// Copyright 2022 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

use std::sync::Arc;

use tracing::instrument;

use native_pkcs11_traits::Backend;
use native_pkcs11_traits::Certificate as P11Certificate;
use native_pkcs11_traits::KeyAlgorithm as P11KeyAlgorithm;
use native_pkcs11_traits::KeySearchOptions as P11KeySearchOptions;
use native_pkcs11_traits::PrivateKey as P11PrivateKey;
use native_pkcs11_traits::PublicKey as P11PublicKey;
use native_pkcs11_traits::Result as P11Result;

#[derive(Debug, Default)]
pub struct YubikeyPivBackend;

impl YubikeyPivBackend {
    pub fn new() -> Self {
        Self
    }
}

impl Backend for YubikeyPivBackend {
    fn name(&self) -> String {
        "Yubikey PIV".into()
    }

    #[instrument]
    fn find_all_certificates(
        &self,
    ) -> P11Result<Vec<Box<dyn P11Certificate>>> {
        Ok(vec![])
        // let certs = find_all_certificates()?
        //     .into_iter()
        //     .map(YubikeyPivCertificate::new)
        //     .filter_map(Result::ok)
        //     .map(|cert| Box::new(cert) as _)
        //     .collect();
        // Ok(certs)
    }

    #[instrument]
    fn find_private_key(
        &self,
        query: P11KeySearchOptions,
    ) -> P11Result<Option<Arc<dyn P11PrivateKey>>> {
        Ok(None)
        // let mut pubkeys_by_pubkey_hash: HashMap<Vec<u8>, SecKey> =
        //     HashMap::from_iter(find_all_certificates()?.into_iter().filter_map(|c| {
        //         c.certificate()
        //             .ok()
        //             .and_then(|cert| cert.public_key().ok())
        //             .and_then(|pk| pk.application_label().map(|pubkey_hash| (pubkey_hash, pk)))
        //     }));
        //
        // let mut find_pubkey_for_seckey = |sec_key: &SecKey| -> Option<YubikeyPivPublicKey> {
        //     sec_key
        //         .application_label()
        //         .and_then(|pubkey_hash| pubkeys_by_pubkey_hash.remove(&pubkey_hash))
        //         //  TODO(kcking): populate label if searching by label
        //         .and_then(|sec_key| YubikeyPivPublicKey::new(sec_key, "").ok())
        // };
        // let opt_key = match query {
        //     P11KeySearchOptions::Label(label) => {
        //         find_key(KeyClass::private(), &label)
        //             .ok()
        //             .map(|sec_key| {
        //                 let cert = find_pubkey_for_seckey(&sec_key);
        //                 YubikeyPivPrivateKey::new(sec_key, label, cert)
        //             })
        //             .transpose()?
        //     }
        //     P11KeySearchOptions::PublicKeyHash(public_key_hash) => {
        //         find_key2(KeyClass::private(), &public_key_hash)?
        //             .map(|sec_key| {
        //                 let cert = find_pubkey_for_seckey(&sec_key);
        //                 YubikeyPivPrivateKey::new(sec_key, "", cert)
        //             })
        //             .transpose()?
        //     }
        // };
        // Ok(opt_key.map(|sec_key| Arc::new(sec_key) as _))
    }

    #[instrument]
    fn find_public_key(
        &self,
        query: P11KeySearchOptions,
    ) -> P11Result<Option<Box<dyn P11PublicKey>>> {
        Ok(None)
        // let opt_key = match query {
        //     P11KeySearchOptions::Label(label) => {
        //         find_key(KeyClass::public(), &label)
        //             .ok()
        //             .map(|sec_key| YubikeyPivPublicKey::new(sec_key, label))
        //             .transpose()?
        //     }
        //     P11KeySearchOptions::PublicKeyHash(public_key_hash) => {
        //         find_key2(KeyClass::public(), &public_key_hash)?
        //             .map(|sec_key| YubikeyPivPublicKey::new(sec_key, ""))
        //             .transpose()?
        //     }
        // };
        // Ok(opt_key.map(|sec_key| Box::new(sec_key) as _))
    }

    fn find_all_private_keys(
        &self,
    ) -> P11Result<Vec<Arc<dyn P11PrivateKey>>> {
        Ok(vec![])
        // let sec_keys = find_all_keys(KeyClass::private())?;
        // let keys = sec_keys
        //     .into_iter()
        //     .filter_map(|sec_key| {
        //         let label: Option<String> = sec_key
        //             .attributes()
        //             .find(unsafe { kSecAttrLabel }.to_void())
        //             .map(|label| {
        //                 unsafe { CFString::wrap_under_get_rule(label.cast()) }.to_string()
        //             });
        //         let label: String = label.unwrap_or_default();
        //
        //         YubikeyPivPrivateKey::new(sec_key, label, None).ok()
        //     })
        //     .map(|k| Arc::new(k) as _);
        //
        // Ok(keys.collect())
    }

    fn find_all_public_keys(
        &self,
    ) -> P11Result<Vec<Arc<dyn P11PublicKey>>> {
        Ok(vec![])
        // let sec_keys = find_all_keys(KeyClass::public())?;
        //
        // let keys = sec_keys
        //     .into_iter()
        //     .filter_map(|sec_key| {
        //         let label: Option<String> = sec_key
        //             .attributes()
        //             .find(unsafe { kSecAttrLabel }.to_void())
        //             .map(|label| {
        //                 unsafe { CFString::wrap_under_get_rule(label.cast()) }.to_string()
        //             });
        //         let label: String = label.unwrap_or_default();
        //
        //         YubikeyPivPublicKey::new(sec_key, label).ok()
        //     })
        //     .map(|k| Arc::new(k) as _);
        //
        // Ok(keys.collect())
    }

    #[instrument]
    fn generate_key(
        &self,
        _algorithm: P11KeyAlgorithm,
        _label: Option<&str>,
    ) -> P11Result<Arc<dyn P11PrivateKey>> {
        Err("Generate key not supported, please use ykman, URL: https://hatter.in/ykman")?
    }
}