/**
 * POST /api/calendars/[id]/invites - Invite-Link erstellen (nur Owner-Admin).
 * GET  /api/calendars/[id]/invites - Invite-Uebersicht (Aktiv/Abgelaufen/Verwendet).
 */
import { NextRequest, NextResponse } from 'next/server';
import { prisma } from '@/lib/db/client';
import { requireCalendarContext } from '@/lib/api/context';
import { createInviteSchema } from '@/lib/validation';
import { canManageCalendar } from '@/lib/permissions/permissions';
import {
  generateInviteToken,
  hashInviteToken,
  defaultInviteExpiry,
} from '@/lib/invites/tokens';
import { getConfig } from '@/lib/config';
import { errorResponse, forbiddenResponse } from '@/lib/api/responses';

interface RouteParams {
  params: Promise<{ id: string }>;
}

export async function POST(
  request: NextRequest,
  { params }: RouteParams,
): Promise<NextResponse> {
  try {
    const { id } = await params;
    const context = await requireCalendarContext(id);

    if (!canManageCalendar(context.user, context.calendar)) {
      return forbiddenResponse();
    }

    const body = createInviteSchema.parse(await request.json());
    const expiry = body.expiresInDays
      ? new Date(Date.now() + body.expiresInDays * 24 * 60 * 60 * 1000)
      : defaultInviteExpiry();

    // Klartext-Token wird genau einmal zurueckgegeben; in der DB
    // liegt ausschliesslich der Hash (plan.md Abschnitt 9).
    const token = generateInviteToken();
    const invite = await prisma.invite.create({
      data: {
        calendarId: id,
        tokenHash: hashInviteToken(token),
        expiresAt: expiry,
      },
      select: { id: true, expiresAt: true, createdAt: true },
    });

    return NextResponse.json(
      {
        invite,
        inviteUrl: `${getConfig().appUrl}/invite/${token}`,
      },
      { status: 201 },
    );
  } catch (error) {
    return errorResponse(error);
  }
}

export async function GET(
  _request: NextRequest,
  { params }: RouteParams,
): Promise<NextResponse> {
  try {
    const { id } = await params;
    const context = await requireCalendarContext(id);

    if (!canManageCalendar(context.user, context.calendar)) {
      return forbiddenResponse();
    }

    const invites = await prisma.invite.findMany({
      where: { calendarId: id },
      orderBy: { createdAt: 'desc' },
      select: { id: true, expiresAt: true, usedAt: true, createdAt: true },
    });

    const now = new Date();
    const summary = {
      active: invites.filter(
        (invite) =>
          invite.usedAt === null &&
          (invite.expiresAt === null || invite.expiresAt > now),
      ).length,
      expired: invites.filter(
        (invite) => invite.usedAt === null && invite.expiresAt !== null && invite.expiresAt <= now,
      ).length,
      used: invites.filter((invite) => invite.usedAt !== null).length,
    };

    return NextResponse.json({ invites, summary });
  } catch (error) {
    return errorResponse(error);
  }
}