use crate::error::*;
use crate::http;

use base64;
use sha1;

pub fn connection_handler(
    client: &mut http::HttpStream,
    req: &http::Request,
    mut res: http::Response,
) {
    client.server_keep_alive = false;

    if let http::Method::GET = req.method {
    } else {
        res.status(405);
        res.add_header("Allow", "GET");
        res.send(&mut client.stream).unwrap();
        return;
    }

    if let Some(connection) = req.find_header("Connection") {
        if !connection.eq_ignore_ascii_case("upgrade") {
            return http::error_handler(
                client,
                res,
                Error::new(Kind::WebSocketError, Class::ClientError)
                    .set_desc("invalid value for header field 'Connection'".to_string()),
            );
        }
    } else {
        return http::error_handler(
            client,
            res,
            Error::new(Kind::WebSocketError, Class::ClientError)
                .set_desc("unable to find header field 'Connection'".to_string()),
        );
    }

    if let Some(upgrade) = req.find_header("Upgrade") {
        if !upgrade.eq_ignore_ascii_case("websocket") {
            return http::error_handler(
                client,
                res,
                Error::new(Kind::WebSocketError, Class::ClientError)
                    .set_desc("invalid value for header field 'Upgrade'".to_string()),
            );
        }
    } else {
        return http::error_handler(
            client,
            res,
            Error::new(Kind::WebSocketError, Class::ClientError)
                .set_desc("unable to find header field 'Upgrade'".to_string()),
        );
    }

    if let Some(version) = req.find_header("Sec-WebSocket-Version") {
        if !version.eq("13") {
            return http::error_handler(
                client,
                res,
                Error::new(Kind::WebSocketError, Class::ClientError)
                    .set_desc("invalid value for header field 'Sec-WebSocket-Key'".to_string()),
            );
        }
    } else {
        return http::error_handler(
            client,
            res,
            Error::new(Kind::WebSocketError, Class::ClientError)
                .set_desc("unable to find header field 'Sec-WebSocket-Version'".to_string()),
        );
    }

    if let Some(key) = req.find_header("Sec-WebSocket-Key") {
        let mut hasher = sha1::Sha1::new();
        hasher.update(key.as_bytes());
        hasher.update("258EAFA5-E914-47DA-95CA-C5AB0DC85B11".as_bytes());
        let key = base64::encode(hasher.digest().bytes());
        res.add_header("Sec-WebSocket-Accept", key.as_str());
    } else {
        return http::error_handler(
            client,
            res,
            Error::new(Kind::WebSocketError, Class::ClientError)
                .set_desc("unable to find header field 'Sec-WebSocket-Key'".to_string()),
        );
    }

    res.add_header("Connection", "Upgrade");
    res.add_header("Upgrade", "websocket");

    // TODO implement websocket
    res.status(101);
    res.send(&mut client.stream).unwrap();
}