/*
    This file is part of jellything (https://codeberg.org/metamuffin/jellything)
    which is licensed under the GNU Affero General Public License (version 3); see /COPYING.
    Copyright (C) 2023 metamuffin <metamuffin.org>
*/
use super::{
    account::session::Session,
    layout::LayoutPage,
    node::{DatabaseNodeUserDataExt, NodeCard},
};
use crate::{
    database::DataAcid,
    routes::ui::{error::MyResult, layout::DynLayoutPage},
};
use anyhow::Context;
use chrono::{Datelike, Utc};
use jellybase::{
    database::{ReadableTable, TableExt, T_NODE, T_USER_NODE},
    CONF,
};
use jellycommon::user::WatchedState;
use rocket::{get, State};
use tokio::fs::read_to_string;

#[get("/")]
pub fn r_home(sess: Session, db: &State<DataAcid>) -> MyResult<DynLayoutPage> {
    let mut items = {
        let txn = db.begin_read()?;
        let nodes = txn.open_table(T_NODE)?;
        let node_users = txn.open_table(T_USER_NODE)?;
        let i = nodes
            .iter()?
            .map(|a| {
                let (x, y) = a.unwrap();
                let (x, y) = (x.value().to_owned(), y.value().0);
                let z = node_users
                    .get(&(sess.user.name.as_str(), x.as_str()))
                    .unwrap()
                    .map(|z| z.value().0)
                    .unwrap_or_default();
                let y = y.public;
                (x, y, z)
            })
            .collect::<Vec<_>>();
        drop(nodes);
        i
    };
    let random = (0..16)
        .flat_map(|i| Some(items[cheap_daily_random(i).checked_rem(items.len())?].clone()))
        .collect::<Vec<_>>();

    let toplevel = T_NODE
        .get(&db, "library")?
        .context("root node missing")?
        .public
        .children
        .into_iter()
        .map(|n| db.get_node_with_userdata(&n, &sess))
        .collect::<anyhow::Result<Vec<_>>>()?
        .into_iter()
        .collect::<Vec<_>>();

    items.sort_by_key(|(_, n, _)| n.release_date.map(|d| -d).unwrap_or(i64::MAX));

    let latest = items
        .iter()
        .take(16)
        .map(|k| k.to_owned())
        .collect::<Vec<_>>();

    let continue_watching = items
        .iter()
        .filter(|(_, _, u)| matches!(u.watched, WatchedState::Progress(_)))
        .map(|k| k.to_owned())
        .collect::<Vec<_>>();

    let watchlist = items
        .iter()
        .filter(|(_, _, u)| matches!(u.watched, WatchedState::Pending))
        .map(|k| k.to_owned())
        .collect::<Vec<_>>();

    Ok(LayoutPage {
        title: "Home".to_string(),
        content: markup::new! {
            h2 { "Explore " @CONF.brand }
            .hlist { ul {@for (id, node, udata) in &toplevel {
                li { @NodeCard { id, node, udata } }
            }}}
            @if !continue_watching.is_empty() {
                h2 { "Continue Watching" }
                .hlist { ul {@for (id, node, udata) in &continue_watching {
                    li { @NodeCard { id, node, udata } }
                }}}
            }
            @if !watchlist.is_empty() {
                h2 { "Watchlist" }
                .hlist { ul {@for (id, node, udata) in &watchlist {
                    li { @NodeCard { id, node, udata } }
                }}}
            }
            h2 { "Latest Releases" }
            .hlist { ul {@for (id, node, udata) in &latest {
                li { @NodeCard { id, node, udata } }
            }}}
            h2 { "Today's Picks" }
            .hlist { ul {@for (id, node, udata) in &random {
                li { @NodeCard { id, node, udata } }
            }}}
            p.error { "TODO: recently added" }
            p.error { "TODO: best rating" }
        },
        ..Default::default()
    })
}

#[get("/", rank = 2)]
pub async fn r_home_unpriv() -> MyResult<DynLayoutPage<'static>> {
    let front = read_to_string(CONF.asset_path.join("front.htm")).await?;
    Ok(LayoutPage {
        title: "Home".to_string(),
        content: markup::new! {
            @markup::raw(&front)
        },
        ..Default::default()
    })
}

fn cheap_daily_random(i: usize) -> usize {
    xorshift(xorshift(Utc::now().num_days_from_ce() as u64) + i as u64) as usize
}

fn xorshift(mut x: u64) -> u64 {
    x ^= x << 13;
    x ^= x >> 7;
    x ^= x << 17;
    x
}