#!/usr/bin/env python3

###
# Generates a ctx.c file, usable for "Context" on https://decomp.me.
#
# Usage:
#   python3 tools/decompctx.py src/file.cpp
#
# If changes are made, please submit a PR to
# https://github.com/encounter/dtk-template
###

import argparse
import os
import re

script_dir = os.path.dirname(os.path.realpath(__file__))
root_dir = os.path.abspath(os.path.join(script_dir, ".."))
src_dir = os.path.join(root_dir, "src")
include_dirs = [
    os.path.join(root_dir, "include"),
    os.path.join(root_dir, "libc"),
]

include_pattern = re.compile(r'^#include\s*[<"](.+?)[>"]$')
guard_pattern = re.compile(r'^#ifndef\s+(.*)$')

defines = set()

def import_h_file(in_file: str, r_path: str) -> str:
    rel_path = os.path.join(root_dir, r_path, in_file)
    if os.path.exists(rel_path):
        return import_c_file(rel_path)
    for include_dir in include_dirs:
        inc_path = os.path.join(include_dir, in_file)
        if os.path.exists(inc_path):
            return import_c_file(inc_path)
    else:
        print("Failed to locate", in_file)
        return ""

def import_c_file(in_file) -> str:
    in_file = os.path.relpath(in_file, root_dir)
    out_text = ''

    try:
      with open(in_file, encoding="utf-8") as file:
        out_text += process_file(in_file, list(file))
    except Exception:
      with open(in_file) as file:
        out_text += process_file(in_file, list(file))
    return out_text

def process_file(in_file: str, lines) -> str:
    out_text = ''
    for idx, line in enumerate(lines):
      guard_match = guard_pattern.match(line.strip())
      if idx == 0:
        if guard_match:
          if guard_match[1] in defines:
            break
          defines.add(guard_match[1])
        print("Processing file", in_file)
      include_match = include_pattern.match(line.strip())
      if include_match and not include_match[1].endswith(".s"):
        out_text += f"/* \"{in_file}\" line {idx} \"{include_match[1]}\" */\n"
        out_text += import_h_file(include_match[1], os.path.dirname(in_file))
        out_text += f"/* end \"{include_match[1]}\" */\n"
      else:
        out_text += line

    return out_text

def main():
    parser = argparse.ArgumentParser(
        description="""Create a context file which can be used for decomp.me"""
    )
    parser.add_argument(
        "c_file",
        help="""File from which to create context""",
    )
    args = parser.parse_args()

    output = import_c_file(args.c_file)

    with open(os.path.join(root_dir, "ctx.c"), "w", encoding="utf-8") as f:
        f.write(output)


if __name__ == "__main__":
    main()