package net.frozenorb.apiv3.model;

import com.google.common.collect.ImmutableSet;
import com.mongodb.async.client.MongoCollection;
import com.mongodb.client.result.DeleteResult;
import com.mongodb.client.result.UpdateResult;
import fr.javatic.mongo.jacksonCodec.Entity;
import fr.javatic.mongo.jacksonCodec.objectId.Id;
import lombok.Getter;
import net.frozenorb.apiv3.APIv3;
import net.frozenorb.apiv3.serialization.gson.ExcludeFromReplies;
import net.frozenorb.apiv3.unsorted.BlockingCallback;
import net.frozenorb.apiv3.util.SyncUtils;
import org.bson.Document;

import java.time.Instant;
import java.util.*;
import java.util.concurrent.TimeUnit;

@Entity
public final class Server {

    private static final MongoCollection<Server> serversCollection = APIv3.getDatabase().getCollection("servers", Server.class);

    private static Map<String, Server> serverCache = null;
    private static List<Server> serverCacheAlt = null;
    private static long serverCacheUpdated = 0;

    @Getter @Id private String id;
    @Getter private String displayName;
    @Getter @ExcludeFromReplies String apiKey;
    @Getter private String serverGroup;
    @Getter private String serverIp;
    @Getter private Instant lastUpdatedAt;
    @Getter private double lastTps;
    @Getter @ExcludeFromReplies private Set<UUID> players;

    public static List<Server> findAll() {
        updateCacheIfNeeded();
        return serverCacheAlt;
    }

    public static Server findById(String id) {
        updateCacheIfNeeded();
        return serverCache.get(id);
    }

    public Server() {} // For Jackson

    public Server(String id, String displayName, String apiKey, ServerGroup serverGroup, String serverIp) {
        this.id = id;
        this.displayName = displayName;
        this.apiKey = apiKey;
        this.serverGroup = serverGroup.getId();
        this.serverIp = serverIp;
        this.lastUpdatedAt = Instant.now();
        this.lastTps = 0;
        this.players = new HashSet<>();
    }

    private static void updateCacheIfNeeded() {
        if (serverCache == null || (System.currentTimeMillis() - serverCacheUpdated) > TimeUnit.MINUTES.toMillis(1)) {
            Map<String, Server> working = new HashMap<>();
            List<Server> workingAlt = new ArrayList<>();

            for (Server server : SyncUtils.blockMulti(serversCollection.find())) {
                working.put(server.getId(), server);
                workingAlt.add(server);
            }

            serverCache = working;
            serverCacheAlt = workingAlt;
            serverCacheUpdated = System.currentTimeMillis();
        }
    }

    public void receivedHeartbeat(double tps, Iterable<UUID> players) {
        this.lastUpdatedAt = Instant.now();
        this.lastTps = tps;
        this.players = ImmutableSet.copyOf(players);
    }

    public void insert() {
        BlockingCallback<Void> callback = new BlockingCallback<>();
        serversCollection.insertOne(this, callback);
        callback.get();
    }

    public void save() {
        BlockingCallback<UpdateResult> callback = new BlockingCallback<>();
        serversCollection.replaceOne(new Document("_id", id), this, callback);
        callback.get();
    }

    public void delete() {
        BlockingCallback<DeleteResult> callback = new BlockingCallback<>();
        serversCollection.deleteOne(new Document("_id", id), callback);
        callback.get();
    }

}