use crate::{Bytes, String, Vec};

use serde::{Deserialize, Serialize};
use serde_indexed::{DeserializeIndexed, SerializeIndexed};

use super::{AuthenticatorOptions, PinAuth};
use crate::ctap2::credential_management::CredentialProtectionPolicy;
use crate::sizes::*;
use crate::webauthn::*;

// // Approach 1:
// pub type AuthenticatorExtensions = heapless::LinearMap<String<11>, bool, 2>;

// impl TryFrom<&String<44>> for CredentialProtectionPolicy {
//     type Error = crate::authenticator::Error;

//     fn try_from(value: &String<44>) -> Result<Self, Self::Error> {
//         Ok(match value.as_str() {
//             "userVerificationOptional" => CredentialProtectionPolicy::Optional,
//             "userVerificationOptionalWithCredentialIDList" => CredentialProtectionPolicy::OptionalWithCredentialIdList,
//             "userVerificationRequired" => CredentialProtectionPolicy::Required,
//             _ => return Err(Self::Error::InvalidParameter),
//         })
//     }
// }

impl TryFrom<u8> for CredentialProtectionPolicy {
    type Error = super::Error;

    fn try_from(value: u8) -> Result<Self, Self::Error> {
        Ok(match value {
            1 => CredentialProtectionPolicy::Optional,
            2 => CredentialProtectionPolicy::OptionalWithCredentialIdList,
            3 => CredentialProtectionPolicy::Required,
            _ => return Err(Self::Error::InvalidParameter),
        })
    }
}

// Approach 2:
#[derive(Clone, Debug, Eq, PartialEq, Serialize, Deserialize)]
pub struct Extensions {
    #[serde(rename = "credProtect")]
    #[serde(skip_serializing_if = "Option::is_none")]
    // pub cred_protect: Option<CredentialProtectionPolicy>,
    pub cred_protect: Option<u8>,
    // #[serde(serialize_with = "u8::from")]
    // pub cred_protect: Option<u8>,
    #[serde(rename = "hmac-secret")]
    #[serde(skip_serializing_if = "Option::is_none")]
    pub hmac_secret: Option<bool>,
}

// // Approach 3:
// #[derive(Clone,Debug,Eq,PartialEq,Serialize,Deserialize)]
// pub enum AuthenticatorExtension {
//     #[serde(rename = "hmac-secret")]
//     HmacSecret(bool),
//     #[serde(rename = "credProtect")]
//     CredProtect(bool),
// }

// #[derive(Clone,Debug,Eq,PartialEq,Serialize,Deserialize)]
// pub struct AuthenticatorExtensions {
//     #[serde(flatten)]
//     pub extensions: Vec<AuthenticatorExtension, 3>,
// }

#[derive(Clone, Debug, Eq, PartialEq, SerializeIndexed, DeserializeIndexed)]
// #[serde(rename_all = "camelCase")]
#[serde_indexed(offset = 1)]
pub struct Request {
    pub client_data_hash: Bytes<32>,
    pub rp: PublicKeyCredentialRpEntity,
    pub user: PublicKeyCredentialUserEntity,
    // e.g. webauthn.io sends 10
    pub pub_key_cred_params: Vec<PublicKeyCredentialParameters, 12>,
    #[serde(skip_serializing_if = "Option::is_none")]
    pub exclude_list: Option<Vec<PublicKeyCredentialDescriptor, 16>>,
    #[serde(skip_serializing_if = "Option::is_none")]
    pub extensions: Option<Extensions>,
    #[serde(skip_serializing_if = "Option::is_none")]
    pub options: Option<AuthenticatorOptions>,
    #[serde(skip_serializing_if = "Option::is_none")]
    pub pin_auth: Option<PinAuth>,
    #[serde(skip_serializing_if = "Option::is_none")]
    pub pin_protocol: Option<u32>,
}

// It would be logical to call this Reponse :)
pub type AttestationObject = Response;

//
// TODO: We have `Option<T>`, use it to combine
// `fmt` and `att_stmt`!
//
// #[derive(Clone,Debug,Eq,PartialEq,Serialize)]
// #[serde(into = "ResponseExplicitEnumOption")]
// pub struct Response {
//     pub auth_data: Bytes<AUTHENTICATOR_DATA_LENGTH>,
//     pub att_stmt: Option<AttestationStatement>,
// }

pub type AuthenticatorData = super::AuthenticatorData<AttestedCredentialData, Extensions>;

// #[derive(Clone,Debug,Eq,PartialEq)]
// // #[serde(rename_all = "camelCase")]
// pub struct AuthenticatorData {
//     pub rp_id_hash: Bytes<32>,
//     pub flags: Flags,
//     pub sign_count: u32,
//     // this can get pretty long
//     // pub attested_credential_data: Option<Bytes<ATTESTED_CREDENTIAL_DATA_LENGTH>>,
//     pub attested_credential_data: Option<AttestedCredentialData>,
//     pub extensions: Option<Extensions>
// }

// pub type SerializedAuthenticatorData = Bytes<AUTHENTICATOR_DATA_LENGTH>;

// // The reason for this non-use of CBOR is for compatibility with
// // FIDO U2F authentication signatures.
// impl AuthenticatorData {
//     pub fn serialize(&self) -> SerializedAuthenticatorData {
//         // let mut bytes = Vec::<u8, AUTHENTICATOR_DATA_LENGTH>::new();
//         let mut bytes = SerializedAuthenticatorData::new();

//         // 32 bytes, the RP id's hash
//         bytes.extend_from_slice(&self.rp_id_hash).unwrap();
//         // flags
//         bytes.push(self.flags.bits()).unwrap();
//         // signature counts as 32-bit unsigned big-endian integer.
//         bytes.extend_from_slice(&self.sign_count.to_be_bytes()).unwrap();

//         // the attested credential data
//         if let Some(ref attested_credential_data) = &self.attested_credential_data {
//             bytes.extend_from_slice(&attested_credential_data.serialize()).unwrap();
//         }

//         // the extensions data
//         if let Some(ref extensions) = &self.extensions {
//             let mut extensions_buf = [0u8; 128];
//             let ser = crate::serde::cbor_serialize(&extensions, &mut extensions_buf).unwrap();
//             bytes.extend_from_slice(ser).unwrap();
//         }

//         bytes
//     }
// }

// NOTE: This is not CBOR, it has a custom encoding...
// https://www.w3.org/TR/webauthn/#sec-attested-credential-data
#[derive(Clone, Debug, Eq, PartialEq)]
pub struct AttestedCredentialData {
    pub aaguid: Bytes<16>,
    // this is where "unlimited non-resident keys" get stored
    // TODO: Model as actual credential ID, with ser/de to bytes (format is up to authenticator)
    pub credential_id: Bytes<MAX_CREDENTIAL_ID_LENGTH>,
    // pub credential_public_key: crate::cose::PublicKey,//Bytes<COSE_KEY_LENGTH>,
    pub credential_public_key: Bytes<COSE_KEY_LENGTH>,
}

impl super::SerializeAttestedCredentialData for AttestedCredentialData {
    fn serialize(&self) -> Bytes<ATTESTED_CREDENTIAL_DATA_LENGTH> {
        let mut bytes = Vec::<u8, ATTESTED_CREDENTIAL_DATA_LENGTH>::new();
        // 16 bytes, the aaguid
        bytes.extend_from_slice(&self.aaguid).unwrap();

        // byte length of credential ID as 16-bit unsigned big-endian integer.
        bytes
            .extend_from_slice(&(self.credential_id.len() as u16).to_be_bytes())
            .unwrap();
        // raw bytes of credential ID
        bytes
            .extend_from_slice(&self.credential_id[..self.credential_id.len()])
            .unwrap();

        // use existing `bytes` buffer
        // let mut cbor_key = [0u8; 128];

        // CHANGE this back if credential_public_key is not serialized again
        // let l = crate::serde::cbor_serialize(&self.credential_public_key, &mut cbor_key).unwrap();
        // bytes.extend_from_slice(&cbor_key[..l]).unwrap();
        bytes
            .extend_from_slice(&self.credential_public_key)
            .unwrap();

        Bytes::from(bytes)
    }
}

#[derive(Clone, Debug, Eq, PartialEq, SerializeIndexed)]
#[serde_indexed(offset = 1)]
pub struct Response {
    pub fmt: String<32>,
    pub auth_data: super::SerializedAuthenticatorData,
    // pub att_stmt: Bytes<64>,
    pub att_stmt: AttestationStatement,
}

#[derive(Clone, Debug, Eq, PartialEq, Serialize)]
#[serde(untagged)]
#[allow(clippy::large_enum_variant)]
pub enum AttestationStatement {
    None(NoneAttestationStatement),
    Packed(PackedAttestationStatement),
}

#[derive(Clone, Debug, Eq, PartialEq, Serialize)]
#[serde(untagged)]
pub enum AttestationStatementFormat {
    None,
    Packed,
    // Tpm,
    // AndroidKey,
    // AndroidSafetynet,
    // FidoU2f,
}

#[derive(Clone, Debug, Eq, PartialEq, Serialize)]
pub struct NoneAttestationStatement {}

#[derive(Clone, Debug, Eq, PartialEq, Serialize)]
pub struct PackedAttestationStatement {
    pub alg: i32,
    pub sig: Bytes<ASN1_SIGNATURE_LENGTH>,
    #[serde(skip_serializing_if = "Option::is_none")]
    pub x5c: Option<Vec<Bytes<1024>, 1>>,
}