class_name ABGEntryBootService
extends RefCounted

const DEFAULT_REQUIRED_RESOURCES: Array[String] = [
	"res://main.tscn",
	"res://entry/entry_shell.gd",
	"res://assets/backgrounds/p9_3_guild_hall.png",
	"res://assets/fonts/NotoSansSC.ttf",
]
const DEFAULT_PREFERENCES_PATH := "user://aetherbound_guild_settings.json"
const DEFAULT_SAVE_PATH := "user://aetherbound_guild_p10_3.json"

var required_resources: Array = DEFAULT_REQUIRED_RESOURCES.duplicate()
var preferences_path := DEFAULT_PREFERENCES_PATH
var save_path := DEFAULT_SAVE_PATH
var checks: Array[Dictionary] = []
var index := 0
var result: Dictionary = {}


func begin() -> Dictionary:
	checks = []
	for path in required_resources:
		checks.append({"kind": "resource", "path": path})
	checks.append({"kind": "storage"})
	checks.append({"kind": "preferences", "path": preferences_path})
	checks.append({"kind": "save", "path": save_path})
	index = 0
	result = {
		"state": "running",
		"completed": 0,
		"total": checks.size(),
		"step": "resources",
		"code": "",
	}
	return result.duplicate(true)


func verify_next() -> Dictionary:
	if checks.is_empty():
		begin()
	if String(result.get("state", "")) != "running":
		return result.duplicate(true)
	if index >= checks.size():
		result["state"] = "complete"
		result["step"] = "complete"
		return result.duplicate(true)

	var check: Dictionary = checks[index]
	var check_result := _run_check(check)
	if not check_result.ok:
		result = {
			"state": "error",
			"completed": index,
			"total": checks.size(),
			"step": String(check_result.step),
			"code": String(check_result.code),
		}
		return result.duplicate(true)

	index += 1
	result["completed"] = index
	result["step"] = _next_step()
	if index >= checks.size():
		result["state"] = "complete"
		result["step"] = "complete"
	return result.duplicate(true)


func _run_check(check: Dictionary) -> Dictionary:
	match String(check.kind):
		"resource":
			var path := String(check.path)
			if not ResourceLoader.exists(path) or ResourceLoader.load(path) == null:
				return {"ok": false, "step": "resources", "code": "REQUIRED_RESOURCE_UNAVAILABLE"}
		"storage":
			var user_root := ProjectSettings.globalize_path("user://")
			if DirAccess.open(user_root) == null:
				return {"ok": false, "step": "storage", "code": "LOCAL_STORAGE_UNAVAILABLE"}
		"preferences":
			if FileAccess.file_exists(String(check.path)):
				var preferences_parser := JSON.new()
				var preferences_error := preferences_parser.parse(FileAccess.get_file_as_string(String(check.path)))
				if preferences_error != OK or not preferences_parser.data is Dictionary:
					return {"ok": false, "step": "preferences", "code": "SETTINGS_FILE_INVALID"}
		"save":
			if FileAccess.file_exists(String(check.path)):
				var save_parser := JSON.new()
				var save_error := save_parser.parse(FileAccess.get_file_as_string(String(check.path)))
				var parsed = save_parser.data
				if save_error != OK or not parsed is Dictionary or not parsed.has("save_kind") or not parsed.has("save_version"):
					return {"ok": false, "step": "save", "code": "SAVE_REVIEW_REQUIRED"}
	return {"ok": true, "step": String(check.kind), "code": ""}


func _next_step() -> String:
	if index >= checks.size():
		return "complete"
	return String(checks[index].kind)