"use client";

import { useRouter } from "next/navigation";
import { useEffect, useMemo, useRef, useTransition } from "react";
import { normalizeNoteBody } from "./normalize-body";
import { sanitizeRichTextHtml } from "./sanitize";
import "./rich-text.css";

type ToggleHandler = (taskIndex: number, checked: boolean) => Promise<void>;

type Props = {
  html: string;
  interactiveChecklists?: boolean;
  onToggleChecklist?: ToggleHandler;
  className?: string;
  clampLines?: number;
};

export function RichTextContent({
  html,
  interactiveChecklists = false,
  onToggleChecklist,
  className,
  clampLines,
}: Props) {
  const router = useRouter();
  const containerRef = useRef<HTMLDivElement>(null);
  const [isPending, startTransition] = useTransition();

  const safeHtml = useMemo(() => {
    const normalized = normalizeNoteBody(html);
    return sanitizeRichTextHtml(normalized);
  }, [html]);

  useEffect(() => {
    const root = containerRef.current;
    if (!root || !interactiveChecklists || !onToggleChecklist) return;

    const items = [...root.querySelectorAll<HTMLLIElement>('li[data-type="taskItem"]')];

    for (const [index, item] of items.entries()) {
      const checked = item.getAttribute("data-checked") === "true";
      let label = item.querySelector("label");
      if (!label) {
        label = document.createElement("label");
        item.insertBefore(label, item.firstChild);
      }

      let input = label.querySelector<HTMLInputElement>('input[type="checkbox"]');
      if (!input) {
        input = document.createElement("input");
        input.type = "checkbox";
        label.prepend(input);
      }

      input.checked = checked;
      input.disabled = isPending;
      input.onclick = (event) => {
        event.preventDefault();
        event.stopPropagation();
        const nextChecked = !input!.checked;
        startTransition(async () => {
          await onToggleChecklist(index, nextChecked);
          router.refresh();
        });
      };
    }
  }, [safeHtml, interactiveChecklists, onToggleChecklist, isPending, router]);

  if (!safeHtml) {
    return <p className="text-sm text-[var(--ink-mute)]">No body text.</p>;
  }

  return (
    <div
      ref={containerRef}
      className={["rich-text-content", className].filter(Boolean).join(" ")}
      style={
        clampLines
          ? {
              display: "-webkit-box",
              WebkitLineClamp: clampLines,
              WebkitBoxOrient: "vertical",
              overflow: "hidden",
            }
          : undefined
      }
      dangerouslySetInnerHTML={{ __html: safeHtml }}
    />
  );
}