MeetUp/src/app/api/event/[eventID]/participant/route.ts

import { prisma } from '@/prisma';
import { auth } from '@/auth';
import { NextResponse } from 'next/server';
import { z } from 'zod/v4';
import { userIdSchema } from '@/lib/validation/user';

const postParticipantSchema = z.object({
  userId: userIdSchema,
});

/**
 * @swagger
 * /api/event/{eventID}/participant:
 *   get:
 *     summary: Get participants of an event
 *     description: Returns all participants of a specific event.
 *     tags:
 *      - Event_Participant
 *     parameters:
 *       - in: path
 *         name: eventID
 *         required: true
 *         schema:
 *           type: string
 *         description: The ID of the event.
 *     responses:
 *       200:
 *         description: List of participants for the event.
 *         content:
 *           application/json:
 *             schema:
 *               type: object
 *               properties:
 *                 success:
 *                   type: boolean
 *                 participants:
 *                   type: array
 *                   items:
 *                     $ref: '#/components/schemas/Participant'
 *       401:
 *         description: Not authenticated.
 *         content:
 *           application/json:
 *             schema:
 *               $ref: '#/components/schemas/ErrorResponse'
 *             example:
 *               success: false
 *               message: Not authenticated
 *       404:
 *         description: User not found.
 *         content:
 *           application/json:
 *             schema:
 *               $ref: '#/components/schemas/ErrorResponse'
 *             example:
 *               success: false
 *               message: User not found
 *       403:
 *         description: User is not a participant or organizer of this event.
 *         content:
 *           application/json:
 *             schema:
 *               $ref: '#/components/schemas/ErrorResponse'
 *             example:
 *               success: false
 *               message: User is not a participant or organizer of this event
 */
export const GET = auth(async (req, { params }) => {
  if (!req.auth)
    return NextResponse.json(
      { success: false, message: 'Not authenticated' },
      { status: 401 },
    );
  if (!req.auth.user || !req.auth.user.id)
    return NextResponse.json(
      { success: false, message: 'User not found' },
      { status: 404 },
    );

  const dbUser = await prisma.user.findUnique({
    where: {
      id: req.auth.user.id,
    },
  });

  if (!dbUser) {
    return NextResponse.json(
      { success: false, message: 'User not found' },
      { status: 404 },
    );
  }

  const eventID = (await params).eventID;

  const isParticipant = await prisma.meetingParticipant.findFirst({
    where: {
      meeting_id: eventID,
      user_id: dbUser.id,
    },
  });

  const isOrganizer = await prisma.meeting.findFirst({
    where: {
      id: eventID,
      organizer_id: dbUser.id,
    },
  });

  if (!isParticipant && !isOrganizer) {
    return NextResponse.json(
      {
        success: false,
        message: 'User is not a participant or organizer of this event',
      },
      { status: 403 },
    );
  }

  const participants = await prisma.meetingParticipant.findMany({
    where: {
      meeting_id: eventID,
    },
    select: {
      user: {
        select: {
          id: true,
          name: true,
        },
      },
      status: true,
    },
  });

  return NextResponse.json({
    success: true,
    participants,
  });
});

/**
 * @swagger
 * /api/event/{eventID}/participant:
 *   post:
 *     summary: Add a participant to an event
 *     description: Adds a user as a participant to a specific event.
 *     tags:
 *      - Event_Participant
 *     parameters:
 *       - in: path
 *         name: eventID
 *         required: true
 *         schema:
 *           type: string
 *         description: The ID of the event.
 *     requestBody:
 *       required: true
 *       content:
 *         application/json:
 *           schema:
 *             type: object
 *             properties:
 *               userId:
 *                 type: string
 *                 description: The ID of the user to add as a participant.
 *     responses:
 *       200:
 *         description: Participant added successfully.
 *         content:
 *           application/json:
 *             schema:
 *               type: object
 *               properties:
 *                 success:
 *                   type: boolean
 *                 participant:
 *                   $ref: '#/components/schemas/Participant'
 *       400:
 *         description: Bad request due to invalid input data.
 *         content:
 *          application/json:
 *            schema:
 *              $ref: '#/components/schemas/ErrorResponse'
 *             example:
 *               success: false
 *               message: 'Invalid input data'
 *       401:
 *         description: Not authenticated.
 *         content:
 *           application/json:
 *             schema:
 *               $ref: '#/components/schemas/ErrorResponse'
 *             example:
 *               success: false
 *               message: Not authenticated
 *       404:
 *         description: User not found.
 *         content:
 *           application/json:
 *             schema:
 *               $ref: '#/components/schemas/ErrorResponse'
 *             example:
 *               success: false
 *               message: User not found
 *       403:
 *         description: Only organizers can add participants.
 *         content:
 *           application/json:
 *             schema:
 *               $ref: '#/components/schemas/ErrorResponse'
 *             example:
 *               success: false
 *               message: Only organizers can add participants
 *       409:
 *         description: User is already a participant of this event.
 *         content:
 *           application/json:
 *             schema:
 *               $ref: '#/components/schemas/ErrorResponse'
 *             example:
 *               success: false
 *               message: User is already a participant of this event
 */
export const POST = auth(async (req, { params }) => {
  if (!req.auth)
    return NextResponse.json(
      { success: false, message: 'Not authenticated' },
      { status: 401 },
    );
  if (!req.auth.user || !req.auth.user.id)
    return NextResponse.json(
      { success: false, message: 'User not found' },
      { status: 404 },
    );

  const dbUser = await prisma.user.findUnique({
    where: {
      id: req.auth.user.id,
    },
  });

  if (!dbUser) {
    return NextResponse.json(
      { success: false, message: 'User not found' },
      { status: 404 },
    );
  }

  const eventID = (await params).eventID;

  const isOrganizer = await prisma.meeting.findFirst({
    where: {
      id: eventID,
      organizer_id: dbUser.id,
    },
  });

  if (!isOrganizer) {
    return NextResponse.json(
      { success: false, message: 'Only organizers can add participants' },
      { status: 403 },
    );
  }

  const dataRaw = await req.json();
  const data = await postParticipantSchema.safeParseAsync(dataRaw);
  if (!data.success) {
    return NextResponse.json(
      {
        success: false,
        message: 'Invalid request data',
        errors: data.error.issues,
      },
      { status: 400 },
    );
  }
  const { userId } = data.data;

  const participantExists = await prisma.meetingParticipant.findFirst({
    where: {
      meeting_id: eventID,
      user_id: userId,
    },
  });

  if (participantExists) {
    return NextResponse.json(
      {
        success: false,
        message: 'User is already a participant of this event',
      },
      { status: 409 },
    );
  }

  const newParticipant = await prisma.meetingParticipant.create({
    data: {
      meeting_id: eventID,
      user_id: userId,
    },
    include: {
      user: true,
    },
  });

  return NextResponse.json({
    success: true,
    participant: {
      user: {
        id: newParticipant.user.id,
        name: newParticipant.user.name,
      },
      status: newParticipant.status,
    },
  });
});