use libraft::errors::Error;
use libraft::raft::{Peer, StateType, Status, NONE};
use libraft::raftpb::{
    ConfChange, ConfChangeType, ConfState, Entry, EntryType, HardState, Message, MessageType,
    Snapshot, SnapshotMetadata,
};
use libraft::raw_node::RawNode;
use libraft::read_only::ReadState;
use libraft::storage::{MemStorage, Storage};
use libraft::util::{is_local_msg, NO_LIMIT};

use protobuf::{self, ProtobufEnum};

use cases::test_raft::new_test_config;

#[test]
fn test_raw_node_step() {
    for &msg_t in MessageType::values() {
        let s = MemStorage::new();
        let mut raw_node = RawNode::new(
            &mut new_test_config(1, vec![], 10, 1),
            s,
            vec![Peer {
                context: Default::default(),
                id: 1,
            }],
        ).unwrap();

        let mut m = Message::new();
        m.set_msg_type(msg_t);
        let err = raw_node.step(m);
        if is_local_msg(msg_t) {
            assert_eq!(Err(Error::StepLocalMsg), err);
        }
    }
}

#[test]
fn test_raw_node_proposal_and_conf_change() {
    let mut s = MemStorage::new();
    let mut raw_node = RawNode::new(
        &mut new_test_config(1, vec![], 10, 1),
        s.clone(),
        vec![Peer {
            context: Default::default(),
            id: 1,
        }],
    ).unwrap();

    assert_eq!(raw_node.raft.state, StateType::Follower);
    assert_eq!(raw_node.raft.lead, NONE);
    assert_eq!(raw_node.raft.raft_log.unstable.entries.len(), 1);
    assert_eq!(raw_node.raft.raft_log.committed, 1);
    assert_eq!(raw_node.pre_hard_state, HardState::new());
    assert_eq!(raw_node.pre_soft_state.lead, NONE);
    assert_eq!(raw_node.pre_soft_state.raft_state, StateType::Follower);

    let rd = raw_node.ready();

    assert_eq!(rd.entries.len(), 1);
    assert_eq!(rd.committed_entries.len(), 1);
    assert_eq!(rd.soft_state, None);
    assert_eq!(rd.hard_state.term, 1);
    assert_eq!(rd.hard_state.vote, NONE);
    assert_eq!(rd.hard_state.commit, 1);

    let _ = s.append(&rd.entries);
    raw_node.advance(rd);
    let _ = raw_node.campaign();

    let mut proposed = false;
    let mut last_index = 0;
    let mut ccdata: Vec<u8> = vec![];

    loop {
        let rd = raw_node.ready();
        let _ = s.append(&rd.entries);
        if !proposed && rd.soft_state.as_ref().unwrap().lead == raw_node.raft.id {
            let _ = raw_node.propose(Vec::from("somedata"));
            let mut cc = ConfChange::new();
            cc.set_change_type(ConfChangeType::ConfChangeAddNode);
            cc.set_node_id(1);
            ccdata = protobuf::Message::write_to_bytes(&cc).expect("unexpected marshal error");

            let _ = raw_node.propose_conf_change(&cc);
            proposed = true;
        }

        raw_node.advance(rd);
        last_index = s.last_index().unwrap();
        if last_index >= 4 {
            break;
        }
    }

    let mut ents = s.entries(last_index - 1, last_index + 1, NO_LIMIT).unwrap();

    assert_eq!(ents.len(), 2);
    assert_eq!(ents[0].take_data(), Vec::from("somedata"));
    assert_eq!(ents[1].get_entry_type(), EntryType::EntryConfChange);
    assert_eq!(ents[1].take_data(), ccdata);
}

// ensures that two proposes to add the same node should
// not affect the later propose to add new node.
#[test]
fn test_raw_node_proposal_add_duplicate_node() {
    let mut s = MemStorage::new();
    let mut raw_node = RawNode::new(
        &mut new_test_config(1, vec![], 10, 1),
        s.clone(),
        vec![Peer {
            context: Default::default(),
            id: 1,
        }],
    ).unwrap();

    let rd = raw_node.ready();
    let _ = s.append(&rd.entries);
    raw_node.advance(rd);
    let _ = raw_node.campaign();

    loop {
        let rd = raw_node.ready();
        let _ = s.append(&rd.entries);
        let lead = rd.soft_state.as_ref().unwrap().lead;
        if lead == raw_node.raft.id {
            raw_node.advance(rd);
            break;
        }
        raw_node.advance(rd);
    }

    let mut propose_conf_change_and_apply = |cc: &ConfChange| {
        let _ = raw_node.propose_conf_change(cc);
        let rd = raw_node.ready();
        let _ = s.write_lock().append(&rd.entries);
        for e in &rd.committed_entries {
            if e.get_entry_type() == EntryType::EntryConfChange {
                let conf_change = protobuf::parse_from_bytes(e.get_data()).unwrap();
                raw_node.apply_conf_change(&conf_change);
            }
        }

        raw_node.advance(rd);
    };

    let mut cc1 = ConfChange::new();
    cc1.set_change_type(ConfChangeType::ConfChangeAddNode);
    cc1.set_node_id(1);
    let ccdata1 = protobuf::Message::write_to_bytes(&cc1).expect("unexpected marshal error");
    propose_conf_change_and_apply(&cc1);
    propose_conf_change_and_apply(&cc1);

    let mut cc2 = ConfChange::new();
    cc2.set_change_type(ConfChangeType::ConfChangeAddNode);
    cc2.set_node_id(2);
    let ccdata2 = protobuf::Message::write_to_bytes(&cc2).expect("unexpected marshal error");

    propose_conf_change_and_apply(&cc2);

    let last_index = s.last_index().unwrap();
    let mut entries = s.entries(last_index - 2, last_index + 1, NO_LIMIT).unwrap();
    assert_eq!(entries.len(), 3);
    assert_eq!(entries[0].take_data(), ccdata1);
    assert_eq!(entries[2].take_data(), ccdata2);
}

#[test]
fn test_raw_node_read_index() {
    let wrs = vec![ReadState {
        index: 1,
        request_ctx: Vec::from("somedata"),
    }];

    let mut s = MemStorage::new();
    let mut c = new_test_config(1, vec![], 10, 1);
    let mut raw_node = RawNode::new(
        &mut c,
        s.clone(),
        vec![Peer {
            context: Default::default(),
            id: 1,
        }],
    ).unwrap();

    raw_node.raft.read_states = wrs.clone();
    let has_ready = raw_node.has_ready();
    assert!(has_ready);

    let rd = raw_node.ready();
    assert_eq!(rd.read_states, wrs);

    let _ = s.append(&rd.entries);
    raw_node.advance(rd);

    assert!(raw_node.raft.read_states.is_empty());

    let wrequest_ctx = Vec::from("somedata2");
    let _ = raw_node.campaign();

    loop {
        let rd = raw_node.ready();
        let _ = s.append(&rd.entries);

        if rd.soft_state.as_ref().unwrap().lead == raw_node.raft.id {
            raw_node.advance(rd);

            raw_node.read_index(wrequest_ctx.clone());
            break;
        }

        raw_node.advance(rd);
    }

    assert_eq!(raw_node.raft.read_states.len(), 1);
    assert_eq!(raw_node.raft.read_states[0].request_ctx, wrequest_ctx);
}

#[test]
fn test_raw_node_start() {
    let mut s = MemStorage::new();
    let mut c = new_test_config(1, vec![], 10, 1);
    let mut raw_node = RawNode::new(
        &mut c,
        s.clone(),
        vec![Peer {
            context: Default::default(),
            id: 1,
        }],
    ).unwrap();

    let rd = raw_node.ready();

    assert_eq!(rd.hard_state.get_term(), 1);
    assert_eq!(rd.hard_state.get_commit(), 1);
    assert_eq!(rd.hard_state.get_vote(), 0);
    assert_eq!(rd.must_sync, true);

    let mut cc = ConfChange::new();
    cc.set_change_type(ConfChangeType::ConfChangeAddNode);
    cc.set_node_id(1);
    let ccdata = protobuf::Message::write_to_bytes(&cc).expect("unexpected marshal error");
    assert_eq!(rd.entries.len(), 1);
    assert_eq!(rd.entries[0].get_entry_type(), EntryType::EntryConfChange);
    assert_eq!(rd.entries[0].get_term(), 1);
    assert_eq!(rd.entries[0].get_index(), 1);
    assert_eq!(Vec::from(rd.entries[0].get_data()), ccdata);

    let _ = s.append(&rd.entries);
    raw_node.advance(rd.clone());
    let _ = s.append(&rd.entries);
    raw_node.advance(rd);
    let _ = raw_node.campaign();
    let rd = raw_node.ready();
    let _ = s.append(&rd.entries);
    raw_node.advance(rd.clone());

    let _ = raw_node.propose(Vec::from("foo"));
    let rd = raw_node.ready();

    assert_eq!(rd.hard_state.get_term(), 2);
    assert_eq!(rd.hard_state.get_commit(), 3);
    assert_eq!(rd.hard_state.get_vote(), 1);
    assert_eq!(rd.must_sync, true);

    assert_eq!(rd.entries.len(), 1);
    assert_eq!(rd.entries[0].get_term(), 2);
    assert_eq!(rd.entries[0].get_index(), 3);
    assert_eq!(Vec::from(rd.entries[0].get_data()), Vec::from("foo"));
}

#[test]
fn test_raw_node_restart() {
    let mut st = HardState::new();
    st.set_term(1);
    st.set_commit(1);
    let mut e1 = Entry::new();
    e1.set_term(1);
    e1.set_index(1);
    let mut e2 = Entry::new();
    e2.set_term(1);
    e2.set_index(2);
    e2.set_data(Vec::from("foo"));
    let entries = vec![e1];
    let mut s = MemStorage::new();
    s.set_hard_state(st);
    let _ = s.append(&entries);

    let mut c = new_test_config(1, vec![], 10, 1);
    let mut raw_node = RawNode::new(
        &mut c,
        s.clone(),
        vec![Peer {
            context: Default::default(),
            id: 1,
        }],
    ).unwrap();

    let rd = raw_node.ready();
    assert_eq!(rd.hard_state, HardState::new());
    assert_eq!(rd.committed_entries.len(), 1);
    assert_eq!(rd.committed_entries[0].get_term(), 1);
    assert_eq!(rd.committed_entries[0].get_index(), 1);
    assert_eq!(rd.must_sync, true);
    raw_node.advance(rd);
    assert_eq!(raw_node.has_ready(), false);
}

#[test]
fn test_raw_node_restart_from_snapshot() {
    let mut snap = Snapshot::new();
    let mut md = SnapshotMetadata::new();
    let mut cs = ConfState::new();
    cs.set_nodes(vec![1, 2]);
    md.set_index(2);
    md.set_term(1);
    md.set_conf_state(cs);
    snap.set_metadata(md);
    let mut st = HardState::new();
    st.set_term(1);
    st.set_commit(3);
    let mut e2 = Entry::new();
    e2.set_term(1);
    e2.set_index(3);
    e2.set_data(Vec::from("foo"));
    let entries = vec![e2];
    let mut s = MemStorage::new();
    s.set_hard_state(st);
    let _ = s.apply_snapshot(snap);
    let _ = s.append(&entries);

    let mut c = new_test_config(1, vec![], 10, 1);
    let mut raw_node = RawNode::new(
        &mut c,
        s.clone(),
        vec![Peer {
            context: Default::default(),
            id: 1,
        }],
    ).unwrap();

    let rd = raw_node.ready();
    assert_eq!(rd.hard_state, HardState::new());
    assert_eq!(rd.committed_entries.len(), 1);
    assert_eq!(rd.committed_entries[0].get_term(), 1);
    assert_eq!(rd.committed_entries[0].get_index(), 3);
    assert_eq!(rd.must_sync, true);
    raw_node.advance(rd);
    assert_eq!(raw_node.has_ready(), false);
}

#[test]
fn test_raw_node_status() {
    let mut c = new_test_config(1, vec![], 10, 1);
    let raw_node = RawNode::new(
        &mut c,
        MemStorage::new(),
        vec![Peer {
            context: Default::default(),
            id: 1,
        }],
    ).unwrap();

    let status = raw_node.status();
    let mut hs = HardState::new();
    hs.set_commit(1);
    hs.set_term(1);
    assert_eq!(
        status,
        Status {
            id: 1,
            hard_state: hs,
            ..Default::default()
        }
    );
}