use std::future;

use futures::{StreamExt, TryStreamExt};
use rocket_db_pools::mongodb::bson::to_bson;

use super::{prelude::*, util::PartyError};

use lan_party_core::event::*;

api_routes!(
    create_event,
    stop_event,
    get_event,
    update_event,
    get_all_events,
    event_outcome,
    delete_event,
);

pub async fn apply_outcome(outcome: &EventOutcome, db: &Connection<Db>) -> Result<(), PartyError> {
    for (player, reward) in outcome.points.iter() {
        db.users()
            .update_one(
                doc! { "name": player.to_string() },
                doc! { "$inc": { "score": reward } },
                None,
            )
            .await?;
    }
    Ok(())
}

/// # Create event
///
/// Returns the created event.
#[openapi(tag = "Event")]
#[post("/", data = "<event>")]
pub async fn create_event(
    _api_key: ApiKey,
    db: Connection<Db>,
    event: Json<EventSpec>,
) -> Result<Json<Event>, PartyError> {
    let event = event.into_inner().create_event()?;
    db.events().insert_one(&event, None).await?;
    Ok(Json(event))
}

/// # Update event
///
/// Update the supplied values in the event with the given name. The `name` of an event cannot be
/// changed and `concluded` will always be false.
#[openapi(tag = "Event")]
#[post("/<name>", data = "<update>")]
pub async fn update_event(
    _api_key: ApiKey,
    db: Connection<Db>,
    name: String,
    update: Json<EventUpdate>,
) -> Result<Status, PartyError> {
    let mut event = db
        .events()
        .find_one(doc! { "name": &name }, None)
        .await?
        .ok_or(PartyError::EventNotFound(name.clone()))?;

    event.apply_update(update.into_inner())?;

    db.events()
        .update_one(
            doc! { "name": &name },
            doc! { "$set": to_bson(&event)? },
            None,
        )
        .await?;

    Ok(Status::Ok)
}

/// # Get event
///
/// Returns the event with the given name
#[openapi(tag = "Event")]
#[get("/<name>")]
pub async fn get_event(
    _api_key: ApiKey,
    db: Connection<Db>,
    name: String,
) -> Result<Json<Event>, PartyError> {
    Ok(Json(
        db.events()
            .find_one(doc! { "name": &name }, None)
            .await?
            .ok_or(PartyError::EventNotFound(name))?,
    ))
}

/// # Get events
///
/// Returns all events
#[openapi(tag = "Event")]
#[get("/?<concluded>")]
pub async fn get_all_events(
    _api_key: ApiKey,
    db: Connection<Db>,
    concluded: Option<bool>,
) -> Result<Json<Vec<Event>>, PartyError> {
    let filter = if let Some(concluded) = concluded {
        doc! { "concluded": concluded }
    } else {
        doc! {}
    };
    Ok(Json(
        db.events()
            .find(filter, None)
            .await?
            .filter(|e| future::ready(e.is_ok()))
            .try_collect()
            .await?,
    ))
}

/// # Get outcome
///
/// Returns the outcome of an event.
#[openapi(tag = "Event")]
#[get("/<name>/outcome")]
pub async fn event_outcome(
    _api_key: ApiKey,
    db: Connection<Db>,
    name: String,
) -> Result<Json<EventOutcome>, PartyError> {
    let event = db
        .events()
        .find_one(doc! { "name": &name }, None)
        .await?
        .ok_or(PartyError::EventNotFound(name.clone()))?;
    Ok(Json(event.outcome()))
}

/// # Stop event
///
/// This will conclude the event, apply the outcome to the users and return the outcome.
#[openapi(tag = "Event")]
#[post("/<name>/stop")]
pub async fn stop_event(
    _api_key: ApiKey,
    db: Connection<Db>,
    name: String,
) -> Result<Json<EventOutcome>, PartyError> {
    let event = db
        .events()
        .find_one(doc! { "name": &name }, None)
        .await?
        .ok_or(PartyError::EventNotFound(name.clone()))?;
    event.conclude();
    db.events()
        .update_one(
            doc! { "name": &name },
            doc! { "$set": { "concluded": true } },
            None,
        )
        .await?;
    let outcome = event.outcome();
    apply_outcome(&outcome, &db).await?;

    Ok(Json(outcome))
}

/// # Delete event by name
#[openapi(tag = "Event")]
#[delete("/<name>")]
pub async fn delete_event(
    _api_key: ApiKey,
    db: Connection<Db>,
    name: String,
) -> Result<Status, PartyError> {
    db.events().delete_one(doc! { "name": name }, None).await?;

    Ok(Status::Ok)
}