// Written in 2014 by Andrew Poelstra <apoelstra@wpsoftware.net>
// SPDX-License-Identifier: CC0-1.0

//! Bitcoin network messages.
//!
//! This module defines the `NetworkMessage` and `RawNetworkMessage` types that
//! are used for (de)serializing Bitcoin objects for transmission on the network.
//!

use crate::prelude::*;

use core::{fmt, iter};
use core::convert::TryFrom;

use crate::io;
use io::Read as _;
use crate::blockdata::block;
use crate::blockdata::transaction;
use crate::network::address::{Address, AddrV2Message};
use crate::network::{message_network, message_bloom};
use crate::network::message_blockdata;
use crate::network::message_filter;
use crate::network::message_compact_blocks;
use crate::network::constants::Magic;
use crate::consensus::encode::{CheckedData, Decodable, Encodable, VarInt};
use crate::consensus::{encode, serialize};
use crate::util::merkleblock::MerkleBlock;

/// The maximum number of [super::message_blockdata::Inventory] items in an `inv` message.
///
/// This limit is not currently enforced by this implementation.
pub const MAX_INV_SIZE: usize = 50_000;

/// Maximum size, in bytes, of an encoded message
/// This by neccessity should be larger tham `MAX_VEC_SIZE`
pub const MAX_MSG_SIZE: usize = 5_000_000;

/// Serializer for command string
#[derive(PartialEq, Eq, Clone, Debug)]
pub struct CommandString(Cow<'static, str>);

impl CommandString {
    /// Convert `&'static str` to `CommandString`
    ///
    /// This is more efficient for string literals than non-static conversions because it avoids
    /// allocation.
    ///
    /// # Errors
    ///
    /// Returns an error if and only if the string is
    /// larger than 12 characters in length.
    pub fn try_from_static(s: &'static str) -> Result<CommandString, CommandStringError> {
        Self::try_from_static_cow(s.into())
    }

    fn try_from_static_cow(cow: Cow<'static, str>) -> Result<CommandString, CommandStringError> {
        if cow.len() > 12 {
            Err(CommandStringError { cow })
        } else {
            Ok(CommandString(cow))
        }
    }
}

impl TryFrom<String> for CommandString {
    type Error = CommandStringError;

    fn try_from(value: String) -> Result<Self, Self::Error> {
        Self::try_from_static_cow(value.into())
    }
}

impl TryFrom<Box<str>> for CommandString {
    type Error = CommandStringError;

    fn try_from(value: Box<str>) -> Result<Self, Self::Error> {
        Self::try_from_static_cow(String::from(value).into())
    }
}

impl<'a> TryFrom<&'a str> for CommandString {
    type Error = CommandStringError;

    fn try_from(value: &'a str) -> Result<Self, Self::Error> {
        Self::try_from_static_cow(value.to_owned().into())
    }
}

impl core::str::FromStr for CommandString {
    type Err = CommandStringError;

    fn from_str(s: &str) -> Result<Self, Self::Err> {
        Self::try_from_static_cow(s.to_owned().into())
    }
}

impl fmt::Display for CommandString {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        f.write_str(self.0.as_ref())
    }
}

impl AsRef<str> for CommandString {
    fn as_ref(&self) -> &str {
        self.0.as_ref()
    }
}

impl Encodable for CommandString {
    #[inline]
    fn consensus_encode<W: io::Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
        let mut rawbytes = [0u8; 12];
        let strbytes = self.0.as_bytes();
        debug_assert!(strbytes.len() <= 12);
        rawbytes[..strbytes.len()].copy_from_slice(strbytes);
        rawbytes.consensus_encode(w)
    }
}

impl Decodable for CommandString {
    #[inline]
    fn consensus_decode<R: io::Read + ?Sized>(r: &mut R) -> Result<Self, encode::Error> {
        let rawbytes: [u8; 12] = Decodable::consensus_decode(r)?;
        let rv = iter::FromIterator::from_iter(
            rawbytes
                .iter()
                .filter_map(|&u| if u > 0 { Some(u as char) } else { None })
        );
        Ok(CommandString(rv))
    }
}

/// Error returned when a command string is invalid.
///
/// This is currently returned for command strings longer than 12.
#[derive(Clone, Debug)]
pub struct CommandStringError {
    cow: Cow<'static, str>,
}

impl fmt::Display for CommandStringError {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(f, "the command string '{}' has length {} which is larger than 12", self.cow, self.cow.len())
    }
}

crate::error::impl_std_error!(CommandStringError);

/// A Network message
#[derive(Clone, Debug, PartialEq, Eq)]
pub struct RawNetworkMessage {
    /// Magic bytes to identify the network these messages are meant for
    pub magic: Magic,
    /// The actual message data
    pub payload: NetworkMessage
}

/// A Network message payload. Proper documentation is available on at
/// [Bitcoin Wiki: Protocol Specification](https://en.bitcoin.it/wiki/Protocol_specification)
#[derive(Clone, PartialEq, Eq, Debug)]
pub enum NetworkMessage {
    /// `version`
    Version(message_network::VersionMessage),
    /// `verack`
    Verack,
    /// `addr`
    Addr(Vec<(u32, Address)>),
    /// `inv`
    Inv(Vec<message_blockdata::Inventory>),
    /// `getdata`
    GetData(Vec<message_blockdata::Inventory>),
    /// `notfound`
    NotFound(Vec<message_blockdata::Inventory>),
    /// `getblocks`
    GetBlocks(message_blockdata::GetBlocksMessage),
    /// `getheaders`
    GetHeaders(message_blockdata::GetHeadersMessage),
    /// `mempool`
    MemPool,
    /// tx
    Tx(transaction::Transaction),
    /// `block`
    Block(block::Block),
    /// `headers`
    Headers(Vec<block::BlockHeader>),
    /// `sendheaders`
    SendHeaders,
    /// `getaddr`
    GetAddr,
    // TODO: checkorder,
    // TODO: submitorder,
    // TODO: reply,
    /// `ping`
    Ping(u64),
    /// `pong`
    Pong(u64),
    /// `merkleblock`
    MerkleBlock(MerkleBlock),
    /// BIP 37 `filterload`
    FilterLoad(message_bloom::FilterLoad),
    /// BIP 37 `filteradd`
    FilterAdd(message_bloom::FilterAdd),
    /// BIP 37 `filterclear`
    FilterClear,
    /// BIP157 getcfilters
    GetCFilters(message_filter::GetCFilters),
    /// BIP157 cfilter
    CFilter(message_filter::CFilter),
    /// BIP157 getcfheaders
    GetCFHeaders(message_filter::GetCFHeaders),
    /// BIP157 cfheaders
    CFHeaders(message_filter::CFHeaders),
    /// BIP157 getcfcheckpt
    GetCFCheckpt(message_filter::GetCFCheckpt),
    /// BIP157 cfcheckpt
    CFCheckpt(message_filter::CFCheckpt),
    /// BIP152 sendcmpct
    SendCmpct(message_compact_blocks::SendCmpct),
    /// BIP152 cmpctblock
    CmpctBlock(message_compact_blocks::CmpctBlock),
    /// BIP152 getblocktxn
    GetBlockTxn(message_compact_blocks::GetBlockTxn),
    /// BIP152 blocktxn
    BlockTxn(message_compact_blocks::BlockTxn),
    /// `alert`
    Alert(Vec<u8>),
    /// `reject`
    Reject(message_network::Reject),
    /// `feefilter`
    FeeFilter(i64),
    /// `wtxidrelay`
    WtxidRelay,
    /// `addrv2`
    AddrV2(Vec<AddrV2Message>),
    /// `sendaddrv2`
    SendAddrV2,

    /// Any other message.
    Unknown {
        /// The command of this message.
        command: CommandString,
        /// The payload of this message.
        payload: Vec<u8>,
    }
}

impl NetworkMessage {
    /// Return the message command as a static string reference.
    ///
    /// This returns `"unknown"` for [NetworkMessage::Unknown],
    /// regardless of the actual command in the unknown message.
    /// Use the [Self::command] method to get the command for unknown messages.
    pub fn cmd(&self) -> &'static str {
        match *self {
            NetworkMessage::Version(_) => "version",
            NetworkMessage::Verack     => "verack",
            NetworkMessage::Addr(_)    => "addr",
            NetworkMessage::Inv(_)     => "inv",
            NetworkMessage::GetData(_) => "getdata",
            NetworkMessage::NotFound(_) => "notfound",
            NetworkMessage::GetBlocks(_) => "getblocks",
            NetworkMessage::GetHeaders(_) => "getheaders",
            NetworkMessage::MemPool    => "mempool",
            NetworkMessage::Tx(_)      => "tx",
            NetworkMessage::Block(_)   => "block",
            NetworkMessage::Headers(_) => "headers",
            NetworkMessage::SendHeaders => "sendheaders",
            NetworkMessage::GetAddr    => "getaddr",
            NetworkMessage::Ping(_)    => "ping",
            NetworkMessage::Pong(_)    => "pong",
            NetworkMessage::MerkleBlock(_) => "merkleblock",
            NetworkMessage::FilterLoad(_) => "filterload",
            NetworkMessage::FilterAdd(_)    => "filteradd",
            NetworkMessage::FilterClear    => "filterclear",
            NetworkMessage::GetCFilters(_) => "getcfilters",
            NetworkMessage::CFilter(_) => "cfilter",
            NetworkMessage::GetCFHeaders(_) => "getcfheaders",
            NetworkMessage::CFHeaders(_) => "cfheaders",
            NetworkMessage::GetCFCheckpt(_) => "getcfcheckpt",
            NetworkMessage::CFCheckpt(_) => "cfcheckpt",
            NetworkMessage::SendCmpct(_) => "sendcmpct",
            NetworkMessage::CmpctBlock(_) => "cmpctblock",
            NetworkMessage::GetBlockTxn(_) => "getblocktxn",
            NetworkMessage::BlockTxn(_) => "blocktxn",
            NetworkMessage::Alert(_)    => "alert",
            NetworkMessage::Reject(_)    => "reject",
            NetworkMessage::FeeFilter(_) => "feefilter",
            NetworkMessage::WtxidRelay => "wtxidrelay",
            NetworkMessage::AddrV2(_) => "addrv2",
            NetworkMessage::SendAddrV2 => "sendaddrv2",
            NetworkMessage::Unknown { .. } => "unknown",
        }
    }

    /// Return the CommandString for the message command.
    pub fn command(&self) -> CommandString {
        match *self {
            NetworkMessage::Unknown { command: ref c, .. } => c.clone(),
            _ => CommandString::try_from_static(self.cmd()).expect("cmd returns valid commands")
        }
    }
}

impl RawNetworkMessage {
    /// Return the message command as a static string reference.
    ///
    /// This returns `"unknown"` for [NetworkMessage::Unknown],
    /// regardless of the actual command in the unknown message.
    /// Use the [Self::command] method to get the command for unknown messages.
    pub fn cmd(&self) -> &'static str {
        self.payload.cmd()
    }

    /// Return the CommandString for the message command.
    pub fn command(&self) -> CommandString {
        self.payload.command()
    }
}

struct HeaderSerializationWrapper<'a>(&'a Vec<block::BlockHeader>);

impl<'a> Encodable for HeaderSerializationWrapper<'a> {
    #[inline]
    fn consensus_encode<W: io::Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
        let mut len = 0;
        len += VarInt(self.0.len() as u64).consensus_encode(w)?;
        for header in self.0.iter() {
            len += header.consensus_encode(w)?;
            len += 0u8.consensus_encode(w)?;
        }
        Ok(len)
    }
}

impl Encodable for RawNetworkMessage {
    fn consensus_encode<W: io::Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
        let mut len = 0;
        len += self.magic.consensus_encode(w)?;
        len += self.command().consensus_encode(w)?;
        len += CheckedData(match self.payload {
            NetworkMessage::Version(ref dat) => serialize(dat),
            NetworkMessage::Addr(ref dat)    => serialize(dat),
            NetworkMessage::Inv(ref dat)     => serialize(dat),
            NetworkMessage::GetData(ref dat) => serialize(dat),
            NetworkMessage::NotFound(ref dat) => serialize(dat),
            NetworkMessage::GetBlocks(ref dat) => serialize(dat),
            NetworkMessage::GetHeaders(ref dat) => serialize(dat),
            NetworkMessage::Tx(ref dat)      => serialize(dat),
            NetworkMessage::Block(ref dat)   => serialize(dat),
            NetworkMessage::Headers(ref dat) => serialize(&HeaderSerializationWrapper(dat)),
            NetworkMessage::Ping(ref dat)    => serialize(dat),
            NetworkMessage::Pong(ref dat)    => serialize(dat),
            NetworkMessage::MerkleBlock(ref dat)    => serialize(dat),
            NetworkMessage::FilterLoad(ref dat)    => serialize(dat),
            NetworkMessage::FilterAdd(ref dat)    => serialize(dat),
            NetworkMessage::GetCFilters(ref dat) => serialize(dat),
            NetworkMessage::CFilter(ref dat) => serialize(dat),
            NetworkMessage::GetCFHeaders(ref dat) => serialize(dat),
            NetworkMessage::CFHeaders(ref dat) => serialize(dat),
            NetworkMessage::GetCFCheckpt(ref dat) => serialize(dat),
            NetworkMessage::CFCheckpt(ref dat) => serialize(dat),
            NetworkMessage::SendCmpct(ref dat) => serialize(dat),
            NetworkMessage::CmpctBlock(ref dat) => serialize(dat),
            NetworkMessage::GetBlockTxn(ref dat) => serialize(dat),
            NetworkMessage::BlockTxn(ref dat) => serialize(dat),
            NetworkMessage::Alert(ref dat)    => serialize(dat),
            NetworkMessage::Reject(ref dat) => serialize(dat),
            NetworkMessage::FeeFilter(ref data) => serialize(data),
            NetworkMessage::AddrV2(ref dat) => serialize(dat),
            NetworkMessage::Verack
            | NetworkMessage::SendHeaders
            | NetworkMessage::MemPool
            | NetworkMessage::GetAddr
            | NetworkMessage::WtxidRelay
            | NetworkMessage::FilterClear
            | NetworkMessage::SendAddrV2 => vec![],
            NetworkMessage::Unknown { payload: ref data, .. } => serialize(data),
        }).consensus_encode(w)?;
        Ok(len)
    }
}

struct HeaderDeserializationWrapper(Vec<block::BlockHeader>);

impl Decodable for HeaderDeserializationWrapper {
    #[inline]
    fn consensus_decode_from_finite_reader<R: io::Read + ?Sized>(r: &mut R) -> Result<Self, encode::Error> {
        let len = VarInt::consensus_decode(r)?.0;
        // should be above usual number of items to avoid
        // allocation
        let mut ret = Vec::with_capacity(core::cmp::min(1024 * 16, len as usize));
        for _ in 0..len {
            ret.push(Decodable::consensus_decode(r)?);
            if u8::consensus_decode(r)? != 0u8 {
                return Err(encode::Error::ParseFailed("Headers message should not contain transactions"));
            }
        }
        Ok(HeaderDeserializationWrapper(ret))
    }

    #[inline]
    fn consensus_decode<R: io::Read + ?Sized>(r: &mut R) -> Result<Self, encode::Error> {
        Self::consensus_decode_from_finite_reader(r.take(MAX_MSG_SIZE as u64).by_ref())
    }
}

impl Decodable for RawNetworkMessage {
    fn consensus_decode_from_finite_reader<R: io::Read + ?Sized>(r: &mut R) -> Result<Self, encode::Error> {
        let magic = Decodable::consensus_decode_from_finite_reader(r)?;
        let cmd = CommandString::consensus_decode_from_finite_reader(r)?;
        let raw_payload = CheckedData::consensus_decode_from_finite_reader(r)?.0;

        let mut mem_d = io::Cursor::new(raw_payload);
        let payload = match &cmd.0[..] {
            "version" => NetworkMessage::Version(Decodable::consensus_decode_from_finite_reader(&mut mem_d)?),
            "verack"  => NetworkMessage::Verack,
            "addr"    => NetworkMessage::Addr(Decodable::consensus_decode_from_finite_reader(&mut mem_d)?),
            "inv"     => NetworkMessage::Inv(Decodable::consensus_decode_from_finite_reader(&mut mem_d)?),
            "getdata" => NetworkMessage::GetData(Decodable::consensus_decode_from_finite_reader(&mut mem_d)?),
            "notfound" => NetworkMessage::NotFound(Decodable::consensus_decode_from_finite_reader(&mut mem_d)?),
            "getblocks" => NetworkMessage::GetBlocks(Decodable::consensus_decode_from_finite_reader(&mut mem_d)?),
            "getheaders" => NetworkMessage::GetHeaders(Decodable::consensus_decode_from_finite_reader(&mut mem_d)?),
            "mempool" => NetworkMessage::MemPool,
            "block"   => NetworkMessage::Block(Decodable::consensus_decode_from_finite_reader(&mut mem_d)?),
            "headers" => NetworkMessage::Headers(
                HeaderDeserializationWrapper::consensus_decode_from_finite_reader(&mut mem_d)?.0
            ),
            "sendheaders" => NetworkMessage::SendHeaders,
            "getaddr" => NetworkMessage::GetAddr,
            "ping"    => NetworkMessage::Ping(Decodable::consensus_decode_from_finite_reader(&mut mem_d)?),
            "pong"    => NetworkMessage::Pong(Decodable::consensus_decode_from_finite_reader(&mut mem_d)?),
            "merkleblock" => NetworkMessage::MerkleBlock(Decodable::consensus_decode_from_finite_reader(&mut mem_d)?),
            "filterload" => NetworkMessage::FilterLoad(Decodable::consensus_decode_from_finite_reader(&mut mem_d)?),
            "filteradd" => NetworkMessage::FilterAdd(Decodable::consensus_decode_from_finite_reader(&mut mem_d)?),
            "filterclear" => NetworkMessage::FilterClear,
            "tx"      => NetworkMessage::Tx(Decodable::consensus_decode_from_finite_reader(&mut mem_d)?),
            "getcfilters" => NetworkMessage::GetCFilters(Decodable::consensus_decode_from_finite_reader(&mut mem_d)?),
            "cfilter" => NetworkMessage::CFilter(Decodable::consensus_decode_from_finite_reader(&mut mem_d)?),
            "getcfheaders" => NetworkMessage::GetCFHeaders(Decodable::consensus_decode_from_finite_reader(&mut mem_d)?),
            "cfheaders" => NetworkMessage::CFHeaders(Decodable::consensus_decode_from_finite_reader(&mut mem_d)?),
            "getcfcheckpt" => NetworkMessage::GetCFCheckpt(Decodable::consensus_decode_from_finite_reader(&mut mem_d)?),
            "cfcheckpt" => NetworkMessage::CFCheckpt(Decodable::consensus_decode_from_finite_reader(&mut mem_d)?),
            "reject" => NetworkMessage::Reject(Decodable::consensus_decode_from_finite_reader(&mut mem_d)?),
            "alert"   => NetworkMessage::Alert(Decodable::consensus_decode_from_finite_reader(&mut mem_d)?),
            "feefilter" => NetworkMessage::FeeFilter(Decodable::consensus_decode_from_finite_reader(&mut mem_d)?),
            "sendcmpct" => NetworkMessage::SendCmpct(Decodable::consensus_decode_from_finite_reader(&mut mem_d)?),
            "cmpctblock" => NetworkMessage::CmpctBlock(Decodable::consensus_decode_from_finite_reader(&mut mem_d)?),
            "getblocktxn" => NetworkMessage::GetBlockTxn(Decodable::consensus_decode_from_finite_reader(&mut mem_d)?),
            "blocktxn" => NetworkMessage::BlockTxn(Decodable::consensus_decode_from_finite_reader(&mut mem_d)?),
            "wtxidrelay" => NetworkMessage::WtxidRelay,
            "addrv2" => NetworkMessage::AddrV2(Decodable::consensus_decode_from_finite_reader(&mut mem_d)?),
            "sendaddrv2" => NetworkMessage::SendAddrV2,
            _ => NetworkMessage::Unknown {
                command: cmd,
                payload: mem_d.into_inner(),
            }
        };
        Ok(RawNetworkMessage {
            magic,
            payload,
        })
    }

    #[inline]
    fn consensus_decode<R: io::Read + ?Sized>(r: &mut R) -> Result<Self, encode::Error> {
        Self::consensus_decode_from_finite_reader(r.take(MAX_MSG_SIZE as u64).by_ref())
    }
}

#[cfg(test)]
mod test {
    use std::net::Ipv4Addr;
    use super::{RawNetworkMessage, NetworkMessage, CommandString};
    use crate::network::constants::{ServiceFlags, Magic, Network};
    use crate::consensus::encode::{deserialize, deserialize_partial, serialize};
    use crate::hashes::hex::FromHex;
    use crate::hashes::sha256d::Hash;
    use crate::hashes::Hash as HashTrait;
    use crate::network::address::{Address, AddrV2, AddrV2Message};
    use super::message_network::{Reject, RejectReason, VersionMessage};
    use crate::network::message_blockdata::{Inventory, GetBlocksMessage, GetHeadersMessage};
    use crate::blockdata::block::{Block, BlockHeader};
    use crate::network::message_filter::{GetCFilters, CFilter, GetCFHeaders, CFHeaders, GetCFCheckpt, CFCheckpt};
    use crate::blockdata::transaction::Transaction;
    use crate::blockdata::script::Script;
    use crate::network::message_bloom::{FilterAdd, FilterLoad, BloomFlags};
    use crate::MerkleBlock;
    use crate::network::message_compact_blocks::{GetBlockTxn, SendCmpct};
    use crate::util::bip152::BlockTransactionsRequest;

    fn hash(slice: [u8;32]) -> Hash {
        Hash::from_slice(&slice).unwrap()
    }

    #[test]
    fn full_round_ser_der_raw_network_message_test() {
        // TODO: Impl Rand traits here to easily generate random values.
        let version_msg: VersionMessage = deserialize(&Vec::from_hex("721101000100000000000000e6e0845300000000010000000000000000000000000000000000ffff0000000000000100000000000000fd87d87eeb4364f22cf54dca59412db7208d47d920cffce83ee8102f5361746f7368693a302e392e39392f2c9f040001").unwrap()).unwrap();
        let tx: Transaction = deserialize(&Vec::from_hex("0100000001a15d57094aa7a21a28cb20b59aab8fc7d1149a3bdbcddba9c622e4f5f6a99ece010000006c493046022100f93bb0e7d8db7bd46e40132d1f8242026e045f03a0efe71bbb8e3f475e970d790221009337cd7f1f929f00cc6ff01f03729b069a7c21b59b1736ddfee5db5946c5da8c0121033b9b137ee87d5a812d6f506efdd37f0affa7ffc310711c06c7f3e097c9447c52ffffffff0100e1f505000000001976a9140389035a9225b3839e2bbf32d826a1e222031fd888ac00000000").unwrap()).unwrap();
        let block: Block = deserialize(&include_bytes!("../../test_data/testnet_block_000000000000045e0b1660b6445b5e5c5ab63c9a4f956be7e1e69be04fa4497b.raw")[..]).unwrap();
        let header: BlockHeader = deserialize(&Vec::from_hex("010000004ddccd549d28f385ab457e98d1b11ce80bfea2c5ab93015ade4973e400000000bf4473e53794beae34e64fccc471dace6ae544180816f89591894e0f417a914cd74d6e49ffff001d323b3a7b").unwrap()).unwrap();
        let script: Script = deserialize(&Vec::from_hex("1976a91431a420903c05a0a7de2de40c9f02ebedbacdc17288ac").unwrap()).unwrap();
        let merkle_block: MerkleBlock = deserialize(&Vec::from_hex("0100000079cda856b143d9db2c1caff01d1aecc8630d30625d10e8b4b8b0000000000000b50cc069d6a3e33e3ff84a5c41d9d3febe7c770fdcc96b2c3ff60abe184f196367291b4d4c86041b8fa45d630100000001b50cc069d6a3e33e3ff84a5c41d9d3febe7c770fdcc96b2c3ff60abe184f19630101").unwrap()).unwrap();
        let cmptblock = deserialize(&Vec::from_hex("00000030d923ad36ff2d955abab07f8a0a6e813bc6e066b973e780c5e36674cad5d1cd1f6e265f2a17a0d35cbe701fe9d06e2c6324cfe135f6233e8b767bfa3fb4479b71115dc562ffff7f2006000000000000000000000000010002000000010000000000000000000000000000000000000000000000000000000000000000ffffffff0302ee00ffffffff0100f9029500000000015100000000").unwrap()).unwrap();
        let blocktxn = deserialize(&Vec::from_hex("2e93c0cff39ff605020072d96bc3a8d20b8447e294d08092351c8583e08d9b5a01020000000001010000000000000000000000000000000000000000000000000000000000000000ffffffff0402dc0000ffffffff0200f90295000000001976a9142b4569203694fc997e13f2c0a1383b9e16c77a0d88ac0000000000000000266a24aa21a9ede2f61c3f71d1defd3fa999dfa36953755c690689799962b48bebd836974e8cf90120000000000000000000000000000000000000000000000000000000000000000000000000").unwrap()).unwrap();


        let msgs = vec![
            NetworkMessage::Version(version_msg),
            NetworkMessage::Verack,
            NetworkMessage::Addr(vec![(45, Address::new(&([123,255,000,100], 833).into(), ServiceFlags::NETWORK))]),
            NetworkMessage::Inv(vec![Inventory::Block(hash([8u8; 32]).into())]),
            NetworkMessage::GetData(vec![Inventory::Transaction(hash([45u8; 32]).into())]),
            NetworkMessage::NotFound(vec![Inventory::Error]),
            NetworkMessage::GetBlocks(GetBlocksMessage::new(vec![hash([1u8; 32]).into(), hash([4u8; 32]).into()], hash([5u8; 32]).into())),
            NetworkMessage::GetHeaders(GetHeadersMessage::new(vec![hash([10u8; 32]).into(), hash([40u8; 32]).into()], hash([50u8; 32]).into())),
            NetworkMessage::MemPool,
            NetworkMessage::Tx(tx),
            NetworkMessage::Block(block),
            NetworkMessage::Headers(vec![header]),
            NetworkMessage::SendHeaders,
            NetworkMessage::GetAddr,
            NetworkMessage::Ping(15),
            NetworkMessage::Pong(23),
            NetworkMessage::MerkleBlock(merkle_block),
            NetworkMessage::FilterLoad(FilterLoad {filter: Vec::from_hex("03614e9b050000000000000001").unwrap(), hash_funcs: 1, tweak: 2, flags: BloomFlags::All}),
            NetworkMessage::FilterAdd(FilterAdd {data: script.as_bytes().to_vec()}),
            NetworkMessage::FilterAdd(FilterAdd {data: hash([29u8; 32]).to_vec()}),
            NetworkMessage::FilterClear,
            NetworkMessage::GetCFilters(GetCFilters{filter_type: 2, start_height: 52, stop_hash: hash([42u8; 32]).into()}),
            NetworkMessage::CFilter(CFilter{filter_type: 7, block_hash: hash([25u8; 32]).into(), filter: vec![1,2,3]}),
            NetworkMessage::GetCFHeaders(GetCFHeaders{filter_type: 4, start_height: 102, stop_hash: hash([47u8; 32]).into()}),
            NetworkMessage::CFHeaders(CFHeaders{filter_type: 13, stop_hash: hash([53u8; 32]).into(), previous_filter_header: hash([12u8; 32]).into(), filter_hashes: vec![hash([4u8; 32]).into(), hash([12u8; 32]).into()]}),
            NetworkMessage::GetCFCheckpt(GetCFCheckpt{filter_type: 17, stop_hash: hash([25u8; 32]).into()}),
            NetworkMessage::CFCheckpt(CFCheckpt{filter_type: 27, stop_hash: hash([77u8; 32]).into(), filter_headers: vec![hash([3u8; 32]).into(), hash([99u8; 32]).into()]}),
            NetworkMessage::Alert(vec![45,66,3,2,6,8,9,12,3,130]),
            NetworkMessage::Reject(Reject{message: "Test reject".into(), ccode: RejectReason::Duplicate, reason: "Cause".into(), hash: hash([255u8; 32])}),
            NetworkMessage::FeeFilter(1000),
            NetworkMessage::WtxidRelay,
            NetworkMessage::AddrV2(vec![AddrV2Message{ addr: AddrV2::Ipv4(Ipv4Addr::new(127, 0, 0, 1)), port: 0, services: ServiceFlags::NONE, time: 0 }]),
            NetworkMessage::SendAddrV2,
            NetworkMessage::CmpctBlock(cmptblock),
            NetworkMessage::GetBlockTxn(GetBlockTxn { txs_request: BlockTransactionsRequest { block_hash: hash([11u8; 32]).into(), indexes: vec![0, 1, 2, 3, 10, 3002] } }),
            NetworkMessage::BlockTxn(blocktxn),
            NetworkMessage::SendCmpct(SendCmpct{send_compact: true, version: 8333}),
        ];

        for msg in msgs {
            let raw_msg = RawNetworkMessage {magic: Magic::from_bytes([57, 0, 0, 0]), payload: msg};
            assert_eq!(deserialize::<RawNetworkMessage>(&serialize(&raw_msg)).unwrap(), raw_msg);
        }

    }

    #[test]
    fn commandstring_test() {
        // Test converting.
        assert_eq!(CommandString::try_from_static("AndrewAndrew").unwrap().as_ref(), "AndrewAndrew");
        assert!(CommandString::try_from_static("AndrewAndrewA").is_err());

        // Test serializing.
        let cs = CommandString("Andrew".into());
        assert_eq!(serialize(&cs), vec![0x41u8, 0x6e, 0x64, 0x72, 0x65, 0x77, 0, 0, 0, 0, 0, 0]);

        // Test deserializing
        let cs: Result<CommandString, _> = deserialize(&[0x41u8, 0x6e, 0x64, 0x72, 0x65, 0x77, 0, 0, 0, 0, 0, 0]);
        assert!(cs.is_ok());
        assert_eq!(cs.as_ref().unwrap().to_string(), "Andrew".to_owned());
        assert_eq!(cs.unwrap(), CommandString::try_from_static("Andrew").unwrap());

        let short_cs: Result<CommandString, _> = deserialize(&[0x41u8, 0x6e, 0x64, 0x72, 0x65, 0x77, 0, 0, 0, 0, 0]);
        assert!(short_cs.is_err());
    }

    #[test]
    fn serialize_verack_test() {
        assert_eq!(serialize(&RawNetworkMessage { magic: Magic::from(Network::Bitcoin), payload: NetworkMessage::Verack }),
                             vec![0xf9, 0xbe, 0xb4, 0xd9, 0x76, 0x65, 0x72, 0x61,
                                  0x63, 0x6B, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
                                  0x00, 0x00, 0x00, 0x00, 0x5d, 0xf6, 0xe0, 0xe2]);
    }

    #[test]
    fn serialize_ping_test() {
        assert_eq!(serialize(&RawNetworkMessage { magic: Magic::from(Network::Bitcoin), payload: NetworkMessage::Ping(100) }),
                             vec![0xf9, 0xbe, 0xb4, 0xd9, 0x70, 0x69, 0x6e, 0x67,
                                  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
                                  0x08, 0x00, 0x00, 0x00, 0x24, 0x67, 0xf1, 0x1d,
                                  0x64, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00]);
    }


    #[test]
    fn serialize_mempool_test() {
        assert_eq!(serialize(&RawNetworkMessage { magic: Magic::from(Network::Bitcoin), payload: NetworkMessage::MemPool }),
                             vec![0xf9, 0xbe, 0xb4, 0xd9, 0x6d, 0x65, 0x6d, 0x70,
                                  0x6f, 0x6f, 0x6c, 0x00, 0x00, 0x00, 0x00, 0x00,
                                  0x00, 0x00, 0x00, 0x00, 0x5d, 0xf6, 0xe0, 0xe2]);
    }

    #[test]
    fn serialize_getaddr_test() {
        assert_eq!(serialize(&RawNetworkMessage { magic: Magic::from(Network::Bitcoin), payload: NetworkMessage::GetAddr }),
                             vec![0xf9, 0xbe, 0xb4, 0xd9, 0x67, 0x65, 0x74, 0x61,
                                  0x64, 0x64, 0x72, 0x00, 0x00, 0x00, 0x00, 0x00,
                                  0x00, 0x00, 0x00, 0x00, 0x5d, 0xf6, 0xe0, 0xe2]);
    }

    #[test]
    fn deserialize_getaddr_test() {
        let msg = deserialize(
            &[0xf9, 0xbe, 0xb4, 0xd9, 0x67, 0x65, 0x74, 0x61,
                0x64, 0x64, 0x72, 0x00, 0x00, 0x00, 0x00, 0x00,
                0x00, 0x00, 0x00, 0x00, 0x5d, 0xf6, 0xe0, 0xe2]);
        let preimage = RawNetworkMessage { magic: Magic::from(Network::Bitcoin), payload: NetworkMessage::GetAddr };
        assert!(msg.is_ok());
        let msg : RawNetworkMessage = msg.unwrap();
        assert_eq!(preimage.magic, msg.magic);
        assert_eq!(preimage.payload, msg.payload);
    }

    #[test]
    fn deserialize_version_test() {
        let msg = deserialize::<RawNetworkMessage>(
            &[  0xf9, 0xbe, 0xb4, 0xd9, 0x76, 0x65, 0x72, 0x73,
                0x69, 0x6f, 0x6e, 0x00, 0x00, 0x00, 0x00, 0x00,
                0x66, 0x00, 0x00, 0x00, 0xbe, 0x61, 0xb8, 0x27,
                0x7f, 0x11, 0x01, 0x00, 0x0d, 0x04, 0x00, 0x00,
                0x00, 0x00, 0x00, 0x00, 0xf0, 0x0f, 0x4d, 0x5c,
                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff,
                0x5b, 0xf0, 0x8c, 0x80, 0xb4, 0xbd, 0x0d, 0x04,
                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
                0xfa, 0xa9, 0x95, 0x59, 0xcc, 0x68, 0xa1, 0xc1,
                0x10, 0x2f, 0x53, 0x61, 0x74, 0x6f, 0x73, 0x68,
                0x69, 0x3a, 0x30, 0x2e, 0x31, 0x37, 0x2e, 0x31,
                0x2f, 0x93, 0x8c, 0x08, 0x00, 0x01 ]);

        assert!(msg.is_ok());
        let msg = msg.unwrap();
        assert_eq!(msg.magic, Magic::from(Network::Bitcoin));
        if let NetworkMessage::Version(version_msg) = msg.payload {
            assert_eq!(version_msg.version, 70015);
            assert_eq!(version_msg.services, ServiceFlags::NETWORK | ServiceFlags::BLOOM | ServiceFlags::WITNESS | ServiceFlags::NETWORK_LIMITED);
            assert_eq!(version_msg.timestamp, 1548554224);
            assert_eq!(version_msg.nonce, 13952548347456104954);
            assert_eq!(version_msg.user_agent, "/Satoshi:0.17.1/");
            assert_eq!(version_msg.start_height, 560275);
            assert!(version_msg.relay);
        } else {
            panic!("Wrong message type");
        }
    }

    #[test]
    fn deserialize_partial_message_test() {
        let data = [  0xf9, 0xbe, 0xb4, 0xd9, 0x76, 0x65, 0x72, 0x73,
            0x69, 0x6f, 0x6e, 0x00, 0x00, 0x00, 0x00, 0x00,
            0x66, 0x00, 0x00, 0x00, 0xbe, 0x61, 0xb8, 0x27,
            0x7f, 0x11, 0x01, 0x00, 0x0d, 0x04, 0x00, 0x00,
            0x00, 0x00, 0x00, 0x00, 0xf0, 0x0f, 0x4d, 0x5c,
            0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
            0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
            0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff,
            0x5b, 0xf0, 0x8c, 0x80, 0xb4, 0xbd, 0x0d, 0x04,
            0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
            0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
            0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
            0xfa, 0xa9, 0x95, 0x59, 0xcc, 0x68, 0xa1, 0xc1,
            0x10, 0x2f, 0x53, 0x61, 0x74, 0x6f, 0x73, 0x68,
            0x69, 0x3a, 0x30, 0x2e, 0x31, 0x37, 0x2e, 0x31,
            0x2f, 0x93, 0x8c, 0x08, 0x00, 0x01, 0, 0 ];
        let msg = deserialize_partial::<RawNetworkMessage>(&data);
        assert!(msg.is_ok());

        let (msg, consumed) = msg.unwrap();
        assert_eq!(consumed, data.to_vec().len() - 2);
        assert_eq!(msg.magic, Magic::from(Network::Bitcoin));
        if let NetworkMessage::Version(version_msg) = msg.payload {
            assert_eq!(version_msg.version, 70015);
            assert_eq!(version_msg.services, ServiceFlags::NETWORK | ServiceFlags::BLOOM | ServiceFlags::WITNESS | ServiceFlags::NETWORK_LIMITED);
            assert_eq!(version_msg.timestamp, 1548554224);
            assert_eq!(version_msg.nonce, 13952548347456104954);
            assert_eq!(version_msg.user_agent, "/Satoshi:0.17.1/");
            assert_eq!(version_msg.start_height, 560275);
            assert!(version_msg.relay);
        } else {
            panic!("Wrong message type");
        }
    }
}