#!/usr/bin/env python3

import os
import re
import sys
from pathlib import Path


def strip_c_comments(text):
    def replacer(match):
        s = match.group(0)
        if s.startswith("/"):
            return " "
        else:
            return s

    pattern = re.compile(
        r'//.*?$|/\*.*?\*/|\'(?:\\.|[^\\\'])*\'|"(?:\\.|[^\\"])*"',
        re.DOTALL | re.MULTILINE,
    )
    return re.sub(pattern, replacer, text)


c_func_pattern = re.compile(r"^(static\s+)?[^\s]+\s+([^\s(]+)\(([^;)]*)\)[^;]+{", re.MULTILINE)


def funcs_in_c(text):
    return (match.group(2) for match in c_func_pattern.finditer(text))


asm_func_pattern = re.compile(r"INCLUDE_ASM\([^,]+, [^,]+, ([^,)]+)", re.MULTILINE)


def include_asms_in_c(text):
    return (match.group(1) for match in asm_func_pattern.finditer(text))


def stuff(version):
    DIR = os.path.dirname(__file__)
    NONMATCHINGS_DIR = Path(os.path.join(DIR, "ver", version, "asm", "nonmatchings"))

    C_FILES = Path(os.path.join(DIR, "src")).rglob("*.c")
    ASM_FILES = NONMATCHINGS_DIR.rglob("*.s")

    matched = []
    asm = []
    for filename in C_FILES:
        with open(filename, "r") as file:
            text = strip_c_comments(file.read())
            matched.extend((m for m in funcs_in_c(text) if not m in matched))
            asm.extend((m for m in include_asms_in_c(text) if not m in asm))

    non_matched = [os.path.splitext(os.path.basename(filename))[0] for filename in ASM_FILES]

    partial_matched = [f for f in matched if f in asm]
    matched = [f for f in matched if not f in partial_matched]
    matched_but_undeleted_asm = set([f for f in matched if f in non_matched and not f in partial_matched])
    orphan_asm = set(non_matched) - set(asm) - matched_but_undeleted_asm

    to_delete = matched_but_undeleted_asm | orphan_asm

    if __name__ == "__main__":
        if "--help" in sys.argv:
            print("--fail-undeleted            exit with error code 1 if obsolete .s functions exist")
            print("--delete                    delete obsolete .s functions without asking")
            exit()

        if len(to_delete) > 0:
            print(f"The following functions can be deleted: {to_delete}")
            if "--fail-undeleted" in sys.argv:
                exit(1)
            elif "--delete" in sys.argv or input("Delete them [y/N]? ").upper() == "Y":
                for func in to_delete:
                    f = next(NONMATCHINGS_DIR.rglob(func + ".s"))
                    os.remove(f)

                # Remove empty directories
                for folder in list(os.walk(NONMATCHINGS_DIR)):
                    if not os.listdir(folder[0]):
                        os.removedirs(folder[0])


stuff("jp")
stuff("us")
stuff("pal")
stuff("ique")