use base64::{engine::general_purpose::STANDARD, Engine};

use serde::ser::Serialize;

use crate::algorithms::AlgorithmFamily;

use crate::crypto;

use crate::errors::{new_error, ErrorKind, Result};

use crate::header::Header;

#[cfg(feature = "use_pem")]

use crate::pem::decoder::PemEncodedKey;

use crate::serialization::b64_encode_part;

/// A key to encode a JWT with. Can be a secret, a PEM-encoded key or a DER-encoded key.

/// This key can be re-used so make sure you only initialize it once if you can for better performance.

#[derive(Clone)]

pub struct EncodingKey {

    pub(crate) family: AlgorithmFamily,

    content: Vec<u8>,

}

impl EncodingKey {

    /// If you're using a HMAC secret that is not base64, use that.

    pub fn from_secret(secret: &[u8]) -> Self {

        EncodingKey { family: AlgorithmFamily::Hmac, content: secret.to_vec() }

    }

    /// If you have a base64 HMAC secret, use that.

    pub fn from_base64_secret(secret: &str) -> Result<Self> {

        let out = STANDARD.decode(secret)?;

        Ok(EncodingKey { family: AlgorithmFamily::Hmac, content: out })

    }

    /// If you are loading a RSA key from a .pem file.

    /// This errors if the key is not a valid RSA key.

    /// Only exists if the feature `use_pem` is enabled.

    ///

    /// # NOTE

    ///

    /// According to the [ring doc](https://docs.rs/ring/latest/ring/signature/struct.RsaKeyPair.html#method.from_pkcs8),

    /// the key should be at least 2047 bits.

    ///

    #[cfg(feature = "use_pem")]

    pub fn from_rsa_pem(key: &[u8]) -> Result<Self> {

        let pem_key = PemEncodedKey::new(key)?;

        let content = pem_key.as_rsa_key()?;

        Ok(EncodingKey { family: AlgorithmFamily::Rsa, content: content.to_vec() })

    }

    /// If you are loading a ECDSA key from a .pem file

    /// This errors if the key is not a valid private EC key

    /// Only exists if the feature `use_pem` is enabled.

    ///

    /// # NOTE

    ///

    /// The key should be in PKCS#8 form.

    ///

    /// You can generate a key with the following:

    ///

    /// ```sh

    /// openssl ecparam -genkey -noout -name prime256v1 \

    ///     | openssl pkcs8 -topk8 -nocrypt -out ec-private.pem

    /// ```

    #[cfg(feature = "use_pem")]

    pub fn from_ec_pem(key: &[u8]) -> Result<Self> {

        let pem_key = PemEncodedKey::new(key)?;

        let content = pem_key.as_ec_private_key()?;

        Ok(EncodingKey { family: AlgorithmFamily::Ec, content: content.to_vec() })

    }

    /// If you are loading a EdDSA key from a .pem file

    /// This errors if the key is not a valid private Ed key

    /// Only exists if the feature `use_pem` is enabled.

    #[cfg(feature = "use_pem")]

    pub fn from_ed_pem(key: &[u8]) -> Result<Self> {

        let pem_key = PemEncodedKey::new(key)?;

        let content = pem_key.as_ed_private_key()?;

        Ok(EncodingKey { family: AlgorithmFamily::Ed, content: content.to_vec() })

    }

    /// If you know what you're doing and have the DER-encoded key, for RSA only

    pub fn from_rsa_der(der: &[u8]) -> Self {

        EncodingKey { family: AlgorithmFamily::Rsa, content: der.to_vec() }

    }

    /// If you know what you're doing and have the DER-encoded key, for ECDSA

    pub fn from_ec_der(der: &[u8]) -> Self {

        EncodingKey { family: AlgorithmFamily::Ec, content: der.to_vec() }

    }

    /// If you know what you're doing and have the DER-encoded key, for EdDSA

    pub fn from_ed_der(der: &[u8]) -> Self {

        EncodingKey { family: AlgorithmFamily::Ed, content: der.to_vec() }

    }

    pub(crate) fn inner(&self) -> &[u8] {

        &self.content

    }

}

/// Encode the header and claims given and sign the payload using the algorithm from the header and the key.

/// If the algorithm given is RSA or EC, the key needs to be in the PEM format.

///

/// ```rust

/// use serde::{Deserialize, Serialize};

/// use jsonwebtoken::{encode, Algorithm, Header, EncodingKey};

///

/// #[derive(Debug, Serialize, Deserialize)]

/// struct Claims {

///    sub: String,

///    company: String

/// }

///

/// let my_claims = Claims {

///     sub: "b@b.com".to_owned(),

///     company: "ACME".to_owned()

/// };

///

/// // my_claims is a struct that implements Serialize

/// // This will create a JWT using HS256 as algorithm

/// let token = encode(&Header::default(), &my_claims, &EncodingKey::from_secret("secret".as_ref())).unwrap();

/// ```

pub fn encode<T: Serialize>(header: &Header, claims: &T, key: &EncodingKey) -> Result<String> {

    if key.family != header.alg.family() {

        return Err(new_error(ErrorKind::InvalidAlgorithm));

    }

    let encoded_header = b64_encode_part(header)?;

    let encoded_claims = b64_encode_part(claims)?;

    let message = [encoded_header, encoded_claims].join(".");

    let signature = crypto::sign(message.as_bytes(), key, header.alg)?;

    Ok([message, signature].join("."))

}

Unexecuted instantiation: jsonwebtoken::encoding::encode::<surrealdb_core::iam::token::Claims>

Unexecuted instantiation: jsonwebtoken::encoding::encode::<_>