import type { AccountUsage, UsageWindow } from "./types.js";

export function toNumber(value: unknown): number | undefined {
	if (typeof value === "number" && Number.isFinite(value)) return value;
	if (typeof value === "string" && value.trim()) {
		const parsed = Number(value);
		if (Number.isFinite(parsed)) return parsed;
	}
	return undefined;
}

function toDate(value: unknown): Date | undefined {
	if (typeof value === "string") {
		const parsed = new Date(value);
		return Number.isNaN(parsed.getTime()) ? undefined : parsed;
	}
	const raw = toNumber(value);
	if (raw === undefined) return undefined;
	return new Date(raw < 1e10 ? raw * 1000 : raw);
}

export function parseClaude(
	body: unknown,
): Pick<AccountUsage, "session" | "weekly"> {
	const root = body as Record<string, unknown>;
	const window = (value: unknown): UsageWindow | undefined => {
		const item = value as Record<string, unknown> | undefined;
		const used = toNumber(item?.utilization);
		return used === undefined
			? undefined
			: { used, resetsAt: toDate(item?.resets_at) };
	};
	return { session: window(root?.five_hour), weekly: window(root?.seven_day) };
}

function codexWindow(
	value: unknown,
): (UsageWindow & { seconds?: number }) | undefined {
	const item = value as Record<string, unknown> | undefined;
	const used = toNumber(item?.used_percent);
	if (used === undefined) return undefined;
	const resetAfter = toNumber(item?.reset_after_seconds);
	return {
		used,
		seconds: toNumber(item?.limit_window_seconds),
		resetsAt:
			toDate(item?.reset_at) ??
			(resetAfter === undefined
				? undefined
				: new Date(Date.now() + resetAfter * 1000)),
	};
}

export function parseCodex(body: unknown): Pick<AccountUsage, "session"> {
	const rate = (body as Record<string, unknown>)?.rate_limit as
		| Record<string, unknown>
		| undefined;
	const windows = [
		codexWindow(rate?.primary_window),
		codexWindow(rate?.secondary_window),
	].filter(Boolean) as Array<UsageWindow & { seconds?: number }>;
	return {
		session:
			windows.find((item) => item.seconds === 18_000) ??
			windows.find((item) => item.seconds !== 604_800) ??
			windows[0],
	};
}

export function parseGrok(body: unknown): Pick<AccountUsage, "weekly"> {
	const config = (body as Record<string, unknown>)?.config as
		| Record<string, unknown>
		| undefined;
	const period = config?.currentPeriod as Record<string, unknown> | undefined;
	if (period?.type !== "USAGE_PERIOD_TYPE_WEEKLY") return {};
	return {
		weekly: {
			used: toNumber(config?.creditUsagePercent) ?? 0,
			resetsAt: toDate(period.end),
		},
	};
}