#![warn(clippy::missing_docs_in_private_items)]

//! Implementation of the `get-room-states` command

use std::{cmp::Ordering, sync::Arc};

use ruma::events::StateEventType;
use serde::Serialize;

use super::GetRoomStatesArgs;
use crate::{
    config, database::KeyValueDatabase, error, services, PduEvent, Services,
};

mod cache;
mod recompute;

/// Serializable information about a state event
#[derive(Serialize, PartialEq, Eq)]
struct StateEvent {
    /// The kind of state event
    kind: StateEventType,

    /// The `state_key` of the event
    key: String,

    /// The event itself
    event: Arc<PduEvent>,
}

impl Ord for StateEvent {
    fn cmp(&self, other: &Self) -> Ordering {
        Ordering::Equal
            .then_with(|| self.event.room_id.cmp(&other.event.room_id))
            .then_with(|| self.kind.cmp(&other.kind))
            .then_with(|| self.key.cmp(&other.key))
            .then_with(|| self.event.event_id.cmp(&other.event.event_id))
    }
}

impl PartialOrd for StateEvent {
    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
        Some(self.cmp(other))
    }
}

/// Subcommand entrypoint
pub(crate) async fn run(
    args: GetRoomStatesArgs,
) -> Result<(), error::DumpStateCommand> {
    use error::DumpStateCommand as Error;

    let config = config::load(args.config.config.as_ref()).await?;

    let db = Box::leak(Box::new(
        KeyValueDatabase::load_or_create(&config).map_err(Error::Database)?,
    ));

    Services::new(db, config, None)
        .map_err(Error::InitializeServices)?
        .install();

    services().globals.err_if_server_name_changed()?;

    db.apply_migrations().await.map_err(Error::Database)?;

    let room_states = if args.recompute {
        recompute::get_room_states(db)
    } else {
        cache::get_room_states().await
    };

    serde_json::to_writer(std::io::stdout(), &room_states)?;

    Ok(())
}