use crate::error::Error;
use crate::schema::{Db, Transaction};
use jsonwebtoken::{decode, Algorithm, DecodingKey, Validation};
use serde::{Deserialize, Serialize};
use warp::header::headers_cloned;
use warp::http::header::{HeaderMap, HeaderValue, AUTHORIZATION};
use warp::{reject, Filter, Rejection};
use thiserror::Error;
use anyhow::*;

const BEARER: &str = "Bearer ";
const PUBLIC_KEY_PEM: &str = "-----BEGIN PUBLIC KEY-----
MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA4nU0G4WjkmcQUx0hq6LQ
uV5Q+ACmUFL/OjoYMDwC/O/6pCd1UZgCfgHN2xEffDPznzcTn8OiFRxr4oWyBiny
rUpnY4mhy0SQUwoeCw7YkcHAyhCjNT74aR/ohX0MCj0qRRdbt5ZQXM/GC3HJuXE1
ptSuhFgQxziItamn8maoJ6JUSVEXVO1NOrrjoM3r7Q+BK2B+sX4/bLZ+VG5g1q2n
EbFdTHS6pHqtZNHQndTmEKwRfh0RYtzEzOXuO6e1gQY42Tujkof40dhGCIU7TeIG
GHwdFxy1niLkXwtHNjV7lnIOkTbx6+sSPamRfQAlZqUWM2Lf5o+7h3qWP3ENB138
sQIDAQAB
-----END PUBLIC KEY-----";

// const private_key_pem: &str = "-----BEGIN RSA PRIVATE KEY-----
// MIIEpAIBAAKCAQEA4nU0G4WjkmcQUx0hq6LQuV5Q+ACmUFL/OjoYMDwC/O/6pCd1
// UZgCfgHN2xEffDPznzcTn8OiFRxr4oWyBinyrUpnY4mhy0SQUwoeCw7YkcHAyhCj
// NT74aR/ohX0MCj0qRRdbt5ZQXM/GC3HJuXE1ptSuhFgQxziItamn8maoJ6JUSVEX
// VO1NOrrjoM3r7Q+BK2B+sX4/bLZ+VG5g1q2nEbFdTHS6pHqtZNHQndTmEKwRfh0R
// YtzEzOXuO6e1gQY42Tujkof40dhGCIU7TeIGGHwdFxy1niLkXwtHNjV7lnIOkTbx
// 6+sSPamRfQAlZqUWM2Lf5o+7h3qWP3ENB138sQIDAQABAoIBAD23nYTmrganag6M
// wPFrBSGP79c3Lhx0EjUHQjJbGKFgsdltG48qM3ut+DF9ACy0Z+/7bbC7+39vaIOq
// 1jLR2d6aiYTaLKseO4s2FawD1sgamvU3BZPsXn0gAhnnU5Gyy8Nas1dccvhoc9wI
// neaZUPrvucQ90AzLfo6r9yacDbYHB1lOyomApUvpJxOgHISGEtc9qGPDrdH19aF0
// 8fCv2bbQRh+TChgN3IB0o5w0wXaI7YAyAouAv/AzHCoEMpt7OGjFTkjh/ujlPL9O
// +FLuJNsQRHDN0gJo2pcvwGwDCsioMixQ9bZ7ZrUu2BNpEQygyeSbj9ZI1iRvhosO
// JU3rwEECgYEA9MppTYA6A9WQbCCwPH1QMpUAmPNVSWVhUVag4lGOEhdCDRcz9ook
// DohQMKctiEB1luKuvDokxo0uMOfMO9/YwjsRB7qjQip7Th1zMJIjD+A+juLzHK4r
// /RiRtWYGAnF8mptDvE+93JsPb3C/lQLvIhio5GQYWBqPJu6SpeosIskCgYEA7NPi
// Gbffzr2UQhW8BNKmctEEh8yFRVojFo3wwwWxSNUVXGSmSm31CL+Q8h817R+2OkPV
// 1ZMUOBU4UJiqFt28kIvTDFqbAJlJQGCpY2mY7OLQiD2A+TVLcFrHmoCaPfCAK1Qd
// hQ0PmFK7Mf8qClpA3E5chop/WfKQfiu46sZv1qkCgYAhGdXPcw1lQ1W6KVlrdI6J
// qHhiNlVMDXdxZkNvFxQdAiQeXQrbxaZGiMw/J/wSNpUwCAsUzM/4QVMDrfSCDCzl
// ZtNQtj4pTlFKKNVQthIjrXEIJUw2jp7IJLBfVSJu5iWxSlmId0f3MsiNizN81N69
// P5Rm/doE3+KHoy8VXGsHcQKBgQCkNh62enqjHWypjex6450qS6f6iWN3PRLLVsw0
// TcQpniZblCaBwVCAKmRUnjOEIdL2/4ZLutnwMTaFG/YEOOfAylMiY8jKV38lNmD9
// X4D78CFr9klxgvS2CRwSE03f2NzmLkLxuKaxldvaxPTfjMkgeO1LFMlNExYBhkuH
// 7uQpUQKBgQCKX6qMNh2gSdgG7qyxfTFZ4y5EGOBoKe/dE+IcVF3Vnh6DZVbCAbBL
// 5EdFWZSrCnDjA4xiKW55mwp95Ud9EZsZAb13L8V9t82eK+UDBoWlb7VRNYpda/x1
// 5/i4qQJ28x2UNJDStpYFpnp4Ba1lvXjKngIbDPkjU+hbBJ+BNGAIeg==
// -----END RSA PRIVATE KEY-----";

/// sub: Subject, user identifier
/// exp: Expiration date, Unix Time, epoch
/// puk: Public Key? Not 100% on this
#[derive(Debug, Serialize, Deserialize)]
struct Claims {
    sub: String,
    exp: usize,
    puk: String,
}

// #[derive(Error, Debug)]
// pub enum Nope {
//     #[error("Invalid header")]
//     InvalidHeader {
//         expected: String,
//         found: String,
//     },
// }

pub fn with_auth(
    db: Db,
    t: Transaction,
) -> impl Filter<Extract = (String,), Error = Rejection> + Clone {
    headers_cloned()
        .map(move |headers: HeaderMap<HeaderValue>| (db.clone(), headers))
        .and_then(authorize)
}

impl warp::reject::Reject for Nope {}

async fn authorize((db, headers): (Db, HeaderMap<HeaderValue>)) -> Result<String, Error> {
    match jwt_from_header(&headers) {
        Ok(jwt) => {
            let decoded = decode::<Claims>(
                &jwt,
                // TODO: what key are we using here? pass db/pw store here to get the claimant's
                // public key <10-04-21, yigit> //
                &DecodingKey::from_rsa_pem(PUBLIC_KEY_PEM.as_bytes()).unwrap(),
                &Validation::new(Algorithm::HS512),
            )
            .map_err(|_| reject::custom(Error::JWTTokenError))
            .unwrap();

            Ok(decoded.claims.puk)
        }
        Err(e) => return Err(anyhow!("missing!"));
    }
}

fn jwt_from_header(headers: &HeaderMap<HeaderValue>) -> Result<String, Error> {
    let header = match headers.get(AUTHORIZATION) {
        Some(v) => v,
        None => return Err(Error::NoAuthHeaderError),
    };
    let auth_header = match std::str::from_utf8(header.as_bytes()) {
        Ok(v) => v,
        Err(_) => return Err(Error::NoAuthHeaderError),
    };
    if !auth_header.starts_with(BEARER) {
        return Err(Error::InvalidAuthHeaderError);
    }
    Ok(auth_header.trim_start_matches(BEARER).to_owned())
}