package net.frozenorb.apiv3.model;

import com.google.common.collect.Collections2;
import com.mongodb.async.SingleResultCallback;
import com.mongodb.async.client.MongoCollection;
import com.mongodb.client.result.UpdateResult;
import fr.javatic.mongo.jacksonCodec.Entity;
import fr.javatic.mongo.jacksonCodec.objectId.Id;
import lombok.AllArgsConstructor;
import lombok.Getter;
import net.frozenorb.apiv3.APIv3;
import net.frozenorb.apiv3.unsorted.BlockingCallback;
import net.frozenorb.apiv3.util.SyncUtils;
import org.bson.Document;
import org.bson.types.ObjectId;

import java.time.Instant;
import java.util.*;
import java.util.stream.Collectors;

@Entity
@AllArgsConstructor
public final class Grant {

    private static final MongoCollection<Grant> grantsCollection = APIv3.getDatabase().getCollection("grants", Grant.class);

    @Getter @Id private String id;
    @Getter private UUID user;
    @Getter private String reason;
    @Getter private Set<String> scopes;
    @Getter private String rank;
    @Getter private Instant expiresAt;

    @Getter private UUID addedBy;
    @Getter private Instant addedAt;

    @Getter private UUID removedBy;
    @Getter private Instant removedAt;
    @Getter private String removalReason;

    public static List<Grant> findAllSync() {
        return SyncUtils.blockMulti(grantsCollection.find().sort(new Document("addedAt", -1)));
    }

    public static List<Grant> findByRankSync(Collection<Rank> ranks) {
        Collection<String> convertedRanks = ranks.stream().map(Rank::getId).collect(Collectors.toList());
        return SyncUtils.blockMulti(grantsCollection.find(new Document("rank", new Document("$in", convertedRanks))));
    }

    public static Grant findByIdSync(String id) {
        return SyncUtils.blockOne(grantsCollection.find(new Document("_id", id)));
    }

    public static List<Grant> findByUserSync(User user) {
        return findByUserSync(user.getId());
    }

    public static List<Grant> findByUserSync(UUID user) {
        return SyncUtils.blockMulti(grantsCollection.find(new Document("user", user)));
    }

    public static void findAllPaginated(int skip, int pageSize, SingleResultCallback<List<Grant>> callback) {
        grantsCollection.find().sort(new Document("addedAt", -1)).skip(skip).limit(pageSize).into(new ArrayList<>(), callback);
    }

    public static void findById(String id, SingleResultCallback<Grant> callback) {
        grantsCollection.find(new Document("_id", id)).first(callback);
    }

    public static void findByUser(User user, SingleResultCallback<List<Grant>> callback) {
        findByUser(user.getId(), callback);
    }

    public static void findByUser(UUID user, SingleResultCallback<List<Grant>> callback) {
        grantsCollection.find(new Document("user", user)).into(new ArrayList<>(), callback);
    }

    public static void findByUserGrouped(Iterable<UUID> users, SingleResultCallback<Map<UUID, List<Grant>>> callback) {
        grantsCollection.find(new Document("user", new Document("$in", users))).into(new ArrayList<>(), (grants, error) -> {
            if (error != null) {
                callback.onResult(null, error);
            } else {
                Map<UUID, List<Grant>> result = new HashMap<>();

                for (UUID user : users) {
                    result.put(user, new ArrayList<>());
                }

                for (Grant grant : grants) {
                    result.get(grant.getUser()).add(grant);
                }

                callback.onResult(result, null);
            }
        });
    }

    public Grant() {} // For Jackson

    public Grant(User user, String reason, Set<ServerGroup> scopes, Rank rank, Instant expiresAt, User addedBy) {
        this.id = new ObjectId().toString();
        this.user = user.getId();
        this.reason = reason;
        this.scopes = new HashSet<>(Collections2.transform(scopes, ServerGroup::getId));
        this.rank = rank.getId();
        this.expiresAt = expiresAt;
        this.addedBy = addedBy == null ? null : addedBy.getId();
        this.addedAt = Instant.now();
    }

    public boolean isActive() {
        return !(isExpired() || isRemoved());
    }

    public boolean isExpired() {
        return expiresAt != null && expiresAt.isBefore(Instant.now());
    }

    public boolean isRemoved() {
        return removedBy != null;
    }

    public boolean appliesOn(ServerGroup serverGroup) {
        return isGlobal() || scopes.contains(serverGroup.getId());
    }

    public boolean isGlobal() {
        return scopes.isEmpty();
    }

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

    public void delete(User removedBy, String reason) {
        this.removedBy = removedBy.getId();
        this.removedAt = Instant.now();
        this.removalReason = reason;

        BlockingCallback<UpdateResult> callback = new BlockingCallback<>();
        grantsCollection.replaceOne(new Document("_id", id), this, callback);
        callback.get();
    }

}