monsta-server 0.0.1

use std::collections::BTreeMap;

use monsta_proto::*;
use tokio::sync::Mutex;

use crate::{database::Database, Error, Result};

pub struct Universe {
    inner: Mutex<Inner>,
}

struct Inner {
    databases: BTreeMap<u64, Database>,
    database_ids: BTreeMap<String, u64>,
    next_database_id: u64,
}

impl Universe {
    pub fn new() -> Self {
        let inner = Inner {
            databases: BTreeMap::new(),
            database_ids: BTreeMap::new(),
            next_database_id: 1,
        };
        Self {
            inner: Mutex::new(inner),
        }
    }

    pub async fn database(&self, id: u64) -> Option<Database> {
        let inner = self.inner.lock().await;
        inner.databases.get(&id).cloned()
    }

    pub async fn create_database(&self, spec: DatabaseSpec) -> Result<Database> {
        let mut inner = self.inner.lock().await;
        if inner.database_ids.contains_key(&spec.name) {
            return Err(Error::AlreadyExists(format!("database name {}", spec.name)));
        }
        let id = inner.next_database_id;
        inner.next_database_id += 1;
        let name = spec.name.clone();
        let db = Database::new(id, spec);
        inner.databases.insert(id, db.clone());
        inner.database_ids.insert(name, id);
        Ok(db)
    }

    pub async fn lookup_database(&self, name: &str) -> Option<Database> {
        let inner = self.inner.lock().await;
        inner
            .database_ids
            .get(name)
            .and_then(|id| inner.databases.get(id).cloned())
    }
}