import express, {Request, Response} from 'express';
import * as VoucherPublicService from './voucher.public.service';
import {sendServerError} from '../tickets.errors';
import {hashIp, redeemLimiter, validateLimiter} from '../tickets.ratelimit';

export const publicRouter = express.Router();

publicRouter.get('/', async (req: Request, res: Response) => {
	res.status(200).send('Nachklang e.V. Tickets API Endpoint');
});

const rateLimitGuard = (req: Request, res: Response, limiter: typeof validateLimiter): string | null => {
	const ipHash = hashIp(req.ip || '');
	if (limiter.isRateLimited(ipHash)) {
		res.status(429).send({status: 'RATE_LIMITED', message: 'Zu viele Anfragen. Bitte versuche es später erneut.'});
		return null;
	}
	return ipHash;
};

/**
 * @swagger
 * /tickets/voucher/{code}:
 *      get:
 *          summary: Validate a voucher code
 *          description: Returns status, prefill data, and eligible events (with deadline/capacity state) for a code. Rate-limited per IP.
 *          tags: [tickets]
 *          parameters:
 *              - in: path
 *                name: code
 *                required: true
 *                schema:
 *                    type: string
 *          responses:
 *              200:
 *                  description: Success
 *                  content:
 *                      application/json:
 *                          schema:
 *                              $ref: '#/components/schemas/VoucherValidation'
 *              404:
 *                  description: Unknown code
 *              429:
 *                  description: Rate limited
 */
publicRouter.get('/voucher/:code', async (req: Request, res: Response) => {
	try {
		const ipHash = rateLimitGuard(req, res, validateLimiter);
		if (!ipHash) return;
		validateLimiter.recordRequest(ipHash);

		const voucher = await VoucherPublicService.validateVoucher(req.params.code.toUpperCase());
		if (!voucher) {
			res.status(404).send({status: 'NOT_FOUND'});
			return;
		}
		res.status(200).send(voucher);
	} catch (e: any) {
		sendServerError(res, e);
	}
});

/**
 * @swagger
 * /tickets/voucher/{code}/redeem:
 *      post:
 *          summary: Redeem a voucher code
 *          description: Marks the code redeemed, records the redemption, and sends a confirmation email with an .ics attachment. Rate-limited per IP.
 *          tags: [tickets]
 *          parameters:
 *              - in: path
 *                name: code
 *                required: true
 *                schema:
 *                    type: string
 *          requestBody:
 *              required: true
 *              content:
 *                  application/json:
 *                      schema:
 *                          $ref: '#/components/schemas/RedeemRequest'
 *          responses:
 *              200:
 *                  description: Redeemed
 *              400:
 *                  description: Invalid request
 *              404:
 *                  description: Unknown code
 *              409:
 *                  description: Code already used, event no longer eligible, deadline passed, or capacity exceeded
 *              429:
 *                  description: Rate limited
 */
publicRouter.post('/voucher/:code/redeem', async (req: Request, res: Response) => {
	try {
		const ipHash = rateLimitGuard(req, res, redeemLimiter);
		if (!ipHash) return;
		redeemLimiter.recordRequest(ipHash);

		const code = req.params.code.toUpperCase();
		const {eventId, contactName, contactEmail, contactAddress, guests} = req.body || {};
		if (!eventId || !contactName || !contactEmail || !Array.isArray(guests)) {
			res.status(400).send({status: 'BAD_REQUEST', message: 'eventId, contactName, contactEmail, and guests are required'});
			return;
		}

		const result = await VoucherPublicService.redeemVoucher(code, {eventId, contactName, contactEmail, contactAddress, guests});

		switch (result.status) {
			case 'OK':
				res.status(200).send({status: 'OK', redemptionId: result.redemptionId});
				return;
			case 'NOT_FOUND':
				res.status(404).send({status: 'NOT_FOUND'});
				return;
			case 'ALREADY_USED':
				res.status(409).send({status: 'ALREADY_USED', message: 'Dieser Code wurde bereits eingelöst.'});
				return;
			case 'INVALID_EVENT':
				res.status(409).send({status: 'INVALID_EVENT', message: 'Dieses Konzert ist für diesen Code nicht verfügbar.'});
				return;
			case 'DEADLINE_PASSED':
				res.status(409).send({status: 'DEADLINE_PASSED', message: 'Die Anmeldefrist für dieses Konzert ist abgelaufen.'});
				return;
			case 'CAPACITY_EXCEEDED':
				res.status(409).send({status: 'CAPACITY_EXCEEDED', message: 'Nicht genügend freie Plätze für dieses Konzert.', spotsRemaining: result.spotsRemaining});
				return;
			case 'ADDRESS_REQUIRED':
				res.status(409).send({status: 'ADDRESS_REQUIRED', message: 'Für dieses Konzert ist eine Adresse erforderlich.'});
				return;
		}
	} catch (e: any) {
		res.status(400).send({status: 'BAD_REQUEST', message: e.message});
	}
});