use atom_syndication::{ContentBuilder, Entry, EntryBuilder, LinkBuilder, Person, PersonBuilder};
use rocket::{
    http::{
        RawStr, Status, uri::{FromUriParam, Query},
        hyper::header::{CacheControl, CacheDirective}
    },
    Outcome,
    request::{self, FromFormValue, FromRequest, Request},
    response::NamedFile,
};
use std::path::{Path, PathBuf};

use plume_models::{Connection, posts::Post};

const ITEMS_PER_PAGE: i32 = 12;

#[derive(Copy, Clone, UriDisplayQuery)]
pub struct Page(i32);

impl<'v> FromFormValue<'v> for Page {
    type Error = &'v RawStr;
    fn from_form_value(form_value: &'v RawStr) -> Result<Page, &'v RawStr> {
        match form_value.parse::<i32>() {
            Ok(page) => Ok(Page(page)),
            _ => Err(form_value),
        }
    }
}

impl FromUriParam<Query, Option<Page>> for Page {
    type Target = Page;

    fn from_uri_param(val: Option<Page>) -> Page {
        val.unwrap_or_default()
    }
}

impl Page {
    /// Computes the total number of pages needed to display n_items
    pub fn total(n_items: i32) -> i32 {
        if n_items % ITEMS_PER_PAGE == 0 {
            n_items / ITEMS_PER_PAGE
        } else {
            (n_items / ITEMS_PER_PAGE) + 1
        }
    }

    pub fn limits(&self) -> (i32, i32) {
        ((self.0 - 1) * ITEMS_PER_PAGE, self.0 * ITEMS_PER_PAGE)
    }
}

pub struct ContentLen(pub u64);

impl<'a, 'r> FromRequest<'a, 'r> for ContentLen {
    type Error = ();

    fn from_request(r: &'a Request<'r>) -> request::Outcome<Self, Self::Error> {
        match r.limits().get("forms") {
            Some(l) => Outcome::Success(ContentLen(l)),
            None => Outcome::Failure((Status::InternalServerError, ())),
        }
    }
}


impl Default for Page {
    fn default() -> Self {
        Page(1)
    }
}

pub fn post_to_atom(post: Post, conn: &Connection) -> Entry {
    EntryBuilder::default()
        .title(format!("<![CDATA[{}]]>", post.title))
        .content(ContentBuilder::default()
            .value(format!("<![CDATA[{}]]>", *post.content.get()))
            .src(post.ap_url.clone())
            .content_type("html".to_string())
            .build().expect("Atom feed: content error"))
        .authors(post.get_authors(&*conn).expect("Atom feed: author error")
            .into_iter()
            .map(|a| PersonBuilder::default()
                .name(a.display_name)
                .uri(a.ap_url)
                .build().expect("Atom feed: author error"))
            .collect::<Vec<Person>>())
        .links(vec![LinkBuilder::default().href(post.ap_url).build().expect("Atom feed: link error")])
        .build().expect("Atom feed: entry error")
}

pub mod blogs;
pub mod comments;
pub mod errors;
pub mod instance;
pub mod likes;
pub mod medias;
pub mod notifications;
pub mod posts;
pub mod reshares;
pub mod session;
pub mod tags;
pub mod user;
pub mod search;
pub mod well_known;

#[derive(Responder)]
#[response()]
pub struct CachedFile {
    inner: NamedFile,
    cache_control: CacheControl
}

#[get("/static/cached/<_build_id>/<file..>", rank = 2)]
pub fn plume_static_files(file: PathBuf, _build_id: &RawStr) -> Option<CachedFile> {
    static_files(file)
}

#[get("/static/<file..>", rank = 3)]
pub fn static_files(file: PathBuf) -> Option<CachedFile> {
    NamedFile::open(Path::new("static/").join(file)).ok()
        .map(|f|
             CachedFile {
                 inner: f,
                 cache_control: CacheControl(vec![CacheDirective::MaxAge(60*60*24*30)])
             })
}