//! FFI-level passkey tests. Responses are checked like a relying party would: CBOR decoded with
//! `ciborium`, authenticatorData parsed by hand, signatures verified with `p256` against the COSE key
//! returned at registration.

use std::sync::Arc;

use ciborium::Value;
use kv_sync::{
    signing::SoftwareSigner,
    test_server::{TestServer, SETUP_TOKEN},
};
use p256::{
    ecdsa::{signature::Verifier, Signature, VerifyingKey},
    EncodedPoint,
};
use sha2::{Digest, Sha256};
use uuid::Uuid;

use crate::{CoreError, DeviceSigner, ItemKindDto, PlatformDto, VaultCore};

const PW: &str = "a long master password";
const RP: &str = "example.com";

fn cdh(tag: &[u8]) -> Vec<u8> {
    Sha256::digest(tag).to_vec()
}

fn map_get(m: &Value, k: Value) -> &Value {
    m.as_map().unwrap().iter().find(|(kk, _)| *kk == k).map(|(_, v)| v).unwrap()
}

/// What a relying party checks at registration. Returns the credential public key.
fn rp_verify_registration(reg: &crate::PasskeyRegistration, rp_id: &str) -> VerifyingKey {
    let att: Value = ciborium::from_reader(reg.attestation_object.as_slice()).unwrap();
    assert_eq!(map_get(&att, Value::Text("fmt".into())), &Value::Text("none".into()));
    let d = map_get(&att, Value::Text("authData".into())).as_bytes().unwrap().clone();
    assert_eq!(d, reg.authenticator_data);
    assert_eq!(&d[..32], Sha256::digest(rp_id.as_bytes()).as_slice());
    assert_eq!(d[32], 0x5d, "UP|UV|BE|BS|AT");
    assert_eq!(&d[33..37], &[0, 0, 0, 0]);
    assert_eq!(Uuid::from_slice(&d[37..53]).unwrap().to_string(), crate::kestrove_aaguid());
    let n = u16::from_be_bytes([d[53], d[54]]) as usize;
    assert_eq!(&d[55..55 + n], reg.credential_id.as_slice());
    assert!(n == 16 || n == 32);
    let mut rest = &d[55 + n..];
    let key: Value = ciborium::from_reader(&mut rest).unwrap();
    assert!(rest.is_empty());
    assert_eq!(&d[55 + n..], reg.cose_public_key.as_slice());
    let i = |v: i64| Value::Integer(v.into());
    assert_eq!(map_get(&key, i(1)), &i(2));
    assert_eq!(map_get(&key, i(3)), &i(-7));
    assert_eq!(map_get(&key, i(-1)), &i(1));
    let x = map_get(&key, i(-2)).as_bytes().unwrap();
    let y = map_get(&key, i(-3)).as_bytes().unwrap();
    let point = EncodedPoint::from_affine_coordinates(x.as_slice().into(), y.as_slice().into(), false);
    let vk = VerifyingKey::from_encoded_point(&point).unwrap();
    use p256::pkcs8::DecodePublicKey;
    assert_eq!(VerifyingKey::from_public_key_der(&reg.public_key_spki).unwrap(), vk);
    vk
}

/// What a relying party checks at sign-in.
fn rp_verify_assertion(a: &crate::PasskeyAssertion, vk: &VerifyingKey, rp_id: &str, client_data_hash: &[u8]) {
    let d = &a.authenticator_data;
    assert_eq!(d.len(), 37);
    assert_eq!(&d[..32], Sha256::digest(rp_id.as_bytes()).as_slice());
    assert_eq!(d[32], 0x1d, "UP|UV|BE|BS");
    assert_eq!(&d[33..37], &[0, 0, 0, 0], "synced passkeys keep signCount 0");
    let mut msg = d.clone();
    msg.extend_from_slice(client_data_hash);
    vk.verify(&msg, &Signature::from_der(&a.signature).unwrap()).unwrap();
}

#[test]
fn create_list_assert_and_rp_isolation() {
    let core = VaultCore::new_in_memory();
    core.create_account(PW.into()).unwrap();

    let reg = core.create_passkey(RP.into(), b"uid-1".to_vec(), "alice".into(), cdh(b"reg"), None).unwrap();
    let vk = rp_verify_registration(&reg, RP);

    // A new login item was created; ItemDto has no passkey material.
    let item = core.get_item(reg.item_id.clone()).unwrap();
    assert_eq!((item.kind, item.title.as_str()), (ItemKindDto::Login, RP));
    assert_eq!(item.username.as_deref(), Some("alice"));
    assert_eq!(item.urls, vec!["https://example.com".to_string()]);

    let found = core.passkeys_for_rp(RP.into(), vec![]).unwrap();
    assert_eq!(found.len(), 1);
    assert_eq!(found[0].credential_id, reg.credential_id);
    assert_eq!((found[0].user_handle.as_slice(), found[0].user_name.as_str()), (&b"uid-1"[..], "alice"));
    assert_eq!(core.passkeys_for_rp(RP.into(), vec![reg.credential_id.clone()]).unwrap().len(), 1);
    assert!(core.passkeys_for_rp(RP.into(), vec![vec![1; 16]]).unwrap().is_empty());
    assert!(core.passkeys_for_rp("login.example.com".into(), vec![]).unwrap().is_empty());

    let h = cdh(b"get");
    let a = core.get_assertion(reg.credential_id.clone(), RP.into(), h.clone()).unwrap();
    assert_eq!((a.user_handle.as_slice(), a.item_id.as_str()), (&b"uid-1"[..], reg.item_id.as_str()));
    rp_verify_assertion(&a, &vk, RP, &h);

    // No cross-RP use, even for a sub- or parent domain.
    for other in ["login.example.com", "com", "example.org"] {
        assert!(matches!(
            core.get_assertion(reg.credential_id.clone(), other.into(), h.clone()),
            Err(CoreError::NotFound)
        ));
    }
    assert!(matches!(core.get_assertion(vec![9; 16], RP.into(), h.clone()), Err(CoreError::NotFound)));
    assert!(matches!(
        core.get_assertion(reg.credential_id.clone(), RP.into(), vec![0; 31]),
        Err(CoreError::Invalid { .. })
    ));
    assert!(matches!(
        core.get_assertion(reg.credential_id.clone(), "Example.com".into(), h.clone()),
        Err(CoreError::Invalid { .. })
    ));
    assert!(matches!(
        core.create_passkey(RP.into(), vec![], "a".into(), h.clone(), None),
        Err(CoreError::Invalid { .. })
    ));

    // Same rp_id + user handle again: replaced in the same item (CTAP2), not duplicated.
    let reg2 = core.create_passkey(RP.into(), b"uid-1".to_vec(), "alice".into(), cdh(b"reg2"), None).unwrap();
    assert_eq!(reg2.item_id, reg.item_id);
    assert_ne!(reg2.credential_id, reg.credential_id);
    assert_eq!(core.list_passkeys().unwrap().len(), 1);
    assert!(matches!(core.get_assertion(reg.credential_id.clone(), RP.into(), h.clone()), Err(CoreError::NotFound)));

    // Explicit item: added next to the password of an existing login.
    let mut dto = core.get_item(reg.item_id.clone()).unwrap();
    dto.password = Some("pw".into());
    core.save_item(dto).unwrap(); // save_item keeps passkeys
    let reg3 =
        core.create_passkey(RP.into(), b"uid-2".to_vec(), "bob".into(), cdh(b"r3"), Some(reg.item_id.clone())).unwrap();
    assert_eq!(reg3.item_id, reg.item_id);
    assert_eq!(core.passkeys_for_rp(RP.into(), vec![]).unwrap().len(), 2);
    assert_eq!(core.get_item(reg.item_id.clone()).unwrap().password.as_deref(), Some("pw"));
    assert!(!core.item_history(reg.item_id.clone()).unwrap().is_empty());

    core.delete_passkey(reg3.credential_id.clone()).unwrap();
    assert_eq!(core.list_passkeys().unwrap().len(), 1);

    core.lock();
    assert!(matches!(core.passkeys_for_rp(RP.into(), vec![]), Err(CoreError::Locked)));
    assert!(matches!(core.get_assertion(reg2.credential_id, RP.into(), h), Err(CoreError::Locked)));
}

#[test]
fn passkeys_survive_reopen() {
    let dir = tempfile::tempdir().unwrap();
    let path = dir.path().join("v.sqlite").to_string_lossy().into_owned();
    let core = VaultCore::open(path.clone()).unwrap();
    let sk = core.create_account(PW.into()).unwrap();
    let reg = core.create_passkey(RP.into(), b"u".to_vec(), "me".into(), cdh(b"r"), None).unwrap();
    let vk = rp_verify_registration(&reg, RP);
    drop(core);

    let core = VaultCore::open(path).unwrap();
    core.unlock(PW.into(), sk).unwrap();
    let h = cdh(b"g");
    rp_verify_assertion(&core.get_assertion(reg.credential_id, RP.into(), h.clone()).unwrap(), &vk, RP, &h);
}

struct TestSigner(SoftwareSigner);

impl DeviceSigner for TestSigner {
    fn device_id(&self) -> String {
        kv_sync::DeviceSigner::device_id(&self.0).to_string()
    }
    fn public_key(&self) -> Vec<u8> {
        kv_sync::DeviceSigner::public_key(&self.0)
    }
    fn sign(&self, message: Vec<u8>) -> crate::Result<Vec<u8>> {
        kv_sync::DeviceSigner::sign(&self.0, &message).map_err(crate::internal)
    }
    fn reset(&self) -> crate::Result<()> {
        Err(crate::internal("not supported in this test"))
    }
}

fn connect(core: &VaultCore, server: &TestServer) {
    core.configure_server(server.url(), vec![]).unwrap();
    core.set_device_signer(
        Arc::new(TestSigner(SoftwareSigner::generate(Uuid::new_v4()))),
        "test".into(),
        PlatformDto::Ios,
    )
    .unwrap();
}

#[tokio::test]
async fn passkey_created_on_one_device_signs_on_another() {
    let server = TestServer::start().await;
    let a = VaultCore::new_in_memory();
    let sk = a.create_account(PW.into()).unwrap();
    connect(&a, &server);
    a.register_account(SETUP_TOKEN.into(), None).await.unwrap();
    let reg = a.create_passkey(RP.into(), b"u".to_vec(), "me".into(), cdh(b"r"), None).unwrap();
    let vk = rp_verify_registration(&reg, RP);
    assert_eq!(a.sync_now().await.unwrap().pushed, 1);

    let b = VaultCore::new_in_memory();
    connect(&b, &server);
    b.login(PW.into(), sk, None, None).await.unwrap();
    b.sync_now().await.unwrap();
    let on_b = b.passkeys_for_rp(RP.into(), vec![]).unwrap();
    assert_eq!(on_b.len(), 1);
    assert_eq!(on_b[0].credential_id, reg.credential_id);
    let h = cdh(b"on b");
    rp_verify_assertion(&b.get_assertion(reg.credential_id.clone(), RP.into(), h.clone()).unwrap(), &vk, RP, &h);

    // Deleting on B propagates to A.
    b.delete_passkey(reg.credential_id.clone()).unwrap();
    b.sync_now().await.unwrap();
    a.sync_now().await.unwrap();
    assert!(a.list_passkeys().unwrap().is_empty());
}