/**************************************************************************/
/*  remote_debugger.cpp                                                   */
/**************************************************************************/
/*                         This file is part of:                          */
/*                             GODOT ENGINE                               */
/*                        https://godotengine.org                         */
/**************************************************************************/
/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                  */
/*                                                                        */
/* Permission is hereby granted, free of charge, to any person obtaining  */
/* a copy of this software and associated documentation files (the        */
/* "Software"), to deal in the Software without restriction, including    */
/* without limitation the rights to use, copy, modify, merge, publish,    */
/* distribute, sublicense, and/or sell copies of the Software, and to     */
/* permit persons to whom the Software is furnished to do so, subject to  */
/* the following conditions:                                              */
/*                                                                        */
/* The above copyright notice and this permission notice shall be         */
/* included in all copies or substantial portions of the Software.        */
/*                                                                        */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,        */
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF     */
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. */
/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY   */
/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,   */
/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE      */
/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                 */
/**************************************************************************/

#include "remote_debugger.h"

#include "core/config/project_settings.h"
#include "core/debugger/debugger_marshalls.h"
#include "core/debugger/engine_debugger.h"
#include "core/debugger/engine_profiler.h"
#include "core/debugger/script_debugger.h"
#include "core/input/input.h"
#include "core/object/script_language.h"
#include "core/os/os.h"

class RemoteDebugger::PerformanceProfiler : public EngineProfiler {
	Object *performance = nullptr;
	int last_perf_time = 0;
	uint64_t last_monitor_modification_time = 0;

public:
	void toggle(bool p_enable, const Array &p_opts) {}
	void add(const Array &p_data) {}
	void tick(double p_frame_time, double p_process_time, double p_physics_time, double p_physics_frame_time) {
		if (!performance) {
			return;
		}

		uint64_t pt = OS::get_singleton()->get_ticks_msec();
		if (pt - last_perf_time < 1000) {
			return;
		}
		last_perf_time = pt;

		Array custom_monitor_names = performance->call("get_custom_monitor_names");

		uint64_t monitor_modification_time = performance->call("get_monitor_modification_time");
		if (monitor_modification_time > last_monitor_modification_time) {
			last_monitor_modification_time = monitor_modification_time;
			EngineDebugger::get_singleton()->send_message("performance:profile_names", custom_monitor_names);
		}

		int max = performance->get("MONITOR_MAX");
		Array arr;
		arr.resize(max + custom_monitor_names.size());
		for (int i = 0; i < max; i++) {
			arr[i] = performance->call("get_monitor", i);
		}

		for (int i = 0; i < custom_monitor_names.size(); i++) {
			Variant monitor_value = performance->call("get_custom_monitor", custom_monitor_names[i]);
			if (!monitor_value.is_num()) {
				ERR_PRINT("Value of custom monitor '" + String(custom_monitor_names[i]) + "' is not a number");
				arr[i + max] = Variant();
			} else {
				arr[i + max] = monitor_value;
			}
		}

		EngineDebugger::get_singleton()->send_message("performance:profile_frame", arr);
	}

	explicit PerformanceProfiler(Object *p_performance) {
		performance = p_performance;
	}
};

Error RemoteDebugger::_put_msg(String p_message, Array p_data) {
	Array msg;
	msg.push_back(p_message);
	msg.push_back(Thread::get_caller_id());
	msg.push_back(p_data);
	Error err = peer->put_message(msg);
	if (err != OK) {
		n_messages_dropped++;
	}
	return err;
}

void RemoteDebugger::_err_handler(void *p_this, const char *p_func, const char *p_file, int p_line, const char *p_err, const char *p_descr, bool p_editor_notify, ErrorHandlerType p_type) {
	if (p_type == ERR_HANDLER_SCRIPT) {
		return; //ignore script errors, those go through debugger
	}

	RemoteDebugger *rd = static_cast<RemoteDebugger *>(p_this);
	if (rd->flushing && Thread::get_caller_id() == rd->flush_thread) { // Can't handle recursive errors during flush.
		return;
	}

	Vector<ScriptLanguage::StackInfo> si;

	for (int i = 0; i < ScriptServer::get_language_count(); i++) {
		si = ScriptServer::get_language(i)->debug_get_current_stack_info();
		if (si.size()) {
			break;
		}
	}

	// send_error will lock internally.
	rd->script_debugger->send_error(String::utf8(p_func), String::utf8(p_file), p_line, String::utf8(p_err), String::utf8(p_descr), p_editor_notify, p_type, si);
}

void RemoteDebugger::_print_handler(void *p_this, const String &p_string, bool p_error, bool p_rich) {
	RemoteDebugger *rd = static_cast<RemoteDebugger *>(p_this);

	if (rd->flushing && Thread::get_caller_id() == rd->flush_thread) { // Can't handle recursive prints during flush.
		return;
	}

	String s = p_string;
	int allowed_chars = MIN(MAX(rd->max_chars_per_second - rd->char_count, 0), s.length());

	if (allowed_chars == 0 && s.length() > 0) {
		return;
	}

	if (allowed_chars < s.length()) {
		s = s.substr(0, allowed_chars);
	}

	MutexLock lock(rd->mutex);

	rd->char_count += allowed_chars;
	bool overflowed = rd->char_count >= rd->max_chars_per_second;
	if (rd->is_peer_connected()) {
		if (overflowed) {
			s += "[...]";
		}

		OutputString output_string;
		output_string.message = s;
		if (p_error) {
			output_string.type = MESSAGE_TYPE_ERROR;
		} else if (p_rich) {
			output_string.type = MESSAGE_TYPE_LOG_RICH;
		} else {
			output_string.type = MESSAGE_TYPE_LOG;
		}
		rd->output_strings.push_back(output_string);

		if (overflowed) {
			output_string.message = "[output overflow, print less text!]";
			output_string.type = MESSAGE_TYPE_ERROR;
			rd->output_strings.push_back(output_string);
		}
	}
}

RemoteDebugger::ErrorMessage RemoteDebugger::_create_overflow_error(const String &p_what, const String &p_descr) {
	ErrorMessage oe;
	oe.error = p_what;
	oe.error_descr = p_descr;
	oe.warning = false;
	uint64_t time = OS::get_singleton()->get_ticks_msec();
	oe.hr = time / 3600000;
	oe.min = (time / 60000) % 60;
	oe.sec = (time / 1000) % 60;
	oe.msec = time % 1000;
	return oe;
}

void RemoteDebugger::flush_output() {
	MutexLock lock(mutex);
	flush_thread = Thread::get_caller_id();
	flushing = true;
	if (!is_peer_connected()) {
		return;
	}

	if (n_messages_dropped > 0) {
		ErrorMessage err_msg = _create_overflow_error("TOO_MANY_MESSAGES", "Too many messages! " + String::num_int64(n_messages_dropped) + " messages were dropped. Profiling might misbheave, try raising 'network/limits/debugger/max_queued_messages' in project setting.");
		if (_put_msg("error", err_msg.serialize()) == OK) {
			n_messages_dropped = 0;
		}
	}

	if (output_strings.size()) {
		// Join output strings so we generate less messages.
		Vector<String> joined_log_strings;
		Vector<String> strings;
		Vector<int> types;
		for (int i = 0; i < output_strings.size(); i++) {
			const OutputString &output_string = output_strings[i];
			if (output_string.type == MESSAGE_TYPE_ERROR) {
				if (!joined_log_strings.is_empty()) {
					strings.push_back(String("\n").join(joined_log_strings));
					types.push_back(MESSAGE_TYPE_LOG);
					joined_log_strings.clear();
				}
				strings.push_back(output_string.message);
				types.push_back(MESSAGE_TYPE_ERROR);
			} else if (output_string.type == MESSAGE_TYPE_LOG_RICH) {
				if (!joined_log_strings.is_empty()) {
					strings.push_back(String("\n").join(joined_log_strings));
					types.push_back(MESSAGE_TYPE_LOG_RICH);
					joined_log_strings.clear();
				}
				strings.push_back(output_string.message);
				types.push_back(MESSAGE_TYPE_LOG_RICH);
			} else {
				joined_log_strings.push_back(output_string.message);
			}
		}

		if (!joined_log_strings.is_empty()) {
			strings.push_back(String("\n").join(joined_log_strings));
			types.push_back(MESSAGE_TYPE_LOG);
		}

		Array arr;
		arr.push_back(strings);
		arr.push_back(types);
		_put_msg("output", arr);
		output_strings.clear();
	}

	while (errors.size()) {
		ErrorMessage oe = errors.front()->get();
		_put_msg("error", oe.serialize());
		errors.pop_front();
	}

	// Update limits
	uint64_t ticks = OS::get_singleton()->get_ticks_usec() / 1000;

	if (ticks - last_reset > 1000) {
		last_reset = ticks;
		char_count = 0;
		err_count = 0;
		n_errors_dropped = 0;
		warn_count = 0;
		n_warnings_dropped = 0;
	}
	flushing = false;
}

void RemoteDebugger::send_message(const String &p_message, const Array &p_args) {
	MutexLock lock(mutex);
	if (is_peer_connected()) {
		_put_msg(p_message, p_args);
	}
}

void RemoteDebugger::send_error(const String &p_func, const String &p_file, int p_line, const String &p_err, const String &p_descr, bool p_editor_notify, ErrorHandlerType p_type) {
	ErrorMessage oe;
	oe.error = p_err;
	oe.error_descr = p_descr;
	oe.source_file = p_file;
	oe.source_line = p_line;
	oe.source_func = p_func;
	oe.warning = p_type == ERR_HANDLER_WARNING;
	uint64_t time = OS::get_singleton()->get_ticks_msec();
	oe.hr = time / 3600000;
	oe.min = (time / 60000) % 60;
	oe.sec = (time / 1000) % 60;
	oe.msec = time % 1000;
	oe.callstack.append_array(script_debugger->get_error_stack_info());

	if (flushing && Thread::get_caller_id() == flush_thread) { // Can't handle recursive errors during flush.
		return;
	}

	MutexLock lock(mutex);

	if (oe.warning) {
		warn_count++;
	} else {
		err_count++;
	}

	if (is_peer_connected()) {
		if (oe.warning) {
			if (warn_count > max_warnings_per_second) {
				n_warnings_dropped++;
				if (n_warnings_dropped == 1) {
					// Only print one message about dropping per second
					ErrorMessage overflow = _create_overflow_error("TOO_MANY_WARNINGS", "Too many warnings! Ignoring warnings for up to 1 second.");
					errors.push_back(overflow);
				}
			} else {
				errors.push_back(oe);
			}
		} else {
			if (err_count > max_errors_per_second) {
				n_errors_dropped++;
				if (n_errors_dropped == 1) {
					// Only print one message about dropping per second
					ErrorMessage overflow = _create_overflow_error("TOO_MANY_ERRORS", "Too many errors! Ignoring errors for up to 1 second.");
					errors.push_back(overflow);
				}
			} else {
				errors.push_back(oe);
			}
		}
	}
}

void RemoteDebugger::_send_stack_vars(List<String> &p_names, List<Variant> &p_vals, int p_type) {
	DebuggerMarshalls::ScriptStackVariable stvar;
	List<String>::Element *E = p_names.front();
	List<Variant>::Element *F = p_vals.front();
	while (E) {
		stvar.name = E->get();
		stvar.value = F->get();
		stvar.type = p_type;
		send_message("stack_frame_var", stvar.serialize());
		E = E->next();
		F = F->next();
	}
}

Error RemoteDebugger::_try_capture(const String &p_msg, const Array &p_data, bool &r_captured) {
	const int idx = p_msg.find(":");
	r_captured = false;
	if (idx < 0) { // No prefix, unknown message.
		return OK;
	}
	const String cap = p_msg.substr(0, idx);
	if (!has_capture(cap)) {
		return ERR_UNAVAILABLE; // Unknown message...
	}
	const String msg = p_msg.substr(idx + 1);
	return capture_parse(cap, msg, p_data, r_captured);
}

void RemoteDebugger::_poll_messages() {
	MutexLock mutex_lock(mutex);

	peer->poll();
	while (peer->has_message()) {
		Array cmd = peer->get_message();
		ERR_CONTINUE(cmd.size() != 3);
		ERR_CONTINUE(cmd[0].get_type() != Variant::STRING);
		ERR_CONTINUE(cmd[1].get_type() != Variant::INT);
		ERR_CONTINUE(cmd[2].get_type() != Variant::ARRAY);

		Thread::ID thread = cmd[1];

		if (!messages.has(thread)) {
			continue; // This thread is not around to receive the messages
		}

		Message msg;
		msg.message = cmd[0];
		msg.data = cmd[2];
		messages[thread].push_back(msg);
	}
}

bool RemoteDebugger::_has_messages() {
	MutexLock mutex_lock(mutex);
	return messages.has(Thread::get_caller_id()) && !messages[Thread::get_caller_id()].is_empty();
}

Array RemoteDebugger::_get_message() {
	MutexLock mutex_lock(mutex);
	ERR_FAIL_COND_V(!messages.has(Thread::get_caller_id()), Array());
	List<Message> &message_list = messages[Thread::get_caller_id()];
	ERR_FAIL_COND_V(message_list.is_empty(), Array());

	Array msg;
	msg.resize(2);
	msg[0] = message_list.front()->get().message;
	msg[1] = message_list.front()->get().data;
	message_list.pop_front();
	return msg;
}

void RemoteDebugger::debug(bool p_can_continue, bool p_is_error_breakpoint) {
	//this function is called when there is a debugger break (bug on script)
	//or when execution is paused from editor

	{
		MutexLock lock(mutex);
		// Tests that require mutex.
		if (script_debugger->is_skipping_breakpoints() && !p_is_error_breakpoint) {
			return;
		}

		ERR_FAIL_COND_MSG(!is_peer_connected(), "Script Debugger failed to connect, but being used anyway.");

		if (!peer->can_block()) {
			return; // Peer does not support blocking IO. We could at least send the error though.
		}
	}

	ScriptLanguage *script_lang = script_debugger->get_break_language();
	const String error_str = script_lang ? script_lang->debug_get_error() : "";
	Array msg;
	msg.push_back(p_can_continue);
	msg.push_back(error_str);
	ERR_FAIL_NULL(script_lang);
	msg.push_back(script_lang->debug_get_stack_level_count() > 0);
	msg.push_back(Thread::get_caller_id() == Thread::get_main_id() ? String(RTR("Main Thread")) : itos(Thread::get_caller_id()));
	if (allow_focus_steal_fn) {
		allow_focus_steal_fn();
	}
	send_message("debug_enter", msg);

	Input::MouseMode mouse_mode = Input::MOUSE_MODE_VISIBLE;

	if (Thread::get_caller_id() == Thread::get_main_id()) {
		mouse_mode = Input::get_singleton()->get_mouse_mode();
		if (mouse_mode != Input::MOUSE_MODE_VISIBLE) {
			Input::get_singleton()->set_mouse_mode(Input::MOUSE_MODE_VISIBLE);
		}
	} else {
		MutexLock mutex_lock(mutex);
		messages.insert(Thread::get_caller_id(), List<Message>());
	}

	while (is_peer_connected()) {
		flush_output();

		_poll_messages();

		if (_has_messages()) {
			Array cmd = _get_message();

			ERR_CONTINUE(cmd.size() != 2);
			ERR_CONTINUE(cmd[0].get_type() != Variant::STRING);
			ERR_CONTINUE(cmd[1].get_type() != Variant::ARRAY);

			String command = cmd[0];
			Array data = cmd[1];

			if (command == "step") {
				script_debugger->set_depth(-1);
				script_debugger->set_lines_left(1);
				break;

			} else if (command == "next") {
				script_debugger->set_depth(0);
				script_debugger->set_lines_left(1);
				break;

			} else if (command == "continue") {
				script_debugger->set_depth(-1);
				script_debugger->set_lines_left(-1);
				break;

			} else if (command == "break") {
				ERR_PRINT("Got break when already broke!");
				break;

			} else if (command == "get_stack_dump") {
				DebuggerMarshalls::ScriptStackDump dump;
				int slc = script_lang->debug_get_stack_level_count();
				for (int i = 0; i < slc; i++) {
					ScriptLanguage::StackInfo frame;
					frame.file = script_lang->debug_get_stack_level_source(i);
					frame.line = script_lang->debug_get_stack_level_line(i);
					frame.func = script_lang->debug_get_stack_level_function(i);
					dump.frames.push_back(frame);
				}
				send_message("stack_dump", dump.serialize());

			} else if (command == "get_stack_frame_vars") {
				ERR_FAIL_COND(data.size() != 1);
				ERR_FAIL_NULL(script_lang);
				int lv = data[0];

				List<String> members;
				List<Variant> member_vals;
				if (ScriptInstance *inst = script_lang->debug_get_stack_level_instance(lv)) {
					members.push_back("self");
					member_vals.push_back(inst->get_owner());
				}
				script_lang->debug_get_stack_level_members(lv, &members, &member_vals);
				ERR_FAIL_COND(members.size() != member_vals.size());

				List<String> locals;
				List<Variant> local_vals;
				script_lang->debug_get_stack_level_locals(lv, &locals, &local_vals);
				ERR_FAIL_COND(locals.size() != local_vals.size());

				List<String> globals;
				List<Variant> globals_vals;
				script_lang->debug_get_globals(&globals, &globals_vals);
				ERR_FAIL_COND(globals.size() != globals_vals.size());

				Array var_size;
				var_size.push_back(local_vals.size() + member_vals.size() + globals_vals.size());
				send_message("stack_frame_vars", var_size);
				_send_stack_vars(locals, local_vals, 0);
				_send_stack_vars(members, member_vals, 1);
				_send_stack_vars(globals, globals_vals, 2);

			} else if (command == "reload_scripts") {
				reload_all_scripts = true;

			} else if (command == "breakpoint") {
				ERR_FAIL_COND(data.size() < 3);
				bool set = data[2];
				if (set) {
					script_debugger->insert_breakpoint(data[1], data[0]);
				} else {
					script_debugger->remove_breakpoint(data[1], data[0]);
				}

			} else if (command == "set_skip_breakpoints") {
				ERR_FAIL_COND(data.size() < 1);
				script_debugger->set_skip_breakpoints(data[0]);
			} else {
				bool captured = false;
				ERR_CONTINUE(_try_capture(command, data, captured) != OK);
				if (!captured) {
					WARN_PRINT("Unknown message received from debugger: " + command);
				}
			}
		} else {
			OS::get_singleton()->delay_usec(10000);
			if (Thread::get_caller_id() == Thread::get_main_id()) {
				// If this is a busy loop on the main thread, events still need to be processed.
				OS::get_singleton()->process_and_drop_events();
			}
		}
	}

	send_message("debug_exit", Array());

	if (Thread::get_caller_id() == Thread::get_main_id()) {
		if (mouse_mode != Input::MOUSE_MODE_VISIBLE) {
			Input::get_singleton()->set_mouse_mode(mouse_mode);
		}
	} else {
		MutexLock mutex_lock(mutex);
		messages.erase(Thread::get_caller_id());
	}
}

void RemoteDebugger::poll_events(bool p_is_idle) {
	if (peer.is_null()) {
		return;
	}

	flush_output();

	_poll_messages();

	while (_has_messages()) {
		Array arr = _get_message();

		ERR_CONTINUE(arr.size() != 2);
		ERR_CONTINUE(arr[0].get_type() != Variant::STRING);
		ERR_CONTINUE(arr[1].get_type() != Variant::ARRAY);

		const String cmd = arr[0];
		const int idx = cmd.find(":");
		bool parsed = false;
		if (idx < 0) { // Not prefix, use scripts capture.
			capture_parse("core", cmd, arr[1], parsed);
			continue;
		}

		const String cap = cmd.substr(0, idx);
		if (!has_capture(cap)) {
			continue; // Unknown message...
		}

		const String msg = cmd.substr(idx + 1);
		capture_parse(cap, msg, arr[1], parsed);
	}

	// Reload scripts during idle poll only.
	if (p_is_idle && reload_all_scripts) {
		for (int i = 0; i < ScriptServer::get_language_count(); i++) {
			ScriptServer::get_language(i)->reload_all_scripts();
		}
		reload_all_scripts = false;
	}
}

Error RemoteDebugger::_core_capture(const String &p_cmd, const Array &p_data, bool &r_captured) {
	r_captured = true;
	if (p_cmd == "reload_scripts") {
		reload_all_scripts = true;

	} else if (p_cmd == "breakpoint") {
		ERR_FAIL_COND_V(p_data.size() < 3, ERR_INVALID_DATA);
		bool set = p_data[2];
		if (set) {
			script_debugger->insert_breakpoint(p_data[1], p_data[0]);
		} else {
			script_debugger->remove_breakpoint(p_data[1], p_data[0]);
		}

	} else if (p_cmd == "set_skip_breakpoints") {
		ERR_FAIL_COND_V(p_data.size() < 1, ERR_INVALID_DATA);
		script_debugger->set_skip_breakpoints(p_data[0]);
	} else if (p_cmd == "break") {
		script_debugger->debug(script_debugger->get_break_language());
	} else {
		r_captured = false;
	}
	return OK;
}

Error RemoteDebugger::_profiler_capture(const String &p_cmd, const Array &p_data, bool &r_captured) {
	r_captured = false;
	ERR_FAIL_COND_V(p_data.size() < 1, ERR_INVALID_DATA);
	ERR_FAIL_COND_V(p_data[0].get_type() != Variant::BOOL, ERR_INVALID_DATA);
	ERR_FAIL_COND_V(!has_profiler(p_cmd), ERR_UNAVAILABLE);
	Array opts;
	if (p_data.size() > 1) { // Optional profiler parameters.
		ERR_FAIL_COND_V(p_data[1].get_type() != Variant::ARRAY, ERR_INVALID_DATA);
		opts = p_data[1];
	}
	r_captured = true;
	profiler_enable(p_cmd, p_data[0], opts);
	return OK;
}

RemoteDebugger::RemoteDebugger(Ref<RemoteDebuggerPeer> p_peer) {
	peer = p_peer;
	max_chars_per_second = GLOBAL_GET("network/limits/debugger/max_chars_per_second");
	max_errors_per_second = GLOBAL_GET("network/limits/debugger/max_errors_per_second");
	max_warnings_per_second = GLOBAL_GET("network/limits/debugger/max_warnings_per_second");

	// Performance Profiler
	Object *perf = Engine::get_singleton()->get_singleton_object("Performance");
	if (perf) {
		performance_profiler = Ref<PerformanceProfiler>(memnew(PerformanceProfiler(perf)));
		performance_profiler->bind("performance");
		profiler_enable("performance", true);
	}

	// Core and profiler captures.
	Capture core_cap(this,
			[](void *p_user, const String &p_cmd, const Array &p_data, bool &r_captured) {
				return static_cast<RemoteDebugger *>(p_user)->_core_capture(p_cmd, p_data, r_captured);
			});
	register_message_capture("core", core_cap);
	Capture profiler_cap(this,
			[](void *p_user, const String &p_cmd, const Array &p_data, bool &r_captured) {
				return static_cast<RemoteDebugger *>(p_user)->_profiler_capture(p_cmd, p_data, r_captured);
			});
	register_message_capture("profiler", profiler_cap);

	// Error handlers
	phl.printfunc = _print_handler;
	phl.userdata = this;
	add_print_handler(&phl);

	eh.errfunc = _err_handler;
	eh.userdata = this;
	add_error_handler(&eh);

	messages.insert(Thread::get_main_id(), List<Message>());
}

RemoteDebugger::~RemoteDebugger() {
	remove_print_handler(&phl);
	remove_error_handler(&eh);
}