package net.minecraft.client.multiplayer;

import com.google.common.base.Strings;
import com.google.gson.JsonElement;
import com.google.gson.JsonParser;
import com.mojang.authlib.exceptions.MinecraftClientException;
import com.mojang.authlib.minecraft.UserApiService;
import com.mojang.authlib.minecraft.InsecurePublicKeyException.MissingException;
import com.mojang.authlib.yggdrasil.response.KeyPairResponse;
import com.mojang.authlib.yggdrasil.response.KeyPairResponse.KeyPair;
import com.mojang.logging.LogUtils;
import com.mojang.serialization.JsonOps;
import java.io.BufferedReader;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.file.Files;
import java.nio.file.Path;
import java.security.PublicKey;
import java.time.DateTimeException;
import java.time.Duration;
import java.time.Instant;
import java.util.Optional;
import java.util.UUID;
import java.util.concurrent.CompletableFuture;
import javax.annotation.Nullable;
import net.minecraft.SharedConstants;
import net.minecraft.Util;
import net.minecraft.util.Crypt;
import net.minecraft.util.CryptException;
import net.minecraft.world.entity.player.ProfileKeyPair;
import net.minecraft.world.entity.player.ProfilePublicKey;
import net.minecraftforge.api.distmarker.Dist;
import net.minecraftforge.api.distmarker.OnlyIn;
import org.slf4j.Logger;

@OnlyIn(Dist.CLIENT)
public class AccountProfileKeyPairManager implements ProfileKeyPairManager {
    private static final Logger LOGGER = LogUtils.getLogger();
    private static final Duration MINIMUM_PROFILE_KEY_REFRESH_INTERVAL = Duration.ofHours(1L);
    private static final Path PROFILE_KEY_PAIR_DIR = Path.of("profilekeys");
    private final UserApiService userApiService;
    private final Path profileKeyPairPath;
    private CompletableFuture<Optional<ProfileKeyPair>> keyPair = CompletableFuture.completedFuture(Optional.empty());
    private Instant nextProfileKeyRefreshTime = Instant.EPOCH;

    public AccountProfileKeyPairManager(UserApiService p_253640_, UUID p_254415_, Path p_253813_) {
        this.userApiService = p_253640_;
        this.profileKeyPairPath = p_253813_.resolve(PROFILE_KEY_PAIR_DIR).resolve(p_254415_ + ".json");
    }

    @Override
    public CompletableFuture<Optional<ProfileKeyPair>> prepareKeyPair() {
        this.nextProfileKeyRefreshTime = Instant.now().plus(MINIMUM_PROFILE_KEY_REFRESH_INTERVAL);
        this.keyPair = this.keyPair.thenCompose(this::readOrFetchProfileKeyPair);
        return this.keyPair;
    }

    @Override
    public boolean shouldRefreshKeyPair() {
        return this.keyPair.isDone() && Instant.now().isAfter(this.nextProfileKeyRefreshTime) ? this.keyPair.join().map(ProfileKeyPair::dueRefresh).orElse(true) : false;
    }

    private CompletableFuture<Optional<ProfileKeyPair>> readOrFetchProfileKeyPair(Optional<ProfileKeyPair> p_254074_) {
        return CompletableFuture.supplyAsync(() -> {
            if (p_254074_.isPresent() && !p_254074_.get().dueRefresh()) {
                if (!SharedConstants.IS_RUNNING_IN_IDE) {
                    this.writeProfileKeyPair(null);
                }

                return p_254074_;
            } else {
                try {
                    ProfileKeyPair profilekeypair = this.fetchProfileKeyPair(this.userApiService);
                    this.writeProfileKeyPair(profilekeypair);
                    return Optional.ofNullable(profilekeypair);
                } catch (CryptException | MinecraftClientException | IOException ioexception) {
                    LOGGER.error("Failed to retrieve profile key pair", (Throwable)ioexception);
                    this.writeProfileKeyPair(null);
                    return p_254074_;
                }
            }
        }, Util.nonCriticalIoPool());
    }

    private Optional<ProfileKeyPair> readProfileKeyPair() {
        if (Files.notExists(this.profileKeyPairPath)) {
            return Optional.empty();
        } else {
            try {
                Optional optional;
                try (BufferedReader bufferedreader = Files.newBufferedReader(this.profileKeyPairPath)) {
                    optional = ProfileKeyPair.CODEC.parse(JsonOps.INSTANCE, JsonParser.parseReader(bufferedreader)).result();
                }

                return optional;
            } catch (Exception exception) {
                LOGGER.error("Failed to read profile key pair file {}", this.profileKeyPairPath, exception);
                return Optional.empty();
            }
        }
    }

    private void writeProfileKeyPair(@Nullable ProfileKeyPair p_254227_) {
        try {
            Files.deleteIfExists(this.profileKeyPairPath);
        } catch (IOException ioexception) {
            LOGGER.error("Failed to delete profile key pair file {}", this.profileKeyPairPath, ioexception);
        }

        if (p_254227_ != null) {
            if (SharedConstants.IS_RUNNING_IN_IDE) {
                ProfileKeyPair.CODEC.encodeStart(JsonOps.INSTANCE, p_254227_).ifSuccess(p_254406_ -> {
                    try {
                        Files.createDirectories(this.profileKeyPairPath.getParent());
                        Files.writeString(this.profileKeyPairPath, p_254406_.toString());
                    } catch (Exception exception) {
                        LOGGER.error("Failed to write profile key pair file {}", this.profileKeyPairPath, exception);
                    }
                });
            }
        }
    }

    @Nullable
    private ProfileKeyPair fetchProfileKeyPair(UserApiService p_253844_) throws CryptException, IOException {
        KeyPairResponse keypairresponse = p_253844_.getKeyPair();
        if (keypairresponse != null) {
            ProfilePublicKey.Data profilepublickey$data = parsePublicKey(keypairresponse);
            return new ProfileKeyPair(
                Crypt.stringToPemRsaPrivateKey(keypairresponse.keyPair().privateKey()),
                new ProfilePublicKey(profilepublickey$data),
                Instant.parse(keypairresponse.refreshedAfter())
            );
        } else {
            return null;
        }
    }

    private static ProfilePublicKey.Data parsePublicKey(KeyPairResponse p_253834_) throws CryptException {
        KeyPair keypair = p_253834_.keyPair();
        if (keypair != null
            && !Strings.isNullOrEmpty(keypair.publicKey())
            && p_253834_.publicKeySignature() != null
            && p_253834_.publicKeySignature().array().length != 0) {
            try {
                Instant instant = Instant.parse(p_253834_.expiresAt());
                PublicKey publickey = Crypt.stringToRsaPublicKey(keypair.publicKey());
                ByteBuffer bytebuffer = p_253834_.publicKeySignature();
                return new ProfilePublicKey.Data(instant, publickey, bytebuffer.array());
            } catch (IllegalArgumentException | DateTimeException datetimeexception) {
                throw new CryptException(datetimeexception);
            }
        } else {
            throw new CryptException(new MissingException("Missing public key"));
        }
    }
}