package eu.dnetlib.broker.controllers;

import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.UUID;
import java.util.function.Predicate;
import java.util.regex.Pattern;

import javax.mail.internet.AddressException;
import javax.mail.internet.InternetAddress;

import org.apache.commons.lang3.StringUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.DeleteMapping;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import eu.dnetlib.broker.LiteratureBrokerServiceApplication;
import eu.dnetlib.broker.common.elasticsearch.NotificationRepository;
import eu.dnetlib.broker.common.subscriptions.MapCondition;
import eu.dnetlib.broker.common.subscriptions.NotificationFrequency;
import eu.dnetlib.broker.common.subscriptions.NotificationMode;
import eu.dnetlib.broker.common.subscriptions.Subscription;
import eu.dnetlib.broker.common.subscriptions.SubscriptionRepository;
import eu.dnetlib.common.controller.AbstractDnetController;
import io.swagger.v3.oas.annotations.Operation;
import io.swagger.v3.oas.annotations.tags.Tag;

@RestController
@RequestMapping("/api/subscriptions")
@Tag(name = LiteratureBrokerServiceApplication.TAG_SUBSCRIPTIONS)
public class SubscriptionsController extends AbstractDnetController {

	@Autowired
	private SubscriptionRepository subscriptionRepo;

	@Autowired
	private NotificationRepository notificationRepo;

	public static final Predicate<String> verifyTopic = Pattern.compile("^([a-zA-Z0-9._-]+(\\/[a-zA-Z0-9._-]+)+)|\\*$").asPredicate();
	public static final Predicate<String> verifyEmail = email -> {
		try {
			new InternetAddress(email).validate();
			return true;
		} catch (final AddressException e) {
			return false;
		}
	};

	@Operation(summary = "Return the list of subscriptions")
	@GetMapping("")
	public Iterable<Subscription> listSubscriptions() {
		return subscriptionRepo.findAll();
	}

	@Operation(summary = "Return a subscription by ID")
	@GetMapping("/{id}")
	public Subscription getSubscription(@PathVariable final String id) {
		return subscriptionRepo.findById(id).get();
	}

	@Operation(summary = "Delete a subscription by ID and its notifications")
	@DeleteMapping("/{id}")
	public void deleteSubscription(@PathVariable final String id) {
		subscriptionRepo.deleteById(id);
		notificationRepo.deleteBySubscriptionId(id);
	}

	@Operation(summary = "Perform a new subscription")
	@PostMapping("")
	public Subscription registerSubscription(@RequestBody final InSubscription inSub) {
		final Subscription sub = inSub.asSubscription();
		subscriptionRepo.save(sub);
		return sub;
	}

	@Operation(summary = "Delete all subscriptions and notifications")
	@DeleteMapping("")
	public Map<String, Object> clearSubscriptions() {
		final Map<String, Object> res = new HashMap<>();
		subscriptionRepo.deleteAll();
		notificationRepo.deleteAll();
		res.put("deleted", "all");
		return res;
	}

	@Operation(summary = "Reset the last notification date")
	@DeleteMapping("/{id}/date")
	public void deleteNotificationDate(@PathVariable final String id) {
		final Subscription s = subscriptionRepo.findById(id).get();
		s.setLastNotificationDate(null);
		subscriptionRepo.save(s);
	}

	@Operation(summary = "Reset all the last notification dates")
	@GetMapping("/resetLastNotificationDates")
	public void deleteAllNotificationDates() {
		for (final Subscription s : subscriptionRepo.findAll()) {
			s.setLastNotificationDate(null);
			subscriptionRepo.save(s);
		}
	}
}

class InSubscription {

	private String subscriber;
	private String topic;
	private NotificationFrequency frequency;
	private NotificationMode mode;
	private List<MapCondition> conditions;

	public InSubscription() {}

	public InSubscription(final String subscriber, final String topic, final NotificationFrequency frequency, final NotificationMode mode,
		final List<MapCondition> conditions) {
		this.subscriber = subscriber;
		this.topic = topic;
		this.frequency = frequency;
		this.mode = mode;
		this.conditions = conditions;
	}

	public String getSubscriber() {
		return subscriber;
	}

	public void setSubscriber(final String subscriber) {
		this.subscriber = subscriber;
	}

	public String getTopic() {
		return topic;
	}

	public void setTopic(final String topic) {
		this.topic = topic;
	}

	public NotificationFrequency getFrequency() {
		return frequency;
	}

	public void setFrequency(final NotificationFrequency frequency) {
		this.frequency = frequency;
	}

	public NotificationMode getMode() {
		return mode;
	}

	public void setMode(final NotificationMode mode) {
		this.mode = mode;
	}

	public List<MapCondition> getConditions() {
		return conditions;
	}

	public void setConditions(final List<MapCondition> conditions) {
		this.conditions = conditions;
	}

	public Subscription asSubscription() {
		if (StringUtils.isBlank(subscriber)) { throw new IllegalArgumentException("subscriber is empty"); }
		if (StringUtils.isBlank(topic)) { throw new IllegalArgumentException("topic is empty"); }

		if (!SubscriptionsController.verifyEmail.test(subscriber)) { throw new IllegalArgumentException("Invalid email: " + subscriber); }
		if (!SubscriptionsController.verifyTopic.test(topic)) { throw new IllegalArgumentException("Invalid topic: " + topic); }

		final String subscriptionId = "sub-" + UUID.randomUUID();

		return new Subscription(subscriptionId, subscriber, topic, frequency, mode, null, new Date(), conditions);
	}
}