /// # Arguments
    /// * `bank` - The bank state.
    /// * `entry_height` - Initial ledger height, passed to replicate stage
    /// * `crdt` - The crdt state.
    /// * `window` - The window state.
    /// * `replicate_socket` - my replicate socket
    /// * `repair_socket` - my repair socket
    /// * `retransmit_socket` - my retransmit socket
    /// * `exit` - The exit signal.
    #[cfg_attr(feature = "cargo-clippy", allow(too_many_arguments))]
    pub fn new(
        keypair: Keypair,
        bank: &Arc<Bank>,
        entry_height: u64,
        crdt: Arc<RwLock<Crdt>>,
        window: SharedWindow,
        blob_recycler: BlobRecycler,
        replicate_sockets: Vec<UdpSocket>,
        repair_socket: UdpSocket,
        retransmit_socket: UdpSocket,
        ledger_path: Option<&str>,
        exit: Arc<AtomicBool>,
    ) -> Self {
        let repair_socket = Arc::new(repair_socket);
        let mut blob_sockets: Vec<Arc<UdpSocket>> =
            replicate_sockets.into_iter().map(Arc::new).collect();
        blob_sockets.push(repair_socket.clone());
        let (fetch_stage, blob_fetch_receiver) =
            BlobFetchStage::new_multi_socket(blob_sockets, exit.clone(), &blob_recycler);
        //TODO
        //the packets coming out of blob_receiver need to be sent to the GPU and verified
        //then sent to the window, which does the erasure coding reconstruction
        let (retransmit_stage, blob_window_receiver) = RetransmitStage::new(
            &crdt,
            window,
            entry_height,
            Arc::new(retransmit_socket),
            repair_socket,
            &blob_recycler,
            blob_fetch_receiver,
        );

        let replicate_stage = ReplicateStage::new(
            keypair,
            bank.clone(),
            crdt,
            blob_recycler,
            blob_window_receiver,
            ledger_path,
            exit,
        );

        Tvu {
            replicate_stage,
            fetch_stage,
            retransmit_stage,
        }
    }

    pub fn close(self) -> thread::Result<()> {
        self.fetch_stage.close();
        self.join()
    }
}

impl Service for Tvu {
    type JoinReturnType = ();

    fn join(self) -> thread::Result<()> {
        self.replicate_stage.join()?;
        self.fetch_stage.join()?;
        self.retransmit_stage.join()?;

        Ok(())
    }
}

#[cfg(test)]
pub mod tests {
    use bank::Bank;
    use bincode::serialize;
    use crdt::{Crdt, Node};
    use entry::Entry;
    use hash::{hash, Hash};
    use logger;
    use mint::Mint;
    use ncp::Ncp;
    use packet::BlobRecycler;
    use service::Service;
    use signature::{Keypair, KeypairUtil};
    use std::net::UdpSocket;
    use std::sync::atomic::AtomicBool;
    use std::sync::mpsc::channel;
    use std::sync::{Arc, RwLock};
    use std::time::Duration;
    use streamer;
    use transaction::Transaction;
    use tvu::Tvu;
    use window::{self, SharedWindow};

    fn new_ncp(
        crdt: Arc<RwLock<Crdt>>,
        gossip: UdpSocket,
        exit: Arc<AtomicBool>,
    ) -> (Ncp, SharedWindow, BlobRecycler) {
        let window = Arc::new(RwLock::new(window::default_window()));
        let recycler = BlobRecycler::default();
        let ncp = Ncp::new(&crdt, window.clone(), recycler.clone(), None, gossip, exit);
        (ncp, window, recycler)
    }

    /// Test that message sent from leader to target1 and replicated to target2
    #[test]
    fn test_replicate() {
        logger::setup();
        let leader = Node::new_localhost();
        let target1_keypair = Keypair::new();
        let target1 = Node::new_localhost_with_pubkey(target1_keypair.pubkey());
        let target2 = Node::new_localhost();
        let exit = Arc::new(AtomicBool::new(false));

        //start crdt_leader
        let mut crdt_l = Crdt::new(leader.info.clone()).expect("Crdt::new");
        crdt_l.set_leader(leader.info.id);

        let cref_l = Arc::new(RwLock::new(crdt_l));
        let dr_l = new_ncp(cref_l, leader.sockets.gossip, exit.clone());

        //start crdt2
        let mut crdt2 = Crdt::new(target2.info.clone()).expect("Crdt::new");
        crdt2.insert(&leader.info);
        crdt2.set_leader(leader.info.id);
        let leader_id = leader.info.id;
        let cref2 = Arc::new(RwLock::new(crdt2));
        let dr_2 = new_ncp(cref2, target2.sockets.gossip, exit.clone());

        // setup some blob services to send blobs into the socket
        // to simulate the source peer and get blobs out of the socket to
        // simulate target peer
        let recycler = BlobRecycler::default();
        let (s_reader, r_reader) = channel();
        let blob_sockets: Vec<Arc<UdpSocket>> = target2
            .sockets
            .replicate
            .into_iter()
            .map(Arc::new)
            .collect();

        let t_receiver = streamer::blob_receiver(
            blob_sockets[0].clone(),
            exit.clone(),
            recycler.clone(),
            s_reader,
        );

        // simulate leader sending messages
        let (s_responder, r_responder) = channel();
        let t_responder = streamer::responder(
            "test_replicate",
            Arc::new(leader.sockets.requests),
            recycler.clone(),
            r_responder,
        );

        let starting_balance = 10_000;
        let mint = Mint::new(starting_balance);
        let replicate_addr = target1.info.contact_info.tvu;
        let bank = Arc::new(Bank::new(&mint));

        //start crdt1
        let mut crdt1 = Crdt::new(target1.info.clone()).expect("Crdt::new");
        crdt1.insert(&leader.info);
        crdt1.set_leader(leader.info.id);
        let cref1 = Arc::new(RwLock::new(crdt1));
        let dr_1 = new_ncp(cref1.clone(), target1.sockets.gossip, exit.clone());

        let tvu = Tvu::new(
            target1_keypair,
            &bank,
            0,
            cref1,
            dr_1.1,
            dr_1.2,
            target1.sockets.replicate,
            target1.sockets.repair,
            target1.sockets.retransmit,
            None,
            exit.clone(),
        );

        let mut alice_ref_balance = starting_balance;
        let mut msgs = Vec::new();
        let mut cur_hash = Hash::default();
        let mut blob_id = 0;
        let num_transfers = 10;
        let transfer_amount = 501;
        let bob_keypair = Keypair::new();
        for i in 0..num_transfers {
            let entry0 = Entry::new(&cur_hash, i, vec![], false);
            bank.register_entry_id(&cur_hash);
            cur_hash = hash(&cur_hash.as_ref());

            let tx0 = Transaction::system_new(
                &mint.keypair(),
                bob_keypair.pubkey(),
                transfer_amount,
                cur_hash,
            );
            bank.register_entry_id(&cur_hash);
            cur_hash = hash(&cur_hash.as_ref());
            let entry1 = Entry::new(&cur_hash, i + num_transfers, vec![tx0], false);
            bank.register_entry_id(&cur_hash);
            cur_hash = hash(&cur_hash.as_ref());

            alice_ref_balance -= transfer_amount;

            for entry in vec![entry0, entry1] {
                let b = recycler.allocate();
                {
                    let mut w = b.write().unwrap();
                    w.set_index(blob_id).unwrap();
                    blob_id += 1;
                    w.set_id(leader_id).unwrap();

                    let serialized_entry = serialize(&entry).unwrap();

                    w.data_mut()[..serialized_entry.len()].copy_from_slice(&serialized_entry);
                    w.set_size(serialized_entry.len());
                    w.meta.set_addr(&replicate_addr);
                }
                msgs.push(b);
            }
        }

        // send the blobs into the socket
        s_responder.send(msgs).expect("send");
        drop(s_responder);

        // receive retransmitted messages
        let timer = Duration::new(1, 0);
        while let Ok(msg) = r_reader.recv_timeout(timer) {
            trace!("msg: {:?}", msg);
        }

        let alice_balance = bank.get_balance(&mint.keypair().pubkey());
        assert_eq!(alice_balance, alice_ref_balance);

        let bob_balance = bank.get_balance(&bob_keypair.pubkey());
        assert_eq!(bob_balance, starting_balance - alice_ref_balance);

        tvu.close().expect("close");
        dr_l.0.join().expect("join");
        dr_2.0.join().expect("join");
        dr_1.0.join().expect("join");
        t_receiver.join().expect("join");
        t_responder.join().expect("join");
    }
}