use crate::{key, schema, server::session::SessionHelper};
use microrm::prelude::*;
use serde::{Deserialize, Serialize};

mod api;
mod authorize;
mod token;

type Request = tide::Request<super::ServerStateWrapper>;

const AUTHORIZE_PATH: &str = "oidc/authorize";
const TOKEN_PATH: &str = "oidc/token";
const JWKS_PATH: &str = "oidc/jwks";
const DISCOVERY_PATH: &str = ".well-known/openid-configuration";

#[derive(serde::Serialize)]
pub enum OIDCErrorType {
    InvalidRequest,
    UnauthorizedClient,
    AccessDenied,
    UnsupportedResponseType,
    // InvalidScope,
    ServerError,
    // TemporarilyUnavailable,
}

pub enum OIDCErrorPayload<'a> {
    Borrowed(&'a str),
    Owned(String),
}

impl<'a> OIDCErrorPayload<'a> {
    fn as_str(&self) -> &str {
        match self {
            Self::Borrowed(s) => s,
            Self::Owned(s) => s.as_str(),
        }
    }
}

impl<'a> From<&'a str> for OIDCErrorPayload<'a> {
    fn from(value: &'a str) -> Self {
        Self::Borrowed(value)
    }
}

impl<'a> From<String> for OIDCErrorPayload<'a> {
    fn from(value: String) -> Self {
        Self::Owned(value)
    }
}

/// error type,
pub struct OIDCError<'a>(OIDCErrorType, OIDCErrorPayload<'a>, Option<&'a str>);

impl<'a> OIDCError<'a> {
    fn into_response(self) -> tide::Response {
        #[derive(Serialize)]
        struct ErrorOut<'a> {
            error: OIDCErrorType,
            error_description: &'a str,
            state: Option<&'a str>,
        }

        let eo = ErrorOut {
            error: self.0,
            error_description: self.1.as_str(),
            state: self.2,
        };

        tide::Response::builder(400)
            .body(serde_json::to_vec(&eo).unwrap())
            .build()
    }
}

impl<'a> From<microrm::Error> for OIDCError<'a> {
    fn from(value: microrm::Error) -> Self {
        Self(
            OIDCErrorType::ServerError,
            format!("Internal database error: {value}").into(),
            None,
        )
    }
}

async fn authorize(request: Request) -> tide::Result<tide::Response> {
    #[derive(Deserialize)]
    struct State {
        state: Option<String>,
    }
    let state: Option<String> = request.query::<State>().ok().and_then(|x| x.state);

    match authorize::do_authorize(request, state.as_deref()) {
        Ok(r) => Ok(r),
        Err(e) => Ok(e.into_response()),
    }
}

async fn token(request: Request) -> tide::Result<tide::Response> {
    match token::do_token(request).await {
        Ok(res) => Ok(res),
        Err(e) => Ok(e.into_response()),
    }
}

async fn jwks(request: Request) -> tide::Result<tide::Response> {
    let shelper = SessionHelper::new(&request);
    let realm = shelper.get_realm()?;

    // build JWK set
    let mut jwkset = jsonwebtoken::jwk::JwkSet { keys: vec![] };

    for key in realm.keys.get()?.into_iter() {
        if *key.key_state.as_ref() == schema::KeyState::Retired {
            continue;
        }

        // skip HMAC keys
        if let key::KeyType::HMac(_) = *key.key_type.as_ref() {
            continue;
        }

        jwkset.keys.push(key.wrapped().into_jwk());
    }

    Ok(tide::Response::builder(200)
        .header(tide::http::headers::ACCESS_CONTROL_ALLOW_ORIGIN, "*")
        .content_type(tide::http::mime::JSON)
        .body(serde_json::to_vec(&jwkset).unwrap())
        .build())
}

async fn discovery_config(request: Request) -> tide::Result<tide::Response> {
    let server_config = &request.state().core.config;
    let base_url = format!(
        "{}/{}",
        server_config.base_url,
        request.param("realm").unwrap()
    );

    let config_response = serde_json::json!({
        "issuer": base_url,
        "authorization_endpoint": format!("{}/{}", base_url, AUTHORIZE_PATH),
        "token_endpoint": format!("{}/{}", base_url, TOKEN_PATH),
        "jwks_uri": format!("{}/{}", base_url, JWKS_PATH),
        "token_endpoint_auth_signing_alg_values_supported": ["EdDSA", "RS256"],
        "response_types_supported": ["code", "id_token", "token id_token"],
        "subject_types_supported": ["public"],
        "id_token_signing_alg_values_supported": ["EdDSA", "RS256"],
    });

    Ok(tide::Response::builder(200)
        .header(tide::http::headers::ACCESS_CONTROL_ALLOW_ORIGIN, "*")
        .body(config_response)
        .build())
}

pub(super) fn oidc_server(mut route: tide::Route<super::ServerStateWrapper>) {
    route.at(AUTHORIZE_PATH).get(authorize).post(authorize);
    route.at(TOKEN_PATH).post(token);
    route.at(JWKS_PATH).get(jwks);
    route.at(DISCOVERY_PATH).get(discovery_config);
}