/*
 *
 * Copyright 2015 gRPC authors.
 *
 * 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.
 *
 */

#include "php_grpc.h"

#include "call.h"
#include "channel.h"
#include "server.h"
#include "timeval.h"
#include "channel_credentials.h"
#include "call_credentials.h"
#include "server_credentials.h"
#include "completion_queue.h"
#include <ext/spl/spl_exceptions.h>
#include <zend_exceptions.h>

ZEND_DECLARE_MODULE_GLOBALS(grpc)
static PHP_GINIT_FUNCTION(grpc);
HashTable grpc_persistent_list;
HashTable grpc_target_upper_bound_map;
/* {{{ grpc_functions[]
 *
 * Every user visible function must have an entry in grpc_functions[].
 */
const zend_function_entry grpc_functions[] = {
    PHP_FE_END /* Must be the last line in grpc_functions[] */
};
/* }}} */

/* {{{ grpc_module_entry
 */
zend_module_entry grpc_module_entry = {
  STANDARD_MODULE_HEADER,
  "grpc",
  grpc_functions,
  PHP_MINIT(grpc),
  PHP_MSHUTDOWN(grpc),
  PHP_RINIT(grpc),
  NULL,
  PHP_MINFO(grpc),
  PHP_GRPC_VERSION,
  PHP_MODULE_GLOBALS(grpc),
  PHP_GINIT(grpc),
  NULL,
  NULL,
  STANDARD_MODULE_PROPERTIES_EX};
/* }}} */

#ifdef COMPILE_DL_GRPC
ZEND_GET_MODULE(grpc)
#endif

/* {{{ PHP_INI
 */
/* Remove comments and fill if you need to have entries in php.ini
   PHP_INI_BEGIN()
   STD_PHP_INI_ENTRY("grpc.global_value", "42", PHP_INI_ALL, OnUpdateLong,
                     global_value, zend_grpc_globals, grpc_globals)
   STD_PHP_INI_ENTRY("grpc.global_string", "foobar", PHP_INI_ALL,
                     OnUpdateString, global_string, zend_grpc_globals,
                     grpc_globals)
   PHP_INI_END()
*/
/* }}} */

/* {{{ php_grpc_init_globals
 */
/* Uncomment this function if you have INI entries
   static void php_grpc_init_globals(zend_grpc_globals *grpc_globals)
   {
     grpc_globals->global_value = 0;
     grpc_globals->global_string = NULL;
   }
*/
/* }}} */
void create_new_channel(
    wrapped_grpc_channel *channel,
    char *target,
    grpc_channel_args args,
    wrapped_grpc_channel_credentials *creds) {
  if (creds == NULL) {
    channel->wrapper->wrapped = grpc_insecure_channel_create(target, &args,
                                                             NULL);
  } else {
    channel->wrapper->wrapped =
        grpc_secure_channel_create(creds->wrapped, target, &args, NULL);
  }
}

void acquire_persistent_locks() {
  zval *data;
  PHP_GRPC_HASH_FOREACH_VAL_START(&grpc_persistent_list, data)
    php_grpc_zend_resource *rsrc  =
                (php_grpc_zend_resource*) PHP_GRPC_HASH_VALPTR_TO_VAL(data)
    if (rsrc == NULL) {
      break;
    }
    channel_persistent_le_t* le = rsrc->ptr;

    gpr_mu_lock(&le->channel->mu);
  PHP_GRPC_HASH_FOREACH_END()
}

void release_persistent_locks() {
  zval *data;
  PHP_GRPC_HASH_FOREACH_VAL_START(&grpc_persistent_list, data)
    php_grpc_zend_resource *rsrc  =
                (php_grpc_zend_resource*) PHP_GRPC_HASH_VALPTR_TO_VAL(data)
    if (rsrc == NULL) {
      break;
    }
    channel_persistent_le_t* le = rsrc->ptr;

    gpr_mu_unlock(&le->channel->mu);
  PHP_GRPC_HASH_FOREACH_END()
}

void destroy_grpc_channels() {
  zval *data;
  PHP_GRPC_HASH_FOREACH_VAL_START(&grpc_persistent_list, data)
    php_grpc_zend_resource *rsrc  =
                (php_grpc_zend_resource*) PHP_GRPC_HASH_VALPTR_TO_VAL(data)
    if (rsrc == NULL) {
      break;
    }
    channel_persistent_le_t* le = rsrc->ptr;

    wrapped_grpc_channel wrapped_channel;
    wrapped_channel.wrapper = le->channel;
    grpc_channel_wrapper *channel = wrapped_channel.wrapper;
    grpc_channel_destroy(channel->wrapped);
  PHP_GRPC_HASH_FOREACH_END()
}

void restart_channels() {
  zval *data;
  PHP_GRPC_HASH_FOREACH_VAL_START(&grpc_persistent_list, data)
    php_grpc_zend_resource *rsrc  =
                (php_grpc_zend_resource*) PHP_GRPC_HASH_VALPTR_TO_VAL(data)
    if (rsrc == NULL) {
      break;
    }
    channel_persistent_le_t* le = rsrc->ptr;

    wrapped_grpc_channel wrapped_channel;
    wrapped_channel.wrapper = le->channel;
    grpc_channel_wrapper *channel = wrapped_channel.wrapper;
    create_new_channel(&wrapped_channel, channel->target, channel->args,
                       channel->creds);
    gpr_mu_unlock(&channel->mu);
  PHP_GRPC_HASH_FOREACH_END()
}

void prefork() {
  acquire_persistent_locks();
}

void postfork_child() {
  TSRMLS_FETCH();

  // loop through persistant list and destroy all underlying grpc_channel objs
  destroy_grpc_channels();

  // clear completion queue
  grpc_php_shutdown_completion_queue(TSRMLS_C);

  // clean-up grpc_core
  grpc_shutdown();
  if (grpc_is_initialized() > 0) {
    zend_throw_exception(spl_ce_UnexpectedValueException,
                         "Oops, failed to shutdown gRPC Core after fork()",
                         1 TSRMLS_CC);
  }

  // restart grpc_core
  grpc_init();
  grpc_php_init_completion_queue(TSRMLS_C);

  // re-create grpc_channel and point wrapped to it
  // unlock wrapped grpc channel mutex
  restart_channels();
}

void postfork_parent() {
  release_persistent_locks();
}

void register_fork_handlers() {
  if (getenv("GRPC_ENABLE_FORK_SUPPORT")) {
#ifdef GRPC_POSIX_FORK_ALLOW_PTHREAD_ATFORK
    pthread_atfork(&prefork, &postfork_parent, &postfork_child);
#endif  // GRPC_POSIX_FORK_ALLOW_PTHREAD_ATFORK
  }
}

/* {{{ PHP_MINIT_FUNCTION
 */
PHP_MINIT_FUNCTION(grpc) {
  /* If you have INI entries, uncomment these lines
     REGISTER_INI_ENTRIES();
  */
  /* Register call error constants */
  REGISTER_LONG_CONSTANT("Grpc\\CALL_OK", GRPC_CALL_OK,
                         CONST_CS | CONST_PERSISTENT);
  REGISTER_LONG_CONSTANT("Grpc\\CALL_ERROR", GRPC_CALL_ERROR,
                         CONST_CS | CONST_PERSISTENT);
  REGISTER_LONG_CONSTANT("Grpc\\CALL_ERROR_NOT_ON_SERVER",
                         GRPC_CALL_ERROR_NOT_ON_SERVER,
                         CONST_CS | CONST_PERSISTENT);
  REGISTER_LONG_CONSTANT("Grpc\\CALL_ERROR_NOT_ON_CLIENT",
                         GRPC_CALL_ERROR_NOT_ON_CLIENT,
                         CONST_CS | CONST_PERSISTENT);
  REGISTER_LONG_CONSTANT("Grpc\\CALL_ERROR_ALREADY_INVOKED",
                         GRPC_CALL_ERROR_ALREADY_INVOKED,
                         CONST_CS | CONST_PERSISTENT);
  REGISTER_LONG_CONSTANT("Grpc\\CALL_ERROR_NOT_INVOKED",
                         GRPC_CALL_ERROR_NOT_INVOKED,
                         CONST_CS | CONST_PERSISTENT);
  REGISTER_LONG_CONSTANT("Grpc\\CALL_ERROR_ALREADY_FINISHED",
                         GRPC_CALL_ERROR_ALREADY_FINISHED,
                         CONST_CS | CONST_PERSISTENT);
  REGISTER_LONG_CONSTANT("Grpc\\CALL_ERROR_TOO_MANY_OPERATIONS",
                         GRPC_CALL_ERROR_TOO_MANY_OPERATIONS,
                         CONST_CS | CONST_PERSISTENT);
  REGISTER_LONG_CONSTANT("Grpc\\CALL_ERROR_INVALID_FLAGS",
                         GRPC_CALL_ERROR_INVALID_FLAGS,
                         CONST_CS | CONST_PERSISTENT);

  /* Register flag constants */
  REGISTER_LONG_CONSTANT("Grpc\\WRITE_BUFFER_HINT", GRPC_WRITE_BUFFER_HINT,
                         CONST_CS | CONST_PERSISTENT);
  REGISTER_LONG_CONSTANT("Grpc\\WRITE_NO_COMPRESS", GRPC_WRITE_NO_COMPRESS,
                         CONST_CS | CONST_PERSISTENT);

  /* Register status constants */
  REGISTER_LONG_CONSTANT("Grpc\\STATUS_OK", GRPC_STATUS_OK,
                         CONST_CS | CONST_PERSISTENT);
  REGISTER_LONG_CONSTANT("Grpc\\STATUS_CANCELLED", GRPC_STATUS_CANCELLED,
                         CONST_CS | CONST_PERSISTENT);
  REGISTER_LONG_CONSTANT("Grpc\\STATUS_UNKNOWN", GRPC_STATUS_UNKNOWN,
                         CONST_CS | CONST_PERSISTENT);
  REGISTER_LONG_CONSTANT("Grpc\\STATUS_INVALID_ARGUMENT",
                         GRPC_STATUS_INVALID_ARGUMENT,
                         CONST_CS | CONST_PERSISTENT);
  REGISTER_LONG_CONSTANT("Grpc\\STATUS_DEADLINE_EXCEEDED",
                         GRPC_STATUS_DEADLINE_EXCEEDED,
                         CONST_CS | CONST_PERSISTENT);
  REGISTER_LONG_CONSTANT("Grpc\\STATUS_NOT_FOUND", GRPC_STATUS_NOT_FOUND,
                         CONST_CS | CONST_PERSISTENT);
  REGISTER_LONG_CONSTANT("Grpc\\STATUS_ALREADY_EXISTS",
                         GRPC_STATUS_ALREADY_EXISTS,
                         CONST_CS | CONST_PERSISTENT);
  REGISTER_LONG_CONSTANT("Grpc\\STATUS_PERMISSION_DENIED",
                         GRPC_STATUS_PERMISSION_DENIED,
                         CONST_CS | CONST_PERSISTENT);
  REGISTER_LONG_CONSTANT("Grpc\\STATUS_UNAUTHENTICATED",
                         GRPC_STATUS_UNAUTHENTICATED,
                         CONST_CS | CONST_PERSISTENT);
  REGISTER_LONG_CONSTANT("Grpc\\STATUS_RESOURCE_EXHAUSTED",
                         GRPC_STATUS_RESOURCE_EXHAUSTED,
                         CONST_CS | CONST_PERSISTENT);
  REGISTER_LONG_CONSTANT("Grpc\\STATUS_FAILED_PRECONDITION",
                         GRPC_STATUS_FAILED_PRECONDITION,
                         CONST_CS | CONST_PERSISTENT);
  REGISTER_LONG_CONSTANT("Grpc\\STATUS_ABORTED", GRPC_STATUS_ABORTED,
                         CONST_CS | CONST_PERSISTENT);
  REGISTER_LONG_CONSTANT("Grpc\\STATUS_OUT_OF_RANGE",
                         GRPC_STATUS_OUT_OF_RANGE,
                         CONST_CS | CONST_PERSISTENT);
  REGISTER_LONG_CONSTANT("Grpc\\STATUS_UNIMPLEMENTED",
                         GRPC_STATUS_UNIMPLEMENTED,
                         CONST_CS | CONST_PERSISTENT);
  REGISTER_LONG_CONSTANT("Grpc\\STATUS_INTERNAL", GRPC_STATUS_INTERNAL,
                         CONST_CS | CONST_PERSISTENT);
  REGISTER_LONG_CONSTANT("Grpc\\STATUS_UNAVAILABLE", GRPC_STATUS_UNAVAILABLE,
                         CONST_CS | CONST_PERSISTENT);
  REGISTER_LONG_CONSTANT("Grpc\\STATUS_DATA_LOSS", GRPC_STATUS_DATA_LOSS,
                         CONST_CS | CONST_PERSISTENT);

  /* Register op type constants */
  REGISTER_LONG_CONSTANT("Grpc\\OP_SEND_INITIAL_METADATA",
                         GRPC_OP_SEND_INITIAL_METADATA,
                         CONST_CS | CONST_PERSISTENT);
  REGISTER_LONG_CONSTANT("Grpc\\OP_SEND_MESSAGE",
                         GRPC_OP_SEND_MESSAGE,
                         CONST_CS | CONST_PERSISTENT);
  REGISTER_LONG_CONSTANT("Grpc\\OP_SEND_CLOSE_FROM_CLIENT",
                         GRPC_OP_SEND_CLOSE_FROM_CLIENT,
                         CONST_CS | CONST_PERSISTENT);
  REGISTER_LONG_CONSTANT("Grpc\\OP_SEND_STATUS_FROM_SERVER",
                         GRPC_OP_SEND_STATUS_FROM_SERVER,
                         CONST_CS | CONST_PERSISTENT);
  REGISTER_LONG_CONSTANT("Grpc\\OP_RECV_INITIAL_METADATA",
                         GRPC_OP_RECV_INITIAL_METADATA,
                         CONST_CS | CONST_PERSISTENT);
  REGISTER_LONG_CONSTANT("Grpc\\OP_RECV_MESSAGE",
                         GRPC_OP_RECV_MESSAGE,
                         CONST_CS | CONST_PERSISTENT);
  REGISTER_LONG_CONSTANT("Grpc\\OP_RECV_STATUS_ON_CLIENT",
                         GRPC_OP_RECV_STATUS_ON_CLIENT,
                         CONST_CS | CONST_PERSISTENT);
  REGISTER_LONG_CONSTANT("Grpc\\OP_RECV_CLOSE_ON_SERVER",
                         GRPC_OP_RECV_CLOSE_ON_SERVER,
                         CONST_CS | CONST_PERSISTENT);

  /* Register connectivity state constants */
  REGISTER_LONG_CONSTANT("Grpc\\CHANNEL_IDLE",
                         GRPC_CHANNEL_IDLE,
                         CONST_CS | CONST_PERSISTENT);
  REGISTER_LONG_CONSTANT("Grpc\\CHANNEL_CONNECTING",
                         GRPC_CHANNEL_CONNECTING,
                         CONST_CS | CONST_PERSISTENT);
  REGISTER_LONG_CONSTANT("Grpc\\CHANNEL_READY",
                         GRPC_CHANNEL_READY,
                         CONST_CS | CONST_PERSISTENT);
  REGISTER_LONG_CONSTANT("Grpc\\CHANNEL_TRANSIENT_FAILURE",
                         GRPC_CHANNEL_TRANSIENT_FAILURE,
                         CONST_CS | CONST_PERSISTENT);
  REGISTER_LONG_CONSTANT("Grpc\\CHANNEL_FATAL_FAILURE",
                         GRPC_CHANNEL_SHUTDOWN,
                         CONST_CS | CONST_PERSISTENT);

  grpc_init_call(TSRMLS_C);
  GRPC_STARTUP(channel);
  grpc_init_server(TSRMLS_C);
  grpc_init_timeval(TSRMLS_C);
  grpc_init_channel_credentials(TSRMLS_C);
  grpc_init_call_credentials(TSRMLS_C);
  grpc_init_server_credentials(TSRMLS_C);
  return SUCCESS;
}
/* }}} */

/* {{{ PHP_MSHUTDOWN_FUNCTION
 */
PHP_MSHUTDOWN_FUNCTION(grpc) {
  /* uncomment this line if you have INI entries
     UNREGISTER_INI_ENTRIES();
  */
  // WARNING: This function IS being called by PHP when the extension
  // is unloaded but the logs were somehow suppressed.
  if (GRPC_G(initialized)) {
    zend_hash_clean(&grpc_persistent_list);
    zend_hash_destroy(&grpc_persistent_list);
    zend_hash_clean(&grpc_target_upper_bound_map);
    zend_hash_destroy(&grpc_target_upper_bound_map);
    grpc_shutdown_timeval(TSRMLS_C);
    grpc_php_shutdown_completion_queue(TSRMLS_C);
    grpc_shutdown();
    GRPC_G(initialized) = 0;
  }
  return SUCCESS;
}
/* }}} */

/* {{{ PHP_MINFO_FUNCTION
 */
PHP_MINFO_FUNCTION(grpc) {
  php_info_print_table_start();
  php_info_print_table_row(2, "grpc support", "enabled");
  php_info_print_table_row(2, "grpc module version", PHP_GRPC_VERSION);
  php_info_print_table_end();
  /* Remove comments if you have entries in php.ini
     DISPLAY_INI_ENTRIES();
  */
}
/* }}} */

/* {{{ PHP_RINIT_FUNCTION
 */
PHP_RINIT_FUNCTION(grpc) {
  if (!GRPC_G(initialized)) {
    grpc_init();
    register_fork_handlers();
    grpc_php_init_completion_queue(TSRMLS_C);
    GRPC_G(initialized) = 1;
  }
  return SUCCESS;
}
/* }}} */

/* {{{ PHP_GINIT_FUNCTION
 */
static PHP_GINIT_FUNCTION(grpc) {
  grpc_globals->initialized = 0;
}
/* }}} */

/* The previous line is meant for vim and emacs, so it can correctly fold and
   unfold functions in source code. See the corresponding marks just before
   function definition, where the functions purpose is also documented. Please
   follow this convention for the convenience of others editing your code.
*/