class_name DmService
extends RefCounted
## The client narrate loop (charter §2: the client owns the loop and consumes
## text). Posts the canon log to /dm/narrate through an injected transport,
## returns the prose to display and the [FACT:] tags to harvest. On ANY failure
## it returns an authored fallback line — never an error. It harvests facts
## only; the Narrator has no authority over disposition or moves, so those tags
## are dropped even if the model emits them (§6). narrate() does not mutate the
## log — the caller applies the returned facts, keeping the state write explicit.

var _transport: DmTransport
var _fallback: FallbackLibrary


func _init(transport: DmTransport, fallback: FallbackLibrary) -> void:
	_transport = transport
	_fallback = fallback


func narrate(canon_log: CanonLog) -> NarrateResult:
	var resp: DmResponse = await _transport.post_json(
		"/dm/narrate", {"canon_log": canon_log.to_dict()})
	if not resp.transport_ok or resp.status != 200 \
			or typeof(resp.body) != TYPE_DICTIONARY or not resp.body.has("prose"):
		return NarrateResult.fallback(_fallback.narrator_line())
	var extracted := TagExtractor.extract(str(resp.body["prose"]))
	return NarrateResult.new(extracted["clean_text"], extracted["facts"], false)