use nickel::{Continue, Middleware, MiddlewareResult, Request, Response};
use photosdir::PhotosDir;
use plugin::Extensible;
use std::path::PathBuf;
use typemap::Key;

pub struct PhotosDirMiddleware {
    dir: PathBuf,
}

impl PhotosDirMiddleware {
    pub fn new(dir: PathBuf) -> Self {
        PhotosDirMiddleware { dir: dir }
    }
}

impl Key for PhotosDirMiddleware {
    type Value = PhotosDir;
}

impl<D> Middleware<D> for PhotosDirMiddleware {
    fn invoke<'mw, 'conn>(
        &self,
        req: &mut Request<'mw, 'conn, D>,
        res: Response<'mw, D>,
    ) -> MiddlewareResult<'mw, D> {
        req.extensions_mut()
            .insert::<PhotosDirMiddleware>(PhotosDir::new(self.dir.clone()));
        Ok(Continue(res))
    }
}

pub trait PhotosDirRequestExtensions {
    fn photos(&self) -> &PhotosDir;
}

impl<'a, 'b, D> PhotosDirRequestExtensions for Request<'a, 'b, D> {
    fn photos(&self) -> &PhotosDir {
        self.extensions().get::<PhotosDirMiddleware>().unwrap()
    }
}