jsonld-syntax 0.24.0

use crate::{CompactIri, ExpandableRef, Keyword, context::definition::KeyOrKeywordRef};
use iri_rs::Iri;
use rdfx::BlankId;
use std::{fmt, hash::Hash};

#[derive(Clone, PartialOrd, Ord, Debug)]
#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
#[cfg_attr(feature = "serde", serde(untagged))]
/// Value of the `@id` entry of a term definition.
pub enum Id {
    /// A JSON-LD keyword, which makes the term an alias of that keyword.
    Keyword(Keyword),
    /// Anything else: an IRI, a compact IRI, a blank node identifier or another
    /// term of the context. Kept unvalidated, as telling those apart requires
    /// the processed context.
    Term(String),
}

impl Id {
    /// Parses this value as an IRI, returning `None` if it is not one.
    #[must_use]
    pub fn as_iri(&self) -> Option<Iri<&str>> {
        match self {
            Self::Term(t) => Iri::parse(t.as_str()).ok(),
            Self::Keyword(_) => None,
        }
    }

    /// Parses this value as a blank node identifier, returning `None` if it is
    /// not one.
    #[must_use]
    pub fn as_blank_id(&self) -> Option<&BlankId> {
        match self {
            Self::Term(t) => BlankId::new(t).ok(),
            Self::Keyword(_) => None,
        }
    }

    /// Parses this value as a compact IRI, returning `None` if it is not one.
    #[must_use]
    pub fn as_compact_iri(&self) -> Option<&CompactIri> {
        match self {
            Self::Term(t) => CompactIri::new(t).ok(),
            Self::Keyword(_) => None,
        }
    }

    /// Returns the keyword, or `None` if this value is not one.
    #[must_use]
    pub fn as_keyword(&self) -> Option<Keyword> {
        match self {
            Self::Keyword(k) => Some(*k),
            Self::Term(_) => None,
        }
    }

    /// Returns this value as it is spelled in the context.
    #[must_use]
    pub fn as_str(&self) -> &str {
        match self {
            Self::Term(t) => t.as_str(),
            Self::Keyword(k) => k.into_str(),
        }
    }

    /// Converts this value into an owned `String`, allocating if it is a
    /// keyword.
    #[must_use]
    pub fn into_string(self) -> String {
        match self {
            Self::Term(t) => t,
            Self::Keyword(k) => k.to_string(),
        }
    }

    /// Checks whether this value is a JSON-LD keyword.
    #[must_use]
    pub fn is_keyword(&self) -> bool {
        matches!(self, Self::Keyword(_))
    }

    /// Checks whether this value is keyword-like: an `@` followed by ASCII
    /// letters. See [`crate::is_keyword_like`].
    #[must_use]
    pub fn is_keyword_like(&self) -> bool {
        crate::is_keyword_like(self.as_str())
    }

    /// Returns a borrowed view of this value.
    #[must_use]
    pub fn as_id_ref(&self) -> IdRef<'_> {
        match self {
            Self::Term(t) => IdRef::Term(t),
            Self::Keyword(k) => IdRef::Keyword(*k),
        }
    }
}

impl PartialEq for Id {
    fn eq(&self, other: &Self) -> bool {
        match (self, other) {
            (Self::Term(a), Self::Term(b)) => a == b,
            (Self::Keyword(a), Self::Keyword(b)) => a == b,
            _ => false,
        }
    }
}

impl Eq for Id {}

impl Hash for Id {
    fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
        self.as_str().hash(state);
    }
}

impl From<String> for Id {
    fn from(s: String) -> Self {
        match Keyword::try_from(s.as_str()) {
            Ok(k) => Self::Keyword(k),
            Err(_) => Self::Term(s),
        }
    }
}

impl<'a> From<&'a Id> for ExpandableRef<'a> {
    fn from(i: &'a Id) -> Self {
        match i {
            Id::Term(t) => Self::String(t),
            Id::Keyword(k) => Self::Keyword(*k),
        }
    }
}

impl fmt::Display for Id {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        match self {
            Self::Term(t) => t.fmt(f),
            Self::Keyword(k) => k.fmt(f),
        }
    }
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
/// Borrowed value of the `@id` entry of a term definition.
pub enum IdRef<'a> {
    /// An IRI, a compact IRI, a blank node identifier or another term of the
    /// context.
    Term(&'a str),
    /// A JSON-LD keyword, which makes the term an alias of that keyword.
    Keyword(Keyword),
}

impl IdRef<'_> {
    /// Returns this value as it is spelled in the context.
    #[must_use]
    pub fn as_str(&self) -> &str {
        match self {
            Self::Term(t) => t,
            Self::Keyword(k) => k.into_str(),
        }
    }

    /// Checks whether this value is a JSON-LD keyword.
    #[must_use]
    pub fn is_keyword(&self) -> bool {
        matches!(self, Self::Keyword(_))
    }

    /// Checks whether this value is keyword-like: an `@` followed by ASCII
    /// letters. See [`crate::is_keyword_like`].
    #[must_use]
    pub fn is_keyword_like(&self) -> bool {
        crate::is_keyword_like(self.as_str())
    }
}

impl<'a> From<&'a str> for IdRef<'a> {
    fn from(s: &'a str) -> Self {
        match Keyword::try_from(s) {
            Ok(k) => Self::Keyword(k),
            Err(_) => Self::Term(s),
        }
    }
}

impl<'a> From<IdRef<'a>> for ExpandableRef<'a> {
    fn from(i: IdRef<'a>) -> Self {
        match i {
            IdRef::Term(t) => Self::String(t),
            IdRef::Keyword(k) => Self::Keyword(k),
        }
    }
}

impl fmt::Display for IdRef<'_> {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        self.as_str().fmt(f)
    }
}

impl<'a> From<IdRef<'a>> for KeyOrKeywordRef<'a> {
    fn from(i: IdRef<'a>) -> Self {
        match i {
            IdRef::Term(t) => Self::Key(t.into()),
            IdRef::Keyword(k) => Self::Keyword(k),
        }
    }
}