// Copyright 2019, The Tari Project
//
// Redistribution and use in source and binary forms, with or without modification, are permitted provided that the
// following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following
// disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the
// following disclaimer in the documentation and/or other materials provided with the distribution.
//
// 3. Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote
// products derived from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
// INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
// WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
// USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

use std::{borrow::Cow, fmt::Display, marker::PhantomData, task::Poll};

use futures::task::Context;
use log::*;
use tower::{Service, layer::Layer};

const LOG_TARGET: &str = "comms::middleware::message_logging";

/// This layer is responsible for logging messages for debugging.
pub struct MessageLoggingLayer<'a, R> {
    prefix_msg: Cow<'a, str>,
    _r: PhantomData<R>,
}

impl<'a, R> MessageLoggingLayer<'a, R> {
    /// Creates a new logging middleware layer
    pub fn new<T: Into<Cow<'a, str>>>(prefix_msg: T) -> Self {
        Self {
            prefix_msg: prefix_msg.into(),
            _r: PhantomData,
        }
    }
}

impl<'a, S, R> Layer<S> for MessageLoggingLayer<'a, R>
where
    S: Service<R>,
    R: Display,
{
    type Service = MessageLoggingService<'a, S>;

    fn layer(&self, service: S) -> Self::Service {
        MessageLoggingService::new(self.prefix_msg.clone(), service)
    }
}

/// [Service](https://tower-rs.github.io/tower/tower_service/) for DHT message logging.
#[derive(Clone)]
pub struct MessageLoggingService<'a, S> {
    prefix_msg: Cow<'a, str>,
    inner: S,
}

impl<'a, S> MessageLoggingService<'a, S> {
    pub fn new(prefix_msg: Cow<'a, str>, service: S) -> Self {
        Self {
            inner: service,
            prefix_msg,
        }
    }
}

impl<S, R> Service<R> for MessageLoggingService<'_, S>
where
    S: Service<R>,
    R: Display,
{
    type Error = S::Error;
    type Future = S::Future;
    type Response = S::Response;

    fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
        self.inner.poll_ready(cx)
    }

    fn call(&mut self, msg: R) -> Self::Future {
        debug!(target: LOG_TARGET, "{}{:#}", self.prefix_msg, msg);
        self.inner.call(msg)
    }
}
