class_name SystemIndex
## Shared, cached system data loader for implant apps (#844, T-949).
##
## T-949: replaces the direct star_map_data.json FileAccess read with a
## StarMapRequest over the bridge (D-010 — the client never reads game data
## files directly). A static cache so every caller (AtlasApp's Reach screen,
## the economics OverviewScreen) shares one fetch instead of each re-asking.
##
## Usage per caller:
##   1. Call request_refresh() once (e.g. in _ready()/on_install()) — idempotent,
##      no-op once loaded or already in flight.
##   2. Connect to SimBridge.star_map_received and, in the handler, re-pull
##      get_sorted_systems() to refresh with the now-populated list.
## The Atlas can open before the bridge finishes its handshake —
## SimBridge.request_star_map() remembers the request and fires it
## automatically the instant the connection reaches CONNECTED, so callers
## never need to poll or retry themselves.

static var _cache: Array = []
static var _loaded: bool = false
static var _requested: bool = false


## Sorted node list (by proper_name, falling back to system_id), or [] if the
## star map has not arrived yet. Callers should re-pull this after
## SimBridge.star_map_received fires.
static func get_sorted_systems() -> Array:
	return _cache


static func is_loaded() -> bool:
	return _loaded


## True while a StarMapRequest is considered in flight — the test-observable
## counterpart of the retry bookkeeping (see ingest()'s Error path).
static func has_pending_request() -> bool:
	return _requested


## Test-only: clear the process-global static cache. Statics leak across
## gdUnit suites in one process — the same class as the
## SimBridge._star_map_wanted leak fixed in this PR (review H2/T1).
## SimBridge.reset_test_state() calls this, so every suite already using it
## gets both resets.
static func reset_test_state() -> void:
	_cache = []
	_loaded = false
	_requested = false


## Ask the bridge for the star map if it hasn't been fetched yet. Safe to call
## from every screen's _ready()/on_install() — idempotent once loaded or a
## request is already in flight.
static func request_refresh() -> void:
	if _loaded or _requested:
		return
	_requested = true
	SimBridge.request_star_map()


## Feed a decoded StarMapResponse (from a SimBridge.star_map_received handler)
## into the cache. Sorts once here so every caller gets the same order for free.
## Only a "Ready" status is trusted — an Error response (protocol.gd's
## star_map_response_from_raw already reduces it to status/error/nodes=[])
## must NOT mark the cache _loaded, and must clear _requested so a later
## request_refresh() retries instead of treating the failed fetch as
## permanently done.
static func ingest(response: Dictionary) -> void:
	if str(response.get("status", "")) != "Ready":
		_requested = false
		return
	var nodes: Array = response.get("nodes", [])
	var sorted: Array = []
	for node: Dictionary in nodes:
		var sid: String = node.get("system_id", "")
		if not sid.is_empty():
			sorted.append(node)
	sorted.sort_custom(
		func(a: Dictionary, b: Dictionary) -> bool:
			var na: String = a.get("proper_name", a.get("system_id", ""))
			var nb: String = b.get("proper_name", b.get("system_id", ""))
			return na < nb
	)
	_cache = sorted
	_loaded = true