CosmicClash/Game/scripts/matchmaking_state.gd

class_name MatchmakingState
extends RefCounted

# Client-side projection of the authenticated control-plane lifecycle. The
# server remains authoritative; this object only decides what the UI may show
# and refuses stale, gapped, or conflicting revisions instead of guessing.

signal changed(snapshot: Dictionary)
signal resync_required(resource_id: String)

const IDLE := "IDLE"
const QUEUED := "QUEUED"
const PROPOSED := "PROPOSED"
const ALLOCATING := "ALLOCATING"
const PROCESS_READY := "PROCESS_READY"
const ASSIGNMENT_READY := "ASSIGNMENT_READY"
const CONNECTING := "CONNECTING"
const LIVE := "LIVE"
const CANCELLED := "CANCELLED"
const EXPIRED := "EXPIRED"
const FAILED := "FAILED"

var phase := IDLE
var ticket_id := ""
var playlist := ""
var revision := 0
var expires_at_unix := 0
var proposal_id := ""
var proposal_revision := 0
var proposal_state := ""
var message := ""
var needs_resync := false


func begin_queue(new_ticket_id: String, new_playlist: String) -> bool:
	if new_ticket_id.is_empty() or (new_playlist != "casual" and new_playlist != "ranked"):
		return false
	_reset()
	ticket_id = new_ticket_id
	playlist = new_playlist
	phase = QUEUED
	_emit_changed()
	return true


func apply_ticket_update(update: Dictionary) -> bool:
	if not _has_string(update, "ticket_id") or not update.has("revision") or not update.has("state"):
		return _request_resync(ticket_id)
	if ticket_id.is_empty() or String(update["ticket_id"]) != ticket_id:
		return _request_resync(ticket_id)
	var incoming_revision := int(update["revision"])
	if incoming_revision < revision:
		return false
	if incoming_revision == revision:
		if _ticket_differs(update):
			return _request_resync(ticket_id)
		return true
	if incoming_revision > revision + 1:
		return _request_resync(ticket_id)
	var incoming_state := String(update["state"])
	if not _is_ticket_state(incoming_state):
		return _request_resync(ticket_id)
	revision = incoming_revision
	phase = incoming_state
	if update.has("playlist"):
		playlist = String(update["playlist"])
	if update.has("expires_at_unix"):
		expires_at_unix = int(update["expires_at_unix"])
	if update.has("message"):
		message = String(update["message"])
	_emit_changed()
	return true


func apply_proposal_update(update: Dictionary) -> bool:
	if not _has_string(update, "proposal_id") or not update.has("revision") or not update.has("state"):
		return _request_resync(proposal_id)
	var incoming_id := String(update["proposal_id"])
	if proposal_id.is_empty():
		proposal_id = incoming_id
	elif proposal_id != incoming_id:
		return _request_resync(proposal_id)
	var incoming_revision := int(update["revision"])
	if incoming_revision < proposal_revision:
		return false
	if incoming_revision == proposal_revision and not proposal_state.is_empty():
		if String(update["state"]) != proposal_state:
			return _request_resync(proposal_id)
		return true
	if not proposal_state.is_empty() and incoming_revision > proposal_revision + 1:
		return _request_resync(proposal_id)
	var incoming_proposal_state := String(update["state"])
	if incoming_proposal_state == "OPEN":
		phase = PROPOSED
	elif incoming_proposal_state == "ACCEPTED":
		phase = ALLOCATING
	elif incoming_proposal_state == "DECLINED":
		phase = FAILED
		message = "A player declined the match proposal"
	elif incoming_proposal_state == "EXPIRED":
		phase = EXPIRED
		message = "The match proposal expired"
	else:
		return _request_resync(proposal_id)
	proposal_revision = incoming_revision
	proposal_state = incoming_proposal_state
	if update.has("expires_at_unix"):
		expires_at_unix = int(update["expires_at_unix"])
	_emit_changed()
	return true


func mark_assignment_ready() -> void:
	phase = ASSIGNMENT_READY
	message = "Match server is ready"
	_emit_changed()


func mark_connecting() -> void:
	phase = CONNECTING
	message = "Connecting to match server"
	_emit_changed()


func mark_live() -> void:
	phase = LIVE
	message = "Match in progress"
	_emit_changed()


func fail(reason: String) -> void:
	phase = FAILED
	message = reason if not reason.is_empty() else "Matchmaking failed"
	_emit_changed()


func can_cancel() -> bool:
	return phase == QUEUED or phase == PROPOSED or phase == ALLOCATING


func snapshot() -> Dictionary:
	return {"phase": phase, "ticket_id": ticket_id, "playlist": playlist, "revision": revision, "expires_at_unix": expires_at_unix, "proposal_id": proposal_id, "proposal_revision": proposal_revision, "proposal_state": proposal_state, "message": message, "needs_resync": needs_resync}


func _ticket_differs(update: Dictionary) -> bool:
	return String(update["state"]) != phase or (update.has("playlist") and String(update["playlist"]) != playlist) or (update.has("expires_at_unix") and int(update["expires_at_unix"]) != expires_at_unix)


func _request_resync(resource_id: String) -> bool:
	needs_resync = true
	resync_required.emit(resource_id)
	return false


func _emit_changed() -> void:
	changed.emit(snapshot())


func _reset() -> void:
	phase = IDLE
	playlist = ""
	revision = 0
	expires_at_unix = 0
	proposal_id = ""
	proposal_revision = 0
	proposal_state = ""
	message = ""
	needs_resync = false


func _is_ticket_state(value: String) -> bool:
	return value in [QUEUED, PROPOSED, ALLOCATING, PROCESS_READY, ASSIGNMENT_READY, CONNECTING, LIVE, CANCELLED, EXPIRED, FAILED]


func _has_string(value: Dictionary, key: String) -> bool:
	return value.has(key) and value[key] is String and not String(value[key]).is_empty()