// Copyright 2015-2020 Parity Technologies (UK) Ltd.
// This file is part of OpenEthereum.

// OpenEthereum 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.

// OpenEthereum 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 OpenEthereum.  If not, see <http://www.gnu.org/licenses/>.

extern crate ansi_term;
use self::ansi_term::{
    Colour,
    Colour::{Blue, Cyan, Green, White, Yellow},
    Style,
};

use std::{
    sync::{
        atomic::{AtomicBool, AtomicUsize, Ordering as AtomicOrdering},
        Arc,
    },
    time::{Duration, Instant},
};

use atty;
use ethcore::{
    client::{
        BlockChainClient, BlockChainInfo, BlockId, BlockInfo, BlockQueueInfo, ChainInfo,
        ChainNotify, Client, ClientIoMessage, ClientReport, NewBlocks,
    },
    snapshot::{service::Service as SnapshotService, RestorationStatus, SnapshotService as SS},
};
use io::{IoContext, IoHandler, TimerToken};
use number_prefix::{binary_prefix, Prefixed, Standalone};
use parity_rpc::{informant::RpcStats, is_major_importing_or_waiting};
use parking_lot::{Mutex, RwLock};
use sync::{ManageNetwork, SyncProvider};
use types::BlockNumber;

/// Format byte counts to standard denominations.
pub fn format_bytes(b: usize) -> String {
    match binary_prefix(b as f64) {
        Standalone(bytes) => format!("{} bytes", bytes),
        Prefixed(prefix, n) => format!("{:.0} {}B", n, prefix),
    }
}

/// Something that can be converted to milliseconds.
pub trait MillisecondDuration {
    /// Get the value in milliseconds.
    fn as_milliseconds(&self) -> u64;
}

impl MillisecondDuration for Duration {
    fn as_milliseconds(&self) -> u64 {
        self.as_secs() * 1000 + self.subsec_nanos() as u64 / 1_000_000
    }
}

#[derive(Default)]
struct CacheSizes {
    sizes: ::std::collections::BTreeMap<&'static str, usize>,
}

impl CacheSizes {
    fn insert(&mut self, key: &'static str, bytes: usize) {
        self.sizes.insert(key, bytes);
    }

    fn display<F>(&self, style: Style, paint: F) -> String
    where
        F: Fn(Style, String) -> String,
    {
        use std::fmt::Write;

        let mut buf = String::new();
        for (name, &size) in &self.sizes {
            write!(buf, " {:>8} {}", paint(style, format_bytes(size)), name)
                .expect("writing to string won't fail unless OOM; qed")
        }

        buf
    }
}

pub struct SyncInfo {
    last_imported_block_number: BlockNumber,
    last_imported_old_block_number: Option<BlockNumber>,
    num_peers: usize,
    max_peers: u32,
    snapshot_sync: bool,
}

pub struct Report {
    importing: bool,
    chain_info: BlockChainInfo,
    client_report: ClientReport,
    queue_info: BlockQueueInfo,
    cache_sizes: CacheSizes,
    sync_info: Option<SyncInfo>,
}

/// Something which can provide data to the informant.
pub trait InformantData: Send + Sync {
    /// Whether it executes transactions
    fn executes_transactions(&self) -> bool;

    /// Whether it is currently importing (also included in `Report`)
    fn is_major_importing(&self) -> bool;

    /// Generate a report of blockchain status, memory usage, and sync info.
    fn report(&self) -> Report;
}

/// Informant data for a full node.
pub struct FullNodeInformantData {
    pub client: Arc<Client>,
    pub sync: Option<Arc<dyn SyncProvider>>,
    pub net: Option<Arc<dyn ManageNetwork>>,
}

impl InformantData for FullNodeInformantData {
    fn executes_transactions(&self) -> bool {
        true
    }

    fn is_major_importing(&self) -> bool {
        let state = self.sync.as_ref().map(|sync| sync.status().state);
        is_major_importing_or_waiting(state, self.client.queue_info(), false)
    }

    fn report(&self) -> Report {
        let (client_report, queue_info, blockchain_cache_info) = (
            self.client.report(),
            self.client.queue_info(),
            self.client.blockchain_cache_info(),
        );

        let chain_info = self.client.chain_info();

        let mut cache_sizes = CacheSizes::default();
        cache_sizes.insert("queue", queue_info.mem_used);
        cache_sizes.insert("chain", blockchain_cache_info.total());

        let importing = self.is_major_importing();
        let sync_info = match (self.sync.as_ref(), self.net.as_ref()) {
            (Some(sync), Some(net)) => {
                let status = sync.status();
                let num_peers_range = net.num_peers_range();
                debug_assert!(num_peers_range.end() >= num_peers_range.start());

                Some(SyncInfo {
                    last_imported_block_number: status
                        .last_imported_block_number
                        .unwrap_or(chain_info.best_block_number),
                    last_imported_old_block_number: status.last_imported_old_block_number,
                    num_peers: status.num_peers,
                    max_peers: status
                        .current_max_peers(*num_peers_range.start(), *num_peers_range.end()),
                    snapshot_sync: status.is_snapshot_syncing(),
                })
            }
            _ => None,
        };

        Report {
            importing,
            chain_info,
            client_report,
            queue_info,
            cache_sizes,
            sync_info,
        }
    }
}

pub struct Informant<T> {
    last_tick: RwLock<Instant>,
    with_color: bool,
    target: T,
    snapshot: Option<Arc<SnapshotService>>,
    rpc_stats: Option<Arc<RpcStats>>,
    last_import: Mutex<Instant>,
    skipped: AtomicUsize,
    skipped_txs: AtomicUsize,
    in_shutdown: AtomicBool,
    last_report: Mutex<ClientReport>,
}

impl<T: InformantData> Informant<T> {
    /// Make a new instance potentially `with_color` output.
    pub fn new(
        target: T,
        snapshot: Option<Arc<SnapshotService>>,
        rpc_stats: Option<Arc<RpcStats>>,
        with_color: bool,
    ) -> Self {
        Informant {
            last_tick: RwLock::new(Instant::now()),
            with_color: with_color,
            target: target,
            snapshot: snapshot,
            rpc_stats: rpc_stats,
            last_import: Mutex::new(Instant::now()),
            skipped: AtomicUsize::new(0),
            skipped_txs: AtomicUsize::new(0),
            in_shutdown: AtomicBool::new(false),
            last_report: Mutex::new(Default::default()),
        }
    }

    /// Signal that we're shutting down; no more output necessary.
    pub fn shutdown(&self) {
        self.in_shutdown
            .store(true, ::std::sync::atomic::Ordering::SeqCst);
    }

    pub fn tick(&self) {
        let now = Instant::now();
        let elapsed = now.duration_since(*self.last_tick.read());

        let (client_report, full_report) = {
            let last_report = self.last_report.lock();
            let full_report = self.target.report();
            let diffed = full_report.client_report.clone() - &*last_report;
            (diffed, full_report)
        };

        let Report {
            importing,
            chain_info,
            queue_info,
            cache_sizes,
            sync_info,
            ..
        } = full_report;

        let rpc_stats = self.rpc_stats.as_ref();
        let snapshot_sync = sync_info.as_ref().map_or(false, |s| s.snapshot_sync)
            && self
                .snapshot
                .as_ref()
                .map_or(false, |s| match s.restoration_status() {
                    RestorationStatus::Ongoing { .. } | RestorationStatus::Initializing { .. } => {
                        true
                    }
                    _ => false,
                });
        if !importing && !snapshot_sync && elapsed < Duration::from_secs(30) {
            return;
        }

        *self.last_tick.write() = now;
        *self.last_report.lock() = full_report.client_report.clone();

        let paint = |c: Style, t: String| match self.with_color && atty::is(atty::Stream::Stdout) {
            true => format!("{}", c.paint(t)),
            false => t,
        };

        info!(target: "import", "{}  {}  {}  {}",
            match importing {
                true => match snapshot_sync {
                    false => format!("Syncing {} {}  {}  {}+{} Qed",
                        paint(White.bold(), format!("{:>8}", format!("#{}", chain_info.best_block_number))),
                        paint(White.bold(), format!("{}", chain_info.best_block_hash)),
                        if self.target.executes_transactions() {
                            format!("{} blk/s {} tx/s {} Mgas/s",
                                paint(Yellow.bold(), format!("{:7.2}", (client_report.blocks_imported * 1000) as f64 / elapsed.as_milliseconds() as f64)),
                                paint(Yellow.bold(), format!("{:6.1}", (client_report.transactions_applied * 1000) as f64 / elapsed.as_milliseconds() as f64)),
                                paint(Yellow.bold(), format!("{:6.1}", (client_report.gas_processed / 1000).low_u64() as f64 / elapsed.as_milliseconds() as f64))
                            )
                        } else {
                            format!("{} hdr/s",
                                paint(Yellow.bold(), format!("{:6.1}", (client_report.blocks_imported * 1000) as f64 / elapsed.as_milliseconds() as f64))
                            )
                        },
                        paint(Green.bold(), format!("{:5}", queue_info.unverified_queue_size)),
                        paint(Green.bold(), format!("{:5}", queue_info.verified_queue_size))
                    ),
                    true => {
                        self.snapshot.as_ref().map_or(String::new(), |s|
                            match s.restoration_status() {
                                RestorationStatus::Ongoing { state_chunks, block_chunks, state_chunks_done, block_chunks_done, .. } => {
                                    format!("Syncing snapshot {}/{}", state_chunks_done + block_chunks_done, state_chunks + block_chunks)
                                },
                                RestorationStatus::Initializing { chunks_done } => {
                                    format!("Snapshot initializing ({} chunks restored)", chunks_done)
                                },
                                _ => String::new(),
                            }
                        )
                    },
                },
                false => String::new(),
            },
            match sync_info.as_ref() {
                Some(ref sync_info) => format!("{}{}/{} peers",
                    match importing {
                        true => format!("{}",
                            if self.target.executes_transactions() {
                                paint(Green.bold(), format!("{:>8}   ", format!("#{}", sync_info.last_imported_block_number)))
                            } else {
                                String::new()
                            }
                        ),
                        false => match sync_info.last_imported_old_block_number {
                            Some(number) => format!("{}   ", paint(Yellow.bold(), format!("{:>8}", format!("#{}", number)))),
                            None => String::new(),
                        }
                    },
                    paint(Cyan.bold(), format!("{:2}", sync_info.num_peers)),
                    paint(Cyan.bold(), format!("{:2}", sync_info.max_peers)),
                ),
                _ => String::new(),
            },
            cache_sizes.display(Blue.bold(), &paint),
            match rpc_stats {
                Some(ref rpc_stats) => format!(
                    "RPC: {} conn, {} req/s, {} µs",
                    paint(Blue.bold(), format!("{:2}", rpc_stats.sessions())),
                    paint(Blue.bold(), format!("{:4}", rpc_stats.requests_rate())),
                    paint(Blue.bold(), format!("{:4}", rpc_stats.approximated_roundtrip())),
                ),
                _ => String::new(),
            },
        );
    }
}

impl ChainNotify for Informant<FullNodeInformantData> {
    fn new_blocks(&self, new_blocks: NewBlocks) {
        if new_blocks.has_more_blocks_to_import {
            return;
        }
        let mut last_import = self.last_import.lock();
        let client = &self.target.client;

        let importing = self.target.is_major_importing();
        let ripe = Instant::now() > *last_import + Duration::from_secs(1) && !importing;
        let txs_imported = new_blocks
            .imported
            .iter()
            .take(
                new_blocks
                    .imported
                    .len()
                    .saturating_sub(if ripe { 1 } else { 0 }),
            )
            .filter_map(|h| client.block(BlockId::Hash(*h)))
            .map(|b| b.transactions_count())
            .sum();

        if ripe {
            if let Some(block) = new_blocks
                .imported
                .last()
                .and_then(|h| client.block(BlockId::Hash(*h)))
            {
                let header_view = block.header_view();
                let size = block.rlp().as_raw().len();
                let (skipped, skipped_txs) = (
                    self.skipped.load(AtomicOrdering::Relaxed) + new_blocks.imported.len() - 1,
                    self.skipped_txs.load(AtomicOrdering::Relaxed) + txs_imported,
                );
                info!(target: "import", "Imported {} {} ({} txs, {} Mgas, {} ms, {} KiB){}",
                    Colour::White.bold().paint(format!("#{}", header_view.number())),
                    Colour::White.bold().paint(format!("{}", header_view.hash())),
                    Colour::Yellow.bold().paint(format!("{}", block.transactions_count())),
                    Colour::Yellow.bold().paint(format!("{:.2}", header_view.gas_used().low_u64() as f32 / 1000000f32)),
                    Colour::Purple.bold().paint(format!("{}", new_blocks.duration.as_milliseconds())),
                    Colour::Blue.bold().paint(format!("{:.2}", size as f32 / 1024f32)),
                    if skipped > 0 {
                        format!(" + another {} block(s) containing {} tx(s)",
                            Colour::Red.bold().paint(format!("{}", skipped)),
                            Colour::Red.bold().paint(format!("{}", skipped_txs))
                        )
                    } else {
                        String::new()
                    }
                );
                self.skipped.store(0, AtomicOrdering::Relaxed);
                self.skipped_txs.store(0, AtomicOrdering::Relaxed);
                *last_import = Instant::now();
            }
        } else {
            self.skipped
                .fetch_add(new_blocks.imported.len(), AtomicOrdering::Relaxed);
            self.skipped_txs
                .fetch_add(txs_imported, AtomicOrdering::Relaxed);
        }
    }
}

const INFO_TIMER: TimerToken = 0;

impl<T: InformantData> IoHandler<ClientIoMessage> for Informant<T> {
    fn initialize(&self, io: &IoContext<ClientIoMessage>) {
        io.register_timer(INFO_TIMER, Duration::from_secs(5))
            .expect("Error registering timer");
    }

    fn timeout(&self, _io: &IoContext<ClientIoMessage>, timer: TimerToken) {
        if timer == INFO_TIMER && !self.in_shutdown.load(AtomicOrdering::SeqCst) {
            self.tick();
        }
    }
}