pub mod query {
    use diesel::prelude::*;
    use crate::models::documents::Document;
    use crate::models::projects::Project;
    use diesel::SqliteConnection;

    /// Users have permissions directly on projects which they are members of.
    pub fn accessible_project_ids(
        db: &mut SqliteConnection,
        user_id: &str,
    ) -> Result<Vec<String>, diesel::result::Error> {
        use crate::schema::project_memberships::dsl as pm;

        let project_ids = pm::project_memberships
            .filter(pm::user_id.eq(user_id))
            .select(pm::project_id)
            .load::<String>(db)?;

        Ok(project_ids)
    }

    /// Users have permissions directly on projects which they are members of.
    pub fn accessible_projects(
        db: &mut SqliteConnection,
        user_id: &str,
    ) -> Result<Vec<Project>, diesel::result::Error> {
        use crate::schema::projects::dsl as p;

        let project_ids = accessible_project_ids(db, user_id)?;
        let projects = p::projects
            .filter(p::id.eq_any(project_ids))
            .load::<Project>(db)?;

        Ok(projects)
    }

    /// Users can access documents which they are members of or which are in
    /// projects they're members of.
    pub fn accessible_document_ids(
        db: &mut SqliteConnection,
        user_id: &str,
    ) -> Result<Vec<String>, diesel::result::Error> {
        use crate::schema::documents::dsl as d;
        use crate::schema::project_memberships::dsl as pm;

        let project_ids = accessible_project_ids(db, user_id)?;

        let direct_documents = pm::project_memberships
            .filter(pm::user_id.eq(user_id))
            .select(pm::project_id)
            .load::<String>(db)?;

        let project_documents = d::documents
            .filter(d::project_id.eq_any(project_ids))
            .select(d::id)
            .load::<String>(db)?;

        let document_ids = direct_documents
            .into_iter()
            .chain(project_documents.into_iter())
            .collect();

        Ok(document_ids)
    }

    /// Users can access documents which they are members of or which are in
    /// projects they're members of.
    pub fn accessible_documents(
        db: &mut SqliteConnection,
        user_id: &str,
    ) -> Result<Vec<Document>, diesel::result::Error> {
        use crate::schema::documents::dsl as d;

        let document_ids = accessible_document_ids(db, user_id)?;
        let documents = d::documents
            .filter(d::id.eq_any(document_ids))
            .load::<Document>(db)?;

        Ok(documents)
    }
}