// Copyright 2015-2020 Parity Technologies (UK) Ltd.
// This file is part of OpenEthereum.

// OpenEthereum is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// OpenEthereum is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with OpenEthereum.  If not, see <http://www.gnu.org/licenses/>.

use std::{
    io::{self, Read, Write},
    net::{SocketAddr, TcpStream},
    str::{self, Lines},
    thread,
    time::Duration,
};

pub struct Response {
    pub status: String,
    pub headers: Vec<String>,
    pub headers_raw: String,
    pub body: String,
}

impl Response {
    pub fn assert_header(&self, header: &str, value: &str) {
        let header = format!("{}: {}", header, value);
        assert!(
            self.headers.iter().any(|h| h == &header),
            "Couldn't find header {} in {:?}",
            header,
            &self.headers
        )
    }

    pub fn assert_status(&self, status: &str) {
        assert_eq!(
            self.status,
            status.to_owned(),
            "Got unexpected code. Body: {:?}",
            self.body
        );
    }

    pub fn assert_security_headers_present(&self, port: Option<u16>) {
        assert_security_headers_present(&self.headers, port)
    }
}

pub fn read_block(lines: &mut Lines, all: bool) -> String {
    let mut block = String::new();
    loop {
        let line = lines.next();
        match line {
            None => break,
            Some("") if !all => break,
            Some(v) => {
                block.push_str(v);
                block.push_str("\n");
            }
        }
    }
    block
}

fn connect(address: &SocketAddr) -> TcpStream {
    let mut retries = 0;
    let mut last_error = None;
    while retries < 10 {
        retries += 1;

        let res = TcpStream::connect(address);
        match res {
            Ok(stream) => {
                return stream;
            }
            Err(e) => {
                last_error = Some(e);
                thread::sleep(Duration::from_millis(retries * 10));
            }
        }
    }
    panic!(
        "Unable to connect to the server. Last error: {:?}",
        last_error
    );
}

pub fn request(address: &SocketAddr, request: &str) -> Response {
    let mut req = connect(address);
    req.set_read_timeout(Some(Duration::from_secs(2))).unwrap();
    req.write_all(request.as_bytes()).unwrap();

    let mut response = Vec::new();
    loop {
        let mut chunk = [0; 32 * 1024];
        match req.read(&mut chunk) {
            Err(ref err) if err.kind() == io::ErrorKind::WouldBlock => break,
            Err(err) => panic!("Unable to read response: {:?}", err),
            Ok(0) => break,
            Ok(read) => response.extend_from_slice(&chunk[..read]),
        }
    }

    let response = String::from_utf8_lossy(&response).into_owned();
    let mut lines = response.lines();
    let status = lines.next().expect("Expected a response").to_owned();
    let headers_raw = read_block(&mut lines, false);
    let headers = headers_raw.split('\n').map(ToOwned::to_owned).collect();
    let body = read_block(&mut lines, true);

    Response {
        status,
        headers,
        headers_raw,
        body,
    }
}

/// Check if all required security headers are present
pub fn assert_security_headers_present(headers: &[String], port: Option<u16>) {
    if port.is_none() {
        assert!(
            headers
                .iter()
                .any(|header| header.as_str() == "X-Frame-Options: SAMEORIGIN"),
            "X-Frame-Options: SAMEORIGIN missing: {:?}",
            headers
        );
    }
    assert!(
        headers
            .iter()
            .any(|header| header.as_str() == "X-XSS-Protection: 1; mode=block"),
        "X-XSS-Protection missing: {:?}",
        headers
    );
    assert!(
        headers
            .iter()
            .any(|header| header.as_str() == "X-Content-Type-Options: nosniff"),
        "X-Content-Type-Options missing: {:?}",
        headers
    );
    assert!(
        headers
            .iter()
            .any(|header| header.starts_with("Content-Security-Policy: ")),
        "Content-Security-Policy missing: {:?}",
        headers
    )
}
