#!/usr/bin/env python
#
# Copyright (c) 2016 Cisco and/or its affiliates.
# Licensed 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.

import os

import callback_gen
import util
from string import Template

notification_registry_template = Template("""
package $plugin_package.$notification_package;

/**
 * <p>Registry for notification callbacks defined in ${plugin_name}.
 * <br>It was generated by notification_gen.py based on $inputfile
 * <br>(python representation of api file generated by vppapigen).
 */
public interface ${plugin_name}EventRegistry extends $base_package.$notification_package.EventRegistry {

    $register_callback_methods

    @Override
    void close();
}
""")

global_notification_callback_template = Template("""
package $plugin_package.$notification_package;

/**
 * <p>Aggregated callback interface for notifications only.
 * <br>It was generated by notification_gen.py based on $inputfile
 * <br>(python representation of api file generated by vppapigen).
 */
public interface Global${plugin_name}EventCallback$callbacks {

}
""")

notification_registry_impl_template = Template("""
package $plugin_package.$notification_package;

/**
 * <p>Notification registry delegating notification processing to registered callbacks.
 * <br>It was generated by notification_gen.py based on $inputfile
 * <br>(python representation of api file generated by vppapigen).
 */
public final class ${plugin_name}EventRegistryImpl implements ${plugin_name}EventRegistry, Global${plugin_name}EventCallback {

    // TODO add a special NotificationCallback interface and only allow those to be registered
    private final java.util.concurrent.ConcurrentMap<Class<?>, $base_package.$callback_package.JVppCallback> registeredCallbacks =
        new java.util.concurrent.ConcurrentHashMap<>();
    private static java.util.logging.Logger LOG = java.util.logging.Logger.getLogger(${plugin_name}EventRegistryImpl.class.getName());

    $register_callback_methods
    $handler_methods

    @Override
    public void close() {
        registeredCallbacks.clear();
    }

    @Override
    public void onError(io.fd.vpp.jvpp.VppCallbackException ex) {
        java.util.logging.Logger LOG = java.util.logging.Logger.getLogger(${plugin_name}EventRegistryImpl.class.getName());
        LOG.log(java.util.logging.Level.WARNING, String.format("Received onError exception: call=%s, context=%d, retval=%d%n", ex.getMethodName(),
            ex.getCtxId(), ex.getErrorCode()), ex);
    }
}
""")

register_callback_impl_template = Template("""
    public java.lang.AutoCloseable register$callback(final $plugin_package.$callback_package.$callback callback){
        if(null != registeredCallbacks.putIfAbsent($plugin_package.$dto_package.$notification.class, callback)){
            throw new IllegalArgumentException("Callback for " + $plugin_package.$dto_package.$notification.class +
                "notification already registered");
        }
        return () -> registeredCallbacks.remove($plugin_package.$dto_package.$notification.class);
    }
""")

handler_impl_template = Template("""
    @Override
    public void on$notification(
        final $plugin_package.$dto_package.$notification_reply notification) {
        if (LOG.isLoggable(java.util.logging.Level.FINE)) {
            LOG.fine(String.format("Received $notification event message: %s", notification));
        }
        final $base_package.$callback_package.JVppCallback jVppCallback = registeredCallbacks.get($plugin_package.$dto_package.$notification.class);
        if (null != jVppCallback) {
            (($plugin_package.$callback_package.$callback) registeredCallbacks
                .get($plugin_package.$dto_package.$notification.class))
                .on$notification(notification);
        }
    }
""")

notification_provider_template = Template("""
package $plugin_package.$notification_package;

 /**
 * Provides ${plugin_name}EventRegistry.
 * <br>The file was generated by notification_gen.py based on $inputfile
 * <br>(python representation of api file generated by vppapigen).
 */
public interface ${plugin_name}EventRegistryProvider extends $base_package.$notification_package.EventRegistryProvider {

    @Override
    public ${plugin_name}EventRegistry getEventRegistry();
}
""")


def generate_notification_registry(func_list, base_package, plugin_package, plugin_name, notification_package,
                                   callback_package, dto_package, inputfile, logger):
    """ Generates notification registry interface and implementation """
    logger.debug("Generating Notification interfaces and implementation for %s" % inputfile)

    if not os.path.exists(notification_package):
        os.mkdir(notification_package)

    callbacks = []
    register_callback_methods = []
    register_callback_methods_impl = []
    handler_methods = []
    for func in func_list:
        camel_case_name_with_suffix = util.underscore_to_camelcase_upper(func['name'])

        if util.is_control_ping(camel_case_name_with_suffix):
            # Skip control ping managed by jvpp registry.
            continue
        if util.is_dump(func['name']) or util.is_request(func['name'], func_list):
            continue

        # Generate callbacks for all messages except for dumps and requests (handled by vpp, not client).
        notification_dto = camel_case_name_with_suffix
        callback_ifc = camel_case_name_with_suffix + callback_gen.callback_suffix
        fully_qualified_callback_ifc = "{0}.{1}.{2}".format(plugin_package, callback_package, callback_ifc)
        callbacks.append(fully_qualified_callback_ifc)

        # TODO create NotificationListenerRegistration and return that instead of AutoCloseable to better indicate
        # that the registration should be closed
        register_callback_methods.append("java.lang.AutoCloseable register{0}({1} callback);"
                                         .format(callback_ifc, fully_qualified_callback_ifc))
        register_callback_methods_impl.append(register_callback_impl_template.substitute(plugin_package=plugin_package,
                                                                                         callback_package=callback_package,
                                                                                         dto_package=dto_package,
                                                                                         notification=camel_case_name_with_suffix,
                                                                                         callback=callback_ifc))
        handler_methods.append(handler_impl_template.substitute(base_package=base_package,
                                                                plugin_package=plugin_package,
                                                                callback_package=callback_package,
                                                                dto_package=dto_package,
                                                                notification=notification_dto,
                                                                notification_reply=camel_case_name_with_suffix,
                                                                callback=callback_ifc))

    callback_file = open(os.path.join(notification_package, "%sEventRegistry.java" % plugin_name), 'w')
    callback_file.write(notification_registry_template.substitute(inputfile=inputfile,
                                                                register_callback_methods="\n    ".join(register_callback_methods),
                                                                base_package=base_package,
                                                                plugin_package=plugin_package,
                                                                plugin_name=plugin_name,
                                                                notification_package=notification_package))
    callback_file.flush()
    callback_file.close()

    callback_file = open(os.path.join(notification_package, "Global%sEventCallback.java" % plugin_name), 'w')

    global_notification_callback_callbacks = ""
    if callbacks:
        global_notification_callback_callbacks = " extends " + ", ".join(callbacks)

    callback_file.write(global_notification_callback_template.substitute(inputfile=inputfile,
                                                                       callbacks=global_notification_callback_callbacks,
                                                                       plugin_package=plugin_package,
                                                                       plugin_name=plugin_name,
                                                                       notification_package=notification_package))
    callback_file.flush()
    callback_file.close()

    callback_file = open(os.path.join(notification_package, "%sEventRegistryImpl.java" % plugin_name), 'w')
    callback_file.write(notification_registry_impl_template.substitute(inputfile=inputfile,
                                                                     callback_package=callback_package,
                                                                     dto_package=dto_package,
                                                                     register_callback_methods="".join(register_callback_methods_impl),
                                                                     handler_methods="".join(handler_methods),
                                                                     base_package=base_package,
                                                                     plugin_package=plugin_package,
                                                                     plugin_name=plugin_name,
                                                                     notification_package=notification_package))
    callback_file.flush()
    callback_file.close()

    callback_file = open(os.path.join(notification_package, "%sEventRegistryProvider.java" % plugin_name), 'w')
    callback_file.write(notification_provider_template.substitute(inputfile=inputfile,
                                                                     base_package=base_package,
                                                                     plugin_package=plugin_package,
                                                                     plugin_name=plugin_name,
                                                                     notification_package=notification_package))
    callback_file.flush()
    callback_file.close()