package net.frozenorb.apiv3.models;

import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
import com.fasterxml.jackson.databind.annotation.JsonSerialize;
import com.google.common.base.Charsets;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.ImmutableSet;
import com.google.common.hash.Hashing;
import com.mongodb.async.SingleResultCallback;
import com.mongodb.async.client.MongoCollection;
import com.mongodb.client.result.UpdateResult;
import fr.javatic.mongo.jacksonCodec.objectId.Id;
import lombok.AllArgsConstructor;
import lombok.Getter;
import lombok.Setter;
import net.frozenorb.apiv3.APIv3;
import net.frozenorb.apiv3.serialization.ExcludeFromReplies;
import net.frozenorb.apiv3.serialization.UUIDJsonDeserializer;
import net.frozenorb.apiv3.serialization.UUIDJsonSerializer;
import net.frozenorb.apiv3.unsorted.BlockingCallback;
import net.frozenorb.apiv3.utils.MojangUtils;
import net.frozenorb.apiv3.utils.PermissionUtils;
import net.frozenorb.apiv3.utils.SyncUtils;
import net.frozenorb.apiv3.utils.UUIDUtils;
import org.bson.Document;

import java.util.*;

@AllArgsConstructor
public final class User {

    private static final MongoCollection<User> usersCollection = APIv3.getDatabase().getCollection("users", User.class);

    @Getter @Id @JsonSerialize(using=UUIDJsonSerializer.class) @JsonDeserialize(using=UUIDJsonDeserializer.class) private UUID id;
    @Getter private String lastUsername;
    @Getter @ExcludeFromReplies private Map<String, Date> aliases = new HashMap<>();
    @Getter @ExcludeFromReplies @Setter private String totpSecret;
    @Getter @ExcludeFromReplies @Setter private String emailToken;
    @Getter @ExcludeFromReplies @Setter private Date emailTokenSetAt;
    @Getter @ExcludeFromReplies private String password;
    @Getter @Setter private String email;
    @Getter private String phoneNumber;
    @Getter private String lastSeenOn;
    @Getter private Date lastSeenAt;
    @Getter private Date firstSeenAt;
    @Getter private boolean online;

    public static List<User> findAllSync() {
        return SyncUtils.blockMulti(usersCollection.find());
    }

    public static User findByIdSync(String id) {
        UUID uuid;

        try {
            uuid = UUID.fromString(id);
        } catch (IllegalArgumentException ex) {
            return null;
        }

        return findByIdSync(uuid);
    }

    public static User findByIdSync(UUID id) {
        if (UUIDUtils.isAcceptableUUID(id)) {
            return SyncUtils.blockOne(usersCollection.find(new Document("_id", id)));
        } else {
            return null;
        }
    }

    public static User findByEmailTokenSync(String emailToken) {
        return SyncUtils.blockOne(usersCollection.find(new Document("emailToken", emailToken)));
    }

    public static User findByLastUsernameSync(String lastUsername) {
        return SyncUtils.blockOne(usersCollection.find(new Document("lastUsername", lastUsername)));
    }

    public static void findAll(SingleResultCallback<List<User>> callback) {
        usersCollection.find().into(new ArrayList<>(), callback);
    }

    public static void findById(String id, SingleResultCallback<User> callback) {
        try {
            UUID uuid = UUID.fromString(id);
            findById(uuid, callback);
        } catch (IllegalArgumentException ex) { // from UUID parsing
            callback.onResult(null, ex);
        }
    }

    public static void findById(UUID id, SingleResultCallback<User> callback) {
        if (UUIDUtils.isAcceptableUUID(id)) {
            usersCollection.find(new Document("_id", id)).first(callback);
        } else {
            callback.onResult(null, null);
        }
    }

    public static void findByIdGrouped(Iterable<UUID> search, SingleResultCallback<Map<UUID, User>> callback) {
        usersCollection.find(new Document("_id", new Document("$in", search))).into(new ArrayList<>(), (users, error) -> {
            if (error != null) {
                callback.onResult(null, error);
            } else {
                Map<UUID, User> result = new HashMap<>();

                for (UUID user : search) {
                    result.put(user, null);
                }

                for (User user : users) {
                    result.put(user.getId(), user);
                }

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

    public static void findByEmailToken(String emailToken, SingleResultCallback<User> callback) {
        usersCollection.find(new Document("emailToken", emailToken)).first(callback);
    }

    public static void findByLastUsername(String lastUsername, SingleResultCallback<User> callback) {
        usersCollection.find(new Document("lastUsername", lastUsername)).first(callback);
    }

    public User() {} // For Morphia

    public User(UUID id, String lastUsername) {
        this.id = id;
        this.lastUsername = ""; // Intentional, so updateUsername actually does something.
        this.aliases = new HashMap<>();
        this.totpSecret = null;
        this.password = null;
        this.email = null;
        this.phoneNumber = null;
        this.lastSeenOn = null;
        this.lastSeenAt = new Date();
        this.firstSeenAt = new Date();

        updateUsername(lastUsername);
    }

    public boolean hasPermissionAnywhere(String permission) {
        Map<String, Boolean> globalPermissions = PermissionUtils.getDefaultPermissions(getHighestRankAnywhere());

        for (Map.Entry<ServerGroup, Rank> serverGroupEntry : getHighestRanks().entrySet()) {
            ServerGroup serverGroup = serverGroupEntry.getKey();
            Rank rank = serverGroupEntry.getValue();

            globalPermissions = PermissionUtils.mergePermissions(
                    globalPermissions,
                    serverGroup.calculatePermissions(rank)
            );
        }

        return globalPermissions.containsKey(permission) && globalPermissions.get(permission);
    }

    // TODO: Clean
    public boolean seenOnServer(Server server) {
        if (online && server.getId().equals(this.lastSeenOn)) {
            return false;
        }

        this.lastSeenOn = server.getId();

        if (!online) {
            this.lastSeenAt = new Date();
        }

        this.online = true;
        return true;
    }

    public void leftServer() {
        this.lastSeenAt = new Date();
        this.online = false;
    }

    public void updateUsername(String username) {
        if (!username.equals(lastUsername)) {
            this.lastUsername = username;

            User withNewUsername;

            while ((withNewUsername = User.findByLastUsernameSync(username)) != null) {
                BlockingCallback<String> callback = new BlockingCallback<>();
                MojangUtils.getName(withNewUsername.getId(), callback);
                String newUsername = callback.get();
                withNewUsername.updateUsername(newUsername);
            }
        }

        this.aliases.put(username, new Date());
    }

    public void setPassword(String input) {
        this.password = Hashing
                .sha256()
                .hashString(input + "$" + id.toString(), Charsets.UTF_8)
                .toString();
    }

    public boolean checkPassword(String input) {
        String hashed = Hashing
                .sha256()
                .hashString(input + "$" + id.toString(), Charsets.UTF_8)
                .toString();

        return hashed.equals(password);
    }

    public Rank getHighestRankAnywhere() {
        return getHighestRankScoped(null);
    }

    public Rank getHighestRankScoped(ServerGroup serverGroup) {
        return getHighestRankScoped(serverGroup, Grant.findByUserSync(this));
    }

    // TODO: Clean
    // This is only used to help batch requests to mongo
    public Rank getHighestRankScoped(ServerGroup serverGroup, Iterable<Grant> grants) {
        Rank highest = null;

        for (Grant grant : grants) {
            if (!grant.isActive() || (serverGroup != null && !grant.appliesOn(serverGroup))) {
                continue;
            }

            Rank rank = Rank.findById(grant.getRank());

            if (highest == null || rank.getWeight() > highest.getWeight()) {
                highest = rank;
            }
        }

        if (highest != null) {
            return highest;
        } else {
            return Rank.findById("default");
        }
    }

    // TODO: Clean
    public Map<ServerGroup, Rank> getHighestRanks() {
        Map<ServerGroup, Rank> highestRanks = new HashMap<>();
        Rank defaultRank = Rank.findById("default");
        List<Grant> userGrants = Grant.findByUserSync(this);

        for (ServerGroup serverGroup : ServerGroup.findAll()) {
            Rank highest = defaultRank;

            for (Grant grant : userGrants) {
                if (!grant.isActive() || !grant.appliesOn(serverGroup)) {
                    continue;
                }

                Rank rank = Rank.findById(grant.getRank());

                if (highest == null || rank.getWeight() > highest.getWeight()) {
                    highest = rank;
                }
            }

            highestRanks.put(serverGroup, highest);
        }

        return highestRanks;
    }

    public Map<String, Object> getLoginInfo(Server server) {
        return createLoginInfo(
                server,
                Punishment.findByUserAndTypeSync(this, ImmutableSet.of(
                    Punishment.PunishmentType.BLACKLIST,
                    Punishment.PunishmentType.BAN,
                    Punishment.PunishmentType.MUTE
                )),
                Grant.findByUserSync(this)
            );
    }

    // This is only used to help batch requests to mongo
    public Map<String, Object> createLoginInfo(Server server, Iterable<Punishment> punishments, Iterable<Grant> grants) {
        Punishment activeMute = null;
        String accessDenialReason = null;

        for (Punishment punishment : punishments) {
            if (!punishment.isActive()) {
                continue;
            }

            if (punishment.getType() == Punishment.PunishmentType.MUTE) {
                activeMute = punishment;
            } else {
                accessDenialReason = punishment.getAccessDenialReason();
            }
        }

        Rank highestRank = getHighestRankScoped(ServerGroup.findById(server.getServerGroup()), grants);

        // Generics are weird, yes we have to do this.
        ImmutableMap.Builder<String, Object> result = ImmutableMap.<String, Object>builder()
                .put("user", this)
                .put("access", ImmutableMap.of(
                        "allowed", accessDenialReason == null,
                        "message", accessDenialReason == null ? "Public server" : accessDenialReason
                ))
                .put("rank", highestRank.getId())
                .put("totpSetup", getTotpSecret() != null);

        if (activeMute != null) {
            result.put("mute", activeMute);
        }

        return result.build();
    }

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

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

}