use alloc::vec::Vec;
use crate::crypto::PublicKey;
use serde::{Serialize, Deserialize};
use sha2::Digest;

/// A tunnel that is used for communication
#[derive(Serialize, Clone, Deserialize)]
pub struct Tunnel {
    /// Tunnel's id.
    /// By the way, this id is `None` until the tunnel is validated in the backward movement
    pub id: Option<u64>,
    /// Ids, each of them is just for local storage on each node until a final global id is created
    pub local_ids: Vec<u64>,
    /// Ids of peers (in transport) by which we can send a message - one for backward direction, another for forward
    pub peer_ids: (u64, u64),
    /// Time at which this tunnel should be destroyed (UNIX epoch)
    pub ttd: u64,
    /// Public keys of nodes in the tunnel
    pub nodes_in_tunnel: Option<Vec<PublicKey>>,
    /// Is this tunnel used for multicast?
    pub is_multicast: bool,
    /// If we created this tunnel, then this is the node that it's used to communicate with
    pub target_node: Option<PublicKey>,
}

/// Tunnel, but only the fields that are ok to share
#[derive(Serialize, Clone, Deserialize)]
pub struct TunnelPublic {
    /// Tunnel's id
    id: Option<u64>,
    /// Ids, each of them is just for local storage on each node until a final global id is created
    local_ids: Vec<u64>,
    /// Time at which this tunnel should be destroyed (UNIX epoch)
    ttd: u64,
    /// Public keys of nodes in the tunnel
    nodes_in_tunnel: Option<Vec<PublicKey>>,
}

impl TunnelPublic {
    pub fn hash(&self) -> Vec<u8> {
        sha2::Sha224::new()
            .chain(serde_cbor::to_vec(self).unwrap().as_slice())
            .result().to_vec()
    }

    #[cfg(test)]
    pub fn new_for_test() -> Self {
        TunnelPublic {
            id: Some(56),
            local_ids: vec![5, 500, 120],
            ttd: 56,
            nodes_in_tunnel: Some(vec![crate::crypto::Keys::generate().get_public()])
        }
    }
}

#[cfg(test)]
use alloc::vec;

#[test]
fn test_tunnel_hashing() {
    let tun = TunnelPublic::new_for_test();
    assert_eq!(tun.hash(), tun.hash());
    assert_ne!(tun.hash(), TunnelPublic {
        id: Some(56),
        local_ids: vec![5, 500, 120],
        ttd: 56,
        nodes_in_tunnel: Some(vec![crate::crypto::Keys::generate().get_public()])
    }.hash());
}