"use client";

import { useEffect, useState } from "react";
import { useParams, useSearchParams } from "next/navigation";
import Link from "next/link";
import {
  ServerIcon,
  CalendarIcon,
  DocumentTextIcon,
  XCircleIcon,
  CreditCardIcon,
} from "@heroicons/react/24/outline";
import { useSubscription } from "@/features/subscriptions/hooks";
import { Formatting } from "@customer-portal/domain/toolkit";
import { PageLayout } from "@/components/templates/PageLayout";
import { SectionCard } from "@/components/molecules/SectionCard";
import { StatusPill } from "@/components/atoms/status-pill";
import { SubscriptionDetailStatsSkeleton } from "@/components/atoms/loading-skeleton";
import { formatIsoDate, cn } from "@/shared/utils";
import { SimManagementSection } from "@/features/subscriptions/components/sim";
import type { SubscriptionStatus, SubscriptionCycle } from "@customer-portal/domain/subscriptions";
import {
  getBillingCycleLabel,
  getSubscriptionStatusVariant,
} from "@/features/subscriptions/utils/status-presenters";

const { formatCurrency: sharedFormatCurrency } = Formatting;

function SubscriptionStatsCard({
  subscription,
}: {
  subscription: {
    status: SubscriptionStatus;
    amount: number;
    cycle: SubscriptionCycle;
    nextDue?: string | undefined;
    registrationDate?: string | undefined;
  };
}) {
  return (
    <div className="bg-card border border-border rounded-xl shadow-[var(--cp-shadow-1)] overflow-hidden">
      <div className="px-6 py-5 grid grid-cols-2 md:grid-cols-4 gap-6">
        <div>
          <h4 className="text-xs font-semibold text-muted-foreground uppercase tracking-wider">
            Service Status
          </h4>
          <div className="mt-2">
            <StatusPill
              label={subscription.status}
              variant={getSubscriptionStatusVariant(subscription.status)}
              size="lg"
            />
          </div>
        </div>
        <div>
          <h4 className="text-xs font-semibold text-muted-foreground uppercase tracking-wider">
            Billing Amount
          </h4>
          <div className="mt-2 flex items-baseline gap-2">
            <p className="text-2xl font-bold text-foreground">
              {sharedFormatCurrency(subscription.amount || 0)}
            </p>
            <span className="text-sm text-muted-foreground">
              {getBillingCycleLabel(subscription.cycle)}
            </span>
          </div>
        </div>
        <div>
          <h4 className="text-xs font-semibold text-muted-foreground uppercase tracking-wider">
            Next Due Date
          </h4>
          <div className="flex items-center mt-2 gap-2">
            <CalendarIcon className="h-4 w-4 text-muted-foreground" />
            <p className="text-lg font-medium text-foreground">
              {formatIsoDate(subscription.nextDue)}
            </p>
          </div>
        </div>
        <div>
          <h4 className="text-xs font-semibold text-muted-foreground uppercase tracking-wider">
            Registration Date
          </h4>
          <div className="flex items-center mt-2 gap-2">
            <CalendarIcon className="h-4 w-4 text-muted-foreground" />
            <p className="text-lg font-medium text-foreground">
              {formatIsoDate(subscription.registrationDate)}
            </p>
          </div>
        </div>
      </div>
    </div>
  );
}

function SimTabNavigation({
  subscriptionId,
  activeTab,
}: {
  subscriptionId: number;
  activeTab: string;
}) {
  return (
    <div className="flex items-center gap-1 p-1 bg-muted rounded-lg w-fit">
      <Link
        href={`/account/subscriptions/${subscriptionId}`}
        className={cn(
          "px-4 py-2 text-sm font-medium rounded-md transition-all flex items-center gap-2",
          activeTab === "overview"
            ? "bg-card text-foreground shadow-sm"
            : "text-muted-foreground hover:text-foreground"
        )}
      >
        <DocumentTextIcon className="h-4 w-4" />
        Overview & Billing
      </Link>
      <Link
        href={`/account/subscriptions/${subscriptionId}#sim-management`}
        className={cn(
          "px-4 py-2 text-sm font-medium rounded-md transition-all flex items-center gap-2",
          activeTab === "sim"
            ? "bg-card text-foreground shadow-sm"
            : "text-muted-foreground hover:text-foreground"
        )}
      >
        <ServerIcon className="h-4 w-4" />
        SIM Management
      </Link>
    </div>
  );
}

function detectServiceType(productName: string | undefined): {
  isSim: boolean;
  isInternet: boolean;
} {
  const lower = productName?.toLowerCase() ?? "";
  const isNttFiber = lower.includes("ntt") && lower.includes("fiber");
  return {
    isSim: lower.includes("sim"),
    isInternet: lower.includes("internet") || lower.includes("sonixnet") || isNttFiber,
  };
}

function getPageError(error: unknown): string | null {
  if (!error) return null;
  if (process.env.NODE_ENV === "development" && error instanceof Error) return error.message;
  return "Unable to load subscription details. Please try again.";
}

function useActiveTab(searchParams: ReturnType<typeof useSearchParams>) {
  const [activeTab, setActiveTab] = useState<"overview" | "sim">("overview");
  useEffect(() => {
    const updateTab = () => {
      const hash = typeof window === "undefined" ? "" : window.location.hash;
      const service = (searchParams.get("service") || "").toLowerCase();
      setActiveTab(hash.includes("sim-management") || service === "sim" ? "sim" : "overview");
    };
    updateTab();
    if (typeof window === "undefined") return;
    window.addEventListener("hashchange", updateTab);
    return () => window.removeEventListener("hashchange", updateTab);
  }, [searchParams]);
  return activeTab;
}

function CancelServiceAction({ subscriptionId }: { subscriptionId: number }) {
  return (
    <Link
      href={`/account/subscriptions/${subscriptionId}/cancel`}
      className="inline-flex items-center gap-2 px-4 py-2 text-sm font-medium text-danger-foreground bg-danger hover:bg-danger/90 rounded-lg transition-colors"
    >
      <XCircleIcon className="h-4 w-4" />
      Cancel Service
    </Link>
  );
}

function SubscriptionDetailContent({
  subscription,
  subscriptionId,
  activeTab,
}: {
  subscription: {
    productName: string;
    status: SubscriptionStatus;
    amount: number;
    cycle: SubscriptionCycle;
    nextDue?: string | undefined;
    registrationDate?: string | undefined;
  };
  subscriptionId: number;
  activeTab: string;
}) {
  const { isSim } = detectServiceType(subscription.productName);
  return (
    <div className="space-y-6">
      <SubscriptionStatsCard subscription={subscription} />
      {isSim && <SimTabNavigation subscriptionId={subscriptionId} activeTab={activeTab} />}
      {activeTab === "sim" && isSim && <SimManagementSection subscriptionId={subscriptionId} />}
      {activeTab === "overview" && (
        <SectionCard
          icon={<CreditCardIcon className="h-5 w-5" />}
          title="Billing Information"
          subtitle="Payment and invoices"
          tone="primary"
          actions={
            <Link
              href="/account/billing"
              className="text-sm font-medium text-primary hover:text-primary/80 transition-colors"
            >
              View Invoices
            </Link>
          }
        >
          <p className="text-sm text-muted-foreground">
            Invoices and payment history are available on the billing page.
          </p>
        </SectionCard>
      )}
    </div>
  );
}

export function SubscriptionDetailContainer() {
  const params = useParams();
  const searchParams = useSearchParams();
  const subscriptionId = Number.parseInt(params["id"] as string);
  const { data: subscription, error } = useSubscription(subscriptionId);
  const activeTab = useActiveTab(searchParams);

  if (!subscription && !error) {
    return (
      <PageLayout
        icon={<ServerIcon className="h-6 w-6" />}
        title="Subscription"
        backLink={{ label: "Back to Subscriptions", href: "/account/subscriptions" }}
      >
        <div className="space-y-6">
          <SubscriptionDetailStatsSkeleton />
        </div>
      </PageLayout>
    );
  }

  const { isInternet } = detectServiceType(subscription?.productName);
  const headerActions =
    isInternet && subscription?.status === "Active" ? (
      <CancelServiceAction subscriptionId={subscriptionId} />
    ) : undefined;

  return (
    <PageLayout
      icon={<ServerIcon className="h-6 w-6" />}
      title={subscription?.productName ?? "Subscription"}
      actions={headerActions}
      backLink={{ label: "Back to Subscriptions", href: "/account/subscriptions" }}
      error={getPageError(error)}
    >
      {subscription ? (
        <SubscriptionDetailContent
          subscription={subscription}
          subscriptionId={subscriptionId}
          activeTab={activeTab}
        />
      ) : null}
    </PageLayout>
  );
}

export default SubscriptionDetailContainer;