//! Handle the OPDS root feed.

use poem::{handler, web::WithContentType, IntoResponse};
use time::OffsetDateTime;

use crate::{
    handlers::error::HandlerError,
    opds::{
        content::Content, entry::Entry, feed::Feed, link::Link, media_type::MediaType,
        relation::Relation,
    },
};

/// Render a root OPDS feed with links to the subsections (authors, books, series and recent).
#[handler]
pub async fn handler() -> Result<WithContentType<String>, poem::Error> {
    let now = OffsetDateTime::now_utc();

    let self_link = Link {
        href: "/opds".to_string(),
        media_type: MediaType::Navigation,
        rel: Relation::Myself,
        title: None,
        count: None,
    };
    let books_entry = Entry {
        title: "Books".to_string(),
        id: "rusty:books".to_string(),
        updated: now,
        content: Some(Content {
            media_type: MediaType::Text,
            content: "Index of all books".to_string(),
        }),
        author: None,
        links: vec![Link {
            href: "/opds/books".to_string(),
            media_type: MediaType::Navigation,
            rel: Relation::Subsection,
            title: None,
            count: None,
        }],
    };

    let authors_entry = Entry {
        title: "Authors".to_string(),
        id: "rusty:authors".to_string(),
        updated: now,
        content: Some(Content {
            media_type: MediaType::Text,
            content: "Index of all authors".to_string(),
        }),
        author: None,
        links: vec![Link {
            href: "/opds/authors".to_string(),
            media_type: MediaType::Navigation,
            rel: Relation::Subsection,
            title: None,
            count: None,
        }],
    };

    let series_entry = Entry {
        title: "Series".to_string(),
        id: "rusty:series".to_string(),
        updated: now,
        content: Some(Content {
            media_type: MediaType::Text,
            content: "Index of all series".to_string(),
        }),
        author: None,
        links: vec![Link {
            href: "/opds/series".to_string(),
            media_type: MediaType::Navigation,
            rel: Relation::Subsection,
            title: None,
            count: None,
        }],
    };

    let recents_entry = Entry {
        title: "Recent Additions".to_string(),
        id: "rusty:recentbooks".to_string(),
        updated: now,
        content: Some(Content {
            media_type: MediaType::Text,
            content: "Recently added books".to_string(),
        }),
        author: None,
        links: vec![Link {
            href: "/opds/recent".to_string(),
            media_type: MediaType::Navigation,
            rel: Relation::Subsection,
            title: None,
            count: None,
        }],
    };

    let feed = Feed::create(
        now,
        "rusty:catalog",
        "Rusty-Library",
        self_link,
        vec![],
        vec![authors_entry, series_entry, books_entry, recents_entry],
    );
    let xml = feed.as_xml().map_err(HandlerError::OpdsError)?;

    Ok(xml.with_content_type("application/atom+xml"))
}