#define USE_CUSTOM_BACKEND false

#include "common.cpp"
#include "timings.cpp"
#include "build_settings.cpp"
#include "tokenizer.cpp"
#include "parser.cpp"
#include "checker.cpp"
#include "ssa.cpp"
#include "ir.cpp"
#include "ir_opt.cpp"
#include "ir_print.cpp"

#if defined(GB_SYSTEM_WINDOWS)
// NOTE(bill): `name` is used in debugging and profiling modes
i32 system_exec_command_line_app(char *name, bool is_silent, char *fmt, ...) {
	STARTUPINFOW start_info = {gb_size_of(STARTUPINFOW)};
	PROCESS_INFORMATION pi = {0};
	char cmd_line[4096] = {0};
	isize cmd_len;
	va_list va;
	gbTempArenaMemory tmp;
	String16 cmd;
	i32 exit_code = 0;

	start_info.dwFlags = STARTF_USESTDHANDLES | STARTF_USESHOWWINDOW;
	start_info.wShowWindow = SW_SHOW;
	start_info.hStdInput   = GetStdHandle(STD_INPUT_HANDLE);
	start_info.hStdOutput  = GetStdHandle(STD_OUTPUT_HANDLE);
	start_info.hStdError   = GetStdHandle(STD_ERROR_HANDLE);

	va_start(va, fmt);
	cmd_len = gb_snprintf_va(cmd_line, gb_size_of(cmd_line), fmt, va);
	va_end(va);
	// gb_printf("%.*s\n", cast(int)cmd_len, cmd_line);

	tmp = gb_temp_arena_memory_begin(&string_buffer_arena);

	cmd = string_to_string16(string_buffer_allocator, make_string(cast(u8 *)cmd_line, cmd_len-1));

	if (CreateProcessW(NULL, cmd.text,
	                   NULL, NULL, true, 0, NULL, NULL,
	                   &start_info, &pi)) {
		WaitForSingleObject(pi.hProcess, INFINITE);
		GetExitCodeProcess(pi.hProcess, cast(DWORD *)&exit_code);

		CloseHandle(pi.hProcess);
		CloseHandle(pi.hThread);
	} else {
		// NOTE(bill): failed to create process
		gb_printf_err("Failed to execute command:\n\t%s\n", cmd_line);
		exit_code = -1;
	}

	gb_temp_arena_memory_end(tmp);
	return exit_code;
}
#elif defined(GB_SYSTEM_OSX) || defined(GB_SYSTEM_UNIX)
i32 system_exec_command_line_app(char *name, bool is_silent, char *fmt, ...) {

	char cmd_line[4096] = {0};
	isize cmd_len;
	va_list va;
	String cmd;
	i32 exit_code = 0;

	va_start(va, fmt);
	cmd_len = gb_snprintf_va(cmd_line, gb_size_of(cmd_line), fmt, va);
	va_end(va);
	cmd = make_string(cast(u8 *)&cmd_line, cmd_len-1);

	exit_code = system(&cmd_line[0]);

	// pid_t pid = fork();
	// int status = 0;

	// if(pid == 0) {
	// 	// in child, pid == 0.
	// 	int ret = execvp(cmd.text, (char* const*) cmd.text);

	// 	if(ret == -1) {
	// 		gb_printf_err("Failed to execute command:\n\t%s\n", cmd_line);

	// 		// we're in the child, so returning won't do us any good -- just quit.
	// 		exit(-1);
	// 	}

	// 	// unreachable
	// 	abort();
	// } else {
	// 	// wait for child to finish, then we can continue cleanup

	// 	int s = 0;
	// 	waitpid(pid, &s, 0);

	// 	status = WEXITSTATUS(s);
	// }

	// exit_code = status;

	return exit_code;
}
#endif





void print_usage_line(i32 indent, char *fmt, ...) {
	while (indent --> 0) {
		gb_printf_err("\t");
	}
	va_list va;
	va_start(va, fmt);
	gb_printf_err_va(fmt, va);
	va_end(va);
	gb_printf_err("\n");
}

void usage(char *argv0) {
	print_usage_line(0, "%s is a tool for managing Odin source code", argv0);
	print_usage_line(0, "Usage:");
	print_usage_line(1, "%s command [arguments]", argv0);
	print_usage_line(0, "Commands:");
	print_usage_line(1, "build        compile .odin file as executable");
	print_usage_line(1, "build_dll    compile .odin file as dll");
	print_usage_line(1, "run          compile and run .odin file");
	print_usage_line(1, "version      print version");
}

int main(int argc, char **argv) {
	if (argc < 2) {
		usage(argv[0]);
		return 1;
	}

	Timings timings = {0};
	timings_init(&timings, str_lit("Total Time"), 128);
	// defer (timings_destroy(&timings));
	init_string_buffer_memory();
	init_scratch_memory(gb_megabytes(10));
	init_global_error_collector();

#if 1

	init_build_context();

	init_universal_scope();

	char *init_filename = NULL;
	bool run_output = false;
	String arg1 = make_string_c(argv[1]);
	if (arg1 == "run") {
		if (argc != 3) {
			usage(argv[0]);
			return 1;
		}
		init_filename = argv[2];
		run_output = true;
	} else if (arg1 == "build_dll") {
		if (argc != 3) {
			usage(argv[0]);
			return 1;
		}
		init_filename = argv[2];
		build_context.is_dll = true;
	} else if (arg1 == "build") {
		if (argc != 3) {
			usage(argv[0]);
			return 1;
		}
		init_filename = argv[2];
	} else if (arg1 == "version") {
		gb_printf("%s version %.*s\n", argv[0], LIT(build_context.ODIN_VERSION));
		return 0;
	} else {
		usage(argv[0]);
		return 1;
	}

	// TODO(bill): prevent compiling without a linker

	timings_start_section(&timings, str_lit("parse files"));

	Parser parser = {0};
	if (!init_parser(&parser)) {
		return 1;
	}
	// defer (destroy_parser(&parser));

	if (parse_files(&parser, init_filename) != ParseFile_None) {
		return 1;
	}


#if 1
	timings_start_section(&timings, str_lit("type check"));

	Checker checker = {0};

	init_checker(&checker, &parser, &build_context);
	// defer (destroy_checker(&checker));

	check_parsed_files(&checker);


#endif
#if USE_CUSTOM_BACKEND
	if (global_error_collector.count != 0) {
		return 1;
	}

	if (checker.parser->total_token_count < 2) {
		return 1;
	}

	if (!ssa_generate(&parser, &checker.info)) {
		return 1;
	}
#else
	irGen ir_gen = {0};
	if (!ir_gen_init(&ir_gen, &checker)) {
		return 1;
	}
	// defer (ssa_gen_destroy(&ir_gen));

	timings_start_section(&timings, str_lit("llvm ir gen"));
	ir_gen_tree(&ir_gen);

	timings_start_section(&timings, str_lit("llvm ir opt tree"));
	ir_opt_tree(&ir_gen);

	timings_start_section(&timings, str_lit("llvm ir print"));
	print_llvm_ir(&ir_gen);

	// prof_print_all();

	#if 1
	timings_start_section(&timings, str_lit("llvm-opt"));

	String output_name = ir_gen.output_name;
	String output_base = ir_gen.output_base;
	int base_name_len = output_base.len;

	i32 optimization_level = 0;
	optimization_level = gb_clamp(optimization_level, 0, 3);

	i32 exit_code = 0;

	#if defined(GB_SYSTEM_WINDOWS)
	// For more passes arguments: http://llvm.org/docs/Passes.html
	exit_code = system_exec_command_line_app("llvm-opt", false,
		"\"%.*sbin/opt\" \"%.*s\".ll -o \"%.*s\".bc "
		"-mem2reg "
		"-memcpyopt "
		"-die "
		// "-dse "
		// "-dce "
		// "-S "
		"",
		LIT(build_context.ODIN_ROOT),
		LIT(output_base), LIT(output_base));
	if (exit_code != 0) {
		return exit_code;
	}
	#else
	// NOTE(zangent): This is separate because it seems that LLVM tools are packaged
	//   with the Windows version, while they will be system-provided on MacOS and GNU/Linux
	exit_code = system_exec_command_line_app("llvm-opt", false,
		"opt \"%.*s\".ll -o \"%.*s\".bc "
		"-mem2reg "
		"-memcpyopt "
		"-die "
		#if defined(GB_SYSTEM_OSX)
			// This sets a requirement of Mountain Lion and up, but the compiler doesn't work without this limit.
			// NOTE: If you change this (although this minimum is as low as you can go with Odin working)
			//       make sure to also change the `macosx_version_min` param passed to `llc`
			"-mtriple=x86_64-apple-macosx10.8 "
		#endif
		// "-dse "
		// "-dce "
		// "-S "
		"",
		LIT(output_base), LIT(output_base));
	if (exit_code != 0) {
		return exit_code;
	}
	#endif

	#if defined(GB_SYSTEM_WINDOWS)
	timings_start_section(&timings, str_lit("llvm-llc"));
	// For more arguments: http://llvm.org/docs/CommandGuide/llc.html
	exit_code = system_exec_command_line_app("llvm-llc", false,
		"\"%.*sbin/llc\" \"%.*s.bc\" -filetype=obj -O%d "
		"%.*s "
		// "-debug-pass=Arguments "
		"",
		LIT(build_context.ODIN_ROOT),
		LIT(output_base),
		optimization_level,
		LIT(build_context.llc_flags));
	if (exit_code != 0) {
		return exit_code;
	}

	timings_start_section(&timings, str_lit("msvc-link"));

	gbString lib_str = gb_string_make(heap_allocator(), "");
	// defer (gb_string_free(lib_str));
	char lib_str_buf[1024] = {0};
	for_array(i, ir_gen.module.foreign_library_paths) {
		String lib = ir_gen.module.foreign_library_paths[i];
		// gb_printf_err("Linking lib: %.*s\n", LIT(lib));
		isize len = gb_snprintf(lib_str_buf, gb_size_of(lib_str_buf),
		                        " \"%.*s\"", LIT(lib));
		lib_str = gb_string_appendc(lib_str, lib_str_buf);
	}

	char *output_ext = "exe";
	char *link_settings = "";
	if (build_context.is_dll) {
		output_ext = "dll";
		link_settings = "/DLL";
	} else {
		link_settings = "/ENTRY:mainCRTStartup";
	}

	exit_code = system_exec_command_line_app("msvc-link", true,
		"link \"%.*s\".obj -OUT:\"%.*s.%s\" %s "
		"/defaultlib:libcmt "
		"/nologo /incremental:no /opt:ref /subsystem:CONSOLE "
		" %.*s "
		" %s "
		"",
		LIT(output_base), LIT(output_base), output_ext,
		lib_str, LIT(build_context.link_flags),
		link_settings
		);
	if (exit_code != 0) {
		return exit_code;
	}

	// timings_print_all(&timings);

	if (run_output) {
		system_exec_command_line_app("odin run", false, "%.*s.exe", LIT(output_base));
	}

	#else

	// NOTE(zangent): Linux / Unix is unfinished and not tested very well.


	timings_start_section(&timings, str_lit("llvm-llc"));
	// For more arguments: http://llvm.org/docs/CommandGuide/llc.html
	exit_code = system_exec_command_line_app("llc", false,
		"llc \"%.*s.bc\" -filetype=obj -relocation-model=pic -O%d "
		"%.*s "
		// "-debug-pass=Arguments "
		"",
		LIT(output_base),
		optimization_level,
		LIT(build_context.llc_flags));
	if (exit_code != 0) {
		return exit_code;
	}

	timings_start_section(&timings, str_lit("ld-link"));

	gbString lib_str = gb_string_make(heap_allocator(), "");
	// defer (gb_string_free(lib_str));
	char lib_str_buf[1024] = {0};
	for_array(i, ir_gen.module.foreign_library_paths) {
		String lib = ir_gen.module.foreign_library_paths[i];

		// NOTE(zangent): Sometimes, you have to use -framework on MacOS.
		//   This allows you to specify '-f' in a #foreign_system_library,
		//   without having to implement any new syntax specifically for MacOS.
		#if defined(GB_SYSTEM_OSX)
			isize len;
			if(lib.len > 2 && lib[0] == '-' && lib[1] == 'f') {
				len = gb_snprintf(lib_str_buf, gb_size_of(lib_str_buf),
				                        " -framework %.*s ", (int)(lib.len) - 2, lib.text + 2);
			} else {
				len = gb_snprintf(lib_str_buf, gb_size_of(lib_str_buf),
				                        " -l%.*s ", LIT(lib));
			}
		#else
			isize len = gb_snprintf(lib_str_buf, gb_size_of(lib_str_buf),
			                        " -l%.*s ", LIT(lib));
		#endif
		lib_str = gb_string_appendc(lib_str, lib_str_buf);
	}

	// Unlike the Win32 linker code, the output_ext includes the dot, because
	// typically executable files on *NIX systems don't have extensions.
	char *output_ext = "";
	char *link_settings = "";
	char *linker;
	if (build_context.is_dll) {
		// Shared libraries are .dylib on MacOS and .so on Linux.
		// TODO(zangent): Is that statement entirely truthful?
		#if defined(GB_SYSTEM_OSX)
			output_ext = ".dylib";
		#else
			output_ext = ".so";
		#endif

		link_settings = "-shared";
	} else {
		// TODO: Do I need anything here?
		link_settings = "";
	}

	#if defined(GB_SYSTEM_OSX)
		linker = "ld";
	#else
		// TODO(zangent): Figure out how to make ld work on Linux.
		//   It probably has to do with including the entire CRT, but
		//   that's quite a complicated issue to solve while remaining distro-agnostic.
		//   Clang can figure out linker flags for us, and that's good enough _for now_.
		linker = "clang -Wno-unused-command-line-argument";
	#endif

	exit_code = system_exec_command_line_app("ld-link", true,
		"%s \"%.*s\".o -o \"%.*s%s\" %s "
		"-lc -lm "
		" %.*s "
		" %s "
		#if defined(GB_SYSTEM_OSX)
			// This sets a requirement of Mountain Lion and up, but the compiler doesn't work without this limit.
			// NOTE: If you change this (although this minimum is as low as you can go with Odin working)
			//       make sure to also change the `mtriple` param passed to `opt`
			" -macosx_version_min 10.8.0 "
			// This points the linker to where the entry point is
			" -e _main "
		#endif
		, linker, LIT(output_base), LIT(output_base), output_ext,
		lib_str, LIT(build_context.link_flags),
		link_settings
		);
	if (exit_code != 0) {
		return exit_code;
	}

	// timings_print_all(&timings);

	if (run_output) {
		system_exec_command_line_app("odin run", false, "%.*s", LIT(output_base));
	}

	#endif
#endif
#endif
#endif

	return 0;
}