class_name ConstructionProvider extends WorkProvider
## WorkProvider for the "construction" work category.
##
## Scans World.build_queue for the nearest buildable site (Wall, Floor, Door —
## anything exposing is_buildable() / on_build_tick() / tile / label()) and
## returns a two-toil Job:
##   walk_to(site.tile) → build_at(site.get_path())
##
## The BUILD toil calls on_build_tick() once per sim tick; the entity internally
## tracks build_progress and calls _complete() when BUILD_TICKS is reached. The
## toil finishes automatically when is_buildable() returns false.
##
## Phase 5 simplification: materials are infinite — no haul-materials step.
## Phase 6+ will prepend walk_to(material_pile) + pickup() toils before walk_to(site).
##
## Duck-typing note: build-site entities are referenced without class_name to
## avoid registration-order issues. We rely only on:
##   site.tile: Vector2i
##   site.is_buildable() -> bool
##   site.label() -> String
##   site.get_path() -> NodePath


func _init() -> void:
	category = &"construction"
	# Higher than chop (5), mine (4), haul (3), rest (0). Players expect their
	# build orders to be serviced before the pawn goes off to chop trees.
	priority = 6


## Returns a Job targeting the nearest buildable site, or null if none exists.
## `pawn` is duck-typed: must expose .tile (Vector2i).
func find_best_for(pawn) -> Job:
	var best = null
	var best_dist: int = 999999

	for site in World.build_queue:
		if not site.is_buildable():
			continue
		var d: int = abs(site.tile.x - pawn.tile.x) + abs(site.tile.y - pawn.tile.y)
		if d < best_dist:
			best_dist = d
			best = site

	if best == null:
		return null

	var j := Job.new()
	j.label = "Build %s at %s" % [best.label(), best.tile]
	j.toils.append(Toil.walk_to(best.tile))
	j.toils.append(Toil.build_at(best.get_path()))
	return j