1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169

use crate::ws;
use bytes::BytesMut;
use http::{header, HeaderValue};
use hyper::header::SEC_WEBSOCKET_KEY;
use hyper::{Body, Error, HeaderMap, Response, StatusCode};
use std::convert::Infallible;
use std::io::Write;
use std::{fmt, io};

pub trait Responder {
    fn status_code(&self) -> StatusCode {
        StatusCode::OK
    }
    fn respond(self) -> Response<Body>;
}

#[derive(Debug)]
pub struct UpgradeWS {
    key: HeaderValue,
}

impl UpgradeWS {
    pub fn from_header(headers: &HeaderMap) -> Option<Self> {
        let key = headers.get(SEC_WEBSOCKET_KEY)?;
        Some(Self { key: key.clone() })
    }
}

impl Responder for UpgradeWS {
    fn respond(self) -> Response<Body> {
        Response::builder()
            .status(StatusCode::SWITCHING_PROTOCOLS)
            .header(header::UPGRADE, "websocket")
            .header(header::CONNECTION, "upgrade")
            .header(
                header::SEC_WEBSOCKET_ACCEPT,
                ws::convert_key(self.key.as_bytes()),
            )
            .body(Body::empty())
            .unwrap()
    }
}

impl Responder for &'static str {
    fn respond(self) -> Response<Body> {
        Response::builder()
            .header(header::CONTENT_TYPE, "text/plain; charset=utf-8")
            .status(StatusCode::OK)
            .body(Body::from(self))
            .unwrap()
    }
}

impl Responder for &'static [u8] {
    fn respond(self) -> Response<Body> {
        Response::builder()
            .header(header::CONTENT_TYPE, "application/octet-stream")
            .status(StatusCode::OK)
            .body(Body::from(self))
            .unwrap()
    }
}

impl Responder for String {
    fn respond(self) -> Response<Body> {
        Response::builder()
            .header(header::CONTENT_TYPE, "text/plain; charset=utf-8")
            .status(StatusCode::OK)
            .body(Body::from(self))
            .unwrap()
    }
}

impl Responder for () {
    fn respond(self) -> Response<Body> {
        Response::builder()
            .header(header::CONTENT_TYPE, "text/plain; charset=utf-8")
            .status(StatusCode::OK)
            .body(Body::empty())
            .unwrap()
    }
}

impl<T> Responder for Option<T>
where
    T: Responder,
{
    fn respond(self) -> Response<Body> {
        match self {
            Some(t) => t.respond(),
            None => Response::builder()
                .status(StatusCode::NOT_FOUND)
                .body(Body::empty())
                .unwrap(),
        }
    }
}

impl<T, E> Responder for Result<T, E>
where
    E: ResponderError,
    T: Responder,
{
    fn respond(self) -> Response<Body> {
        match self {
            Ok(t) => t.respond(),
            Err(e) => e.respond_err(),
        }
    }
}

pub trait ResponderError: fmt::Display {
    fn status_code(&self) -> StatusCode {
        StatusCode::INTERNAL_SERVER_ERROR
    }
    fn respond_err(&self) -> Response<Body> {
        let mut buf = BytesMut::new();
        let _ = write!(ByteWriter(&mut buf), "{}", self);
        let b = buf.freeze();

        Response::builder()
            .header(header::CONTENT_TYPE, "text/plain; charset=utf-8")
            .status(self.status_code())
            .body(Body::from(b))
            .expect("this cannot happen")
    }
}

impl ResponderError for tokio::task::JoinError {}

struct ByteWriter<'a>(pub &'a mut BytesMut);

impl<'a> Write for ByteWriter<'a> {
    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
        self.0.extend_from_slice(buf);
        Ok(buf.len())
    }

    fn flush(&mut self) -> io::Result<()> {
        Ok(())
    }
}

impl ResponderError for Infallible {}
impl ResponderError for String {}
impl ResponderError for &str {}
impl ResponderError for Error {}
impl ResponderError for dyn std::error::Error {}

pub trait ErrResponder<E, B>
where
    E: std::error::Error,
{
    fn respond_err(e: E) -> Response<B>;
}

impl<T> ErrResponder<crate::request::QueryPayloadError, Body> for Option<T> {
    fn respond_err(e: crate::request::QueryPayloadError) -> Response<Body> {
        let msg = match e {
            crate::request::QueryPayloadError::Deserialize(de) => de.to_string(),
            crate::request::QueryPayloadError::NotExist => "missing query params".to_string(),
        };

        Response::builder()
            .status(StatusCode::BAD_REQUEST)
            .body(Body::from(msg))
            .expect("this not to happen!")
    }
}