import type { TUI } from "@earendil-works/pi-tui";

export const MIN_FULLSCREEN_WHEEL_SCROLL_LINES = 1;
export const MAX_FULLSCREEN_WHEEL_SCROLL_LINES = 10;
export const DEFAULT_FULLSCREEN_WHEEL_SCROLL_LINES = 4;

export function normalizeFullscreenWheelScrollLines(
	value: unknown,
	fallback = DEFAULT_FULLSCREEN_WHEEL_SCROLL_LINES,
): number {
	if (typeof value !== "number" || !Number.isFinite(value)) return fallback;
	return Math.min(
		MAX_FULLSCREEN_WHEEL_SCROLL_LINES,
		Math.max(MIN_FULLSCREEN_WHEEL_SCROLL_LINES, Math.floor(value)),
	);
}

type FullscreenWheelTui = TUI & { wheelScrollLines?: unknown };

/**
 * Pi 0.84.2 keeps this constructor option in a private runtime field. Remove
 * this shim once Pi exposes a public setter; incompatible versions are no-ops.
 */
export function applyFullscreenWheelScrollLines(tui: TUI, value: number): boolean {
	try {
		const fullscreenTui = tui as FullscreenWheelTui;
		if (fullscreenTui.mode !== "fullscreen" || typeof fullscreenTui.wheelScrollLines !== "number") {
			return false;
		}
		return Reflect.set(fullscreenTui, "wheelScrollLines", normalizeFullscreenWheelScrollLines(value));
	} catch {
		return false;
	}
}