"use client";

import React, { Suspense, useEffect, useMemo, useState } from "react";
import { useAuth } from "@/hooks/useAuth";
import { useRouter, useSearchParams } from "next/navigation";
import { apiFetch } from "@/lib/api";
import { useDismissingState } from "@/hooks/useDismissingState";
import { Ticket } from "lucide-react";

// Format a Date (or date-like input) to the value expected by <input type="datetime-local">
// This returns local time (browser timezone) as YYYY-MM-DDTHH:mm
function toLocalDateTimeInputValue(input: string | number | Date | null | undefined): string {
  if (input == null) return "";
  const d = new Date(input);
  if (isNaN(d.getTime())) return "";
  const y = d.getFullYear();
  const m = String(d.getMonth() + 1).padStart(2, "0");
  const day = String(d.getDate()).padStart(2, "0");
  const hh = String(d.getHours()).padStart(2, "0");
  const mm = String(d.getMinutes()).padStart(2, "0");
  return `${y}-${m}-${day}T${hh}:${mm}`;
}

function EarlyBirdTiersEditor({ option, onSave }: { option: any; onSave: (tiers: { deadline: string; price: number; order?: number }[]) => void }) {
  const [rows, setRows] = React.useState<{ id?: string; deadline: string; price: string; order?: number }[]>([]);
  const [open, setOpen] = React.useState(false);
  const [saving, setSaving] = React.useState(false);

  React.useEffect(() => {
    const tiers = Array.isArray(option?.earlyBirdTiers) ? option.earlyBirdTiers : [];
    const normalized = tiers
      .slice()
      .sort((a: any, b: any) => new Date(a.deadline).getTime() - new Date(b.deadline).getTime() || (a.order || 0) - (b.order || 0))
      .map((t: any, i: number) => ({ id: t.id, deadline: toLocalDateTimeInputValue(t.deadline), price: String(t.price ?? ''), order: typeof t.order === 'number' ? t.order : i }));
    setRows(normalized);
  }, [option?.id, option?.earlyBirdTiers]);

  const addRow = () => {
    setRows((r) => [...r, { deadline: '', price: '', order: (r.length || 0) }]);
  };
  const removeRow = (idx: number) => {
    const copy = rows.slice();
    copy.splice(idx, 1);
    setRows(copy);
  };
  const updateRow = (idx: number, patch: Partial<{ deadline: string; price: string; order?: number }>) => {
    const copy = rows.slice();
    copy[idx] = { ...copy[idx], ...patch } as any;
    setRows(copy);
  };

  const save = async () => {
    setSaving(true);
    try {
      const tiers = rows
        .filter((r) => !!r.deadline && String(r.price).trim() !== '')
        .map((r, i) => ({ deadline: new Date(r.deadline).toISOString(), price: parseFloat(r.price), order: typeof r.order === 'number' ? r.order : i }))
        .filter((t) => t.price >= 0 && !isNaN(new Date(t.deadline).getTime()));
      onSave(tiers);
    } finally {
      setSaving(false);
    }
  };

  return (
    <div className="mt-3 border-t pt-3">
      <button type="button" className="text-xs px-2 py-1 rounded bg-gray-100 hover:bg-gray-200" onClick={() => setOpen(!open)}>
        {open ? 'Hide early-bird tiers' : 'Manage early-bird tiers'}
      </button>
      {open && (
        <div className="mt-2 bg-gray-50 border rounded p-2">
          {rows.length === 0 ? (
            <div className="text-xs text-gray-600 mb-2">No tiers yet. Add deadlines and prices for early-bird discounts.</div>
          ) : (
            <ul className="space-y-2 mb-2">
              {rows.map((row, idx) => (
                <li key={idx} className="bg-white border rounded p-2">
                  <div className="flex flex-wrap items-center gap-2">
                    <input className="border rounded px-2 py-1 text-xs" type="datetime-local" value={row.deadline} onChange={(e) => updateRow(idx, { deadline: e.target.value })} />
                    <input className="border rounded px-2 py-1 text-xs w-24" type="number" step="0.01" value={row.price} onChange={(e) => updateRow(idx, { price: e.target.value })} placeholder="Price" />
                    <input className="border rounded px-2 py-1 text-xs w-16" type="number" step="1" value={typeof row.order === 'number' ? String(row.order) : ''} onChange={(e) => updateRow(idx, { order: parseInt(e.target.value || '0', 10) })} placeholder="#" />
                    <button type="button" className="text-xs px-2 py-1 rounded bg-red-600 text-white hover:bg-red-700" onClick={() => removeRow(idx)}>Remove</button>
                  </div>
                </li>
              ))}
            </ul>
          )}
          <div className="flex items-center gap-2">
            <button type="button" className="text-xs px-2 py-1 rounded bg-brand-600 text-white hover:bg-brand-700" onClick={addRow}>Add tier</button>
            <button type="button" className="text-xs px-2 py-1 rounded bg-brand-600 text-white hover:bg-brand-700 disabled:opacity-60" onClick={save} disabled={saving}>{saving ? 'Saving…' : 'Save tiers'}</button>
          </div>
        </div>
      )}
    </div>
  );
}

function EventOptionsContent() {
  const { user, loading, token } = useAuth();
  const router = useRouter();
  const search = useSearchParams();

  const canView = useMemo(() => {
    const role = user?.role;
    return role === "admin" || role === "supervisor";
  }, [user]);

  useEffect(() => {
    if (loading) return;
    if (!user) router.replace("/login");
  }, [user, loading, router]);

  const [events, setEvents] = useState<any[]>([]);
  const [selectedEventId, setSelectedEventId] = useState<string>("");
  const [options, setOptions] = useState<any[]>([]);
  const [loadingEv, setLoadingEv] = useState(false);
  const [error, setError] = useDismissingState<string | null>(null);
  const [info, setInfo] = useDismissingState<string | null>(null);

  const loadEvents = async () => {
    if (!token) return;
    try {
      setLoadingEv(true);
      const evs = await apiFetch<any[]>("/api/events/all", { authToken: token });
      setEvents(evs || []);
    } catch (e) {
      // ignore
    } finally {
      setLoadingEv(false);
    }
  };

  useEffect(() => { loadEvents(); }, [token]);

  // Preselect event from query (?eventId=)
  useEffect(() => {
    const q = search?.get("eventId");
    if (!q) return;
    // if events already loaded, ensure it exists then set; otherwise, set directly and let options hook handle
    setSelectedEventId(q);
  }, [search]);

  useEffect(() => {
    const ev = events.find(e => e.id === selectedEventId);
    if (ev) {
      setOptions(ev.options || ev.eventOptions || []);
    } else {
      setOptions([]);
    }
  }, [selectedEventId, events]);

  const [newOpt, setNewOpt] = useState({ name: "", price: "", isMainTicket: false });

  const createOption = async () => {
    if (!token || !selectedEventId) return;
    setError(null); setInfo(null);
    if (!newOpt.name) { setError("Option name is required"); return; }
    const priceNum = parseFloat(newOpt.price || "0");
    try {
      await apiFetch(`/api/events/${encodeURIComponent(selectedEventId)}/options`, {
        method: "POST",
        authToken: token,
        body: { name: newOpt.name, price: priceNum || 0, isMainTicket: !!newOpt.isMainTicket }
      });
      setNewOpt({ name: "", price: "", isMainTicket: false });
      setInfo("Option created");
      await loadEvents();
    } catch (e: any) {
      setError(e?.message || "Failed to create option");
    }
  };

  const updateOption = async (opt: any, patch: any) => {
    if (!token) return;
    setError(null); setInfo(null);
    try {
      await apiFetch(`/api/events/options/${encodeURIComponent(opt.id)}`, {
        method: "PUT",
        authToken: token,
        body: patch
      });
      setInfo("Option updated");
      await loadEvents();
    } catch (e: any) {
      setError(e?.message || "Failed to update option");
    }
  };

  const deleteOption = async (opt: any) => {
    if (!token) return;
    setError(null); setInfo(null);
    try {
      await apiFetch(`/api/events/options/${encodeURIComponent(opt.id)}`, {
        method: "DELETE",
        authToken: token,
      });
      setInfo("Option deleted");
      await loadEvents();
    } catch (e: any) {
      setError(e?.message || "Failed to delete option");
    }
  };

  return (
    <div className="max-w-5xl mx-auto w-full p-6">
      <div className="flex items-center justify-between mb-4 flex-wrap gap-3">
        <div className="flex items-center gap-3">
          <div className="w-10 h-10 rounded-xl bg-brand-50 flex items-center justify-center shrink-0">
            <Ticket className="w-5 h-5 text-brand-600" />
          </div>
          <h1 className="text-2xl font-semibold text-gray-900">Event options</h1>
        </div>
        <button className="px-3 py-1.5 text-sm rounded-lg bg-gray-100 hover:bg-gray-200 text-gray-800 shadow-sm" onClick={() => router.push('/dashboard/supervisor/events')}>Back</button>
      </div>

      {!canView && (
        <div className="p-3 border rounded bg-yellow-50 text-yellow-800 text-sm mb-4">
          You need supervisor or admin access to use this page.
        </div>
      )}

      {error && <div className="p-3 mb-3 border rounded bg-red-50 text-red-700 text-sm">{error}</div>}
      {info && <div className="p-3 mb-3 border rounded bg-emerald-50 text-emerald-800 text-sm">{info}</div>}

      <div className="border rounded-xl p-4 bg-white shadow-sm mb-6">
        <div className="text-lg font-semibold mb-3">Select event</div>
        <select className="w-full border rounded px-3 py-2 text-sm" value={selectedEventId} onChange={e => setSelectedEventId(e.target.value)}>
          <option value="">Select an event…</option>
          {events.map(ev => (
            <option key={ev.id} value={ev.id}>{ev.title}</option>
          ))}
        </select>
        {selectedEventId && (
          <div className="mt-3 text-xs text-gray-600">
            {(() => {
              const ev = events.find(e => e.id === selectedEventId);
              if (!ev) return null;
              return <>
                <div>{new Date(ev.startDate).toLocaleString()} - {new Date(ev.endDate).toLocaleString()}</div>
              </>;
            })()}
          </div>
        )}
      </div>

      {selectedEventId && (
        <div className="grid lg:grid-cols-3 gap-6">
          <div className="lg:col-span-2 border rounded-xl p-4 bg-white shadow-sm">
            <div className="text-lg font-semibold mb-3">Options</div>
            {options.length === 0 ? (
              <div className="text-sm text-gray-500">No options yet.</div>
            ) : (
              <ul className="space-y-3">
                {options.map(opt => (
                  <li key={opt.id} className="border rounded p-3">
                    <div className="flex items-center justify-between gap-3">
                      <div>
                        <div className="font-medium text-sm">{opt.name}</div>
                        <div className="text-xs text-gray-500">Price: R {(opt.price || 0).toFixed(2)} {opt.isMainTicket ? "• Main ticket" : ""}</div>
                      </div>
                      <div className="flex items-center gap-2">
                        <input className="w-36 border rounded px-2 py-1 text-sm" defaultValue={opt.name} onBlur={e => { const v = e.target.value.trim(); if (v && v !== opt.name) updateOption(opt, { name: v }); }} />
                        <input className="w-28 border rounded px-2 py-1 text-sm" type="number" step="0.01" defaultValue={(opt.price || 0)} onBlur={e => { const v = parseFloat(e.target.value || '0'); if (!isNaN(v) && v !== opt.price) updateOption(opt, { price: v }); }} />
                        <label className="text-xs flex items-center gap-1"><input type="checkbox" defaultChecked={!!opt.isMainTicket} onChange={e => updateOption(opt, { isMainTicket: e.target.checked })} /> Main</label>
                        {user?.role === 'admin' && (
                          <button onClick={() => deleteOption(opt)} className="text-xs px-2 py-1 rounded bg-red-600 text-white hover:bg-red-700">
                            Delete
                          </button>
                        )}
                      </div>
                    </div>
                    {/* Early Bird Tiers Editor */}
                    <EarlyBirdTiersEditor
                      option={opt}
                      onSave={(tiers) => updateOption(opt, { earlyBirdTiers: tiers })}
                    />
                  </li>
                ))}
              </ul>
            )}
          </div>

          <div className="border rounded-xl p-4 bg-white shadow-sm">
            <div className="text-lg font-semibold mb-3">Create new option</div>
            <div className="grid gap-2">
              <input className="border rounded px-3 py-2 text-sm" placeholder="Name" value={newOpt.name} onChange={e => setNewOpt({ ...newOpt, name: e.target.value })} />
              <input className="border rounded px-3 py-2 text-sm" placeholder="Price" type="number" step="0.01" value={newOpt.price} onChange={e => setNewOpt({ ...newOpt, price: e.target.value })} />
              <label className="text-sm flex items-center gap-2"><input type="checkbox" checked={newOpt.isMainTicket} onChange={e => setNewOpt({ ...newOpt, isMainTicket: e.target.checked })} /> Main ticket</label>
              <button onClick={createOption} className="px-3 py-1.5 text-sm rounded bg-brand-600 text-white hover:bg-brand-700 shadow-sm">Create option</button>
            </div>
          </div>
        </div>
      )}
    </div>
  );
}

export default function EventOptionsPage() {
  return (
    <Suspense fallback={<div className="p-6">Loading...</div>}>
      <EventOptionsContent />
    </Suspense>
  );
}