/*
 * Copyright 2014-2018 Groupon, Inc
 * Copyright 2014-2018 The Billing Project, LLC
 *
 * The Billing Project licenses this file to you under the Apache License, version 2.0
 * (the "License"); you may not use this file except in compliance with the
 * License.  You may obtain a copy of the License at:
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
 * License for the specific language governing permissions and limitations
 * under the License.
 */

package org.killbill.billing.payment.caching;

import java.io.ByteArrayInputStream;
import java.io.InputStream;

import javax.inject.Inject;
import javax.inject.Named;

import org.killbill.automaton.DefaultStateMachineConfig;
import org.killbill.automaton.StateMachineConfig;
import org.killbill.billing.ErrorCode;
import org.killbill.billing.ObjectType;
import org.killbill.billing.callcontext.InternalTenantContext;
import org.killbill.billing.payment.api.PaymentApiException;
import org.killbill.billing.payment.glue.PaymentModule;
import org.killbill.billing.tenant.api.TenantInternalApi;
// import org.killbill.billing.tenant.api.TenantInternalApi.CacheInvalidationCallback;
import org.killbill.billing.tenant.api.TenantKV.TenantKey;
// import org.killbill.billing.util.cache.Cachable.CacheType;
// import org.killbill.billing.util.cache.CacheController;
import org.killbill.billing.util.cache.CacheControllerDispatcher;
// import org.killbill.billing.util.cache.CacheLoaderArgument;
// import org.killbill.billing.util.cache.TenantStateMachineConfigCacheLoader.LoaderCallback;
import org.killbill.billing.util.callcontext.InternalCallContextFactory;
import org.killbill.xmlloader.XMLLoader;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.google.common.io.Resources;

import br.ufrgs.inf.prosoft.cache.*;

public class DefaultStateMachineConfigCache implements StateMachineConfigCache {

    private static final Logger logger = LoggerFactory.getLogger(DefaultStateMachineConfigCache.class);

public static Caffeine<String, StateMachineConfig> cacheController = new Caffeine<>("static-multi:DefaultStateMachineConfigCache.cacheController");

    // private final CacheController<String, StateMachineConfig> cacheController;
    // private final LoaderCallback loaderCallback;

    private DefaultStateMachineConfig defaultPaymentStateMachineConfig;

    private final TenantInternalApi tenantApi;

    @Inject
    public DefaultStateMachineConfigCache(final TenantInternalApi tenantInternalApi
                                          // final CacheControllerDispatcher cacheControllerDispatcher,
                                          // @Named(PaymentModule.STATE_MACHINE_CONFIG_INVALIDATION_CALLBACK) final CacheInvalidationCallback cacheInvalidationCallback
                                          ) {
        this.tenantApi = tenantInternalApi;
        // Can be null if mis-configured (e.g. missing in ehcache.xml)
        // this.cacheController = cacheControllerDispatcher.getCacheController(CacheType.TENANT_PAYMENT_STATE_MACHINE_CONFIG);
        // this.loaderCallback = new LoaderCallback() {
        //     public Object loadStateMachineConfig(final String stateMachineConfigXML) throws PaymentApiException {
        //         // tenantInternalApi.initializeCacheInvalidationCallback(TenantKey.PLUGIN_PAYMENT_STATE_MACHINE_, cacheInvalidationCallback);

        //         try {
        //             final InputStream stream = new ByteArrayInputStream(stateMachineConfigXML.getBytes());
        //             return XMLLoader.getObjectFromStream(stream, DefaultStateMachineConfig.class);
        //         } catch (final Exception e) {
        //             // TODO 0.17 proper error code
        //             throw new PaymentApiException(e, ErrorCode.PAYMENT_INTERNAL_ERROR, "Invalid payment state machine config");
        //         }
        //     }
        // };
    }

    @Override
    public void loadDefaultPaymentStateMachineConfig(final String url) throws PaymentApiException {
        if (url != null) {
            try {
                defaultPaymentStateMachineConfig = XMLLoader.getObjectFromString(Resources.getResource(url).toExternalForm(), DefaultStateMachineConfig.class);
            } catch (final Exception e) {
                // TODO 0.17 proper error code
                throw new PaymentApiException(e, ErrorCode.PAYMENT_INTERNAL_ERROR, "Invalid default payment state machine config");
            }
        }
    }

    @Override
    public StateMachineConfig getPaymentStateMachineConfig(final String pluginName, final InternalTenantContext tenantContext) throws PaymentApiException {
        if (InternalCallContextFactory.INTERNAL_TENANT_RECORD_ID.equals(tenantContext.getTenantRecordId()) ){// || cacheController == null) {
            return defaultPaymentStateMachineConfig;
        }

        final String pluginConfigKey = getCacheKeyName(pluginName, tenantContext);
        // final CacheLoaderArgument cacheLoaderArgument = createCacheLoaderArgument(pluginName);


return cacheController.computeIfAbsent(pluginConfigKey, () -> {
        try {
            final String tenantRecordId = String.valueOf(tenantContext.getTenantRecordId());

            final InternalTenantContext internalTenantContext = new InternalTenantContext(Long.valueOf(tenantRecordId));
            final String stateMachineConfigXML = tenantApi.getPluginPaymentStateMachineConfig(pluginName, internalTenantContext);
            
            if (stateMachineConfigXML == null) {
                throw new RuntimeException();
            }
            StateMachineConfig pluginPaymentStateMachineConfig = null;
            try {

                logger.info("Loading config state machine cache for pluginName='{}', tenantRecordId='{}'", pluginName, tenantContext.getTenantRecordId());
                final InputStream stream = new ByteArrayInputStream(stateMachineConfigXML.getBytes());
                pluginPaymentStateMachineConfig = XMLLoader.getObjectFromStream(stream, DefaultStateMachineConfig.class);
            // } catch (final PaymentApiException e) {
            //     throw new IllegalStateException(String.format("Failed to de-serialize state machine config for tenantRecordId='%s'", internalTenantContext.getTenantRecordId()), e);
            // }
                    } catch (final Exception e) {
                        // TODO 0.17 proper error code
                        // throw new PaymentApiException(e, ErrorCode.PAYMENT_INTERNAL_ERROR, "Invalid payment state machine config");
                        throw new RuntimeException(e);
                    }

            // It means we are using the default state machine config in a multi-tenant deployment
            if (pluginPaymentStateMachineConfig == null) {
                pluginPaymentStateMachineConfig = defaultPaymentStateMachineConfig;
            }

            ((DefaultStateMachineConfig)pluginPaymentStateMachineConfig).initialize(defaultPaymentStateMachineConfig);
            return pluginPaymentStateMachineConfig;
        } catch (final IllegalStateException e) {
            // TODO 0.17 proper error code
            // throw new PaymentApiException(e, ErrorCode.PAYMENT_INTERNAL_ERROR, "Invalid payment state machine");
            throw new RuntimeException(e);
        }
});
    }

    // See also DefaultTenantUserApi - we use the same conventions as the main XML cache (so we can re-use the invalidation code)
    private String getCacheKeyName(final String pluginName, final InternalTenantContext internalContext) {
        final StringBuilder tenantKey = new StringBuilder(TenantKey.PLUGIN_PAYMENT_STATE_MACHINE_.toString());
        tenantKey.append(pluginName);
        tenantKey.append(CacheControllerDispatcher.CACHE_KEY_SEPARATOR);
        tenantKey.append(internalContext.getTenantRecordId());
        return tenantKey.toString();
    }

    @Override
    public void clearPaymentStateMachineConfig(final String pluginName, final InternalTenantContext tenantContext) {
        if (!InternalCallContextFactory.INTERNAL_TENANT_RECORD_ID.equals(tenantContext.getTenantRecordId()) && cacheController != null) {
            final String key = getCacheKeyName(pluginName, tenantContext);
            cacheController.invalidate(key);
        }
    }

    // private CacheLoaderArgument createCacheLoaderArgument(final String pluginName) {
    //     final Object[] args = new Object[2];
    //     args[0] = loaderCallback;
    //     args[1] = pluginName;
    //     final ObjectType irrelevant = null;
    //     final InternalTenantContext notUsed = null;
    //     return new CacheLoaderArgument(irrelevant, args, notUsed);
    // }
}
