code-moniker 0.1.0

use std::collections::BTreeSet;

use code_moniker_core::core::code_graph::{CodeGraph, DefRecord, RefRecord};
use code_moniker_core::core::kinds::{
	KIND_COMMENT, KIND_LOCAL, KIND_MODULE, KIND_PARAM, REF_ANNOTATES, REF_CALLS, REF_DI_REGISTER,
	REF_DI_REQUIRE, REF_EXTENDS, REF_IMPLEMENTS, REF_IMPORTS_MODULE, REF_IMPORTS_SYMBOL,
	REF_INSTANTIATES, REF_METHOD_CALL, REF_READS, REF_REEXPORTS, REF_USES_TYPE,
};
use code_moniker_core::core::moniker::Moniker;
use code_moniker_core::lang::Lang;

#[derive(Clone, Debug)]
pub enum Predicate {
	Eq(Moniker),
	Lt(Moniker),
	Le(Moniker),
	Gt(Moniker),
	Ge(Moniker),
	AncestorOf(Moniker),
	DescendantOf(Moniker),
	Bind(Moniker),
}

impl Predicate {
	pub fn matches(&self, m: &Moniker) -> bool {
		match self {
			Self::Eq(o) => m == o,
			Self::Lt(o) => m < o,
			Self::Le(o) => m <= o,
			Self::Gt(o) => m > o,
			Self::Ge(o) => m >= o,
			Self::AncestorOf(o) => m.is_ancestor_of(o),
			Self::DescendantOf(o) => o.is_ancestor_of(m),
			Self::Bind(o) => m.bind_match(o),
		}
	}
}

/// A matched ref paired with the moniker of its source def, pre-resolved at
/// filter time so consumers don't have to carry the graph around.
#[derive(Debug)]
pub struct RefMatch<'g> {
	pub record: &'g RefRecord,
	pub source: &'g Moniker,
}

#[derive(Debug, Default)]
pub struct MatchSet<'g> {
	pub defs: Vec<&'g DefRecord>,
	pub refs: Vec<RefMatch<'g>>,
}

/// A def matches when its own moniker satisfies every predicate; a ref matches
/// when its **target** moniker does. `kinds` is OR-combined; empty means any.
pub fn filter<'g>(
	graph: &'g CodeGraph,
	predicates: &[Predicate],
	kinds: &[String],
) -> MatchSet<'g> {
	let kinds_set: Vec<&[u8]> = kinds.iter().map(|s| s.as_bytes()).collect();
	let kind_ok = |k: &[u8]| -> bool { kinds_set.is_empty() || kinds_set.contains(&k) };
	let mut defs: Vec<&DefRecord> = graph
		.defs()
		.filter(|d| kind_ok(&d.kind) && predicates.iter().all(|p| p.matches(&d.moniker)))
		.collect();
	let refs: Vec<&RefRecord> = graph
		.refs()
		.filter(|r| kind_ok(&r.kind) && predicates.iter().all(|p| p.matches(&r.target)))
		.collect();
	defs.sort_by(|a, b| a.moniker.as_bytes().cmp(b.moniker.as_bytes()));
	let mut keyed: Vec<RefMatch<'g>> = refs
		.into_iter()
		.map(|r| RefMatch {
			record: r,
			source: &graph.def_at(r.source).moniker,
		})
		.collect();
	keyed.sort_by(|a, b| {
		(
			a.source.as_bytes(),
			a.record.target.as_bytes(),
			a.record.position,
		)
			.cmp(&(
				b.source.as_bytes(),
				b.record.target.as_bytes(),
				b.record.position,
			))
	});
	MatchSet { defs, refs: keyed }
}

const CROSS_LANG_KINDS: &[&[u8]] = &[
	KIND_MODULE,
	KIND_COMMENT,
	KIND_LOCAL,
	KIND_PARAM,
	REF_IMPORTS_SYMBOL,
	REF_IMPORTS_MODULE,
	REF_REEXPORTS,
	REF_DI_REGISTER,
	REF_DI_REQUIRE,
	REF_CALLS,
	REF_METHOD_CALL,
	REF_READS,
	REF_USES_TYPE,
	REF_INSTANTIATES,
	REF_EXTENDS,
	REF_IMPLEMENTS,
	REF_ANNOTATES,
];

pub fn known_kinds<'a>(langs: impl IntoIterator<Item = &'a Lang>) -> BTreeSet<&'static str> {
	let mut out: BTreeSet<&'static str> = BTreeSet::new();
	for k in CROSS_LANG_KINDS {
		out.insert(std::str::from_utf8(k).expect("kind constants are ASCII"));
	}
	for lang in langs {
		for k in lang.allowed_kinds() {
			out.insert(*k);
		}
	}
	out
}

pub fn unknown_kinds(kinds: &[String], known: &BTreeSet<&'static str>) -> Vec<String> {
	kinds
		.iter()
		.filter(|k| !known.contains(k.as_str()))
		.cloned()
		.collect()
}

#[cfg(test)]
mod tests {
	use super::*;
	use code_moniker_core::core::moniker::MonikerBuilder;

	fn m(segments: &[(&[u8], &[u8])]) -> Moniker {
		let mut b = MonikerBuilder::new();
		b.project(b"app");
		for (k, n) in segments {
			b.segment(k, n);
		}
		b.build()
	}

	fn build_graph() -> CodeGraph {
		let root = m(&[]);
		let mut g = CodeGraph::new(root.clone(), b"module");
		let foo = m(&[(b"class", b"Foo")]);
		let bar = m(&[(b"class", b"Foo"), (b"method", b"bar")]);
		let baz = m(&[(b"class", b"Baz")]);
		g.add_def(foo.clone(), b"class", &root, Some((1, 0)))
			.unwrap();
		g.add_def(bar, b"method", &foo, Some((2, 2))).unwrap();
		g.add_def(baz.clone(), b"class", &root, Some((10, 0)))
			.unwrap();
		g.add_ref(&baz, foo, b"EXTENDS", Some((10, 14))).unwrap();
		g
	}

	#[test]
	fn no_predicate_matches_everything() {
		let g = build_graph();
		let r = filter(&g, &[], &[]);
		assert_eq!(r.defs.len(), 4);
		assert_eq!(r.refs.len(), 1);
	}

	#[test]
	fn kind_filter_or_combines() {
		let g = build_graph();
		let r = filter(&g, &[], &["method".to_string()]);
		assert_eq!(r.defs.len(), 1);
		assert_eq!(r.defs[0].kind, b"method");
		let r = filter(&g, &[], &["method".to_string(), "module".to_string()]);
		assert_eq!(r.defs.len(), 2);
	}

	#[test]
	fn descendant_of_keeps_only_strict_descendants_and_target() {
		let g = build_graph();
		let foo = m(&[(b"class", b"Foo")]);
		let r = filter(&g, &[Predicate::DescendantOf(foo)], &[]);
		let names: Vec<&[u8]> = r.defs.iter().map(|d| d.kind.as_slice()).collect();
		assert!(names.contains(&b"class".as_slice()));
		assert!(names.contains(&b"method".as_slice()));
		assert_eq!(r.defs.len(), 2);
	}

	#[test]
	fn equality_matches_one_def() {
		let g = build_graph();
		let foo = m(&[(b"class", b"Foo")]);
		let r = filter(&g, &[Predicate::Eq(foo.clone())], &[]);
		assert_eq!(r.defs.len(), 1);
		assert_eq!(&r.defs[0].moniker, &foo);
		assert_eq!(r.refs.len(), 1, "ref to Foo also matches via target");
	}

	#[test]
	fn ordering_predicates_use_byte_lex() {
		let g = build_graph();
		let baz = m(&[(b"class", b"Baz")]);
		let r = filter(&g, &[Predicate::Lt(baz.clone())], &[]);
		assert!(r.defs.iter().all(|d| d.moniker < baz));
		let r = filter(&g, &[Predicate::Ge(baz.clone())], &[]);
		assert!(r.defs.iter().all(|d| d.moniker >= baz));
	}

	#[test]
	fn ancestor_of_includes_self() {
		let g = build_graph();
		let bar = m(&[(b"class", b"Foo"), (b"method", b"bar")]);
		let r = filter(&g, &[Predicate::AncestorOf(bar)], &[]);
		let kinds: Vec<&[u8]> = r.defs.iter().map(|d| d.kind.as_slice()).collect();
		assert!(kinds.contains(&b"module".as_slice()));
		assert!(kinds.contains(&b"class".as_slice()));
		assert!(kinds.contains(&b"method".as_slice()));
	}

	#[test]
	fn predicate_and_kind_compose() {
		let g = build_graph();
		let foo = m(&[(b"class", b"Foo")]);
		let r = filter(&g, &[Predicate::DescendantOf(foo)], &["method".to_string()]);
		assert_eq!(r.defs.len(), 1);
		assert_eq!(r.defs[0].kind, b"method");
	}

	#[test]
	fn ref_filtered_by_target_moniker() {
		let g = build_graph();
		let foo = m(&[(b"class", b"Foo")]);
		let r = filter(&g, &[Predicate::Eq(foo)], &[]);
		assert_eq!(r.refs.len(), 1, "EXTENDS ref targets Foo");
	}

	#[test]
	fn known_kinds_for_ts_includes_class_function_and_ref_kinds() {
		let k = known_kinds(std::iter::once(&Lang::Ts));
		assert!(k.contains("class"));
		assert!(k.contains("function"));
		assert!(k.contains("method"));
		assert!(k.contains("calls"));
		assert!(k.contains("imports_module"));
		assert!(k.contains("module"));
		assert!(!k.contains("fn"), "fn is Rust-specific, not in ts vocab");
	}

	#[test]
	fn known_kinds_union_picks_up_per_lang_specifics() {
		let langs = [Lang::Ts, Lang::Rs];
		let k = known_kinds(langs.iter());
		assert!(k.contains("function"), "TS contributes `function`");
		assert!(k.contains("fn"), "Rust contributes `fn`");
	}

	#[test]
	fn unknown_kinds_flags_typos_and_lang_mismatches() {
		let langs = [Lang::Ts];
		let k = known_kinds(langs.iter());
		let unknown = unknown_kinds(
			&[
				"function".to_string(),
				"fn".to_string(),
				"clazz".to_string(),
			],
			&k,
		);
		assert_eq!(unknown, vec!["fn".to_string(), "clazz".to_string()]);
	}

	#[test]
	fn defs_sorted_by_moniker_bytes() {
		let g = build_graph();
		let r = filter(&g, &[], &[]);
		let mut prev: Option<&[u8]> = None;
		for d in &r.defs {
			let cur = d.moniker.as_bytes();
			if let Some(p) = prev {
				assert!(p <= cur, "defs not sorted: {p:?} then {cur:?}");
			}
			prev = Some(cur);
		}
	}
}