locutus-server/src/http/handler.rs

use super::Method;
use crate::usimp;
use crate::websocket;
use crate::error::*;
use serde_json;

pub struct HttpStream {
    pub stream: super::Stream,
    pub request_num: u32,
    pub client_keep_alive: bool,
    pub server_keep_alive: bool,
}

pub fn connection_handler(client: super::Stream) {
    let mut client = super::HttpStream {
        stream: client,
        request_num: 0,
        client_keep_alive: true,
        server_keep_alive: true,
    };

    while client.request_num < super::REQUESTS_PER_CONNECTION
        && client.client_keep_alive
        && client.server_keep_alive
    {
        request_handler(&mut client);
        client.request_num += 1;
    }
}

fn request_handler(client: &mut super::HttpStream) {
    let mut res = super::Response::new();

    match super::parser::parse_request(&mut client.stream) {
        Ok(Some(req)) => {
            println!("{} {}", req.method, req.uri);

            if !req.uri.starts_with("/")
                || req.uri.contains("/./")
                || req.uri.contains("/../")
                || req.uri.ends_with("/..")
            {
                res.status(400);
            } else if req.uri.contains("/.") {
                res.status(404);
            } else if req.uri.eq("/") {
                res.status(200);
            } else if req.uri.eq("/_usimp/websocket") {
                return websocket::connection_handler(client, &req);
            } else if req.uri.starts_with("/_usimp/") {
                let parts: Vec<&str> = req.uri.split('/').collect();
                match parts[2..] {
                    ["entity", entity] => res.status(501),
                    [endpoint] => match req.method {
                        Method::POST => return endpoint_handler(client, &req, &mut res, endpoint),
                        _ => {
                            res.status(405);
                            res.add_header("Allow", "POST");
                        }
                    },
                    _ => res.status(400),
                }
            } else {
                res.status(404);
            }
        }
        Ok(None) => {
            client.client_keep_alive = false;
            return;
        }
        Err(e) => {
            res.status(400);
            res.error_info(format!("{}", &e));
            println!("{}", &e);
            client.server_keep_alive = false;
        }
    }

    if let Err(e) = res.send(&mut client.stream) {
        println!("Unable to send: {}", e);
        client.server_keep_alive = false;
    }
    client.server_keep_alive = false;
}

fn endpoint_handler(
    client: &mut super::HttpStream,
    req: &super::Request,
    res: &mut super::Response,
    endpoint: &str,
) {
    res.add_header("Cache-Control", "no-store");

    let mut error = |error: Error, client: &mut super::HttpStream| {
        println!("{}", error.to_string());
        res.status(match &error.class() {
            Class::ClientError => 400,
            Class::ServerError => 500,
        });
        res.error_info(error.to_string());

        let mut obj = serde_json::Value::Object(serde_json::Map::new());
        obj["status"] = serde_json::Value::String("error".to_string());
        obj["message"] = serde_json::Value::String(error.to_string());
        let buf = obj.to_string() + "\r\n";

        let length = buf.as_bytes().len();
        res.add_header("Content-Length", length.to_string().as_str());
        res.add_header("Content-Type", "application/json; charset=utf-8");

        if let Err(e) = res.send(&mut client.stream) {
            println!("Unable to send: {}", e);
            client.server_keep_alive = false;
        }

        client.stream.write_all(buf.as_bytes());
    };

    let length = req.find_header("Content-Length");
    let length: usize = match match length {
        Some(length) => length,
        None => {
            return error(
                Error::new(Kind::HttpRequestParseError, Class::ClientError)
                    .set_desc("field 'Content-Length' missing".to_string()),
                client,
            )
        }
    }
    .parse()
    {
        Ok(length) => length,
        Err(e) => {
            return error(
                Error::new(Kind::HttpRequestParseError, Class::ClientError)
                    .set_desc(format!("unable to parse field 'Content-Length': {}", &e).to_string()),
                client,
            )
        }
    };

    let mut buf = [0; 8192];
    client.stream.read_exact(&mut buf[..length]);

    // TODO decompress
    let input = match serde_json::from_slice(&buf[..length]) {
        Ok(val) => val,
        Err(e) => {
            return error(e.into(), client)
        }
    };

    let buf = match usimp::endpoint(endpoint, input) {
        Ok(output) => output.to_string() + "\r\n",
        Err(e) => return error(e, client),
    };

    // TODO compress
    let length = buf.as_bytes().len();
    res.add_header("Content-Length", length.to_string().as_str());
    res.add_header("Content-Type", "application/json; charset=utf-8");

    res.status(200);
    res.send(&mut client.stream);
    client.stream.write_all(buf.as_bytes());
}