import type { JSX } from "@solidjs/web";
import { type Accessor, createContext, createMemo, useContext } from "solid-js";
import { createPopupCore } from "../internals/create-popup-core";
import { type MaybeAccessor, readOption } from "../internals/maybe-accessor";
import {
	SNAPSHOT_KEYS,
	type Snapshottable,
	snapshotKeys,
} from "../internals/observability/snapshot";

/**
 * Why the preview card's open state changed.
 *
 * - `"trigger-hover"` — pointer entered / left the trigger.
 * - `"trigger-focus"` — keyboard focus moved to / from the trigger.
 * - `"escape-key"` — Escape dismissed the card.
 * - `"outside-press"` — pointer pressed outside.
 * - `"imperative"` — `pc.setOpen()` called programmatically.
 */
export type PreviewCardChangeReason =
	| "trigger-hover"
	| "trigger-focus"
	| "escape-key"
	| "outside-press"
	| "imperative";

/**
 * Options for {@link createPreviewCard}.
 */
export interface CreatePreviewCardOptions {
	/**
	 * Open state. Consumer-owned signal.
	 */
	open: MaybeAccessor<boolean>;
	/**
	 * Whether interaction is suppressed.
	 * @default false
	 */
	disabled?: MaybeAccessor<boolean>;
	/**
	 * Pre-change callback fired via `runWithOwner(null, ...)`.
	 */
	onOpenChange?: (
		open: boolean,
		event: Event,
		reason: PreviewCardChangeReason,
	) => void;
	/**
	 * Delay before opening (ms).
	 * @default 600
	 */
	delay?: MaybeAccessor<number>;
	/**
	 * Delay before closing on hover-out (ms).
	 * @default 300
	 */
	closeDelay?: MaybeAccessor<number>;
}

/**
 * Public API returned by {@link createPreviewCard}.
 */
export interface PreviewCardApi {
	/** Reactive accessor for the current open state. */
	open: Accessor<boolean>;
	/** Whether interaction is suppressed. */
	disabled: Accessor<boolean>;
	/** Open delay in ms. */
	delay: Accessor<number>;
	/** Close delay in ms. */
	closeDelay: Accessor<number>;

	/** Imperative open setter. */
	setOpen: (
		next: boolean,
		event?: Event,
		reason?: PreviewCardChangeReason,
	) => void;
	/** Flip open (no-op when disabled). */
	toggle: (event?: Event, reason?: PreviewCardChangeReason) => void;

	/** Context provider. */
	Provider: (props: { children: JSX.Element }) => JSX.Element;
}

const PreviewCardContext = createContext<PreviewCardApi | null>(null);

/**
 * Read the nearest {@link PreviewCardApi}. Throws unless `optional` is true.
 */
export function usePreviewCard(): PreviewCardApi;
export function usePreviewCard(optional: true): PreviewCardApi | null;
export function usePreviewCard(optional?: boolean): PreviewCardApi | null {
	const ctx = useContext(PreviewCardContext);
	if (ctx == null && !optional) {
		throw new Error(
			"Base UI: usePreviewCard() must be called inside a <pc.Provider>.",
		);
	}
	return ctx;
}

/**
 * Headless primitive for a preview-card compound. Hover-triggered with open
 * and close delays. DOM machinery lives in `<PreviewCard.Root>`.
 */
export function createPreviewCard(
	options: CreatePreviewCardOptions,
): PreviewCardApi {
	const core = createPopupCore<PreviewCardChangeReason>({
		open: options.open,
		disabled: options.disabled,
		onOpenChange: options.onOpenChange,
	});

	const delay = createMemo<number>(() => readOption(options.delay) ?? 600, {
		name: "previewCard.delay",
	});

	const closeDelay = createMemo<number>(
		() => readOption(options.closeDelay) ?? 300,
		{ name: "previewCard.closeDelay" },
	);

	const api: PreviewCardApi = {
		open: core.open,
		disabled: core.disabled,
		delay,
		closeDelay,
		setOpen: core.setOpen,
		toggle: core.toggle,
		Provider: (props) => (
			<PreviewCardContext value={api}>{props.children}</PreviewCardContext>
		),
	};

	(api as PreviewCardApi & Snapshottable)[SNAPSHOT_KEYS] =
		PREVIEW_CARD_SNAPSHOT_KEYS;

	return api;
}

const PREVIEW_CARD_SNAPSHOT_KEYS = snapshotKeys<PreviewCardApi>(
	"open",
	"disabled",
	"delay",
	"closeDelay",
);