"use client";

import React, { useEffect, useState } from "react";
import Link from "next/link";
import { AdminHeader, AlertBanner } from "./_components/AdminComponents";
import {
  adminGetStatsSummary,
  adminGetResearchProjects,
  adminGetResearchAreas,
  adminGetMembers,
  adminGetAlumni,
  adminGetPublications,
  adminGetPatents,
  adminGetSemesters,
  adminGetStandardsBodies,
  AdminStatsSummary,
} from "../../lib/adminApi";

export default function AdminDashboardPage() {
  const [stats, setStats] = useState<AdminStatsSummary | null>(null);
  const [counts, setCounts] = useState<{
    projects: number;
    areas: number;
    members: number;
    alumni: number;
    intlPubs: number;
    domPubs: number;
    patents: number;
    semesters: number;
    courses: number;
    bodies: number;
    docs: number;
  }>({
    projects: 0,
    areas: 0,
    members: 0,
    alumni: 0,
    intlPubs: 0,
    domPubs: 0,
    patents: 0,
    semesters: 0,
    courses: 0,
    bodies: 0,
    docs: 0,
  });
  const [isLoading, setIsLoading] = useState(true);
  const [error, setError] = useState<string | null>(null);

  useEffect(() => {
    async function loadData() {
      try {
        setIsLoading(true);
        const [
          statsData,
          projects,
          areas,
          members,
          alumni,
          intlPubs,
          domPubs,
          patents,
          semesters,
          bodies,
        ] = await Promise.all([
          adminGetStatsSummary().catch(() => null),
          adminGetResearchProjects().catch(() => []),
          adminGetResearchAreas().catch(() => []),
          adminGetMembers().catch(() => []),
          adminGetAlumni().catch(() => []),
          adminGetPublications("intl-journal-conf").catch(() => []),
          adminGetPublications("domestic-journal-conf").catch(() => []),
          adminGetPatents().catch(() => []),
          adminGetSemesters().catch(() => []),
          adminGetStandardsBodies().catch(() => []),
        ]);

        if (statsData) setStats(statsData);

        const totalCourses = semesters.reduce((acc, s) => acc + (s.courses?.length || 0), 0);
        const totalDocs = bodies.reduce(
          (acc, b) => acc + (b.projects?.reduce((pAcc, p) => pAcc + (p.documents?.length || 0), 0) || 0),
          0
        );

        setCounts({
          projects: projects.length,
          areas: areas.length,
          members: members.length,
          alumni: alumni.length,
          intlPubs: intlPubs.length,
          domPubs: domPubs.length,
          patents: patents.length,
          semesters: semesters.length,
          courses: totalCourses,
          bodies: bodies.length,
          docs: totalDocs,
        });
      } catch (err: any) {
        setError(err?.message || "Failed to load dashboard data from backend API.");
      } finally {
        setIsLoading(false);
      }
    }

    loadData();
  }, []);

  const cards = [
    {
      title: "Research Projects",
      count: counts.projects,
      sub: `${counts.areas} Research Areas`,
      href: "/console/research-projects",
      color: "border-cobalt/30 hover:border-cobalt",
    },
    {
      title: "Members & Alumni",
      count: counts.members,
      sub: `${counts.alumni} Alumni Records`,
      href: "/console/members",
      color: "border-emerald-500/30 hover:border-emerald-500",
    },
    {
      title: "Publications & Patents",
      count: counts.intlPubs + counts.domPubs,
      sub: `${counts.intlPubs} Intl / ${counts.domPubs} Dom / ${counts.patents} Patents`,
      href: "/console/publications",
      color: "border-blue-500/30 hover:border-blue-500",
    },
    {
      title: "Lectures & Courses",
      count: counts.semesters,
      sub: `${counts.courses} Total Courses across Semesters`,
      href: "/console/lectures",
      color: "border-amber-500/30 hover:border-amber-500",
    },
    {
      title: "Standardization",
      count: counts.bodies,
      sub: `${counts.docs} Standard Documents`,
      href: "/console/standardization",
      color: "border-purple-500/30 hover:border-purple-500",
    },
    {
      title: "Research Areas",
      count: counts.areas,
      sub: "Active Laboratory Focus Areas",
      href: "/console/research-areas",
      color: "border-indigo-500/30 hover:border-indigo-500",
    },
  ];

  return (
    <div>
      <AdminHeader
        title="Administrative Overview"
        description="Live status of all ANL laboratory records and datasets stored in the backend."
      />

      {error && <AlertBanner type="error" message={error} onClose={() => setError(null)} />}

      {isLoading ? (
        <div className="py-12 text-center text-sm text-ink/70">Loading dashboard statistics...</div>
      ) : (
        <div className="grid grid-cols-1 sm:grid-cols-2 lg:grid-cols-3 gap-6">
          {cards.map((card) => (
            <Link
              key={card.title}
              href={card.href}
              className={`p-6 bg-paper rounded-lg border ${card.color} transition-all shadow-sm flex flex-col justify-between`}
            >
              <div>
                <h2 className="text-base font-semibold text-ink">{card.title}</h2>
                <div className="text-3xl font-extrabold text-cobalt mt-3">{card.count}</div>
                <p className="text-xs text-ink/70 mt-1">{card.sub}</p>
              </div>
              <div className="mt-4 pt-4 border-t border-line text-xs font-medium text-cobalt flex items-center justify-between">
                <span>Manage Records</span>
                <span>&rarr;</span>
              </div>
            </Link>
          ))}
        </div>
      )}
    </div>
  );
}
