use errors::{new_error, Error, ErrorKind, Result};
use std::str::FromStr;

/// The algorithms supported for signing/verifying
#[derive(Debug, PartialEq, Copy, Clone, Serialize, Deserialize)]
pub enum Algorithm {
    /// HMAC using SHA-256
    HS256,
    /// HMAC using SHA-384
    HS384,
    /// HMAC using SHA-512
    HS512,

    /// ECDSA using SHA-256
    ES256,
    /// ECDSA using SHA-384
    ES384,

    /// RSASSA-PKCS1-v1_5 using SHA-256
    RS256,
    /// RSASSA-PKCS1-v1_5 using SHA-384
    RS384,
    /// RSASSA-PKCS1-v1_5 using SHA-512
    RS512,

    /// RSASSA-PSS using SHA-256
    PS256,
    /// RSASSA-PSS using SHA-384
    PS384,
    /// RSASSA-PSS using SHA-512
    PS512,
}

impl Default for Algorithm {
    fn default() -> Self {
        Algorithm::HS256
    }
}

impl FromStr for Algorithm {
    type Err = Error;
    fn from_str(s: &str) -> Result<Self> {
        match s {
            "HS256" => Ok(Algorithm::HS256),
            "HS384" => Ok(Algorithm::HS384),
            "HS512" => Ok(Algorithm::HS512),
            "ES256" => Ok(Algorithm::ES256),
            "ES384" => Ok(Algorithm::ES384),
            "RS256" => Ok(Algorithm::RS256),
            "RS384" => Ok(Algorithm::RS384),
            "PS256" => Ok(Algorithm::PS256),
            "PS384" => Ok(Algorithm::PS384),
            "PS512" => Ok(Algorithm::PS512),
            "RS512" => Ok(Algorithm::RS512),
            _ => Err(new_error(ErrorKind::InvalidAlgorithmName)),
        }
    }
}