use actix_web::http::{
    header::{HeaderMap, InvalidHeaderValue, ToStrError},
    uri::PathAndQuery,
    Method,
};
use failure::Fail;
use futures::future::IntoFuture;
use std::{collections::BTreeMap, fmt::Display};

mod sign;

#[cfg(feature = "digest")]
pub mod digest;

pub mod create;
pub mod middleware;
pub mod prelude {
    pub use crate::{
        middleware::VerifySignature, verify::Unverified, Config, Sign, SignatureVerify, Verify,
        VerifyError,
    };

    #[cfg(feature = "digest")]
    pub use crate::digest::{
        middleware::VerifyDigest, DigestClient, DigestCreate, DigestPart, DigestVerify, SignExt,
    };

    pub use actix_web::http::header::{InvalidHeaderValue, ToStrError};
}
pub mod verify;

use self::{
    create::Unsigned,
    verify::{Algorithm, Unverified},
};

pub trait Verify {
    fn begin_verify(&self, config: &Config) -> Result<Unverified, VerifyError>;
}

pub trait SignatureVerify {
    type Error: actix_web::ResponseError;
    type Future: IntoFuture<Item = bool, Error = Self::Error>;

    fn signature_verify(
        &mut self,
        algorithm: Option<Algorithm>,
        key_id: &str,
        signature: &str,
        signing_string: &str,
    ) -> Self::Future;
}

pub trait Sign {
    fn authorization_signature<F, E, K>(self, config: &Config, key_id: K, f: F) -> Result<Self, E>
    where
        F: FnOnce(&str) -> Result<String, E>,
        E: From<ToStrError> + From<InvalidHeaderValue>,
        K: Display,
        Self: Sized;

    fn signature<F, E, K>(self, config: &Config, key_id: K, f: F) -> Result<Self, E>
    where
        F: FnOnce(&str) -> Result<String, E>,
        E: From<ToStrError> + From<InvalidHeaderValue>,
        K: Display,
        Self: Sized;
}

#[derive(Clone, Debug, Default)]
pub struct Config {
    pub config: http_signature_normalization::Config,
}

#[derive(Debug, Fail)]
pub enum VerifyError {
    #[fail(display = "Signature error, {}", _0)]
    Sig(#[cause] http_signature_normalization::VerifyError),

    #[fail(display = "Failed to read header, {}", _0)]
    Header(#[cause] ToStrError),
}

impl Config {
    pub fn begin_sign(
        &self,
        method: &Method,
        path_and_query: Option<&PathAndQuery>,
        headers: HeaderMap,
    ) -> Result<Unsigned, ToStrError> {
        let headers = headers
            .iter()
            .map(|(k, v)| v.to_str().map(|v| (k.to_string(), v.to_string())))
            .collect::<Result<BTreeMap<_, _>, ToStrError>>()?;

        let path_and_query = path_and_query
            .map(|p| p.to_string())
            .unwrap_or(String::from("/"));

        let unsigned = self
            .config
            .begin_sign(&method.to_string(), &path_and_query, headers);

        Ok(Unsigned { unsigned })
    }

    pub fn begin_verify(
        &self,
        method: &Method,
        path_and_query: Option<&PathAndQuery>,
        headers: HeaderMap,
    ) -> Result<Unverified, VerifyError> {
        let headers = headers
            .iter()
            .map(|(k, v)| v.to_str().map(|v| (k.to_string(), v.to_string())))
            .collect::<Result<BTreeMap<_, _>, ToStrError>>()?;

        let path_and_query = path_and_query
            .map(|p| p.to_string())
            .unwrap_or(String::from("/"));

        let unverified = self
            .config
            .begin_verify(&method.to_string(), &path_and_query, headers)?;

        Ok(unverified)
    }
}

impl From<http_signature_normalization::VerifyError> for VerifyError {
    fn from(e: http_signature_normalization::VerifyError) -> Self {
        VerifyError::Sig(e)
    }
}

impl From<ToStrError> for VerifyError {
    fn from(e: ToStrError) -> Self {
        VerifyError::Header(e)
    }
}