from __future__ import annotations

from typing import Any

# Immutable-in-practice graph state for the loaded DUT test set.
_TESTS_BY_ID: dict[str, Any] = {}
_GRAPH: dict[str, set[str]] = {}


def reset_graph_state() -> None:
	global _TESTS_BY_ID, _GRAPH
	_TESTS_BY_ID = {}
	_GRAPH = {}


def is_graph_built() -> bool:
	return bool(_GRAPH)


def build_graph_once(tests: list[Any]) -> dict[str, set[str]]:
	"""Build DUT-only compatibility adjacency graph once per load lifecycle."""
	global _TESTS_BY_ID, _GRAPH
	if _GRAPH:
		return _GRAPH

	# Keep only one representative per DUT test_id.
	_TESTS_BY_ID = {str(t.test_id): t for t in tests if getattr(t, "test_id", None)}
	_GRAPH = _build_graph(_TESTS_BY_ID)
	return _GRAPH


def get_graph() -> dict[str, set[str]]:
	return _GRAPH


def _build_graph(tests: dict[str, Any]) -> dict[str, set[str]]:
	test_ids = list(tests.keys())
	graph = {test_id: set() for test_id in test_ids}
	for i in range(len(test_ids)):
		for j in range(i + 1, len(test_ids)):
			a_id = test_ids[i]
			b_id = test_ids[j]
			a = tests[a_id]
			b = tests[b_id]
			if _compatible(a, b):
				graph[a_id].add(b_id)
				graph[b_id].add(a_id)
	return graph


def _compatible(a: Any, b: Any) -> bool:
	# Compatible when same rotation, or both non-P3P and overlap has identical testpoints.
	if a.rotation == b.rotation:
		return True
	if a.test_type != "P3P" and b.test_type != "P3P" and _same_test_points_for_overlap(a.config, b.config):
		return True
	return False


def _same_test_points_for_overlap(
	config_a: dict[str, dict[str, str | None]],
	config_b: dict[str, dict[str, str | None]],
) -> bool:
	station_map_a = _build_station_testpoint_map(config_a)
	station_map_b = _build_station_testpoint_map(config_b)

	overlap = set(station_map_a.keys()) & set(station_map_b.keys())
	for station in overlap:
		if station_map_a[station] != station_map_b[station]:
			return False
	return True


def _build_station_testpoint_map(config: dict[str, dict[str, str | None]]) -> dict[str, str]:
	station_to_testpoint: dict[str, str] = {}

	def _add_entry(entry: dict[str, str | None]) -> None:
		testpoint = _norm(entry.get("test_point") or entry.get("Testpoint"))
		sta_raw = _norm(entry.get("sta") or entry.get("STA"))
		if not testpoint or not sta_raw:
			return
		for sta in sta_raw.split(","):
			sta_clean = _norm(sta)
			if sta_clean:
				station_to_testpoint[sta_clean] = testpoint

	for band in ("5G", "6G", "2G"):
		entry = config.get(band) or {}
		_add_entry(entry)

	for station_key in ("Station 1", "Station 2", "Station 3"):
		entry = config.get(station_key) or {}
		_add_entry(entry)

	return station_to_testpoint


def _norm(value: Any) -> str:
	if value is None:
		return ""
	return " ".join(str(value).strip().upper().split())