use crate::database::*;
use crate::util::result::{Error, Result};

use mongodb::bson::doc;
use rocket_contrib::json::JsonValue;
use ulid::Ulid;

#[get("/<target>/dm")]
pub async fn req(user: User, target: Ref) -> Result<JsonValue> {
    let query = if user.id == target.id {
        doc! {
            "channel_type": "SavedMessages",
            "user": &user.id
        }
    } else {
        doc! {
            "channel_type": "DirectMessage",
            "recipients": {
                "$all": [ &user.id, &target.id ]
            }
        }
    };

    let existing_channel = get_collection("channels")
        .find_one(query, None)
        .await
        .map_err(|_| Error::DatabaseError {
            operation: "find_one",
            with: "channel",
        })?;

    if let Some(doc) = existing_channel {
        Ok(json!(doc))
    } else {
        let id = Ulid::new().to_string();
        let channel = if user.id == target.id {
            Channel::SavedMessages { id, user: user.id }
        } else {
            Channel::DirectMessage {
                id,
                active: false,
                recipients: vec![user.id, target.id],
                last_message: None,
            }
        };

        channel.clone().publish().await?;
        Ok(json!(channel))
    }
}