import json
import plistlib
import re
import textwrap
from pathlib import Path

PLIST_RE = re.compile(r"def plist\s+<<\~EOS\s+(?P<plist>.*)\s+EOS\s+end", re.DOTALL)
PLIST_OPTIONS_RE = re.compile(r"plist_options .*")


def plist_to_service(plist: str) -> str:
    data = plistlib.loads(plist.encode())
    if "StartInterval" in data or "StartCalendarInterval" in data:
        print("ERROR: run_type not yet supported")
        exit(1)
    service = {
        "run": data.get("Program") or data.get("ProgramArguments"),
        "keep_alive": data.get("KeepAlive"),
        "working_dir": data.get("WorkingDirectory"),
        "root_dir": data.get("RootDirectory"),
        "input_path": data.get("StandardInPath"),
        "log_path": data.get("StandardOutputPath"),
        "error_log_path": data.get("StandardErrorPath"),
        "environment_variables": data.get("EnvironmentVariables"),
    }
    block = "service do\n"
    for k, v in service.items():
        if v is not None:
            block += f"  {k} {json.dumps(v)}\n"
    block += "end"
    return block


if __name__ == "__main__":
    from argparse import ArgumentParser

    parser = ArgumentParser(description="Migrate plist file to a service")
    parser.add_argument("file", type=Path, help="plist file to migrate")
    parser.add_argument(
        "-i", "--in-place", action="store_true", help="rewrite in-place"
    )

    args = parser.parse_args()
    contents = args.file.read_text()
    if not (match := PLIST_RE.search(contents)):
        print(f"ERROR: Failed to find a plist in {args.file}")
        exit(1)

    service = plist_to_service(match.group("plist"))
    if args.in_place:
        service = textwrap.indent(service, " " * 2).lstrip()
        contents = PLIST_RE.sub(service, contents, count=1)
        contents = PLIST_OPTIONS_RE.sub("", contents, count=1)
        args.file.write_text(contents)
    else:
        print(service)