/**
 * Context set by `<Drawer.Provider>` — a global coordinator that tracks
 * which drawers are open and exposes a non-reactive visual-state store
 * consumed by `<Drawer.Indent>` / `<Drawer.IndentBackground>`.
 *
 * 1:1 port of Base UI React's `DrawerProviderContext`.
 */

import { type Accessor, createContext, useContext } from "solid-js";

/**
 * Non-reactive visual-state store. Driven by swipe progress updates; read
 * by `<Drawer.Indent>` to push CSS vars on its element without any Solid
 * reactivity round-trip (matches React's `useSyncExternalStore` model).
 */
export interface DrawerVisualState {
	swipeProgress: number;
	frontmostHeight: number;
}

export interface DrawerVisualStateStore {
	getSnapshot: () => DrawerVisualState;
	subscribe: (listener: () => void) => () => void;
	set: (state: Partial<DrawerVisualState>) => void;
}

export interface DrawerProviderContextValue {
	/** Register/update a drawer's open flag. */
	setDrawerOpen: (drawerId: string, open: boolean) => void;
	/** Remove a drawer from the registry. */
	removeDrawer: (drawerId: string) => void;
	/** Whether ANY registered drawer is currently open. */
	active: Accessor<boolean>;
	/** Visual-state store. */
	visualStateStore: DrawerVisualStateStore;
}

/**
 * Null-sentinel context. `<Drawer.Provider>` is optional; most
 * drawer parts consult it via `useDrawerProviderContext(true)`.
 */
export const DrawerProviderContext =
	createContext<DrawerProviderContextValue | null>(null);

export function useDrawerProviderContext(): DrawerProviderContextValue;
export function useDrawerProviderContext(
	optional: true,
): DrawerProviderContextValue | null;
export function useDrawerProviderContext(
	optional?: boolean,
): DrawerProviderContextValue | null {
	const context = useContext(DrawerProviderContext);
	if (context == null && !optional) {
		throw new Error(
			"Base UI: DrawerProviderContext is missing. Use <Drawer.Provider>.",
		);
	}
	return context;
}