#!/usr/bin/env python3

from argparse import ArgumentParser
from dataclasses import dataclass
from os import execvp
from pathlib import Path
import importlib.util

@dataclass
class Options:
	args: list[str]
	gdb: str
	dev_id: str | None

def parse_arguments() -> Options:
	parser = ArgumentParser(prog="dbg", description="GDB wrapper with automatic stuff")

	parser.add_argument("--gdb", default="arm-none-eabi-gdb", help="GDB executable to use")
	parser.add_argument("-i", "--dev-id", type=str, help="J-Link probe serial number to connect to (USB)")

	options, remainder = parser.parse_known_args()
	if len(remainder) > 0 and remainder[0] == "--":
		del remainder[0]
	return Options(**vars(options), args=remainder)

def gdbarg_eval(eval_command: str):
	return "--eval-command=" + eval_command

def gdbarg_exec(path: str, secondary: bool = False):
	if not secondary:
		return "--se=" + path
	else:
		return gdbarg_eval("add-symbol-file " + path)


def find_zephyr_sysbuild_executable() -> list[str]:
	# TODO
	return [  ]

def find_zephyr_executable() -> list[str]:
	out = []

	if not Path("build/zephyr").exists():
		return out

	if not out:
		zephyr = Path("build/zephyr/zephyr.elf")
		if zephyr.exists():
			out.append(gdbarg_exec(str(zephyr), False))
			tfm = Path("build/tfm/bin/tfm_s.elf")
			if tfm.exists():
				out.append(gdbarg_exec(str(tfm), True))
	
	if not out:
		out += find_zephyr_sysbuild_executable()

	return out

def find_generic_executable(base: Path = Path("."), maxdepth: int = 3) -> list[str]:
	if maxdepth == 0:
		return []
	out = []
	for child in base.iterdir():
		if child.is_dir():
			out += find_generic_executable(child, maxdepth - 1)
			if out:
				return out
		elif child.is_file():
			if not child.name.endswith(".elf"):
				continue
			return [gdbarg_exec(str(child))]
		else:
			continue
	return []

def find_executable() -> list[str]:
	out = []

	out += find_zephyr_executable()
	if out:
		return out

	out += find_generic_executable()
	if out:
		return out

	return out

if __name__ == "__main__":
	options = parse_arguments()

	if len(options.args) == 0:
		options.args += find_executable()
	
	if importlib.util.find_spec("debug_renesas") is not None:
		if options.dev_id is not None:
			options.args.append(gdbarg_eval(f"jlink server usb {options.dev_id}"))
		options.args += [
			gdbarg_eval("set jlink autoconnect on"),
			gdbarg_eval("set jlink watchdog on"),
		]

	execvp(options.gdb, [options.gdb] + options.args)