class_name EventScheduler
extends RefCounted

const Rules := preload("res://src/core/rules.gd")
const VenueScenario := preload("res://src/core/venue_scenario.gd")
## Schedules routine traffic and scripted events for a shift according to the
## scenario's event pool (ADR-0001, Shift Structure).

signal event_ready(event_data: Dictionary)

var rng := RandomNumberGenerator.new()
var _scenario: VenueScenario = null
var _weighted_pool: Array[Dictionary] = []
## Difficulty/pacing knob: <1 is calmer, >1 sends more events and routine traffic.
var spawn_rate_multiplier := 1.0
var _recent_scripted: Array[String] = []

func _init() -> void:
	pass

func setup(scenario: VenueScenario, seed_value: int = 0) -> void:
	_scenario = scenario
	if seed_value != 0:
		rng.seed = seed_value
	_weighted_pool = []
	for event in scenario.event_pool:
		if event.get("enabled", true):
			_weighted_pool.append(event)

## Pull events due for the current elapsed time and phase.
## Returns Array[Dictionary] of event data to spawn.
func pull_due(elapsed_s: float, phase: int) -> Array[Dictionary]:
	var due: Array[Dictionary] = []
	if _scenario == null:
		return due
	for event in _weighted_pool:
		var time_range: Vector2 = event.get("time_range_s", Vector2(0, _scenario.shift_duration_s))
		if elapsed_s < time_range.x or elapsed_s > time_range.y:
			continue
		if event.get("phase", -1) != phase:
			continue
		var prob: float = event.get("probability", 0.0)
		var base: float = event.get("base_weight", 1.0)
		var event_id := str(event.get("id", ""))
		if str(event.get("kind", "routine")) == "scripted" and event_id in _recent_scripted:
			continue
		var spawn_rate: float = event.get("spawn_rate", 0.0)
		var due_event := false
		if spawn_rate > 0.0:
			# Rate-based spawning: emit at most one per second window.
			if rng.randf() < clampf(spawn_rate * spawn_rate_multiplier, 0.0, 1.0):
				if rng.randf() < prob:
					due_event = true
		else:
			if rng.randf() < clampf(prob * base * spawn_rate_multiplier, 0.0, 1.0):
				due_event = true
		if due_event:
			due.append(event.duplicate())
			if str(event.get("kind", "routine")) == "scripted" and event_id != "":
				_recent_scripted.append(event_id)
				if _recent_scripted.size() > 4:
					_recent_scripted.pop_front()
	return due

## Debug/content preview: events that could be selected now, without consuming
## RNG or marking anything as recently played.
func preview(elapsed_s: float, phase: int) -> Array[String]:
	var out: Array[String] = []
	if _scenario == null:
		return out
	for event in _weighted_pool:
		var time_range: Vector2 = event.get("time_range_s", Vector2(0, _scenario.shift_duration_s))
		if elapsed_s < time_range.x or elapsed_s > time_range.y:
			continue
		if int(event.get("phase", -1)) != phase:
			continue
		var event_id := str(event.get("id", ""))
		if str(event.get("kind", "routine")) == "scripted" and event_id in _recent_scripted:
			continue
		out.append("%s (%s)" % [event_id, str(event.get("kind", "routine"))])
		if out.size() >= 8:
			break
	return out

func fallback_routine_traffic(phase: int) -> Array[Dictionary]:
	## Cheap routine traffic so the street never feels empty.
	var out: Array[Dictionary] = []
	var pool := _routine_pool(phase)
	if pool.is_empty():
		return out
	for i in 3:
		if rng.randf() < clampf(0.35 * spawn_rate_multiplier, 0.0, 1.0):
			out.append(pool[rng.randi_range(0, pool.size() - 1)].duplicate())
	return out

func snapshot() -> Dictionary:
	return {"rng_state": rng.state, "recent_scripted": _recent_scripted.duplicate()}

func restore(data: Dictionary) -> void:
	rng.state = int(data.get("rng_state", rng.state))
	_recent_scripted.clear()
	for event_id in data.get("recent_scripted", []):
		_recent_scripted.append(str(event_id))

func _routine_pool(phase: int) -> Array:
	var out: Array = []
	for event in _weighted_pool:
		if event.get("kind", "routine") == "routine" and event.get("phase", -1) == phase:
			out.append(event)
	return out