import type { FriendMode, OverlaySettings } from "./types.ts";

/** Keys accepted in overlay.toml (snake_case). */
export interface OverlayToml {
	chat_request_database?: string;
	cover?: boolean;
	map_info?: boolean;
	time?: boolean;
	score?: boolean;
	friends?: boolean;
	friend_mode?: string;
	bsr?: boolean;
	beatleader_player_id?: string;
	right?: boolean;
	bottom?: boolean;
	scale?: number;
	fade?: number;
}

export interface OverlayConfigApiBody {
	defaults: Partial<OverlaySettings>;
}

const FRIEND_MODES = new Set<FriendMode>(["mutual", "following", "followers"]);

/** Merge `/api/overlay-config` into the object used as `defaults` before applying the URL hash. */
export function mergeOverlayConfigResponse(
	target: OverlaySettings,
	body: { defaults?: Partial<OverlaySettings> },
): void {
	const d = body.defaults;
	if (!d) return;
	const out = target as unknown as Record<string, unknown>;
	for (const key of Object.keys(d) as (keyof OverlaySettings)[]) {
		const v = d[key];
		if (v !== undefined) out[key as string] = v;
	}
}

function asBool(v: unknown): boolean | undefined {
	if (typeof v === "boolean") return v;
	return undefined;
}

function asNum(v: unknown): number | undefined {
	if (typeof v === "number" && Number.isFinite(v)) return v;
	return undefined;
}

/**
 * Maps parsed TOML (snake_case) to overlay defaults. Collects warnings for invalid values.
 */
export function overlayTomlToDefaults(toml: OverlayToml): {
	chatRequestDatabase: string | undefined;
	defaults: Partial<OverlaySettings>;
	beatleaderPlayerIdConfigured: boolean;
	warnings: string[];
} {
	const warnings: string[] = [];
	const defaults: Partial<OverlaySettings> = {};

	const db = typeof toml.chat_request_database === "string" ? toml.chat_request_database.trim() : "";
	const chatRequestDatabase = db || undefined;

	const bCover = asBool(toml.cover);
	if (bCover !== undefined) defaults.cover = bCover;
	const bMap = asBool(toml.map_info);
	if (bMap !== undefined) defaults.mapInfo = bMap;
	const bTime = asBool(toml.time);
	if (bTime !== undefined) defaults.time = bTime;
	const bScore = asBool(toml.score);
	if (bScore !== undefined) defaults.score = bScore;
	const bFriends = asBool(toml.friends);
	if (bFriends !== undefined) defaults.friends = bFriends;
	const bBsr = asBool(toml.bsr);
	if (bBsr !== undefined) defaults.bsr = bBsr;
	const bRight = asBool(toml.right);
	if (bRight !== undefined) defaults.right = bRight;
	const bBottom = asBool(toml.bottom);
	if (bBottom !== undefined) defaults.bottom = bBottom;

	if (toml.friend_mode !== undefined) {
		const raw = String(toml.friend_mode).trim().toLowerCase();
		if (FRIEND_MODES.has(raw as FriendMode)) defaults.friendMode = raw as FriendMode;
		else {
			warnings.push(
				`overlay.toml: invalid friend_mode "${toml.friend_mode}" (expected mutual, following, or followers)`,
			);
		}
	}

	const scale = asNum(toml.scale);
	if (scale !== undefined) defaults.scale = scale;

	const fade = asNum(toml.fade);
	if (fade !== undefined) defaults.fade = fade;

	let beatleaderPlayerIdConfigured = false;
	if (typeof toml.beatleader_player_id === "string") {
		const id = toml.beatleader_player_id.trim();
		if (id) {
			defaults.beatLeaderId = id;
			beatleaderPlayerIdConfigured = true;
		}
	}

	return { chatRequestDatabase, defaults, beatleaderPlayerIdConfigured, warnings };
}