use crate::addressing::Address;
use crate::entry::Attribute;
use crate::entry::InvariantEntry;
use crate::hash::{LargeMultihash, UpMultihash};

/// Attribute denoting (hierarchical) relation, in the "upwards" direction. For example, a file `IN` a group, an image `IN` photos, etc.
pub const ATTR_IN: &str = "IN";
/// Attribute denoting that an entry belongs to the set relating to a given (hierarchical) relation.
/// For example, a data blob may have a label entry, and to qualify that label within the context of belonging to a given hierarchical group, that label entry and the hierarchical entry will be linked with `BY`.
pub const ATTR_BY: &str = "BY";
/// Attribute denoting that an attribute belongs to a given "tagging" entity. If an entity belongs to (`IN`) a "tagging" entity, it is expected to have attributes that are `OF` that entity.
pub const ATTR_OF: &str = "OF";
/// Attribute denoting a human readable label.
pub const ATTR_LABEL: &str = "LBL";
/// Attribute denoting the date & time an entity was noted in the database.
/// (TODO: This info can be trivially derived from existing entry timestamps, while at the same time the "Introduction problem" is still open.)
pub const ATTR_ADDED: &str = "ADDED";
/// Attribute for cross-vault unambiguous referencing of non-hashable (e.g. UUID) entities.
pub const ATTR_KEY: &str = "KEY";

lazy_static! {
    pub static ref HIER_ROOT_INVARIANT: InvariantEntry = InvariantEntry {
        attribute: ATTR_KEY.parse().unwrap(),
        value: "HIER_ROOT".into(),
    };
    pub static ref HIER_ROOT_ADDR: Address = HIER_ROOT_INVARIANT.entity().unwrap();
    pub static ref TYPE_HASH_ADDRESS: Address =
        Address::Hash(UpMultihash::from(LargeMultihash::default()));
    pub static ref TYPE_UUID_ADDRESS: Address = Address::Uuid(uuid::Uuid::nil());
    pub static ref TYPE_ATTRIBUTE_ADDRESS: Address = Address::Attribute(Attribute::null());
    pub static ref TYPE_URL_ADDRESS: Address = Address::Url(url::Url::parse("up:").unwrap());
}