#![warn(clippy::missing_docs_in_private_items)]

//! Implementation of the `delete-room` subcommand

use std::error::Error;

use ruma::RoomId;
use tracing as t;

use super::DeleteRoomArgs;
use crate::{
    config, database::KeyValueDatabase, services, utils, PduEvent, Services,
};

/// Subcommand entrypoint
pub(crate) async fn run(args: DeleteRoomArgs) -> Result<(), Box<dyn Error>> {
    let config = config::load(args.config.config.as_ref()).await?;

    let db = Box::leak(Box::new(KeyValueDatabase::load_or_create(&config)?));

    Services::build(db, config, None)?.install();

    services().globals.err_if_server_name_changed()?;

    db.apply_migrations().await?;

    pdus(db, &args.room_id);

    Ok(())
}

/// Delete PDUs
fn pdus(db: &KeyValueDatabase, room_id: &RoomId) {
    let mut count = 0_usize;

    let filter_map = |(k, v): (Vec<u8>, Vec<u8>)| {
        let pdu = match serde_json::from_slice::<PduEvent>(&v) {
            Ok(x) => x,
            Err(error) => {
                t::warn!(
                    %error,
                    key = utils::u8_slice_to_hex(&k),
                    "Failed to deserialize PDU, skipping it",
                );
                return None;
            }
        };

        if pdu.room_id != room_id {
            return None;
        }

        Some((k, pdu))
    };

    // Accepted PDUs
    for (k, v) in db.pduid_pdu.iter().filter_map(filter_map) {
        if let Err(error) = db.eventid_pduid.remove(v.event_id.as_bytes()) {
            t::warn!(
                %error,
                key = utils::u8_slice_to_hex(&k),
                "Failed to delete event ID to PDU ID relationship",
            );

            continue;
        }

        if let Err(error) = db.pduid_pdu.remove(&k) {
            t::warn!(
                %error,
                key = utils::u8_slice_to_hex(&k),
                "Failed to delete PDU",
            );

            continue;
        }

        count += 1;
    }

    // Outlier PDUs
    for (k, _) in db.eventid_outlierpdu.iter().filter_map(filter_map) {
        if let Err(error) = db.eventid_outlierpdu.remove(&k) {
            t::warn!(
                %error,
                key = utils::u8_slice_to_hex(&k),
                "Failed to delete PDU",
            );

            continue;
        }

        count += 1;
    }

    t::info!(count, "Deleted PDUs");
}