//! X.509 helper objects definitions and registry
//!
//! All OID objects and definitions are now stored in the [oid-registry](https://crates.io/crates/oid-registry) crate.
//!
//! This crate is re-exporting `oid-registry`, so to access the OID constants the
//! `x509_parser::oid_oid_registry` namespace can be used (see example below).
//!
//! ## Example
//!
//! To get the short name for a given OID:
//!
//! ```rust
//! use x509_parser::objects::*;
//! use x509_parser::oid_registry::*;
//!
//! let oid = &OID_X509_COMMON_NAME;
//! let sn = oid2sn(oid, oid_registry());
//! assert_eq!(sn, Ok("commonName"));
//! ```

use crate::error::NidError;
use asn1_rs::{oid, Oid};
use lazy_static::lazy_static;
use oid_registry::*;
use std::collections::HashMap;

lazy_static! {
    static ref OID_REGISTRY: OidRegistry<'static> = {
        let mut reg = OidRegistry::default().with_all_crypto().with_x509();
        // OIDs not in the default registry can be added here
        let entry = OidEntry::new("id-mgf1", "Mask Generator Function 1 (MGF1)");
        reg.insert(oid! {1.2.840.113549.1.1.8}, entry);
        reg
    };
    static ref ABBREV_MAP: HashMap<Oid<'static>, &'static str> = {
        let mut m = HashMap::new();
        m.insert(OID_X509_COMMON_NAME, "CN");
        m.insert(OID_X509_COUNTRY_NAME, "C");
        m.insert(OID_X509_LOCALITY_NAME, "L");
        m.insert(OID_X509_STATE_OR_PROVINCE_NAME, "ST");
        m.insert(OID_X509_ORGANIZATION_NAME, "O");
        m.insert(OID_X509_ORGANIZATIONAL_UNIT, "OU");
        m.insert(OID_DOMAIN_COMPONENT, "DC");
        m.insert(OID_PKCS9_EMAIL_ADDRESS, "Email");
        m
    };
}

/// Return the abbreviation (for ex. CN for Common Name), or if not found, the OID short name
pub fn oid2abbrev<'a>(oid: &'a Oid, registry: &'a OidRegistry) -> Result<&'a str, NidError> {
    if let Some(abbrev) = ABBREV_MAP.get(oid) {
        return Ok(abbrev);
    }
    registry.get(oid).map(|entry| entry.sn()).ok_or(NidError)
}

/// Returns the short name corresponding to the OID
pub fn oid2sn<'a>(oid: &'a Oid, registry: &'a OidRegistry) -> Result<&'a str, NidError> {
    registry.get(oid).map(|o| o.sn()).ok_or(NidError)
}

/// Returns the description corresponding to the OID
pub fn oid2description<'a>(oid: &'a Oid, registry: &'a OidRegistry) -> Result<&'a str, NidError> {
    registry.get(oid).map(|o| o.description()).ok_or(NidError)
}

/// Return a reference to the default registry of known OIDs
pub fn oid_registry() -> &'static OidRegistry<'static> {
    &OID_REGISTRY
}

#[cfg(test)]
mod tests {
    use super::*;
    use der_parser::oid;

    // This test is meant to check syntax of pattern matching with OID objects
    #[test]
    fn test_oid_match() {
        let oid = oid!(1.2.840 .113549 .1 .1 .5);
        if oid == OID_PKCS1_SHA1WITHRSA {
            // ok
        }
        // matching is not possible with Cow constants in pattern,
        // see https://rust-lang.github.io/rfcs/1445-restrict-constants-in-patterns.html
        //
        // match oid {
        //     OID_PKCS1_SHA1WITHRSA => (),
        //     _ => (),
        // }
    }
}