/*
    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) 2024 metamuffin <metamuffin.org>
*/
use crate::routes::ui::{account::session::Session, error::MyResult, CacheControlFile};
use anyhow::{anyhow, Context};
use base64::Engine;
use jellybase::{
    assetfed::AssetInner,
    cache::async_cache_file,
    database::{DataAcid, TableExt, T_NODE, T_NODE_EXTENDED},
    federation::Federation,
    permission::NodePermissionExt,
    CONF,
};
pub use jellycommon::AssetRole;
use jellycommon::{LocalTrack, PeopleGroup, SourceTrackKind, TrackSource};
use log::info;
use rocket::{get, http::ContentType, response::Redirect, State};
use std::path::PathBuf;

#[get("/asset/<token>?<width>")]
pub async fn r_asset(
    _session: Session,
    fed: &State<Federation>,
    token: &str,
    width: Option<usize>,
) -> MyResult<(ContentType, CacheControlFile)> {
    let asset = AssetInner::deser(token)?;

    let source = resolve_asset(asset, fed).await.context("resolving asset")?;

    // fit the resolution into a finite set so the maximum cache is finite too.
    let width = 2usize.pow(width.unwrap_or(2048).clamp(128, 2048).ilog2());
    // TODO configure avif quality and speed.
    let path = jellytranscoder::image::transcode(source, 50., 5, width)
        .await
        .context("transcoding asset")?;
    info!("loading asset from {path:?}");
    Ok((
        ContentType::AVIF,
        CacheControlFile::new_cachekey(&path.abs()).await?,
    ))
}

pub async fn resolve_asset(asset: AssetInner, fed: &State<Federation>) -> anyhow::Result<PathBuf> {
    match asset {
        AssetInner::Federated { host, asset } => {
            let session = fed.get_session(&host).await?;

            let asset = base64::engine::general_purpose::URL_SAFE.encode(asset);
            Ok(async_cache_file(&["fed-asset", &asset], |out| async {
                session.asset(out, &asset, 2048).await
            })
            .await?
            .abs())
        }
        AssetInner::Cache(c) => Ok(c.abs()),
        AssetInner::Assets(c) => Ok(CONF.asset_path.join(c)),
        AssetInner::Library(c) => Ok(CONF.library_path.join(c)),
    }
}

#[get("/n/<id>/asset?<role>&<width>")]
pub async fn r_item_assets(
    session: Session,
    db: &State<DataAcid>,
    id: &str,
    role: AssetRole,
    width: Option<usize>,
) -> MyResult<Redirect> {
    let node = T_NODE
        .get(&db, id)?
        .only_if_permitted(&session.user.permissions)
        .ok_or(anyhow!("node does not exist"))?;

    let mut asset = match role {
        AssetRole::Backdrop => node.public.backdrop,
        AssetRole::Poster => node.public.poster,
    };
    if let None = asset {
        if let Some(parent) = &node.public.path.last() {
            let parent = T_NODE
                .get(&db, parent.as_str())?
                .ok_or(anyhow!("node does not exist"))?;
            asset = match role {
                AssetRole::Backdrop => parent.public.backdrop,
                AssetRole::Poster => parent.public.poster,
            };
        }
    };
    let asset = asset.unwrap_or_else(|| {
        AssetInner::Assets(
            format!("fallback-{:?}.avif", node.public.kind.unwrap_or_default()).into(),
        )
        .ser()
    });
    Ok(Redirect::temporary(rocket::uri!(r_asset(asset.0, width))))
}

#[get("/n/<id>/person/<index>/asset?<group>&<width>")]
pub async fn r_person_asset(
    session: Session,
    db: &State<DataAcid>,
    id: &str,
    index: usize,
    group: PeopleGroup,
    width: Option<usize>,
) -> MyResult<Redirect> {
    T_NODE
        .get(&db, id)?
        .only_if_permitted(&session.user.permissions)
        .ok_or(anyhow!("node does not exist"))?;

    let ext = T_NODE_EXTENDED.get(db, id)?.unwrap_or_default();
    let app = ext
        .people
        .get(&group)
        .ok_or(anyhow!("group has no members"))?
        .get(index)
        .ok_or(anyhow!("person does not exist"))?;

    let asset = app
        .person
        .headshot
        .to_owned()
        .unwrap_or(AssetInner::Assets(format!("fallback-Person.avif").into()).ser());
    Ok(Redirect::temporary(rocket::uri!(r_asset(asset.0, width))))
}

// TODO this can create "federation recursion" because track selection cannot be relied on.
//? TODO is this still relevant?

#[get("/n/<id>/thumbnail?<t>&<width>")]
pub async fn r_node_thumbnail(
    session: Session,
    db: &State<DataAcid>,
    fed: &State<Federation>,
    id: &str,
    t: f64,
    width: Option<usize>,
) -> MyResult<Redirect> {
    let node = T_NODE
        .get(&db, id)?
        .only_if_permitted(&session.user.permissions)
        .ok_or(anyhow!("node does not exist"))?;

    let media = node.public.media.ok_or(anyhow!("no media"))?;
    let (thumb_track_index, thumb_track) = media
        .tracks
        .iter()
        .enumerate()
        .find(|(_i, t)| matches!(t.kind, SourceTrackKind::Video { .. }))
        .ok_or(anyhow!("no video track to create a thumbnail of"))?;
    let source = node.private.source.ok_or(anyhow!("no source"))?;
    let thumb_track_source = &source[thumb_track_index];

    if t < 0. || t > media.duration {
        Err(anyhow!("thumbnail instant not within media duration"))?
    }

    let step = 8.;
    let t = (t / step).floor() * step;

    let asset = match thumb_track_source {
        TrackSource::Local(LocalTrack { path, .. }) => {
            // the track selected might be different from thumb_track
            jellytranscoder::thumbnail::create_thumbnail(path, t).await?
        }
        TrackSource::Remote(_) => {
            // TODO in the new system this is preferrably a property of node ext for regular fed
            let session = fed
                .get_session(
                    thumb_track
                        .federated
                        .last()
                        .ok_or(anyhow!("federation broken"))?,
                )
                .await?;

            async_cache_file(&["fed-thumb", id, &format!("{t}")], |out| {
                session.node_thumbnail(out, id, 2048, t)
            })
            .await?
        }
    };

    Ok(Redirect::temporary(rocket::uri!(r_asset(
        AssetInner::Cache(asset).ser().0,
        width
    ))))
}