// Copyright 2023 MaidSafe.net limited.
//
// This SAFE Network Software is licensed to you under The General Public License (GPL), version 3.
// Unless required by applicable law or agreed to in writing, the SAFE Network Software distributed
// under the GPL Licence is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied. Please review the Licences for the specific language governing
// permissions and limitations relating to use of the SAFE Network Software.

/// Errors.
pub mod error;
/// Messages types
pub mod messages;
/// Storage types for spends, chunks and registers.
pub mod storage;

use self::storage::{ChunkAddress, DbcAddress, RegisterAddress};
use libp2p::{
    kad::{record::Key as RecordKey, KBucketDistance as Distance, KBucketKey as Key},
    PeerId,
};
use serde::{Deserialize, Serialize};
use std::fmt::{self, Debug, Display, Formatter};
use xor_name::XorName;

/// This is the address in the network by which proximity/distance
/// to other items (whether nodes or data chunks) are calculated.
///
/// This is the mapping from the XOR name used
/// by for example self encryption, or the libp2p `PeerId`,
/// to the key used in the Kademlia DHT.
/// All our xorname calculations shall be replaced with the `KBucketKey` calculations,
/// for getting proximity/distance to other items (whether nodes or data).
#[derive(Clone, Eq, PartialEq, Ord, PartialOrd, Hash, Serialize, Deserialize)]
pub enum NetworkAddress {
    /// The NetworkAddress is representing a PeerId.
    PeerId(Vec<u8>),
    /// The NetworkAddress is representing a ChunkAddress.
    ChunkAddress(ChunkAddress),
    /// The NetworkAddress is representing a DbcAddress.
    DbcAddress(DbcAddress),
    /// The NetworkAddress is representing a ChunkAddress.
    RegisterAddress(RegisterAddress),
    /// The NetworkAddress is representing a RecordKey.
    RecordKey(Vec<u8>),
}

impl NetworkAddress {
    /// Return a `NetworkAddress` representation of the `ChunkAddress`.
    pub fn from_chunk_address(chunk_address: ChunkAddress) -> Self {
        NetworkAddress::ChunkAddress(chunk_address)
    }

    /// Return a `NetworkAddress` representation of the `DbcAddress`.
    pub fn from_dbc_address(dbc_address: DbcAddress) -> Self {
        NetworkAddress::DbcAddress(dbc_address)
    }

    /// Return a `NetworkAddress` representation of the `RegisterAddress`.
    pub fn from_register_address(register_address: RegisterAddress) -> Self {
        NetworkAddress::RegisterAddress(register_address)
    }

    /// Return a `NetworkAddress` representation of the `PeerId` by encapsulating its bytes.
    pub fn from_peer(peer_id: PeerId) -> Self {
        NetworkAddress::PeerId(peer_id.to_bytes())
    }

    /// Return a `NetworkAddress` representation of the `RecordKey` by encapsulating its bytes.
    pub fn from_record_key(record_key: RecordKey) -> Self {
        NetworkAddress::RecordKey(record_key.to_vec())
    }

    /// Return the encapsulated bytes of this `NetworkAddress`.
    pub fn as_bytes(&self) -> Vec<u8> {
        match self {
            NetworkAddress::PeerId(bytes) | NetworkAddress::RecordKey(bytes) => bytes.to_vec(),
            NetworkAddress::ChunkAddress(chunk_address) => chunk_address.name().0.to_vec(),
            NetworkAddress::DbcAddress(dbc_address) => dbc_address.name().0.to_vec(),
            NetworkAddress::RegisterAddress(register_address) => register_address.id().0.to_vec(),
        }
    }

    /// Try to return the represented `PeerId`.
    pub fn as_peer_id(&self) -> Option<PeerId> {
        if let NetworkAddress::PeerId(bytes) = self {
            if let Ok(peer_id) = PeerId::from_bytes(bytes) {
                return Some(peer_id);
            }
        }

        None
    }

    /// Try to return the represented `RecordKey`.
    pub fn as_record_key(&self) -> Option<RecordKey> {
        match self {
            NetworkAddress::RecordKey(bytes) => Some(RecordKey::new(bytes)),
            _ => None,
        }
    }

    /// Return the convertable `RecordKey`.
    pub fn to_record_key(&self) -> RecordKey {
        match self {
            NetworkAddress::RecordKey(bytes) => RecordKey::new(bytes),
            NetworkAddress::ChunkAddress(chunk_address) => RecordKey::new(chunk_address.name()),
            NetworkAddress::RegisterAddress(register_address) => {
                let mut reg_name: Vec<u8> = register_address.name().to_vec();
                reg_name.extend(register_address.tag.to_be_bytes());
                RecordKey::new(&XorName::from_content(&reg_name))
            }
            NetworkAddress::DbcAddress(dbc_address) => RecordKey::new(dbc_address.name()),
            NetworkAddress::PeerId(bytes) => RecordKey::new(bytes),
        }
    }

    /// Return the `KBucketKey` representation of this `NetworkAddress`.
    ///
    /// The `KBucketKey` is used for calculating proximity/distance to other items (whether nodes or data).
    /// Important to note is that it will always SHA256 hash any bytes it receives.
    /// Therefore, the canonical use of distance/proximity calculations in the network
    /// is via the `KBucketKey`, or the convenience methods of `NetworkAddress`.
    pub fn as_kbucket_key(&self) -> Key<Vec<u8>> {
        Key::new(self.as_bytes())
    }

    /// Compute the distance of the keys according to the XOR metric.
    pub fn distance(&self, other: &NetworkAddress) -> Distance {
        self.as_kbucket_key().distance(&other.as_kbucket_key())
    }

    // NB: Leaving this here as to demonstrate what we can do with this.
    // /// Return the uniquely determined key with the given distance to `self`.
    // ///
    // /// This implements the following equivalence:
    // ///
    // /// `self xor other = distance <==> other = self xor distance`
    // pub fn for_distance(&self, d: Distance) -> libp2p::kad::kbucket::KeyBytes {
    //     self.as_kbucket_key().for_distance(d)
    // }
}

impl Debug for NetworkAddress {
    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
        let name_str = match self {
            NetworkAddress::PeerId(_) => "NetworkAddress::PeerId(".to_string(),
            NetworkAddress::ChunkAddress(chunk_address) => {
                format!("NetworkAddress::ChunkAddress({:?} - ", chunk_address.name())
            }
            NetworkAddress::DbcAddress(dbc_address) => {
                format!("NetworkAddress::DbcAddress({:?} - ", dbc_address.name())
            }
            NetworkAddress::RegisterAddress(register_address) => format!(
                "NetworkAddress::RegisterAddress({:?} - ",
                register_address.id()
            ),
            NetworkAddress::RecordKey(_) => "NetworkAddress::RecordKey(".to_string(),
        };
        write!(
            f,
            "{name_str} - {:?} - {:?})",
            self.to_record_key(),
            self.as_kbucket_key()
        )
    }
}

impl Display for NetworkAddress {
    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
        match self {
            NetworkAddress::PeerId(id) => {
                write!(f, "NetworkAddress::PeerId({})", hex::encode(id))
            }
            NetworkAddress::ChunkAddress(addr) => {
                write!(f, "NetworkAddress::ChunkAddress({addr:?})")
            }
            NetworkAddress::DbcAddress(addr) => {
                write!(f, "NetworkAddress::DbcAddress({addr:?})")
            }
            NetworkAddress::RegisterAddress(addr) => {
                write!(f, "NetworkAddress::RegisterAddress({addr:?})")
            }
            NetworkAddress::RecordKey(key) => {
                write!(f, "NetworkAddress::RecordKey({})", hex::encode(key))
            }
        }
    }
}