+// Copyright (c) 2020  Teddy Wing
+//
+// This file is part of FastCGI-Conduit.
+//
+// FastCGI-Conduit 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.
+//
+// FastCGI-Conduit 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 FastCGI-Conduit. If not, see <https://www.gnu.org/licenses/>.
+
+use std::io;
+use std::io::Read;
+use std::net::SocketAddr;
+
+use inflector::cases::traincase::to_train_case;
+
+use snafu::{ResultExt, Snafu};
+
+
+/// Errors parsing a FastCGI request.
+#[derive(Debug, Snafu)]
+pub enum Error {
+    /// The HTTP method is invalid.
+    #[snafu(context(false))]
+    InvalidMethod { source: http::method::InvalidMethod },
+
+    /// An invalid HTTP header name.
+    #[snafu(context(false))]
+    InvalidHeaderName { source: conduit::header::InvalidHeaderName },
+
+    /// An invalid HTTP header value.
+    #[snafu(context(false))]
+    InvalidHeaderValue { source: conduit::header::InvalidHeaderValue },
+
+    /// An invalid remote address.
+    #[snafu(context(false))]
+    InvalidRemoteAddr { source: RemoteAddrError },
+}
+
+/// A convenience `Result` that contains a request `Error`.
+pub type RequestResult<T, E = Error> = std::result::Result<T, E>;
+
+/// Errors parsing an HTTP remote address.
+#[derive(Debug, Snafu)]
+pub enum RemoteAddrError {
+    /// Error parsing the address part.
+    #[snafu(display("Could not parse address {}: {}", address, source))]
+    AddrParseError {
+        address: String,
+        source: std::net::AddrParseError,
+    },
+
+    /// Error parsing the port part.
+    #[snafu(display("Could not parse port {}: {}", port, source))]
+    PortParseError {
+        port: String,
+        source: std::num::ParseIntError
+    },
+}
+
+
+/// Wraps a [`fastcgi::Request`][fastcgi::Request] to implement
+/// [`conduit::RequestExt`][conduit::RequestExt].
+///
+/// [fastcgi::Request]: ../../fastcgi/struct.Request.html
+/// [conduit::RequestExt]: ../../conduit/trait.RequestExt.html
+pub struct FastCgiRequest<'a> {
+    request: &'a mut fastcgi::Request,
+    http_version: conduit::Version,
+    host: String,
+    method: conduit::Method,
+    headers: conduit::HeaderMap,
+    path: String,
+    query: Option<String>,
+    remote_addr: SocketAddr,
+    content_length: Option<u64>,
+    extensions: conduit::Extensions,
+}
+
+impl<'a> FastCgiRequest<'a> {
+    /// Create a new `FastCgiRequest`.
+    pub fn new(request: &'a mut fastcgi::Request) -> RequestResult<Self> {
+        let version = Self::version(request);
+        let host = Self::host(request);
+        let method = Self::method(request)?;
+        let headers = Self::headers(request.params())?;
+        let path = Self::path(request);
+        let query = Self::query(request);
+        let remote_addr = Self::remote_addr(request)?;
+        let content_length = Self::content_length(request);
+
+        Ok(Self {
+            request: request,
+            http_version: version,
+            host: host,
+            method: method,
+            headers: headers,
+            path: path,
+            query: query,
+            remote_addr: remote_addr,
+            content_length: content_length,
+            extensions: conduit::TypeMap::new(),
+        })
+    }
+
+    /// Extract the HTTP version.
+    fn version(request: &fastcgi::Request) -> conduit::Version {
+        match request.param("SERVER_PROTOCOL").unwrap_or_default().as_str() {
+            "HTTP/0.9" => conduit::Version::HTTP_09,
+            "HTTP/1.0" => conduit::Version::HTTP_10,
+            "HTTP/1.1" => conduit::Version::HTTP_11,
+            "HTTP/2.0" => conduit::Version::HTTP_2,
+            "HTTP/3.0" => conduit::Version::HTTP_3,
+            _ => conduit::Version::default(),
+        }
+    }
+
+    /// Get the request scheme (HTTP or HTTPS).
+    fn scheme(&self) -> conduit::Scheme {
+        let scheme = self.request.param("REQUEST_SCHEME").unwrap_or_default();
+
+        if scheme == "https" {
+            conduit::Scheme::Https
+        } else {
+            conduit::Scheme::Http
+        }
+    }
+
+    /// Get the HTTP host.
+    ///
+    /// This looks like `localhost:8000`.
+    fn host(request: &fastcgi::Request) -> String {
+        request.param("HTTP_HOST").unwrap_or_default()
+    }
+
+    /// Get the HTTP method (GET, HEAD, POST, etc.).
+    fn method(
+        request: &fastcgi::Request
+    ) -> Result<conduit::Method, http::method::InvalidMethod> {
+        conduit::Method::from_bytes(
+            request.param("REQUEST_METHOD")
+                .unwrap_or_default()
+                .as_bytes()
+        )
+    }
+
+    /// Build a map of request headers.
+    fn headers(params: fastcgi::Params) -> RequestResult<conduit::HeaderMap> {
+        let mut map = conduit::HeaderMap::new();
+        let headers = Self::headers_from_params(params);
+
+        for (name, value) in headers
+            .iter()
+            .map(|(name, value)| (name.as_bytes(), value.as_bytes()))
+        {
+            map.append(
+                conduit::header::HeaderName::from_bytes(name)?,
+                conduit::header::HeaderValue::from_bytes(value)?,
+            );
+        }
+
+        Ok(map)
+    }
+
+    /// Extract headers from request params. Transform these into pairs of
+    /// canonical header names and values.
+    fn headers_from_params(params: fastcgi::Params) -> Vec<(String, String)> {
+        return params
+            .filter(|(key, _)| key.starts_with("HTTP_"))
+            .map(|(key, value)| {
+                let key = key.get(5..).unwrap_or_default();
+                let key = &key.replace("_", "-");
+                let key = &to_train_case(&key);
+
+                (key.to_owned(), value)
+            })
+            .collect()
+    }
+
+    /// Get the URI path.
+    ///
+    /// Returns `/path` when the URI is `http://localhost:8000/path?s=query`.
+    /// When the path is empty, returns `/`.
+    fn path(request: &fastcgi::Request) -> String {
+        match request.param("SCRIPT_NAME") {
+            Some(p) => p,
+            None => "/".to_owned(),
+        }
+    }
+
+    /// Get the URI query string.
+    ///
+    /// Returns `s=query&lang=en` when the URI is
+    /// `http://localhost:8000/path?s=query&lang=en`.
+    fn query(request: &fastcgi::Request) -> Option<String> {
+        request.param("QUERY_STRING")
+    }
+
+    /// Get the remote address of the request.
+    fn remote_addr(request: &fastcgi::Request) -> Result<SocketAddr, RemoteAddrError> {
+        let addr = request.param("REMOTE_ADDR").unwrap_or_default();
+        let port = request.param("REMOTE_PORT").unwrap_or_default();
+
+        Ok(
+            SocketAddr::new(
+                addr.parse().context(AddrParseError { address: addr })?,
+                port.parse().context(PortParseError { port })?,
+            )
+        )
+    }
+
+    /// Get the request's content length.
+    fn content_length(request: &fastcgi::Request) -> Option<u64> {
+        request.param("CONTENT_LENGTH").and_then(|l| l.parse().ok())
+    }
+}
+
+impl<'a> Read for FastCgiRequest<'a> {
+    /// Read from the underlying FastCGI request's [`Stdin`][Stdin]
+    ///
+    /// [Stdin]: ../../fastcgi/struct.Stdin.html
+    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
+        self.request.stdin().read(buf)
+    }
+}
+
+impl<'a> conduit::RequestExt for FastCgiRequest<'a> {
+   fn http_version(&self) -> conduit::Version {
+       self.http_version
+   }
+
+   fn method(&self) -> &conduit::Method {
+       &self.method
+   }
+
+   fn scheme(&self) -> conduit::Scheme {
+       self.scheme()
+   }
+
+   fn host(&self) -> conduit::Host<'_> {
+       conduit::Host::Name(&self.host)
+   }
+
+   fn virtual_root(&self) -> std::option::Option<&str> {
+       None
+   }
+
+   fn path(&self) -> &str {
+       &self.path
+   }
+
+   fn query_string(&self) -> std::option::Option<&str> {
+       self.query.as_ref()
+           .map(|p| p.as_str())
+   }
+
+   fn remote_addr(&self) -> std::net::SocketAddr {
+       self.remote_addr
+   }
+
+   fn content_length(&self) -> std::option::Option<u64> {
+       self.content_length
+   }
+
+   fn headers(&self) -> &conduit::HeaderMap {
+       &self.headers
+   }
+
+   fn body(&mut self) -> &mut (dyn std::io::Read) {
+       self
+   }
+
+   fn extensions(&self) -> &conduit::Extensions {
+       &self.extensions
+   }
+
+   fn mut_extensions(&mut self) -> &mut conduit::Extensions {
+       &mut self.extensions
+   }
+}
+

+