use actix::prelude::*;
use anyhow::{anyhow, Result};
use filebuffer::FileBuffer;
use serde::{Deserialize, Serialize};
use std::path::PathBuf;
use tiny_keccak::{Hasher, KangarooTwelve};

#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
pub struct Hash(pub Vec<u8>);

impl AsRef<[u8]> for Hash {
    fn as_ref(&self) -> &[u8] {
        self.0.as_ref()
    }
}

// impl Hash {
//     pub fn encode(&self) -> String {
//         encode(self.0.clone()).into_string()
//     }
//
//     pub fn decode<T: AsRef<str>>(string: T) -> Result<Hash> {
//         Ok(Hash(decode(string.as_ref())?))
//     }
// }

// impl std::fmt::Display for Hash {
//     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
//         write!(f, "{}", self.encode())
//     }
// }

pub trait Hashable {
    fn hash(&self) -> Result<Hash>;
}

pub struct HasherWorker;

impl Actor for HasherWorker {
    type Context = SyncContext<Self>;
}

#[derive(Message)]
#[rtype(result = "Result<Hash>")]
pub struct ComputeHash {
    pub path: PathBuf,
}

impl Handler<ComputeHash> for HasherWorker {
    type Result = Result<Hash>;

    fn handle(&mut self, msg: ComputeHash, _: &mut Self::Context) -> Self::Result {
        msg.path.hash()
    }
}

impl Hashable for PathBuf {
    fn hash(self: &PathBuf) -> Result<Hash> {
        let fbuffer = FileBuffer::open(self)?;
        Ok(hash(&fbuffer))
    }
}

pub fn hash<T: AsRef<[u8]>>(input: T) -> Hash {
    let mut k12 = KangarooTwelve::new(b"");
    k12.update(input.as_ref());

    let mut result = [0u8; 256 / 8];
    k12.finalize(&mut result);
    Hash(Vec::from(result))
}

pub fn encode<T: AsRef<[u8]>>(vec: T) -> String {
    // multibase base58
    format!("z{}", bs58::encode(vec).into_string())
}

pub fn decode<T: AsRef<str>>(string: T) -> Result<Vec<u8>> {
    let string = string.as_ref();
    let (base, data) = string.split_at(1);

    // multibase base58
    if base != "z" {
        Err(anyhow!("data not base58 encoded, bailing"))
    } else {
        Ok(bs58::decode(data).into_vec()?)
    }
}