"use client";

import { useState, useEffect, useMemo } from "react";
import { adminFetch } from "@/lib/csrf";
import { type BookingFilter, type BaseBooking, type BookingGroup } from "./types";
import { LoadingSpinner } from "./BookingComponents";
import { GenericBookingsList } from "./GenericBookingsList";

interface McRegistration extends BaseBooking {
  masterClassTitle: string;
}

interface McSlot { date: string; startTime: string }
interface McItem { title: string; slots: McSlot[] }

export function McRegistrationsTab({ filter, onDataChange }: { filter: BookingFilter; onDataChange?: () => void }) {
  const [regs, setRegs] = useState<McRegistration[]>([]);
  const [mcDates, setMcDates] = useState<Record<string, string>>({});
  const [loading, setLoading] = useState(true);

  useEffect(() => {
    Promise.all([
      adminFetch("/api/admin/mc-registrations").then((r) => r.json()),
      adminFetch("/api/admin/sections/masterClasses").then((r) => r.json()),
    ]).then(([regData, mcData]: [McRegistration[], { items?: McItem[] }]) => {
      setRegs(regData);
      const dates: Record<string, string> = {};
      const mcItems = mcData.items || [];
      for (const mc of mcItems) {
        const earliestSlot = mc.slots?.reduce((min, s) => s.date < min ? s.date : min, mc.slots[0]?.date ?? "");
        if (earliestSlot) dates[mc.title] = earliestSlot;
      }
      const regTitles = new Set(regData.map((r) => r.masterClassTitle));
      for (const regTitle of regTitles) {
        if (dates[regTitle]) continue;
        for (const mc of mcItems) {
          const earliestSlot = mc.slots?.reduce((min, s) => s.date < min ? s.date : min, mc.slots[0]?.date ?? "");
          if (!earliestSlot) continue;
          if (regTitle.toLowerCase().includes(mc.title.toLowerCase()) || mc.title.toLowerCase().includes(regTitle.toLowerCase())) {
            dates[regTitle] = earliestSlot;
            break;
          }
        }
      }
      setMcDates(dates);
    }).catch(() => {}).finally(() => setLoading(false));
  }, []);

  const today = new Date().toISOString().split("T")[0];

  const groups = useMemo((): BookingGroup<McRegistration>[] => {
    const map: Record<string, McRegistration[]> = {};
    for (const r of regs) {
      if (!map[r.masterClassTitle]) map[r.masterClassTitle] = [];
      map[r.masterClassTitle].push(r);
    }
    return Object.entries(map).map(([title, items]) => {
      const date = mcDates[title];
      const isArchived = !date || date < today;
      return {
        key: title,
        label: title,
        dateBadge: date ? new Date(date + "T12:00").toLocaleDateString("ru-RU", { day: "numeric", month: "short" }) : undefined,
        items,
        isArchived,
      };
    });
  }, [regs, mcDates, today]);

  if (loading) return <LoadingSpinner />;

  return (
    <GenericBookingsList<McRegistration>
      items={regs}
      endpoint="/api/admin/mc-registrations"
      filter={filter}
      onItemsChange={setRegs}
      onDataChange={onDataChange}
      groups={groups}
    />
  );
}