#include <std_include.hpp>
#include "loader/component_loader.hpp"

#include "console.hpp"
#include "fastfiles.hpp"
#include "filesystem.hpp"
#include "logfile.hpp"
#include "gsc.hpp"
#include "scripting.hpp"

#include "game/dvars.hpp"
#include "game/scripting/functions.hpp"

#include <xsk/gsc/types.hpp>
#include <xsk/gsc/interfaces/compiler.hpp>
#include <xsk/gsc/interfaces/assembler.hpp>
#include <xsk/resolver.hpp>
#include <interface.hpp>

#include <utils/hook.hpp>
#include <utils/io.hpp>
#include <utils/string.hpp>

namespace gsc
{
	void* func_table[0x1000]{};
	void* meth_table[0x1000]{};

	namespace
	{
		game::dvar_t* developer_script = nullptr;

		auto compiler = ::gsc::compiler();
		auto assembler = ::gsc::assembler();

		std::unordered_map<std::string, unsigned int> main_handles;
		std::unordered_map<std::string, unsigned int> init_handles;
		std::unordered_map<std::string, game::ScriptFile*> loaded_scripts;

		std::unordered_map<builtin_function, unsigned int> functions;
		std::unordered_map<builtin_method, unsigned int> methods;

		std::optional<std::string> gsc_error;

		bool force_error_print = false;

		auto function_id_start = 0x30A;
		auto method_id_start = 0x8586;

		std::string unknown_function_error{};
		unsigned int current_filename{};

		char* allocate_buffer(size_t size)
		{
			// PMem_AllocFromSource_NoDebug
			return utils::hook::invoke<char*>(SELECT_VALUE(0x41FB50_b, 0x5A4DC0_b), size, 4, 1, 5);
		}

		bool read_scriptfile(const std::string& name, std::string* data)
		{
			if (filesystem::read_file(name, data))
			{
				return true;
			}

			// TODO: check back on this to see if there is a property we can distinguish compared to our rawfiles, like compressedLen?
			// this will filter out the rawfile "gsc" the game zones actually have, this seems to get all of them
			if (name.starts_with("maps/createfx") || name.starts_with("maps/createart")
				|| (name.starts_with("maps/mp") && name.ends_with("_fx.gsc")))
			{
				return false;
			}

			const auto name_str = name.data();

			if (game::DB_XAssetExists(game::ASSET_TYPE_RAWFILE, name_str) &&
				!game::DB_IsXAssetDefault(game::ASSET_TYPE_RAWFILE, name_str))
			{
				const auto asset = game::DB_FindXAssetHeader(game::ASSET_TYPE_RAWFILE, name_str, false);
				const auto len = game::DB_GetRawFileLen(asset.rawfile);
				data->resize(len);
				game::DB_GetRawBuffer(asset.rawfile, data->data(), len);
				if (len > 0)
				{
					data->pop_back();
				}

				return true;
			}

			return false;
		}

		game::ScriptFile* load_custom_script(const char* file_name, const std::string& real_name)
		{
			if (loaded_scripts.find(real_name) != loaded_scripts.end())
			{
				return loaded_scripts[real_name];
			}

			std::string source_buffer{};
			if (!read_scriptfile(real_name + ".gsc", &source_buffer))
			{
				return nullptr;
			}

			auto data = std::vector<uint8_t>{source_buffer.begin(), source_buffer.end()};

			try
			{
				compiler->compile(real_name, data);
			}
			catch (const std::exception& e)
			{
				console::error("*********** script compile error *************\n");
				console::error("failed to compile '%s':\n%s", real_name.data(), e.what());
				console::error("**********************************************\n");
				return nullptr;
			}

			auto assembly = compiler->output();

			try
			{
				assembler->assemble(real_name, assembly);
			}
			catch (const std::exception& e)
			{
				console::error("*********** script compile error *************\n");
				console::error("failed to assemble '%s':\n%s", real_name.data(), e.what());
				console::error("**********************************************\n");
				return nullptr;
			}

			const auto script_file_ptr = reinterpret_cast<game::ScriptFile*>(allocate_buffer(sizeof(game::ScriptFile)));
			script_file_ptr->name = file_name;

			const auto stack = assembler->output_stack();
			script_file_ptr->len = static_cast<int>(stack.size());

			const auto script = assembler->output_script();
			script_file_ptr->bytecodeLen = static_cast<int>(script.size());

			const auto script_size = script.size();
			const auto buffer_size = script_size + stack.size() + 2;

			const auto buffer = allocate_buffer(buffer_size);
			std::memcpy(buffer, script.data(), script_size);
			std::memcpy(&buffer[script_size], stack.data(), stack.size());

			script_file_ptr->bytecode = &buffer[0];
			script_file_ptr->buffer = &buffer[script.size()];
			script_file_ptr->compressedLen = 0;

			loaded_scripts[real_name] = script_file_ptr;

			return script_file_ptr;
		}

		void load_script(const std::string& name)
		{
			if (!game::Scr_LoadScript(name.data()))
			{
				return;
			}

			const auto main_handle = game::Scr_GetFunctionHandle(name.data(),
				xsk::gsc::h1::resolver::token_id("main"));
			const auto init_handle = game::Scr_GetFunctionHandle(name.data(),
				xsk::gsc::h1::resolver::token_id("init"));

			if (main_handle)
			{
				console::info("Loaded '%s::main'\n", name.data());
				main_handles[name] = main_handle;
			}

			if (init_handle)
			{
				console::info("Loaded '%s::init'\n", name.data());
				init_handles[name] = init_handle;
			}
		}

		void load_scripts(const std::filesystem::path& root_dir, const std::filesystem::path& script_dir)
		{
			std::filesystem::path script_dir_path = root_dir / script_dir;
			if (!utils::io::directory_exists(script_dir_path.generic_string()))
			{
				return;
			}

			const auto scripts = utils::io::list_files(script_dir_path.generic_string());
			for (const auto& script : scripts)
			{
				if (!script.ends_with(".gsc"))
				{
					continue;
				}

				std::filesystem::path path(script);
				const auto relative = path.lexically_relative(root_dir).generic_string();
				const auto base_name = relative.substr(0, relative.size() - 4);

				load_script(base_name);
			}
		}

		void clear()
		{
			main_handles.clear();
			init_handles.clear();
			loaded_scripts.clear();
		}

		void load_gametype_script_stub(void* a1, void* a2)
		{
			utils::hook::invoke<void>(SELECT_VALUE(0x2B9DA0_b, 0x18BC00_b), a1, a2);

			if (game::VirtualLobby_Loaded())
			{
				return;
			}

			clear();

			for (const auto& path : filesystem::get_search_paths())
			{
				load_scripts(path, "scripts/");
				if (game::environment::is_sp())
				{
					load_scripts(path, "scripts/sp/");
				}
				else
				{
					load_scripts(path, "scripts/mp/");
				}
			}
		}

		int db_is_xasset_default(game::XAssetType type, const char* name)
		{
			if (loaded_scripts.find(name) != loaded_scripts.end())
			{
				return 0;
			}

			return game::DB_IsXAssetDefault(type, name);
		}

		void db_get_raw_buffer_stub(const game::RawFile* rawfile, char* buf, const int size)
		{
			if (rawfile->len > 0 && rawfile->compressedLen == 0)
			{
				std::memset(buf, 0, size);
				std::memcpy(buf, rawfile->buffer, std::min(rawfile->len, size));
				return;
			}

			utils::hook::invoke<void>(SELECT_VALUE(0x1F1E00_b, 0x396080_b), rawfile, buf, size);
		}

		std::optional<std::pair<std::string, std::string>> find_function(const char* pos)
		{
			for (const auto& file : scripting::script_function_table_sort)
			{
				for (auto i = file.second.begin(); i != file.second.end() && std::next(i) != file.second.end(); ++i)
				{
					const auto next = std::next(i);
					if (pos >= i->second && pos < next->second)
					{
						return {std::make_pair(i->first, file.first)};
					}
				}
			}

			return {};
		}

		void print_callstack()
		{
			for (auto frame = game::scr_VmPub->function_frame; frame != game::scr_VmPub->function_frame_start; --frame)
			{
				const auto pos = frame == game::scr_VmPub->function_frame 
					? game::scr_function_stack->pos 
					: frame->fs.pos;
				const auto function = find_function(pos);

				if (function.has_value())
				{
					console::warn("\tat function \"%s\" in file \"%s.gsc\"", 
						function.value().first.data(), function.value().second.data());
				}
				else
				{
					console::warn("\tat unknown location %p", pos);
				}
			}
		}

		std::optional<std::string> get_opcode_name(const std::uint8_t opcode)
		{
			try
			{
				return {xsk::gsc::h1::resolver::opcode_name(opcode)};
			}
			catch (...)
			{
				return {};
			}
		}

		void builtin_call_error(const std::string& error_str)
		{
			const auto pos = game::scr_function_stack->pos;
			const auto function_id = *reinterpret_cast<std::uint16_t*>(
				reinterpret_cast<size_t>(pos - 2));

			if (function_id > 0x1000)
			{
				console::warn("in call to builtin method \"%s\"%s",
					xsk::gsc::h1::resolver::method_name(function_id).data(), error_str.data());
			}
			else
			{
				console::warn("in call to builtin function \"%s\"%s",
					xsk::gsc::h1::resolver::function_name(function_id).data(), error_str.data());
			}
		}

		void* vm_error_stub(void* a1)
		{
			if (!developer_script->current.enabled && !force_error_print)
			{
				return utils::hook::invoke<void*>(SELECT_VALUE(0x415C90_b, 0x59DDA0_b), a1);
			}

			console::warn("*********** script runtime error *************\n");

			const auto opcode_id = *reinterpret_cast<std::uint8_t*>(SELECT_VALUE(0xC4015E8_b, 0xB7B8968_b));
			const std::string error_str = gsc_error.has_value()
				? utils::string::va(": %s", gsc_error.value().data())
				: "";

			if ((opcode_id >= 0x1A && opcode_id <= 0x20) || (opcode_id >= 0xA9 && opcode_id <= 0xAF))
			{
				builtin_call_error(error_str);
			}
			else
			{
				const auto opcode = get_opcode_name(opcode_id);
				if (opcode.has_value())
				{
					console::warn("while processing instruction %s%s\n",
						opcode.value().data(), error_str.data());
				}
				else
				{
					console::warn("while processing instruction 0x%X%s\n",
						opcode_id, error_str.data());
				}
			}

			force_error_print = false;
			gsc_error = {};

			print_callstack();
			console::warn("**********************************************\n");
			return utils::hook::invoke<void*>(SELECT_VALUE(0x415C90_b, 0x59DDA0_b), a1);
		}

		void get_unknown_function_error(const char* code_pos)
		{
			const auto function = find_function(code_pos);
			if (function.has_value())
			{
				const auto& pos = function.value();
				unknown_function_error = utils::string::va(
					"while processing function '%s' in script '%s':\nunknown script '%s'",
					pos.first.data(), pos.second.data(), scripting::current_file.data()
				);
			}
			else
			{
				unknown_function_error = utils::string::va(
					"unknown script '%s'",
					scripting::current_file.data()
				);
			}
		}

		std::string get_filename_name()
		{
			const auto filename_str = game::SL_ConvertToString(
				static_cast<game::scr_string_t>(current_filename));
			const auto id = std::atoi(filename_str);
			if (id == 0)
			{
				return filename_str;
			}

			return scripting::get_token(id);
		}

		void get_unknown_function_error(unsigned int thread_name)
		{
			const auto filename = get_filename_name();
			const auto name = scripting::get_token(thread_name);

			unknown_function_error = utils::string::va(
				"while processing script '%s':\nunknown function '%s::%s'",
				scripting::current_file.data(), filename.data(), name.data()
			);
		}

		void unknown_function_stub(const char* code_pos)
		{
			get_unknown_function_error(code_pos);
			game::Com_Error(game::ERR_DROP, "script link error\n%s",
				unknown_function_error.data());
		}

		unsigned int find_variable_stub(unsigned int parent_id, unsigned int thread_name)
		{
			const auto res = game::FindVariable(parent_id, thread_name);
			if (!res)
			{
				get_unknown_function_error(thread_name);
				game::Com_Error(game::ERR_DROP, "script link error\n%s",
					unknown_function_error.data());
			}
			return res;
		}

		void register_gsc_functions_stub(void* a1, void* a2)
		{
			utils::hook::invoke<void>(SELECT_VALUE(0x2E0F50_b, 0x1CE010_b), a1, a2);
			for (const auto& function : functions)
			{
				game::Scr_RegisterFunction(function.first, 0, function.second);
			}
		}

		void register_gsc_methods_stub(void* a1, void* a2)
		{
			utils::hook::invoke<void>(SELECT_VALUE(0x2E0FB0_b, 0x1CE120_b), a1, a2);
			for (const auto& method : methods)
			{
				game::Scr_RegisterFunction(method.first, 0, method.second);
			}
		}

		void execute_custom_function(builtin_function function)
		{
			auto error = false;

			try
			{
				function();
			}
			catch (const std::exception& e)
			{
				error = true;
				force_error_print = true;
				gsc_error = e.what();
			}

			if (error)
			{
				game::Scr_ErrorInternal();
			}
		}

		void execute_custom_method(scripting::script_function method, game::scr_entref_t ent_ref)
		{
			auto error = false;

			try
			{
				method(ent_ref);
			}
			catch (const std::exception& e)
			{
				error = true;
				force_error_print = true;
				gsc_error = e.what();
			}

			if (error)
			{
				game::Scr_ErrorInternal();
			}
		}

		void vm_call_builtin_function_stub(builtin_function function)
		{
			auto is_custom_function = false;
			{
				is_custom_function = functions.find(function) != functions.end();
			}

			if (!is_custom_function)
			{
				function();
			}
			else
			{
				execute_custom_function(function);
			}
		}

		utils::hook::detour scr_emit_function_hook;
		void scr_emit_function_stub(unsigned int filename, unsigned int thread_name, char* code_pos)
		{
			current_filename = filename;
			scr_emit_function_hook.invoke<void>(filename, thread_name, code_pos);
		}
	}

	game::ScriptFile* find_script(game::XAssetType /*type*/, const char* name, int /*allow_create_default*/)
	{
		if (game::VirtualLobby_Loaded())
		{
			return game::DB_FindXAssetHeader(game::ASSET_TYPE_SCRIPTFILE, name, 1).scriptfile;
		}

		std::string real_name = name;
		const auto id = static_cast<std::uint16_t>(std::atoi(name));
		if (id)
		{
			real_name = xsk::gsc::h1::resolver::token_name(id);
		}

		const auto script = load_custom_script(name, real_name);
		if (script)
		{
			return script;
		}

		return game::DB_FindXAssetHeader(game::ASSET_TYPE_SCRIPTFILE, name, 1).scriptfile;
	}

	void load_main_handles()
	{
		for (auto& function_handle : main_handles)
		{
			console::info("Executing '%s::main'\n", function_handle.first.data());
			game::RemoveRefToObject(game::Scr_ExecThread(function_handle.second, 0));
		}
	}

	void load_init_handles()
	{
		for (auto& function_handle : init_handles)
		{
			console::info("Executing '%s::init'\n", function_handle.first.data());
			game::RemoveRefToObject(game::Scr_ExecThread(function_handle.second, 0));
		}
	}

	scripting::script_value get_argument(int index)
	{
		if (index >= static_cast<int>(game::scr_VmPub->outparamcount))
		{
			return {};
		}

		return game::scr_VmPub->top[-index];
	}

	namespace function
	{
		void add(const std::string& name, builtin_function function)
		{
			if (xsk::gsc::h1::resolver::find_function(name))
			{
				const auto id = xsk::gsc::h1::resolver::function_id(name);
				functions[function] = id;
			}
			else
			{
				const auto id = ++function_id_start;
				xsk::gsc::h1::resolver::add_function(name, static_cast<std::uint16_t>(id));
				functions[function] = id;
			}
		}
	}

	namespace method
	{
		void add(const std::string& name, scripting::script_function method)
		{
			if (xsk::gsc::h1::resolver::find_method(name))
			{
				const auto id = xsk::gsc::h1::resolver::method_id(name);
				methods[method] = id;
			}
			else
			{
				const auto id = ++method_id_start;
				xsk::gsc::h1::resolver::add_method(name, static_cast<std::uint16_t>(id));
				methods[method] = id;
			}
		}
	}

	class component final : public component_interface
	{
	public:
		void post_unpack() override
		{
			developer_script = dvars::register_bool("developer_script", false, 0, "Print GSC errors");

			// Allow custom scripts to include other custom scripts
			xsk::gsc::h1::resolver::init([](const auto& include_name)
			{
				const auto real_name = include_name + ".gsc";

				std::string file_buffer;
				if (!read_scriptfile(real_name, &file_buffer) || file_buffer.empty())
				{
					throw std::runtime_error(std::format("could not load gsc file '{}'", real_name));
				}

				std::vector<std::uint8_t> result;
				result.assign(file_buffer.begin(), file_buffer.end());

				return result;
			});

			// hook xasset functions to return our own custom scripts
			utils::hook::call(SELECT_VALUE(0x3C7217_b, 0x50E357_b), find_script);
			utils::hook::call(SELECT_VALUE(0x3C7227_b, 0x50E367_b), db_is_xasset_default);

			// loads scripts with an uncompressed stack
			utils::hook::call(SELECT_VALUE(0x3C7280_b, 0x50E3C0_b), db_get_raw_buffer_stub);

			// load script handles
			utils::hook::call(SELECT_VALUE(0x2BA152_b, 0x18C325_b), load_gametype_script_stub);

			utils::hook::call(SELECT_VALUE(0x3CC9F3_b, 0x513A53_b), vm_error_stub);

			// patch error to drop + give more information
			utils::hook::call(SELECT_VALUE(0x3BD626_b, 0x504606_b), unknown_function_stub); // CompileError
			utils::hook::call(SELECT_VALUE(0x3BD672_b, 0x504652_b), unknown_function_stub); // ^
			utils::hook::call(SELECT_VALUE(0x3BD75A_b, 0x50473A_b), find_variable_stub);
			scr_emit_function_hook.create(SELECT_VALUE(0x3BD680_b, 0x504660_b), scr_emit_function_stub);

			utils::hook::call(SELECT_VALUE(0x3BDC4F_b, 0x504C7F_b), register_gsc_functions_stub);
			utils::hook::call(SELECT_VALUE(0x3BDC5B_b, 0x504C8B_b), register_gsc_methods_stub);

			utils::hook::set<uint32_t>(SELECT_VALUE(0x3BD86C_b, 0x50484C_b), 0x1000); // change builtin func count

			utils::hook::set<uint32_t>(SELECT_VALUE(0x3BD872_b, 0x504852_b) + 4,
				static_cast<uint32_t>(reverse_b((&func_table))));
			utils::hook::set<uint32_t>(SELECT_VALUE(0x3CB718_b, 0x512778_b) + 4,
				static_cast<uint32_t>(reverse_b((&func_table))));
			utils::hook::inject(SELECT_VALUE(0x3BDC28_b, 0x504C58_b) + 3, &func_table);
			utils::hook::set<uint32_t>(SELECT_VALUE(0x3BDC1E_b, 0x504C4E_b), sizeof(func_table));

			utils::hook::set<uint32_t>(SELECT_VALUE(0x3BD882_b, 0x504862_b) + 4, 
				static_cast<uint32_t>(reverse_b((&meth_table))));
			utils::hook::set<uint32_t>(SELECT_VALUE(0x3CBA3B_b, 0x512A9B_b) + 4,
				static_cast<uint32_t>(reverse_b(&meth_table)));
			utils::hook::inject(SELECT_VALUE(0x3BDC36_b, 0x504C66_b) + 3, &meth_table);
			utils::hook::set<uint32_t>(SELECT_VALUE(0x3BDC3F_b, 0x504C6F_b), sizeof(meth_table));

			utils::hook::nop(SELECT_VALUE(0x3CB723_b, 0x512783_b), 8);
			utils::hook::call(SELECT_VALUE(0x3CB723_b, 0x512783_b), vm_call_builtin_function_stub);

			function::add("print", []()
			{
				const auto num = game::Scr_GetNumParam();
				std::string buffer{};

				for (auto i = 0; i < num; i++)
				{
					const auto str = game::Scr_GetString(i);
					buffer.append(str);
					buffer.append("\t");
				}

				console::info("%s\n", buffer.data());
			});

			function::add("assert", []()
			{
				const auto expr = get_argument(0).as<int>();
				if (!expr)
				{
					throw std::runtime_error("assert fail");
				}
			});

			function::add("assertex", []()
			{
				const auto expr = get_argument(0).as<int>();
				if (!expr)
				{
					const auto error = get_argument(1).as<std::string>();
					throw std::runtime_error(error);
				}
			});

			function::add("replacefunc", []()
			{
				const auto what = get_argument(0).get_raw();
				const auto with = get_argument(1).get_raw();

				if (what.type != game::SCRIPT_FUNCTION)
				{
					throw std::runtime_error("replaceFunc: parameter 1 must be a function");
				}

				if (with.type != game::SCRIPT_FUNCTION)
				{
					throw std::runtime_error("replaceFunc: parameter 2 must be a function");
				}

				logfile::set_gsc_hook(what.u.codePosValue, with.u.codePosValue);
			});

			function::add("toupper", []()
			{
				const auto string = get_argument(0).as<std::string>();
				game::Scr_AddString(utils::string::to_upper(string).data());
			});

			function::add("logprint", []()
			{
				std::string buffer{};

				const auto params = game::Scr_GetNumParam();
				for (auto i = 0; i < params; i++)
				{
					const auto string = game::Scr_GetString(i);
					buffer.append(string);
				}

				game::G_LogPrintf("%s", buffer.data());
			});

			scripting::on_shutdown([](int free_scripts)
			{
				if (free_scripts)
				{
					clear();
				}
			});
		}
	};
}

REGISTER_COMPONENT(gsc::component)