/*
  +----------------------------------------------------------------------+
  | PHP Version 7                                                        |
  +----------------------------------------------------------------------+
  | Copyright (c) 1997-2016 The PHP Group                                |
  +----------------------------------------------------------------------+
  | http://www.opensource.org/licenses/mit-license.php  MIT License      |
  +----------------------------------------------------------------------+
  | Author: Jani Taskinen <jani.taskinen@iki.fi>                         |
  | Author: Patrick Reilly <preilly@php.net>                             |
  | Author: Stefan Siegl <stesie@php.net>                                |
  +----------------------------------------------------------------------+
*/

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "php_v8js_macros.h"
#include "v8js_v8.h"
#include "v8js_timer.h"
#include "v8js_exceptions.h"

extern "C" {
#include "ext/date/php_date.h"
#include "ext/standard/php_string.h"
#include "zend_interfaces.h"
#include "zend_closures.h"
#include "zend_exceptions.h"
}

#include <libplatform/libplatform.h>


void v8js_v8_init() /* {{{ */
{
	/* Run only once; thread-local test first */
	if (V8JSG(v8_initialized)) {
		return;
	}

	/* Set thread-local flag, that V8 was initialized. */
	V8JSG(v8_initialized) = 1;

#ifdef ZTS
	v8js_process_globals.lock.lock();

	if(v8js_process_globals.v8_initialized) {
		/* V8 already has been initialized by another thread */
		v8js_process_globals.lock.unlock();
		return;
	}
#endif


#if defined(PHP_V8_SNAPSHOT_BLOB_PATH)
#if !defined(PHP_V8_NATIVES_BLOB_PATH)
	/* Newer V8 version don't have a natives blob anymore. */
	v8::V8::InitializeExternalStartupDataFromFile(
		PHP_V8_SNAPSHOT_BLOB_PATH
	);
#else
	/* V8 doesn't work without startup data, load it. */
	v8::V8::InitializeExternalStartupData(
		PHP_V8_NATIVES_BLOB_PATH,
		PHP_V8_SNAPSHOT_BLOB_PATH
	);
#endif
#endif

	v8js_process_globals.v8_platform = v8::platform::NewDefaultPlatform();
	v8::V8::InitializePlatform(v8js_process_globals.v8_platform.get());

#ifdef V8_HAS_INITIALIZE_SANDBOX
	v8::V8::InitializeSandbox();
#endif

	/* Set V8 command line flags (must be done before V8::Initialize()!) */
	if (v8js_process_globals.v8_flags) {
		size_t flags_len = strlen(v8js_process_globals.v8_flags);

		if (flags_len > std::numeric_limits<int>::max()) {
			zend_throw_exception(php_ce_v8js_exception,
				"Length of V8 flags exceeds maximum supported length", 0);
		}
		else {
			v8::V8::SetFlagsFromString(v8js_process_globals.v8_flags, static_cast<int>(flags_len));
		}
	}

#if PHP_V8_API_VERSION >= 5003178
	/* Initialize ICU, call introduced in V8 5.3.178 */
	if (v8js_process_globals.icudtl_dat_path != NULL && v8js_process_globals.icudtl_dat_path[0] != 0) {
		v8::V8::InitializeICUDefaultLocation(nullptr, v8js_process_globals.icudtl_dat_path);
	}
#ifdef PHP_V8_EXEC_PATH
	else {
		v8::V8::InitializeICUDefaultLocation(PHP_V8_EXEC_PATH, nullptr);
	}
#endif
#endif  /* PHP_V8_API_VERSION >= 5003178 */

	/* Initialize V8 */
	v8::V8::Initialize();

#ifdef ZTS
	v8js_process_globals.v8_initialized = 1;
	v8js_process_globals.lock.unlock();
#endif
}
/* }}} */


/**
 * Prepare V8 call trampoline with time & memory limit, exception handling, etc.
 *
 * The caller MUST check V8JSG(fatal_error_abort) and trigger further bailout
 * either immediately after this function returns (or possibly after freeing
 * heap allocated memory).
 */
void v8js_v8_call(v8js_ctx *c, zval **return_value,
				  long flags, long time_limit, size_t memory_limit,
				  std::function< v8::MaybeLocal<v8::Value>(v8::Isolate *) >& v8_call) /* {{{ */
{
	char *tz = NULL;

	// hold extra reference on v8 instance as long as we call into V8 (issue #472)
	zend_object *obj = v8js_ctx_to_zend_object(c);
	zval zv_v8inst;
	ZVAL_OBJ(&zv_v8inst, obj);
	Z_ADDREF_P(&zv_v8inst);

	{
		V8JS_CTX_PROLOGUE(c);

		V8JSG(timer_mutex).lock();
		c->time_limit_hit = false;
		c->memory_limit_hit = false;
		V8JSG(timer_mutex).unlock();

		/* Catch JS exceptions */
		v8::TryCatch try_catch(isolate);

		/* Set flags for runtime use */
		c->flags = flags;

		/* Check if timezone has been changed and notify V8 */
		tz = getenv("TZ");

		if (tz != NULL) {
			if (c->tz == NULL) {
				c->tz = strdup(tz);
			}
			else if (strcmp(c->tz, tz) != 0) {
				c->isolate->DateTimeConfigurationChangeNotification(v8::Isolate::TimeZoneDetection::kRedetect);

				free(c->tz);
				c->tz = strdup(tz);
			}
		}

		if (time_limit > 0 || memory_limit > 0) {
			// If timer thread is not running then start it
			if (!V8JSG(timer_thread)) {
				// If not, start timer thread
				V8JSG(timer_thread) = new std::thread(v8js_timer_thread, ZEND_MODULE_GLOBALS_BULK(v8js));
			}
		}

		/* Always pass the timer to the stack so there can be follow-up changes to
		 * the time & memory limit. */
		v8js_timer_push(time_limit, memory_limit, c);

		/* Execute script */
		c->in_execution++;
		v8::MaybeLocal<v8::Value> result = v8_call(c->isolate);
		c->in_execution--;

		/* Pop our context from the stack and read (possibly updated) limits
		 * into local variables. */
		V8JSG(timer_mutex).lock();
		v8js_timer_ctx *timer_ctx = V8JSG(timer_stack).front();
		V8JSG(timer_stack).pop_front();
		V8JSG(timer_mutex).unlock();

		time_limit = timer_ctx->time_limit;
		memory_limit = timer_ctx->memory_limit;

		efree(timer_ctx);

		if(!V8JSG(fatal_error_abort)) {
			char exception_string[64];

			if (c->time_limit_hit) {
				// Execution has been terminated due to time limit
				sprintf(exception_string, "Script time limit of %lu milliseconds exceeded", time_limit);
				zend_throw_exception(php_ce_v8js_time_limit_exception, exception_string, 0);
				zval_ptr_dtor(&zv_v8inst);
				return;
			}

			if (memory_limit && !c->memory_limit_hit) {
				// Re-check memory limit (very short executions might never be hit by timer thread)
				v8::HeapStatistics hs;
				isolate->GetHeapStatistics(&hs);

				if (hs.used_heap_size() > memory_limit) {
					isolate->LowMemoryNotification();
					isolate->GetHeapStatistics(&hs);

					if (hs.used_heap_size() > memory_limit) {
						c->memory_limit_hit = true;
					}
				}
			}

			if (c->memory_limit_hit) {
				// Execution has been terminated due to memory limit
				sprintf(exception_string, "Script memory limit of %lu bytes exceeded", memory_limit);
				zend_throw_exception(php_ce_v8js_memory_limit_exception, exception_string, 0);
				zval_ptr_dtor(&zv_v8inst);
				return;
			}

			if (!try_catch.CanContinue()) {
				// At this point we can't re-throw the exception
				zval_ptr_dtor(&zv_v8inst);
				return;
			}

			/* Handle runtime JS exceptions */
			if (try_catch.HasCaught()) {

				/* Pending exceptions are set only in outer caller, inner caller exceptions are always rethrown */
				if (c->in_execution < 1) {
					v8js_throw_script_exception(c->isolate, &try_catch);
					zval_ptr_dtor(&zv_v8inst);
					return;
				}

				/* Rethrow back to JS */
				try_catch.ReThrow();
				zval_ptr_dtor(&zv_v8inst);
				return;
			}

			/* Convert V8 value to PHP value */
			if (return_value && !result.IsEmpty()) {
				v8js_to_zval(result.ToLocalChecked(), *return_value, flags, c->isolate);
			}
		}
	}

	zval_ptr_dtor(&zv_v8inst);
}
/* }}} */

void v8js_terminate_execution(v8::Isolate *isolate) /* {{{ */
{
	if(isolate->IsExecutionTerminating()) {
		/* Execution already terminating, needn't trigger it again and
		 * especially must not execute the spinning loop (which would cause
		 * crashes in V8 itself, at least with 4.2 and 4.3 version lines). */
		return;
	}

	/* Unfortunately just calling TerminateExecution on the isolate is not
	 * enough, since v8 just marks the thread as "to be aborted" and doesn't
	 * immediately do so.  Hence we enter an endless loop after signalling
	 * termination, so we definitely don't execute JS code after the exit()
	 * statement. */
	v8::Locker locker(isolate);
	v8::Isolate::Scope isolate_scope(isolate);
	v8::HandleScope handle_scope(isolate);

	v8js_ctx *ctx = (v8js_ctx *) isolate->GetData(0);
	v8::Local<v8::Context> context = v8::Local<v8::Context>::New(isolate, ctx->context);

	v8::Local<v8::String> source = V8JS_STR("for(;;);");
	v8::Local<v8::Script> script = v8::Script::Compile(context, source).ToLocalChecked();
	isolate->TerminateExecution();
	script->Run(context);
}
/* }}} */


int v8js_get_properties_hash(v8::Local<v8::Value> jsValue, HashTable *retval, int flags, v8::Isolate *isolate) /* {{{ */
{
	v8js_ctx *ctx = (v8js_ctx *) isolate->GetData(0);
	v8::Local<v8::Context> v8_context = v8::Local<v8::Context>::New(isolate, ctx->context);

	v8::Local<v8::Object> jsObj;
	v8::Local<v8::Array> jsKeys;
	if (!jsValue->ToObject(v8_context).ToLocal(&jsObj)
			|| !jsObj->GetPropertyNames(v8_context).ToLocal(&jsKeys)) {
		return FAILURE;
	}

	for (unsigned i = 0; i < jsKeys->Length(); i++)
	{
		v8::Local<v8::Value> jsKeySlot;
		v8::Local<v8::String> jsKey;

		if (!jsKeys->Get(v8_context, i).ToLocal(&jsKeySlot)
				|| !jsKeySlot->ToString(v8_context).ToLocal(&jsKey)) {
			continue;
		}

		/* Skip any prototype properties */
		if (!jsObj->HasOwnProperty(isolate->GetEnteredOrMicrotaskContext(), jsKey).FromMaybe(false)
			&& !jsObj->HasRealNamedProperty(v8_context, jsKey).FromMaybe(false)
			&& !jsObj->HasRealNamedCallbackProperty(v8_context, jsKey).FromMaybe(false)) {
			continue;
		}

		v8::Local<v8::Value> jsVal;

		if (!jsObj->Get(v8_context, jsKey).ToLocal(&jsVal)) {
			continue;
		}

		v8::String::Utf8Value cstr(isolate, jsKey);
		zend_string *key = zend_string_init(ToCString(cstr), cstr.length(), 0);
		zval value;
		ZVAL_UNDEF(&value);

		v8::Local<v8::Object> jsValObject;
		if (jsVal->IsObject() && !jsVal->IsArrayBufferView() && !jsVal->IsArrayBuffer()
			&& jsVal->ToObject(v8_context).ToLocal(&jsValObject) && (jsValObject->InternalFieldCount() == 2)) {
			/* This is a PHP object, passed to JS and back. */
			zend_object *object = reinterpret_cast<zend_object *>(jsValObject->GetAlignedPointerFromInternalField(1));
			ZVAL_OBJ(&value, object);
			Z_ADDREF_P(&value);
		}
		else {
			if (v8js_to_zval(jsVal, &value, flags, isolate) == FAILURE) {
				zval_ptr_dtor(&value);
				return FAILURE;
			}
		}

		if ((flags & V8JS_FLAG_FORCE_ARRAY) || jsValue->IsArray()) {
			zend_symtable_update(retval, key, &value);
		} else {
			zend_hash_update(retval, key, &value);
		}

		zend_string_release(key);
	}
	return SUCCESS;
}
/* }}} */




/*
 * Local variables:
 * tab-width: 4
 * c-basic-offset: 4
 * indent-tabs-mode: t
 * End:
 * vim600: noet sw=4 ts=4 fdm=marker
 * vim<600: noet sw=4 ts=4
 */