use crate::item::Item;

/// Collect database results into a `Vec<_>`
#[macro_export]
macro_rules! collect_results {
    ($res:expr) => {{
        use futures::stream::TryStreamExt;
        let mut ret = vec![];

        while let Some(doc) = $res.try_next().await.unwrap() {
            ret.push(doc);
        }

        ret
    }};
}

/// Get a database collection
#[macro_export]
macro_rules! cdb_col {
    ($db:expr, $col:expr) => {
        $db.database("cdb")
            .collection::<mongodb::bson::Document>($col)
    };
}

/// Get a MongoDB Client from the environment
#[macro_export]
macro_rules! get_mongo {
    () => {
        mongodb::Client::with_uri_str(std::env::var("DB_URI").unwrap())
            .await
            .unwrap()
    };
}

/// MongoDB filter for the `_id` field.
#[macro_export]
macro_rules! id_of {
    ($id:expr) => {
        doc! { "_id": $id}
    };
}

/// Item database
pub struct ItemDB {
    index: mdq::Index,
}

impl ItemDB {
    /// Create a new item database using `dir` as the base.
    ///
    /// The directory should contain markdown documents with valid frontmatter to be parsed into `Item`s
    pub async fn new(dir: &str) -> Self {
        // scan for markdown item entries
        let index = mdq::Index::new(dir, true);
        let mongodb = get_mongo!();

        for item in &index.documents {
            let item = Item::new(item);
            item.init_db(&mongodb).await;
        }

        Self { index }
    }

    /// Retrieves an item by name
    pub fn get_item(&self, item: &str) -> Option<Item> {
        Some(
            self.index
                .documents
                .iter()
                .map(Item::new) // <-- todo : performance?
                .find(|x| x.name == item)?,
        )
    }

    /// Get all items
    pub fn items(&self) -> Vec<String> {
        let mut ret = vec![];
        for item in &self.index.documents {
            let item = Item::new(item);
            ret.push(item.name);
        }
        ret
    }
}