use crate::{config, jwt, key, schema, UIDCError};
use microrm::prelude::*;

#[derive(Debug)]
pub enum TokenError {
    DBError(microrm::Error),
    InternalError(&'static str),
    RequestError(&'static str),
}

impl From<microrm::Error> for TokenError {
    fn from(value: microrm::Error) -> Self {
        Self::DBError(value)
    }
}

impl From<ring::error::KeyRejected> for TokenError {
    fn from(_value: ring::error::KeyRejected) -> Self {
        Self::InternalError("could not load realm key")
    }
}

pub fn generate_access_token<'a>(
    config: &config::Config,
    realm: &schema::Realm,
    client: &schema::Client,
    user: &schema::User,
    scopes: impl Iterator<Item = &'a str>,
) -> Result<String, UIDCError> {
    let issuer = format!("{}/{}", config.base_url, realm.shortname,);

    let iat = std::time::SystemTime::now();
    let exp = iat + std::time::Duration::from_secs(config.auth_token_expiry);

    // find all roles the user can possibly have access to
    let mut user_roles = user.groups.join(schema::Group::Roles).get()?;

    // find all roles requested by the scopes
    let mut requested_roles = vec![];
    for scope_name in scopes {
        if let Some(scope) = realm
            .scopes
            .with(schema::Scope::Shortname, scope_name)
            .first()
            .get()?
        {
            requested_roles.extend(scope.roles.get()?.into_iter());
        }
    }

    user_roles.sort_by_key(|k| k.id());
    user_roles.dedup();
    requested_roles.sort_by_key(|k| k.id());
    requested_roles.dedup();

    // find the intersection between requested roles and the ones the user actually has

    let resulting_roles = requested_roles
        .into_iter()
        .filter(|req| user_roles.contains(req))
        .map(|role| Ok(serde_json::Value::String(role.wrapped().shortname)));

    let token = jwt::JWTData {
        sub: user.username.as_str(),
        iss: issuer.as_str(),
        aud: client.shortname.as_str(),
        iat: iat.duration_since(std::time::UNIX_EPOCH).unwrap().as_secs(),
        exp: exp.duration_since(std::time::UNIX_EPOCH).unwrap().as_secs(),
        extras: [(
            "roles",
            serde_json::Value::Array(resulting_roles.collect::<Result<Vec<_>, UIDCError>>()?),
        )]
        .into(),
    };

    let mut realmkeys = key::RealmKeys::new(realm.clone());

    let key = realmkeys
        .by_type(*client.key_type.as_ref())?
        .ok_or(UIDCError::Abort("no matching signing key for realm"))?;

    Ok(jwt::JWT::sign(&key, token).into_string())
}

pub fn generate_refresh_token<'a>(
    config: &config::Config,
    realm: &schema::Realm,
    client: &schema::Client,
    user: &schema::User,
    scopes: impl Iterator<Item = &'a str>,
) -> Result<String, UIDCError> {
    todo!()
}