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

export const patchParticipantSchema = z.object({
  status: z.enum(['ACCEPTED', 'DECLINED', 'TENTATIVE', 'PENDING']),
});

/**
 * @swagger
 * /api/event/{eventID}/participant/{user}:
 *   get:
 *     summary: Get a specific participant's details in an event
 *     description: Returns the details of a specific participant in an event.
 *     tags:
 *      - Event_Participant
 *     parameters:
 *       - in: path
 *         name: eventID
 *         required: true
 *         schema:
 *           type: string
 *         description: The ID of the event.
 *       - in: path
 *         name: user
 *         required: true
 *         schema:
 *           type: string
 *         description: The ID or name of the user.
 *     responses:
 *       200:
 *         description: Details of the participant.
 *         content:
 *           application/json:
 *             schema:
 *               type: object
 *               properties:
 *                 success:
 *                   type: boolean
 *                 participant:
 *                   $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 user = (await params).user;

  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 participant = await prisma.meetingParticipant.findUnique({
    where: {
      meeting_id_user_id: {
        meeting_id: eventID,
        user_id: user,
      },
    },
    select: {
      user: {
        select: {
          id: true,
          name: true,
        },
      },
      status: true,
    },
  });

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

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

/**
 * @swagger
 * /api/event/{eventID}/participant/{user}:
 *   delete:
 *     summary: Remove a participant from an event
 *     description: Removes a participant from an event. Only the organizer can remove participants.
 *     tags:
 *      - Event_Participant
 *     parameters:
 *       - in: path
 *         name: eventID
 *         required: true
 *         schema:
 *           type: string
 *         description: The ID of the event.
 *       - in: path
 *         name: user
 *         required: true
 *         schema:
 *           type: string
 *         description: The ID or name of the user to be removed.
 *     responses:
 *       200:
 *         description: Participant removed successfully.
 *         content:
 *           application/json:
 *             schema:
 *               type: object
 *               properties:
 *                 success:
 *                   type: boolean
 *                 message:
 *                   type: string
 *       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 organizer can remove participants.
 *         content:
 *           application/json:
 *             schema:
 *               $ref: '#/components/schemas/ErrorResponse'
 *             example:
 *               success: false
 *               message: Only organizer can remove participants
 */
export const DELETE = 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 user = (await params).user;

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

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

  const participant = await prisma.meetingParticipant.findUnique({
    where: {
      meeting_id_user_id: {
        meeting_id: eventID,
        user_id: user,
      },
    },
  });

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

  await prisma.meetingParticipant.delete({
    where: {
      meeting_id_user_id: {
        meeting_id: eventID,
        user_id: user,
      },
    },
  });

  return NextResponse.json({
    success: true,
    message: 'Participant removed successfully',
  });
});

/**
 * @swagger
 * /api/event/{eventID}/participant/{user}:
 *   patch:
 *     summary: Update a participant's status in an event
 *     description: Updates the status of a participant in an event. Only the participant can update their own status.
 *     tags:
 *      - Event_Participant
 *     parameters:
 *       - in: path
 *         name: eventID
 *         required: true
 *         schema:
 *           type: string
 *         description: The ID of the event.
 *       - in: path
 *         name: user
 *         required: true
 *         schema:
 *           type: string
 *         description: The ID or name of the user whose status is being updated.
 *     requestBody:
 *       required: true
 *       content:
 *         application/json:
 *           schema:
 *             type: object
 *             properties:
 *               status:
 *                 type: string
 *                 enum: [accepted, declined, tentative]
 *                 description: The new status of the participant.
 *     responses:
 *       200:
 *         description: Participant status updated 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 participant can update their status.
 *         content:
 *           application/json:
 *             schema:
 *               $ref: '#/components/schemas/ErrorResponse'
 *             example:
 *               success: false
 *               message: Only participant can update their status
 */
export const PATCH = 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 user = (await params).user;

  if (dbUser.id !== user && dbUser.name !== user) {
    return NextResponse.json(
      { success: false, message: 'You can only update your own participation' },
      { status: 403 },
    );
  }

  const participant = await prisma.meetingParticipant.findUnique({
    where: {
      meeting_id_user_id: {
        meeting_id: eventID,
        user_id: dbUser.id,
      },
    },
    select: {
      user: {
        select: {
          id: true,
          name: true,
        },
      },
      status: true,
    },
  });

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

  const body = await req.json();
  const parsedBody = patchParticipantSchema.safeParse(body);
  if (!parsedBody.success) {
    return NextResponse.json(
      {
        success: false,
        message: 'Invalid request body',
        errors: parsedBody.error.issues,
      },
      { status: 400 },
    );
  }
  const { status } = parsedBody.data;

  await prisma.meetingParticipant.update({
    where: {
      meeting_id_user_id: {
        meeting_id: eventID,
        user_id: dbUser.id,
      },
    },
    data: {
      status,
    },
  });

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