"use client";

import { useMemo, useState, type ReactNode } from "react";
import { site } from "@/data/home";

type ProductTabsProps = {
  description?: string | null;
  technicalNotes?: string | null;
  deliveryNotes?: string | null;
  technicalValues?: unknown;
};

type TabId = "description" | "technical" | "comments";

const tabMeta: Record<
  TabId,
  { label: string; labelEn: string }
> = {
  description: { label: "توضیحات", labelEn: "Description" },
  technical: { label: "مشخصات فنی", labelEn: "Technical Info" },
  comments: { label: "نظرات", labelEn: "Comments" },
};

function renderTechnicalValues(value: unknown): ReactNode {
  if (value === null || value === undefined) return null;

  if (typeof value === "string") {
    return (
      <p className="whitespace-pre-line text-base leading-8 text-muted">
        {value}
      </p>
    );
  }

  if (Array.isArray(value)) {
    if (value.length === 0) return null;
    return (
      <ul className="space-y-2 text-base leading-8 text-muted">
        {value.map((item, index) => (
          <li key={index} className="flex gap-2">
            <span className="text-brand">•</span>
            <span>{typeof item === "object" ? JSON.stringify(item) : String(item)}</span>
          </li>
        ))}
      </ul>
    );
  }

  if (typeof value === "object") {
    const entries = Object.entries(value as Record<string, unknown>);
    if (entries.length === 0) return null;
    return (
      <div className="overflow-x-auto">
        <table className="w-full min-w-[20rem] border-collapse text-sm">
          <tbody>
            {entries.map(([key, val]) => (
              <tr key={key} className="border-b border-line">
                <th className="px-4 py-3 text-right font-bold text-brand-ink">
                  {key}
                </th>
                <td className="px-4 py-3 text-muted">
                  {val === null || val === undefined ? "—" : String(val)}
                </td>
              </tr>
            ))}
          </tbody>
        </table>
      </div>
    );
  }

  return <p className="text-base leading-8 text-muted">{String(value)}</p>;
}

export function ProductTabs({
  description,
  technicalNotes,
  deliveryNotes,
  technicalValues,
}: ProductTabsProps) {
  const tabs = useMemo(() => {
    const items: { id: TabId; label: string; labelEn: string }[] = [];

    if (description?.trim()) {
      items.push({ id: "description", ...tabMeta.description });
    }

    const hasTechnical =
      Boolean(technicalNotes?.trim()) ||
      Boolean(deliveryNotes?.trim()) ||
      (technicalValues !== null &&
        technicalValues !== undefined &&
        !(typeof technicalValues === "object" &&
          !Array.isArray(technicalValues) &&
          Object.keys(technicalValues as object).length === 0) &&
        !(Array.isArray(technicalValues) && technicalValues.length === 0));

    if (hasTechnical) {
      items.push({ id: "technical", ...tabMeta.technical });
    }

    items.push({ id: "comments", ...tabMeta.comments });

    return items;
  }, [deliveryNotes, description, technicalNotes, technicalValues]);

  const [activeTab, setActiveTab] = useState<TabId>(tabs[0]?.id ?? "comments");

  if (tabs.length === 0) return null;

  return (
    <div className="mt-12 border border-line bg-surface">
      <div
        role="tablist"
        aria-label="جزئیات محصول"
        className="flex flex-wrap justify-center gap-1 border-b border-line px-2"
      >
        {tabs.map((tab) => {
          const isActive = activeTab === tab.id;
          return (
            <button
              key={tab.id}
              type="button"
              role="tab"
              aria-selected={isActive}
              onClick={() => setActiveTab(tab.id)}
              className={`relative flex flex-col items-center px-3 py-2 transition ${
                isActive
                  ? "text-brand"
                  : "text-muted hover:text-brand-ink"
              }`}
            >
              <span className="text-sm font-extrabold">{tab.label}</span>
              <span
                className={`mt-0.5 font-industrial text-[0.58rem] tracking-[0.16em] uppercase ${
                  isActive ? "text-brand/70" : "text-steel"
                }`}
              >
                {tab.labelEn}
              </span>
              {isActive ? (
                <span className="absolute inset-x-0 bottom-0 h-0.5 bg-brand" />
              ) : null}
            </button>
          );
        })}
      </div>

      <div className="p-4 md:p-5">
        {activeTab === "description" && description ? (
          <div role="tabpanel">
            <p className="whitespace-pre-line text-base leading-8 text-muted">
              {description}
            </p>
          </div>
        ) : null}

        {activeTab === "technical" ? (
          <div role="tabpanel" className="space-y-6">
            {technicalNotes ? (
              <div>
                <h3 className="font-industrial text-xs tracking-[0.16em] text-brand">
                  TECHNICAL NOTES
                </h3>
                <p className="mt-3 whitespace-pre-line text-base leading-8 text-muted">
                  {technicalNotes}
                </p>
              </div>
            ) : null}

            {renderTechnicalValues(technicalValues)}

            {deliveryNotes ? (
              <div>
                <h3 className="font-industrial text-xs tracking-[0.16em] text-brand">
                  DELIVERY
                </h3>
                <p className="mt-3 whitespace-pre-line text-base leading-8 text-muted">
                  {deliveryNotes}
                </p>
              </div>
            ) : null}
          </div>
        ) : null}

        {activeTab === "comments" ? (
          <div role="tabpanel" className="text-center">
            <div className="mx-auto max-w-md py-3">
              <p className="font-industrial text-sm tracking-[0.16em] text-brand">
                COMMENTS
              </p>
              <h3 className="mt-3 text-xl font-extrabold text-brand-ink">
                برای ثبت نظر وارد حساب کاربری شوید
              </h3>
              <p className="mt-3 text-sm leading-7 text-muted">
                پس از ورود می‌توانید تجربه خود از این محصول را با سایر خریداران
                به اشتراک بگذارید.
              </p>
              <a
                href={site.customerLoginUrl}
                target="_blank"
                rel="noopener noreferrer"
                className="btn-primary mt-6 inline-flex"
              >
                ورود / ثبت‌نام
              </a>
            </div>
          </div>
        ) : null}
      </div>
    </div>
  );
}