/*
    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>
*/
pub mod log;
pub mod user;

use super::{
    account::session::AdminSession,
    assets::{resolve_asset, AVIF_QUALITY, AVIF_SPEED},
};
use crate::{
    database::DataAcid,
    routes::ui::{
        admin::log::rocket_uri_macro_r_admin_log,
        error::MyResult,
        layout::{DynLayoutPage, FlashDisplay, LayoutPage},
    },
    uri,
};
use anyhow::{anyhow, Context};
use humansize::{format_size, DECIMAL};
use jellybase::{
    assetfed::AssetInner,
    database::{
        redb::{ReadableTable, ReadableTableMetadata},
        tantivy::query::Bm25StatisticsProvider,
        TableExt, T_INVITE, T_NODE, T_NODE_EXTENDED, T_USER_NODE,
    },
    federation::Federation,
    CONF,
};
use jellyimport::{import, is_importing};
use markup::DynRender;
use rand::Rng;
use rocket::{form::Form, get, post, FromForm, State};
use std::time::Instant;
use tokio::sync::Semaphore;
use user::rocket_uri_macro_r_admin_users;

#[get("/admin/dashboard")]
pub fn r_admin_dashboard(
    _session: AdminSession,
    database: &State<DataAcid>,
) -> MyResult<DynLayoutPage<'static>> {
    admin_dashboard(database, None)
}

pub fn admin_dashboard<'a>(
    database: &DataAcid,
    flash: Option<MyResult<String>>,
) -> MyResult<DynLayoutPage<'a>> {
    let invites = {
        let txn = database.begin_read()?;
        let table = txn.open_table(T_INVITE)?;
        let i = table
            .iter()?
            .map(|a| {
                let (x, _) = a.unwrap();
                x.value().to_owned()
            })
            .collect::<Vec<_>>();
        drop(table);
        i
    };
    let flash = flash.map(|f| f.map_err(|e| format!("{e:?}")));

    let database = database.to_owned();
    Ok(LayoutPage {
        title: "Admin Dashboard".to_string(),
        content: markup::new! {
            h1 { "Admin Panel" }
            @FlashDisplay { flash: flash.clone() }
            ul {
                li{a[href=uri!(r_admin_log(true))] { "Server Log (Warnings only)" }}
                li{a[href=uri!(r_admin_log(false))] { "Server Log (Full) " }}
            }
            h2 { "Library" }
            @if is_importing() {
                section.message { p.warn { "An import is currently running." } }
            }
            @if is_transcoding() {
                section.message { p.warn { "Currently transcoding posters." } }
            }
            form[method="POST", action=uri!(r_admin_import())] {
                input[type="submit", disabled=is_importing(), value="(Re-)Import Library"];
            }
            form[method="POST", action=uri!(r_admin_transcode_posters())] {
                input[type="submit", disabled=is_transcoding(), value="Transcode all posters with low resolution"];
            }
            form[method="POST", action=uri!(r_admin_delete_cache())] {
                input.danger[type="submit", value="Delete Cache"];
            }
            h2 { "Users" }
            p { a[href=uri!(r_admin_users())] "Manage Users" }
            h2 { "Invitations" }
            form[method="POST", action=uri!(r_admin_invite())] {
                input[type="submit", value="Generate new invite code"];
            }
            ul { @for t in &invites {
                li {
                    form[method="POST", action=uri!(r_admin_remove_invite())] {
                        span { @t }
                        input[type="text", name="invite", value=&t, hidden];
                        input[type="submit", value="Invalidate"];
                    }
                }
            }}

            h2 { "Database" }
            @match db_stats(&database) {
                Ok(s) => { @s }
                Err(e) => { pre.error { @format!("{e:?}") } }
            }
        },
        ..Default::default()
    })
}

#[post("/admin/generate_invite")]
pub fn r_admin_invite(
    _session: AdminSession,
    database: &State<DataAcid>,
) -> MyResult<DynLayoutPage<'static>> {
    let i = format!("{}", rand::thread_rng().gen::<u128>());
    T_INVITE.insert(&database, &*i, ())?;

    admin_dashboard(database, Some(Ok(format!("Invite: {}", i))))
}

#[derive(FromForm)]
pub struct DeleteInvite {
    invite: String,
}

#[post("/admin/remove_invite", data = "<form>")]
pub fn r_admin_remove_invite(
    session: AdminSession,
    database: &State<DataAcid>,
    form: Form<DeleteInvite>,
) -> MyResult<DynLayoutPage<'static>> {
    drop(session);
    T_INVITE
        .remove(&database, form.invite.as_str())?
        .ok_or(anyhow!("invite did not exist"))?;

    admin_dashboard(database, Some(Ok("Invite invalidated".into())))
}

#[post("/admin/import")]
pub async fn r_admin_import(
    session: AdminSession,
    database: &State<DataAcid>,
    federation: &State<Federation>,
) -> MyResult<DynLayoutPage<'static>> {
    drop(session);
    let t = Instant::now();
    let r = import(&database, &federation).await;
    admin_dashboard(
        &database,
        Some(
            r.map_err(|e| e.into())
                .map(|_| format!("Import successful; took {:?}", t.elapsed())),
        ),
    )
}

#[post("/admin/delete_cache")]
pub async fn r_admin_delete_cache(
    session: AdminSession,
    database: &State<DataAcid>,
) -> MyResult<DynLayoutPage<'static>> {
    drop(session);
    let t = Instant::now();
    let r = tokio::fs::remove_dir_all(&CONF.cache_path).await;
    tokio::fs::create_dir(&CONF.cache_path).await?;
    admin_dashboard(
        &database,
        Some(
            r.map_err(|e| e.into())
                .map(|_| format!("Cache deleted; took {:?}", t.elapsed())),
        ),
    )
}

static SEM_TRANSCODING: Semaphore = Semaphore::const_new(1);
fn is_transcoding() -> bool {
    SEM_TRANSCODING.available_permits() == 0
}

#[post("/admin/transcode_posters")]
pub async fn r_admin_transcode_posters(
    session: AdminSession,
    database: &State<DataAcid>,
) -> MyResult<DynLayoutPage<'static>> {
    drop(session);
    let _permit = SEM_TRANSCODING
        .try_acquire()
        .context("transcoding in progress")?;

    let t = Instant::now();

    {
        let txn = database.begin_read()?;
        let nodes = txn.open_table(T_NODE)?;
        for node in nodes.iter()? {
            let (_, node) = node?;
            if let Some(poster) = &node.value().0.public.poster {
                let asset = AssetInner::deser(&poster.0)?;
                if asset.is_federated() {
                    continue;
                }
                let source = resolve_asset(asset).await.context("resolving asset")?;
                jellytranscoder::image::transcode(source, AVIF_QUALITY, AVIF_SPEED, 1024)
                    .await
                    .context("transcoding asset")?;
            }
        }
    }
    drop(_permit);

    admin_dashboard(
        &database,
        Some(Ok(format!(
            "All posters pre-transcoded; took {:?}",
            t.elapsed()
        ))),
    )
}

fn db_stats(db: &DataAcid) -> anyhow::Result<DynRender> {
    let txn = db.inner.begin_read()?;
    let stats = [
        ("node", txn.open_table(T_NODE)?.stats()?),
        ("node-ext", txn.open_table(T_NODE_EXTENDED)?.stats()?),
        ("user", txn.open_table(T_USER_NODE)?.stats()?),
        ("user-node", txn.open_table(T_USER_NODE)?.stats()?),
        ("invite", txn.open_table(T_INVITE)?.stats()?),
    ];

    let cache_stats = db.node_index.reader.searcher().doc_store_cache_stats();
    let ft_total_docs = db.node_index.reader.searcher().total_num_docs()?;

    Ok(markup::new! {
        h3 { "Key-Value-Store Statistics" }
        table {
            tbody {
                tr {
                    th { "table name" }
                    th { "tree height" }
                    th { "stored bytes" }
                    th { "metadata bytes" }
                    th { "fragmented bytes" }
                    th { "branch pages" }
                    th { "leaf pages" }
                }
                @for (name, stats) in &stats { tr {
                    td { @name }
                    td { @stats.tree_height() }
                    td { @format_size(stats.stored_bytes(), DECIMAL) }
                    td { @format_size(stats.metadata_bytes(), DECIMAL) }
                    td { @format_size(stats.fragmented_bytes(), DECIMAL) }
                    td { @stats.branch_pages() }
                    td { @stats.leaf_pages() }
                }}
            }
        }
        h3 { "Search Engine Statistics" }
        ul {
            li { "Total documents: " @ft_total_docs }
            li { "Cache misses: " @cache_stats.cache_misses }
            li { "Cache hits: " @cache_stats.cache_hits }
        }
    })
}