extern crate rand;

use crate::ed25519_dalek::ed25519::signature::Signature;
use crate::ed25519_dalek::Signer;
use crate::ed25519_dalek::Verifier;
use alloc::vec::Vec;
use ed25519_dalek::{Keypair, PublicKey as PK};
use rand::rngs::OsRng;
use serde::{Deserialize, Serialize};

#[derive(Debug, PartialEq, Serialize, Deserialize, Clone)]
pub struct PublicKey {
    pub key: [u8; 32],
}

impl PublicKey {
    pub fn verify_sign(&self, raw: &Vec<u8>, sign: &Vec<u8>) -> bool {
        PK::from_bytes(&self.key)
            .unwrap()
            .verify(
                raw,
                &Signature::from_bytes(sign.clone().into_boxed_slice().as_ref()).unwrap(),
            )
            .is_ok()
    }
}

pub struct Keys {
    pub pair: Keypair,
}

impl Keys {
    pub fn gen() -> Keys {
        Keys {
            pair: Keypair::generate(&mut OsRng {}),
        }
    }
}

#[derive(Debug, PartialEq, Serialize, Deserialize, Clone)]
pub enum Sign {
    NoSign,
    Signed(PublicKey /* source */, Vec<u8> /* sign */),
}

pub fn verify_sign(data: &Vec<u8>, sign: &Sign) -> bool {
    match sign {
        Sign::NoSign => true,
        Sign::Signed(key, sign) => key.verify_sign(data, sign),
    }
}

impl Keys {
    pub fn sign(&self, content: &Vec<u8>) -> Vec<u8> {
        self.pair.sign(content.as_ref()).to_bytes().to_vec()
    }

    pub fn get_public(&self) -> PublicKey {
        PublicKey {
            key: *self.clone().pair.public.as_bytes(),
        }
    }
}