"use client";

import { useEffect, useState } from "react";
import Link from "next/link";
import { AuthGuard } from "@/components/AuthGuard";
import { Button, SectionTitle } from "@/components/ui";
import { useMe } from "@/hooks/useMe";
import {
  loadCommercialInvoices,
  loadCommercialPricing,
  loadCommercialTransactions,
  loadCommercialUsage,
} from "../adapters";
import { commercialGet, commercialPost } from "../adapters/http";
import type {
  CommercialInvoice,
  CommercialTransaction,
} from "../adapters/billing-ledger";
import type { AdapterResult, CommercialPricingItem, CommercialUsageCounter } from "../types";
import { CommercialEmptyState, PlanBadge, PlatformShell, SubscriptionBanner } from "../components";

type CommercialSubscription = {
  id?: string;
  status?: string | null;
  plan_code?: string | null;
  bundle_code?: string | null;
  pricing_item_code?: string | null;
  trial_ends_at?: string | null;
  current_period_end?: string | null;
};

function BillingInner() {
  const { me, loading: meLoading } = useMe();
  const [pricing, setPricing] = useState<AdapterResult<CommercialPricingItem[]> | null>(null);
  const [usage, setUsage] = useState<AdapterResult<CommercialUsageCounter[]> | null>(null);
  const [invoices, setInvoices] = useState<AdapterResult<CommercialInvoice[]> | null>(null);
  const [txns, setTxns] = useState<AdapterResult<CommercialTransaction[]> | null>(null);
  const [sub, setSub] = useState<CommercialSubscription | null>(null);
  const [coupon, setCoupon] = useState("");
  const [error, setError] = useState("");
  const [busy, setBusy] = useState(false);
  const [msg, setMsg] = useState("");

  useEffect(() => {
    void loadCommercialPricing().then(setPricing);
  }, []);

  useEffect(() => {
    if (!me?.current_tenant_id) return;
    const tenantId = me.current_tenant_id;
    void (async () => {
      const dash = await commercialGet<{
        subscription?: CommercialSubscription | null;
      }>(`/api/v1/commercial/dashboard?tenant_id=${encodeURIComponent(tenantId)}`);
      if (dash.ok) setSub(dash.data.subscription ?? null);
      else setError(dash.message || "بارگذاری اشتراک commercial ناموفق بود");
      void Promise.all([
        loadCommercialUsage(tenantId).then(setUsage),
        loadCommercialInvoices(tenantId).then(setInvoices),
        loadCommercialTransactions(tenantId).then(setTxns),
      ]);
    })();
  }, [me?.current_tenant_id]);

  const activatePricing = async (
    item: CommercialPricingItem,
    mode: "trial" | "active" | "upgrade" | "downgrade"
  ) => {
    if (!me?.current_tenant_id) return;
    setBusy(true);
    setError("");
    setMsg("");
    try {
      const commercial = await commercialPost<{
        subscription?: CommercialSubscription;
        id?: string;
        status?: string;
        plan_code?: string | null;
        trial_ends_at?: string | null;
      }>("/api/v1/commercial/subscriptions", {
        tenant_id: me.current_tenant_id,
        pricing_item_code: item.pricing_item_code,
        mode,
        status: mode === "trial" ? "trialing" : "active",
        coupon_code: coupon.trim() || undefined,
      });

      if (!commercial.ok) {
        setError(commercial.message || "فعال‌سازی نیازمند Commercial Runtime subscriptions API است.");
        return;
      }

      const next = commercial.data.subscription ?? {
        id: commercial.data.id,
        status: commercial.data.status,
        plan_code: commercial.data.plan_code ?? item.pricing_item_code,
        pricing_item_code: item.pricing_item_code,
        trial_ends_at: commercial.data.trial_ends_at ?? null,
      };
      setSub(next);
      setMsg(`عملیات ${mode} از Commercial Runtime ثبت شد.`);
    } catch (err) {
      setError(err instanceof Error ? err.message : "عملیات ناموفق بود");
    } finally {
      setBusy(false);
    }
  };

  const applyCoupon = async () => {
    if (!me?.current_tenant_id || !coupon.trim()) return;
    setBusy(true);
    setError("");
    setMsg("");
    // Coupons SoT is Commercial Runtime registry — apply via published coupon codes
    // attached to pricing activation (coupon_code on subscriptions POST).
    setMsg(
      `کد «${coupon.trim()}» را هنگام Trial/فعال‌سازی ارسال کنید. مدیریت کوپن فقط در Admin Commercial.`
    );
    setBusy(false);
  };

  if (meLoading) {
    return (
      <PlatformShell title="Billing">
        <p className="text-sm text-gray-500">در حال بارگذاری...</p>
      </PlatformShell>
    );
  }

  const planLabel = sub?.plan_code || sub?.pricing_item_code || sub?.bundle_code || undefined;

  return (
    <PlatformShell
      title="Billing و Subscription"
      subtitle="قیمت، فاکتور، تراکنش و ارتقا فقط از Commercial Runtime"
    >
      <div className="mb-4">
        <Link href="/dashboard">
          <Button variant="outline" size="sm">
            داشبورد
          </Button>
        </Link>
      </div>

      <SubscriptionBanner status={sub?.status ?? undefined} planName={planLabel} />
      {sub ? (
        <div className="mt-3">
          <PlanBadge label={planLabel || "—"} status={sub.status ?? undefined} />
          {sub.trial_ends_at ? (
            <p className="mt-2 text-xs text-gray-500" dir="ltr">
              trial_ends_at: {sub.trial_ends_at}
            </p>
          ) : null}
        </div>
      ) : null}

      {error ? <p className="mt-4 rounded-lg bg-red-50 px-3 py-2 text-sm text-red-600">{error}</p> : null}
      {msg ? <p className="mt-4 rounded-lg bg-emerald-50 px-3 py-2 text-sm text-emerald-700">{msg}</p> : null}

      <section className="mt-8">
        <SectionTitle title="کوپن / تخفیف" />
        <div className="flex flex-wrap gap-2">
          <input
            className="rounded-xl border border-gray-200 px-3 py-2 text-sm"
            dir="ltr"
            placeholder="COUPON"
            value={coupon}
            onChange={(e) => setCoupon(e.target.value)}
          />
          <Button size="sm" disabled={busy || !coupon.trim()} onClick={() => void applyCoupon()}>
            اعمال
          </Button>
        </div>
      </section>

      <section className="mt-10">
        <SectionTitle title="کاتالوگ قیمت (Commercial Runtime)" />
        {!pricing || pricing.availability === "loading" ? (
          <p className="text-sm text-gray-500">در حال بارگذاری...</p>
        ) : pricing.availability !== "ready" || !pricing.data.length ? (
          <CommercialEmptyState
            title="قیمتی در رجیستری نیست"
            description="از Admin Commercial → Pricing یک آیتم منتشر کنید."
            actionHref="/admin/commercial/pricing"
            actionLabel="مدیریت Pricing"
          />
        ) : (
          <ul className="mt-4 space-y-3">
            {pricing.data.map((item) => (
              <li
                key={item.pricing_item_code}
                className="flex flex-wrap items-center justify-between gap-3 rounded-2xl border border-gray-100 bg-white p-4"
              >
                <div>
                  <p className="font-semibold text-secondary">{item.display_name}</p>
                  <p className="text-xs text-gray-500" dir="ltr">
                    {item.pricing_item_code}
                    {item.amount != null ? ` · ${item.amount} ${item.currency || ""}` : ""}
                    {item.trial_days != null ? ` · trial ${item.trial_days}d` : ""}
                  </p>
                </div>
                <div className="flex flex-wrap gap-2">
                  <Button
                    size="sm"
                    variant="outline"
                    disabled={busy}
                    onClick={() => void activatePricing(item, "trial")}
                  >
                    Trial
                  </Button>
                  <Button size="sm" disabled={busy} onClick={() => void activatePricing(item, "active")}>
                    فعال‌سازی
                  </Button>
                  <Button
                    size="sm"
                    variant="outline"
                    disabled={busy}
                    onClick={() => void activatePricing(item, "upgrade")}
                  >
                    ارتقا
                  </Button>
                </div>
              </li>
            ))}
          </ul>
        )}
      </section>

      <section className="mt-10">
        <SectionTitle title="Usage" />
        {usage?.availability === "ready" && usage.data.length ? (
          <ul className="mt-3 space-y-2 text-sm">
            {usage.data.map((u) => (
              <li key={u.key} className="rounded-xl bg-gray-50 px-3 py-2" dir="ltr">
                {u.key}: {u.used ?? 0}/{u.limit ?? "∞"}
              </li>
            ))}
          </ul>
        ) : (
          <p className="text-sm text-gray-500">Usage از Commercial Runtime خالی است.</p>
        )}
      </section>

      <section className="mt-10">
        <SectionTitle title="Invoices / Transactions" />
        <p className="mb-3 text-xs text-gray-500">
          لجر مالی متعلق به Payment است؛ Commercial فقط نمای خالی/پروکسی صادقانه برمی‌گرداند.
        </p>
        {invoices?.availability === "ready" && invoices.data.length ? (
          <ul className="space-y-2 text-sm">
            {invoices.data.map((inv) => (
              <li key={inv.id} dir="ltr">
                {inv.id} · {inv.status} · {inv.amount}
              </li>
            ))}
          </ul>
        ) : (
          <p className="text-sm text-gray-500">فاکتوری نیست.</p>
        )}
        {txns?.availability === "ready" && txns.data.length ? (
          <ul className="mt-3 space-y-2 text-sm">
            {txns.data.map((t) => (
              <li key={t.id} dir="ltr">
                {t.id} · {t.status} · {t.amount}
              </li>
            ))}
          </ul>
        ) : (
          <p className="mt-2 text-sm text-gray-500">تراکنشی نیست.</p>
        )}
      </section>
    </PlatformShell>
  );
}

export function CommercialBillingPage() {
  return (
    <AuthGuard>
      <BillingInner />
    </AuthGuard>
  );
}