"use client";

import { useState, type FormEvent } from "react";
import type { ApiComment } from "@/lib/api";
import { formatDate } from "@/lib/format";
import { customerLoginUrl } from "@/lib/customer";
import { useSession } from "@/lib/session";
import { RichContent } from "./RichContent";

type Props = {
  productId: string;
  descriptionHtml?: string | null;
  comments: ApiComment[];
};

type Tab = {
  id: "description" | "comments";
  fa: string;
  en: string;
};

const tabs: Tab[] = [
  { id: "description", fa: "توضیحات محصول", en: "Description" },
  { id: "comments", fa: "نظرات", en: "Comments" },
];

export function ProductTabs({ productId, descriptionHtml, comments: initialComments }: Props) {
  const [tab, setTab] = useState<"description" | "comments">("description");
  const [comments, setComments] = useState(initialComments);
  const [sent, setSent] = useState(false);
  const [sending, setSending] = useState(false);
  const { isAuthenticated: loggedIn, user } = useSession();
  const authorName = user?.firstName?.trim() || "کاربر";

  async function onSubmit(event: FormEvent<HTMLFormElement>) {
    event.preventDefault();
    if (!loggedIn) return;
    const form = event.currentTarget;
    const text = String(new FormData(form).get("text") || "").trim();
    if (!text) return;
    setSending(true);
    try {
      const response = await fetch("/api/comments", {
        method: "POST",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify({
          entityType: "product",
          entityId: productId,
          authorName,
          text,
        }),
      });
      if (response.ok) {
        setSent(true);
        form.reset();
        setComments((current) => [
          {
            id: `local-${Date.now()}`,
            authorName,
            text,
            createdAt: new Date().toISOString(),
          },
          ...current,
        ]);
      }
    } finally {
      setSending(false);
    }
  }

  return (
    <div className="mt-10 rounded-2xl border border-black/5">
      <div className="flex justify-center gap-5 border-b border-black/5">
        {tabs.map((item) => {
          const active = tab === item.id;
          const label = item.id === "comments" && comments.length
            ? `${item.fa} (${comments.length.toLocaleString("fa-IR")})`
            : item.fa;
          return (
            <button
              key={item.id}
              type="button"
              onClick={() => setTab(item.id)}
              className={`px-2 py-3 text-center ${
                active ? "border-b-2 border-brand text-brand" : "text-zinc-500"
              }`}
            >
              <span className={`block text-base leading-none ${active ? "font-bold" : ""}`}>{label}</span>
              <span dir="ltr" className="mt-0.5 block font-oswald text-[9px] font-normal leading-none tracking-[0.16em] uppercase opacity-70">
                {item.en}
              </span>
            </button>
          );
        })}
      </div>

      <div className="p-5 md:p-8">
        {tab === "description" ? (
          descriptionHtml ? (
            <RichContent html={descriptionHtml} />
          ) : (
            <p className="text-sm text-zinc-500">توضیحی برای این محصول ثبت نشده است.</p>
          )
        ) : (
          <div className="space-y-6">
            <div className="space-y-4">
              {comments.length ? (
                comments.map((comment) => (
                  <article key={comment.id} className="rounded-xl bg-zinc-50 p-4">
                    <div className="mb-2 flex items-center justify-between gap-3 text-xs text-zinc-400">
                      <span className="font-bold text-ink">{comment.authorName || "کاربر"}</span>
                      {comment.createdAt ? <time>{formatDate(comment.createdAt)}</time> : null}
                    </div>
                    <p className="text-sm leading-7 text-zinc-600">{comment.text}</p>
                  </article>
                ))
              ) : (
                <p className="text-sm text-zinc-500">هنوز نظری ثبت نشده است.</p>
              )}
            </div>

            {loggedIn ? (
              <form onSubmit={onSubmit} className="rounded-xl border border-black/5 p-4">
                {sent ? (
                  <p className="text-sm leading-7 text-zinc-600">نظر شما ثبت شد و پس از تایید نمایش داده می‌شود.</p>
                ) : (
                  <div className="flex gap-3">
                    <input
                      required
                      name="text"
                      placeholder="نظر خود را بنویسید..."
                      className="min-w-0 flex-1 rounded-xl border border-black/5 bg-zinc-50 px-4 py-2.5 text-sm outline-none focus:border-brand"
                    />
                    <button
                      type="submit"
                      disabled={sending}
                      className="shrink-0 rounded-xl bg-brand px-5 py-2.5 text-sm text-white disabled:opacity-60"
                    >
                      ارسال
                    </button>
                  </div>
                )}
              </form>
            ) : (
              <div className="rounded-xl bg-zinc-50 px-4 py-5 text-center">
                <p className="text-sm text-zinc-600">برای ثبت نظر ابتدا وارد حساب کاربری شوید.</p>
                <a
                  href={customerLoginUrl("/")}
                  className="mt-3 inline-block text-sm text-brand"
                >
                  ورود / ثبت نام
                </a>
              </div>
            )}
          </div>
        )}
      </div>
    </div>
  );
}