import { useEffect, useState } from "react";
import { useNavigate, useParams } from "react-router-dom";
import { ArrowLeft, House, Plus } from "lucide-react";

import { useCourses } from "@/contexts/AdminCoursesContext";
import AppBreadcrumb from "@/components/generic/Breadcrumb/AppBreadcrumb";
import { Spinner } from "@/components/ui/spinner";
import UnitsTable from "../../../components/courses/UnitsTable";
import { Badge } from "@/components/ui/badge";

export default function UnitsList() {
  const navigate = useNavigate();
  const { courseId } = useParams();
  const { fetchCourse, course, loading } = useCourses();
  const [initializing, setInitializing] = useState(true);

  useEffect(() => {
    (async () => {
      await fetchCourse(courseId);
      setInitializing(false);
    })();
  }, [courseId]);

  const items = [
    { label: "Home", icon: <House className="size-4" />, to: "/admin" },
    { label: "Courses", to: "/admin/courses" },
    { label: course?.title ?? "..." },
  ];

  // Replace the loading check
  if (initializing) {
    return (
      <div className="flex items-center justify-center h-64">
        <Spinner className="h-6 w-6" />
      </div>
    );
  }

  return (
    <section className="bg-muted/60 h-full">
      <div className="lg:container lg:mx-auto lg:px-0 flex flex-col items-start px-4">
        <div className="flex flex-col gap-2 my-6">
          <AppBreadcrumb items={items} />
        </div>

        <div className="w-full space-y-6">

          {/* ── Course header ── */}
          <div className="bg-white rounded-xl border p-6 space-y-4">
            {/* Title + Status */}
            <div>
              <h6 className="text-xs tracking-widest mb-1">COURSE</h6>
              <div className="flex items-center gap-2">
                <h1 className="text-xl font-semibold">{course?.title}</h1>
                <span
                  className={`inline-flex items-center px-2 py-0.5 rounded-full text-xs font-medium ${!course.deletedBy
                    ? "bg-green-100 text-green-700"
                    : "bg-red-100 text-red-600"
                    }`}
                >
                  {!course.deletedBy ? "Active" : "Inactive"}
                </span>
              </div>
              {course?.description && (
                <p className="text-sm text-muted-foreground mt-0.5">{course.description}</p>
              )}
            </div>

            {/* Stats row */}
            <div className="grid grid-cols-2 lg:grid-cols-4 gap-3">
              <div className="bg-muted/60 rounded-lg p-3 space-y-1">
                <p className="text-xs text-muted-foreground uppercase tracking-wide font-medium">Level</p>
                <p className="font-semibold text-sm capitalize">{course?.level}</p>
              </div>
              <div className="bg-muted/60 rounded-lg p-3 space-y-1">
                <p className="text-xs text-muted-foreground uppercase tracking-wide font-medium">Units</p>
                <p className="font-semibold text-sm">{course?.units.length}</p>
              </div>
              <div className="bg-muted/60 rounded-lg p-3 space-y-1">
                <p className="text-xs text-muted-foreground uppercase tracking-wide font-medium">Created</p>
                <p className="font-semibold text-sm">
                  {course?.createdAt ? new Date(course.createdAt).toLocaleDateString('en-US', { month: 'short', day: 'numeric', year: 'numeric' }) : '—'}
                </p>
              </div>
              <div className="bg-muted/60 rounded-lg p-3 space-y-1">
                <p className="text-xs text-muted-foreground uppercase tracking-wide font-medium">Last Updated</p>
                <p className="font-semibold text-sm">
                  {course?.updatedAt ? new Date(course.updatedAt).toLocaleDateString('en-US', { month: 'short', day: 'numeric', year: 'numeric' }) : '—'}
                </p>
              </div>
            </div>
          </div>

          {/* ── Units ── */}
          <UnitsTable courseId={courseId} />

        </div>
      </div>
    </section>
  );
}