use http::Method;
use futures::Future;

use error::Error;
use pred::{self, Predicate};
use handler::{Reply, Handler, FromRequest, RouteHandler, AsyncHandler, WrapHandler};
use httpcodes::HTTPNotFound;
use httprequest::HttpRequest;
use httpresponse::HttpResponse;


/// Resource route definition
///
/// Route uses builder-like pattern for configuration.
/// If handler is not explicitly set, default *404 Not Found* handler is used.
pub struct Route<S> {
    preds: Vec<Box<Predicate<S>>>,
    handler: Box<RouteHandler<S>>,
}

impl<S: 'static> Default for Route<S> {

    fn default() -> Route<S> {
        Route {
            preds: Vec::new(),
            handler: Box::new(WrapHandler::new(|_| HTTPNotFound)),
        }
    }
}

impl<S: 'static> Route<S> {

    pub(crate) fn check(&self, req: &mut HttpRequest<S>) -> bool {
        for pred in &self.preds {
            if !pred.check(req) {
                return false
            }
        }
        true
    }

    pub(crate) fn handle(&self, req: HttpRequest<S>) -> Reply {
        self.handler.handle(req)
    }

    /// Add method check to route. This method could be called multiple times.
    pub fn method(&mut self, method: Method) -> &mut Self {
        self.preds.push(pred::Method(method));
        self
    }

    /// Add predicates to route.
    pub fn predicates<P>(&mut self, preds: P) -> &mut Self
        where P: IntoIterator<Item=Box<Predicate<S>>>
    {
        self.preds.extend(preds.into_iter());
        self
    }

    /// Add match predicate to route.
    pub fn p(&mut self, p: Box<Predicate<S>>) -> &mut Self {
        self.preds.push(p);
        self
    }

    /// Set handler object. Usually call to this method is last call
    /// during route configuration, because it does not return reference to self.
    pub fn h<H: Handler<S>>(&mut self, handler: H) {
        self.handler = Box::new(WrapHandler::new(handler));
    }

    /// Set handler function. Usually call to this method is last call
    /// during route configuration, because it does not return reference to self.
    pub fn f<F, R>(&mut self, handler: F)
        where F: Fn(HttpRequest<S>) -> R + 'static,
              R: FromRequest + 'static,
    {
        self.handler = Box::new(WrapHandler::new(handler));
    }

    /// Set async handler function.
    pub fn a<F, R>(&mut self, handler: F)
        where F: Fn(HttpRequest<S>) -> R + 'static,
              R: Future<Item=HttpResponse, Error=Error> + 'static,
    {
        self.handler = Box::new(AsyncHandler::new(handler));
    }
}