class_name ABGBattleOpeningPageController
extends RefCounted

## UI-independent BAT-001 Battle Opening view-data assembly.
##
## BattleService remains responsible for loading the active battle and starting
## observation. This controller only validates/copies the phase-zero facts and
## exposes opening-state command eligibility.

const VALID_STATES: Array[String] = ["ready_to_observe", "interrupted_resume", "opening_handoff", "snapshot_mismatch"]


func snapshot(
	company: Dictionary,
	battle: Dictionary,
	opening_state := "ready_to_observe",
	notice := "",
	handoff_receipt: Dictionary = {},
	commitment_receipt: Dictionary = {},
	locale := "zh_CN"
) -> Dictionary:
	if company.is_empty():
		return {"ok": false, "code": "COMPANY_REQUIRED"}
	var raw_contract = company.get("active_contract", {})
	if not raw_contract is Dictionary or Dictionary(raw_contract).is_empty():
		return {"ok": false, "code": "OPENING_CONTRACT_REQUIRED"}
	if battle.is_empty():
		return {"ok": false, "code": "OPENING_BATTLE_REQUIRED"}
	if String(battle.get("status", "")) != "active":
		return {"ok": false, "code": "OPENING_BATTLE_INVALID"}
	if int(battle.get("phase_index", -1)) != 0 or not Array(battle.get("phase_events", [])).is_empty():
		return {"ok": false, "code": "OPENING_PHASE_NOT_ZERO"}
	if opening_state not in VALID_STATES:
		return {"ok": false, "code": "OPENING_STATE_INVALID"}

	var contract: Dictionary = Dictionary(raw_contract).duplicate(true)
	var formation: Dictionary = Dictionary(contract.get("formation", {})).duplicate(true)
	var raw_snapshot = formation.get("accepted_party_snapshot", {})
	if not raw_snapshot is Dictionary or Dictionary(raw_snapshot).is_empty():
		return {"ok": false, "code": "OPENING_PARTY_SNAPSHOT_REQUIRED"}
	var party_snapshot: Dictionary = Dictionary(raw_snapshot).duplicate(true)
	var members := _members_by_id(company.get("owned_recruits", []))
	var party_ids = battle.get("front_to_rear_ids", party_snapshot.get("front_to_rear_ids", []))
	if not party_ids is Array or party_ids.size() != int(contract.get("line_capacity", 4)):
		return {"ok": false, "code": "OPENING_PARTY_ORDER_INVALID"}
	var order_validation := _validate_ids(party_ids, members)
	if not order_validation.ok:
		return order_validation
	var enemy_ids = battle.get("enemy_ids", [])
	if not enemy_ids is Array or enemy_ids.is_empty():
		return {"ok": false, "code": "OPENING_ENEMY_LINE_INVALID"}

	var operation_id := String(battle.get("operation_id", ""))
	if operation_id.is_empty():
		return {"ok": false, "code": "OPENING_OPERATION_REQUIRED"}
	var copied_relations: Array = _copy_array(party_snapshot.get("relations", formation.get("relations", [])))
	var relation_by_id := _relations_by_id(copied_relations)
	var ordered_recruits: Array[Dictionary] = []
	for position in range(order_validation.ids.size()):
		var recruit_id := String(order_validation.ids[position])
		ordered_recruits.append({
			"position": position,
			"recruit_id": recruit_id,
			"recruit": Dictionary(members[recruit_id]).duplicate(true),
			"relation": Dictionary(relation_by_id.get(recruit_id, {})).duplicate(true),
		})

	var resolved_receipt: Dictionary = Dictionary(commitment_receipt).duplicate(true)
	if resolved_receipt.is_empty():
		resolved_receipt = _receipt_for_operation(contract.get("battle_receipts", []), operation_id)
	var copied_battle: Dictionary = battle.duplicate(true)
	var copied_handoff: Dictionary = Dictionary(handoff_receipt).duplicate(true)
	var copied_enemy_ids: Array = _copy_array(enemy_ids)
	var handoff := opening_state == "opening_handoff"
	var mismatch := opening_state == "snapshot_mismatch"
	var interrupted := opening_state == "interrupted_resume"
	var can_start := not handoff and not mismatch and not resolved_receipt.is_empty()
	return {
		"ok": true,
		"page_id": "battle_opening",
		"locale": String(locale),
		"company": {
			"company_id": String(company.get("company_id", "")),
			"owned_count": members.size(),
			"line_capacity": int(contract.get("line_capacity", order_validation.ids.size())),
		},
		"contract": {
			"contract_id": String(contract.get("contract_id", "")),
			"run_id": String(contract.get("run_id", "")),
			"contract_hash": String(contract.get("contract_hash", "")),
		},
		"battle": {
			"operation_id": operation_id,
			"battle_hash": String(battle.get("battle_hash", "")),
			"status": String(battle.get("status", "active")),
			"risk_option_id": String(battle.get("risk_option_id", "")),
			"risk": int(battle.get("risk", 0)),
			"snapshot_id": String(battle.get("snapshot_id", party_snapshot.get("snapshot_id", ""))),
			"snapshot_hash": String(battle.get("snapshot_hash", party_snapshot.get("snapshot_hash", ""))),
			"phase_index": int(battle.get("phase_index", 0)),
			"total_phases": int(battle.get("total_phases", 0)),
			"front_to_rear_ids": order_validation.ids.duplicate(true),
			"enemy_ids": copied_enemy_ids,
			"phase_events": _copy_array(battle.get("phase_events", [])),
			"copy": copied_battle,
		},
		"receipt": {
			"present": not resolved_receipt.is_empty(),
			"battle": resolved_receipt,
			"handoff": copied_handoff,
		},
		"party": {
			"snapshot_id": String(party_snapshot.get("snapshot_id", "")),
			"snapshot_hash": String(party_snapshot.get("snapshot_hash", "")),
			"front_to_rear_ids": order_validation.ids.duplicate(true),
			"ordered_recruits": ordered_recruits,
			"orientation": String(party_snapshot.get("orientation", formation.get("orientation", "rear_left_front_right"))),
			"front_position": int(party_snapshot.get("front_position", formation.get("front_position", 0))),
			"relations": copied_relations,
			"coverage": Dictionary(party_snapshot.get("coverage", formation.get("coverage", {}))).duplicate(true),
			"first_threat": Dictionary(formation.get("first_threat", {})).duplicate(true),
		},
		"enemies": {
			"ids": copied_enemy_ids,
			"count": copied_enemy_ids.size(),
		},
		"state": {
			"name": String(opening_state),
			"notice": String(notice),
			"phase_zero": true,
			"interrupted_resume": interrupted,
			"handoff": handoff,
			"snapshot_mismatch": mismatch,
		},
		"commands": {
			"pause_enabled": true,
			"speed_enabled": true,
			"inspect_enabled": true,
			"settings_enabled": true,
			"start_observation_enabled": can_start,
		},
	}


func _validate_ids(values: Array, members: Dictionary) -> Dictionary:
	var ids: Array = []
	for value in values:
		var recruit_id := String(value)
		if not members.has(recruit_id):
			return {"ok": false, "code": "OPENING_RECRUIT_UNKNOWN"}
		if recruit_id in ids:
			return {"ok": false, "code": "OPENING_RECRUIT_DUPLICATE"}
		ids.append(recruit_id)
	return {"ok": true, "code": "OPENING_PARTY_VALID", "ids": ids}


func _receipt_for_operation(values, operation_id: String) -> Dictionary:
	if not values is Array:
		return {}
	for value in values:
		if value is Dictionary and String(value.get("operation_id", "")) == operation_id:
			return Dictionary(value).duplicate(true)
	return {}


func _members_by_id(values) -> Dictionary:
	var result := {}
	if not values is Array:
		return result
	for value in values:
		if value is Dictionary:
			var copied: Dictionary = Dictionary(value).duplicate(true)
			var recruit_id := String(copied.get("recruit_id", ""))
			if not recruit_id.is_empty():
				result[recruit_id] = copied
	return result


func _relations_by_id(values: Array) -> Dictionary:
	var result := {}
	for value in values:
		if value is Dictionary:
			result[String(value.get("recruit_id", ""))] = Dictionary(value).duplicate(true)
	return result


func _copy_array(values) -> Array:
	var result: Array = []
	if not values is Array:
		return result
	for value in values:
		result.append(value.duplicate(true) if value is Dictionary or value is Array else value)
	return result