class_name AuthorityEvidence
extends RefCounted

enum DiscoveryMethod {
	LATENT,
	REACHED,
	LINE_OF_SIGHT,
	TRUSTED_SOURCE,
	KNOWN_ILLEGAL,
}

var evidence_id: StringName = &""
var incident_id: StringName = &""
var source: StringName = &""
var severity := 0
var facility_id: StringName = &""
var location_cell := Vector3i.ZERO
var created_at := 0
var expires_at := -1
var discovered_at := -1
var discovered_by: StringName = &""
var discovery_method: DiscoveryMethod = DiscoveryMethod.LATENT
var revision := 0


func configure(
	p_evidence_id: StringName,
	p_source: StringName,
	p_severity: int,
	options: Dictionary = {}
) -> AuthorityEvidence:
	evidence_id = p_evidence_id
	incident_id = StringName(_value(options, &"incident_id", &""))
	source = p_source
	severity = clampi(p_severity, 0, 100)
	facility_id = StringName(_value(options, &"facility_id", &""))
	location_cell = _vector3i(_value(options, &"location_cell", Vector3i.ZERO))
	created_at = maxi(int(_value(options, &"created_at", 0)), 0)
	expires_at = int(_value(options, &"expires_at", -1))
	discovered_at = int(_value(options, &"discovered_at", -1))
	discovered_by = StringName(_value(options, &"discovered_by", &""))
	discovery_method = _method_from_value(_value(options, &"discovery_method", DiscoveryMethod.LATENT))
	revision = maxi(int(_value(options, &"revision", 0)), 0)
	return self


func is_discovered() -> bool:
	return discovered_at >= 0


func is_expired(absolute_minute: int) -> bool:
	return expires_at >= 0 and absolute_minute >= expires_at


func mark_discovered(
	inspector_id: StringName,
	absolute_minute: int,
	method: DiscoveryMethod
) -> bool:
	if is_discovered() or inspector_id.is_empty() or absolute_minute < created_at:
		return false
	if method == DiscoveryMethod.LATENT:
		return false
	discovered_at = absolute_minute
	discovered_by = inspector_id
	discovery_method = method
	revision += 1
	return true


func is_valid() -> bool:
	if evidence_id.is_empty() or source.is_empty() or severity < 0 or severity > 100:
		return false
	if created_at < 0 or expires_at < -1 or revision < 0:
		return false
	if expires_at >= 0 and expires_at < created_at:
		return false
	if discovered_at < -1:
		return false
	if discovered_at >= 0:
		if discovered_by.is_empty() or discovery_method == DiscoveryMethod.LATENT:
			return false
		if discovered_at < created_at:
			return false
	else:
		if not discovered_by.is_empty() or discovery_method != DiscoveryMethod.LATENT:
			return false
	return true


func create_snapshot() -> Dictionary:
	return {
		&"evidence_id": String(evidence_id),
		&"incident_id": String(incident_id),
		&"source": String(source),
		&"severity": severity,
		&"facility_id": String(facility_id),
		&"location_cell": [location_cell.x, location_cell.y, location_cell.z],
		&"created_at": created_at,
		&"expires_at": expires_at,
		&"discovered_at": discovered_at,
		&"discovered_by": String(discovered_by),
		&"discovery_method": DiscoveryMethod.keys()[discovery_method],
		&"revision": revision,
	}


static func from_snapshot(snapshot: Dictionary) -> AuthorityEvidence:
	if not _snapshot_is_valid(snapshot):
		return null
	var evidence := AuthorityEvidence.new().configure(
		StringName(_value(snapshot, &"evidence_id", &"")),
		StringName(_value(snapshot, &"source", &"")),
		int(_value(snapshot, &"severity", -1)),
		snapshot
	)
	return evidence if evidence.is_valid() else null


static func _snapshot_is_valid(snapshot: Dictionary) -> bool:
	for key: StringName in [
		&"evidence_id", &"incident_id", &"source", &"severity", &"facility_id",
		&"location_cell", &"created_at", &"expires_at", &"discovered_at",
		&"discovered_by", &"discovery_method", &"revision",
	]:
		if not _has_key(snapshot, key):
			return false
	if StringName(_value(snapshot, &"evidence_id", &"")).is_empty() \
		or StringName(_value(snapshot, &"source", &"")).is_empty():
		return false
	if not _value(snapshot, &"location_cell", null) is Array \
		or (_value(snapshot, &"location_cell", []) as Array).size() != 3:
		return false
	var severity_value := int(_value(snapshot, &"severity", -1))
	if severity_value < 0 or severity_value > 100:
		return false
	if int(_value(snapshot, &"created_at", -1)) < 0 \
		or int(_value(snapshot, &"expires_at", -2)) < -1 \
		or int(_value(snapshot, &"discovered_at", -2)) < -1 \
		or int(_value(snapshot, &"revision", -1)) < 0:
		return false
	return DiscoveryMethod.keys().has(String(_value(snapshot, &"discovery_method", "")))


static func _method_from_value(value: Variant) -> DiscoveryMethod:
	if value is String or value is StringName:
		var index := DiscoveryMethod.keys().find(String(value))
		return (index as DiscoveryMethod) if index >= 0 else DiscoveryMethod.LATENT
	var number := int(value)
	return (number as DiscoveryMethod) if number >= 0 and number < DiscoveryMethod.size() else DiscoveryMethod.LATENT


static func _vector3i(value: Variant) -> Vector3i:
	if value is Vector3i:
		return value
	if value is Array and value.size() >= 3:
		return Vector3i(int(value[0]), int(value[1]), int(value[2]))
	if value is Dictionary:
		return Vector3i(int(value.get(&"x", 0)), int(value.get(&"y", 0)), int(value.get(&"z", 0)))
	return Vector3i.ZERO


static func _value(source: Dictionary, key: StringName, fallback: Variant) -> Variant:
	if source.has(key):
		return source[key]
	return source.get(String(key), fallback)


static func _has_key(source: Dictionary, key: StringName) -> bool:
	return source.has(key) or source.has(String(key))