use std::io;
use std::fs;
use std::fs::{File};
use std::path::Path;
use std::io::prelude::*;
use openpgp::parse::Parse;
use openpgp::*;
use openpgp::parse::stream::*;


pub struct KnownKeys {
 keys: Vec<openpgp::TPK>
}
impl VerificationHelper for &KnownKeys {

    fn get_public_keys(&mut self, _ids: &[KeyID]) -> Result<Vec<TPK>> {
        Ok(self.keys.clone())
    }
    fn check(&mut self, structure: &MessageStructure) -> Result<()> {
        Ok(()) // Implement your verification policy here.
    }
}

impl KnownKeys {
    pub fn load_dir(dir: impl AsRef<Path>) -> io::Result<KnownKeys> {
        let mut keys: Vec<openpgp::TPK> = Vec::with_capacity(3);
        for f in fs::read_dir(dir)? {
            let f = f?;
            if f.metadata()?.is_dir() {
                continue;
            }
            let tpk = openpgp::TPK::from_file(f.path()).unwrap();
            println!("Fingerprint: {}", tpk.fingerprint());
            keys.push(tpk);
        }
        Ok(KnownKeys{
            keys: keys
        })
    }

    pub fn verify(&mut self, r: impl Read) -> io::Result<Vec<u8>> {
        let mut content = Vec::with_capacity(2048);
        let helper = &*self;
        let mut v = Verifier::<&KnownKeys>::from_reader(r, helper, None).map_err(|e| dbg!(e)).unwrap();
        if v.read_to_end(&mut content).is_err() {
            return Err(io::Error::new(io::ErrorKind::InvalidData, "Signature Mismatch"));
        }
        Ok(content)
    }
}