'use client';

import React, { useState } from 'react';
import Link from 'next/link';
import { ChevronDown } from 'lucide-react';
import type { FaqCategory, FaqItem, FaqPageData } from '@/lib/faqDefaults';

export function FaqAccordionList({ faqs }: { faqs: FaqItem[] }) {
  const [openIdx, setOpenIdx] = useState<number | null>(null);

  if (faqs.length === 0) {
    return (
      <p className="text-[13px] text-gray-500 py-8 text-center">
        No questions in this category yet.
      </p>
    );
  }

  return (
    <div className="space-y-3">
      {faqs.map((faq, idx) => {
        const isOpen = openIdx === idx;
        const collapsed =
          faq.answer.length > 180 ? `${faq.answer.slice(0, 180).trim()}…` : faq.answer;
        return (
          <article
            key={`${faq.question}-${idx}`}
            className="bg-white border border-gray-200 rounded-xl px-5 py-4 shadow-xs"
          >
            <button
              type="button"
              onClick={() => setOpenIdx(isOpen ? null : idx)}
              className="w-full text-left flex items-start justify-between gap-3 cursor-pointer"
            >
              <h3 className="text-[15px] font-bold text-[#1E293B] leading-snug">
                {idx + 1}) {faq.question}
              </h3>
              <ChevronDown
                className={`w-4 h-4 mt-1 shrink-0 text-gray-400 transition-transform ${
                  isOpen ? 'rotate-180 text-primary' : ''
                }`}
              />
            </button>
            <div className="mt-2 text-[13px] text-gray-600 leading-relaxed">
              <p className="font-semibold text-gray-800 mb-1">Answer:</p>
              <p>{isOpen ? faq.answer : collapsed}</p>
              {faq.answer.length > 180 ? (
                <button
                  type="button"
                  onClick={() => setOpenIdx(isOpen ? null : idx)}
                  className="mt-2 text-[12px] font-semibold text-primary hover:underline cursor-pointer"
                >
                  {isOpen ? 'read less' : 'read more'}
                </button>
              ) : null}
            </div>
          </article>
        );
      })}
    </div>
  );
}

export function FaqCategoryNav({
  categories,
  activeSlug,
}: {
  categories: FaqCategory[];
  activeSlug?: string;
}) {
  return (
    <nav className="bg-white border border-gray-200 rounded-xl p-4">
      <h2 className="text-[11px] font-bold uppercase tracking-[0.08em] text-gray-400 mb-3">
        FAQ Categories
      </h2>
      <ul className="space-y-1">
        <li>
          <Link
            href="/faqs"
            className={`block rounded-lg px-3 py-2 text-[13px] font-semibold transition-colors ${
              !activeSlug
                ? 'bg-primary/10 text-primary'
                : 'text-gray-600 hover:bg-gray-50 hover:text-primary'
            }`}
          >
            All FAQs
          </Link>
        </li>
        {categories.map((cat) => {
          const active = cat.slug === activeSlug;
          return (
            <li key={cat.slug}>
              <Link
                href={`/faqs/${cat.slug}`}
                className={`block rounded-lg px-3 py-2 text-[13px] font-semibold transition-colors ${
                  active
                    ? 'bg-primary/10 text-primary'
                    : 'text-gray-600 hover:bg-gray-50 hover:text-primary'
                }`}
              >
                {cat.title}
              </Link>
            </li>
          );
        })}
      </ul>
    </nav>
  );
}

export function FaqHub({ data }: { data: FaqPageData }) {
  return (
    <div className="space-y-8">
      <div>
        <h1 className="text-[28px] md:text-[32px] font-bold text-[#1E293B]">
          {data.title}
        </h1>
        {data.subtitle ? (
          <p className="text-[14px] text-gray-500 mt-2 max-w-2xl">{data.subtitle}</p>
        ) : null}
      </div>

      <div className="grid grid-cols-1 sm:grid-cols-2 lg:grid-cols-3 gap-4">
        {data.categories.map((cat) => (
          <Link
            key={cat.slug}
            href={`/faqs/${cat.slug}`}
            className="bg-white border border-gray-200 rounded-xl p-5 hover:border-primary/40 hover:shadow-sm transition-all"
          >
            <h2 className="text-[16px] font-bold text-[#1E293B]">{cat.title}</h2>
            {cat.description ? (
              <p className="text-[13px] text-gray-500 mt-2 leading-relaxed">
                {cat.description}
              </p>
            ) : null}
            <p className="text-[12px] font-semibold text-primary mt-4">
              {cat.faqs.length} question{cat.faqs.length === 1 ? '' : 's'} →
            </p>
          </Link>
        ))}
      </div>
    </div>
  );
}

export function FaqCategoryPage({
  data,
  category,
}: {
  data: FaqPageData;
  category: FaqCategory;
}) {
  return (
    <div className="grid grid-cols-1 lg:grid-cols-[260px_minmax(0,1fr)] gap-6 lg:gap-8">
      <aside className="lg:sticky lg:top-28 h-fit">
        <FaqCategoryNav categories={data.categories} activeSlug={category.slug} />
      </aside>

      <div className="min-w-0">
        <h1 className="text-[26px] md:text-[30px] font-bold text-[#1E293B]">
          {category.title}
        </h1>
        {category.description ? (
          <p className="text-[14px] text-gray-500 mt-1.5 mb-6">{category.description}</p>
        ) : (
          <div className="mb-6" />
        )}

        <FaqAccordionList faqs={category.faqs} />
      </div>
    </div>
  );
}