import type { JSX, ValidComponent } from "@solidjs/web";
import { dynamic } from "@solidjs/web";
import { createEffect, createSignal, omit } from "solid-js";
import { composeRefs, userRef } from "../../internals/compose-refs";
import { mergeRootProps } from "../../internals/merge-root-props";
import { resolveClassStyle } from "../../internals/resolve-class-style";
import type { BaseUIComponentProps } from "../../internals/types";
import {
	type ScrollAreaRootState,
	useScrollAreaRootContext,
} from "../root/scroll-area-root-context.ts";
import { scrollAreaDataAttrs } from "../utils/state-attrs.ts";
import { useScrollAreaViewportContext } from "../viewport/scroll-area-viewport-context.ts";

export interface ScrollAreaContentState extends ScrollAreaRootState {}

export interface ScrollAreaContentProps
	extends BaseUIComponentProps<"div", ScrollAreaContentState> {
	/** Tag/component to render. Defaults to `"div"`. */
	as?: ValidComponent;
}

/**
 * Container for the scrollable content. Renders a `<div>` element (or `as`
 * override). Runs a `ResizeObserver` on its own wrapper so size changes within
 * the content re-trigger the viewport's thumb recompute.
 *
 * §1 wave 3: replaces `renderElement` with `dynamic(() => props.as ?? "div")`.
 */
export function ScrollAreaContent(props: ScrollAreaContentProps): JSX.Element {
	const root = useScrollAreaRootContext();
	const viewport = useScrollAreaViewportContext();

	const [contentWrapper, setContentWrapper] =
		createSignal<HTMLDivElement | null>(null, { ownedWrite: true });

	createEffect(
		() => contentWrapper(),
		(el) => {
			if (typeof ResizeObserver === "undefined" || !el) return;
			let hasInitialized = false;
			const ro = new ResizeObserver(() => {
				// Skip the initial delivery to avoid double-counting the mount
				// pass which the viewport already performed.
				if (!hasInitialized) {
					hasInitialized = true;
					return;
				}
				viewport.computeThumbPosition();
			});
			ro.observe(el);
			return () => {
				ro.disconnect();
			};
		},
	);

	const userStyling = resolveClassStyle(props, () => root.viewportState());

	const userProps = omit(props, "class", "style", "attrs", "as");

	const localRef = (el: HTMLDivElement | null): void => {
		setContentWrapper(el);
	};

	const internalSlot = {
		role: "presentation" as const,
		style: { "min-width": "fit-content" } as JSX.CSSProperties,
	};

	const styledUserProps = mergeRootProps(userStyling, userProps);

	let merged: Record<string, unknown> = mergeRootProps(
		internalSlot,
		scrollAreaDataAttrs(root.viewportState),
	);
	merged = mergeRootProps(merged, styledUserProps);

	const Tag = dynamic(() => props.as ?? "div");
	return <Tag {...merged} ref={composeRefs(localRef, userRef(props))} />;
}