#!/usr/bin/env python3
"""
Update the DUMPER_VERSION placeholder in cpp_python_debug/core/gdb_dumper.py.

Usage:
    python tools/update_dumper_version.py [--version X.Y.Z] [--commit]

Behavior:
 - If --version is provided, that version will be used.
 - Otherwise the script will try, in order:
     1) read cpp_python_debug/_version.py for __version__
     2) run `git describe --tags --always` in the repository root (searching upwards)
 - The script replaces the first occurrence of DUMPER_VERSION = "..." in
   `cpp_python_debug/core/gdb_dumper.py` with the chosen version string.
 - If --commit is passed and the repo is a git repo, it will stage and commit
   the updated file with a message.

Note: This script does not assume the dumper will be executed in the repo; it
writes the version directly into the dumper file so that copies of the file
still carry a concrete version string.
"""

import argparse
import os
import re
import subprocess
import sys

ROOT = os.path.abspath(os.path.join(os.path.dirname(__file__), os.pardir))
DUMPER_PATH = os.path.join(ROOT, "cpp_python_debug", "core", "gdb_dumper.py")
VERSION_FILE = os.path.join(ROOT, "cpp_python_debug", "_version.py")


def read_version_from_file():
    if not os.path.exists(VERSION_FILE):
        return None
    content = open(VERSION_FILE, "r", encoding="utf-8").read()
    m = re.search(r"^__version__\s*=\s*['\"]([^'\"]+)['\"]", content, re.M)
    return m.group(1) if m else None


def git_describe_from(path):
    # Walk upwards looking for a .git directory
    cur = os.path.abspath(path)
    for _ in range(50):
        if os.path.isdir(os.path.join(cur, ".git")):
            try:
                out = subprocess.check_output(["git", "-C", cur, "describe", "--tags", "--always"], stderr=subprocess.DEVNULL)
                return out.decode().strip()
            except Exception:
                return None
        parent = os.path.dirname(cur)
        if parent == cur:
            break
        cur = parent
    # As a last resort, try running git describe in the provided path
    try:
        out = subprocess.check_output(["git", "describe", "--tags", "--always"], cwd=path, stderr=subprocess.DEVNULL)
        return out.decode().strip()
    except Exception:
        return None


def replace_dumper_version(new_version: str, commit: bool = False):
    if not os.path.exists(DUMPER_PATH):
        print(f"ERROR: dumper file not found at {DUMPER_PATH}")
        return 2
    txt = open(DUMPER_PATH, "r", encoding="utf-8").read()
    # Replace the first occurrence of DUMPER_VERSION = "..."
    new_txt, count = re.subn(r"DUMPER_VERSION\s*=\s*\"[^\"]*\"", f'DUMPER_VERSION = "{new_version}"', txt, count=1)
    if count == 0:
        print("WARNING: placeholder not found; inserting at top of file")
        # Prepend definition after imports block heuristically
        new_txt = txt.replace("from typing import Optional, Dict, Any, List, Tuple\n", "from typing import Optional, Dict, Any, List, Tuple\n\n# DUMPER_VERSION injected by tools/update_dumper_version.py\nDUMPER_VERSION = \"{0}\"\n".format(new_version), 1)
    if new_txt == txt:
        print("No changes needed (version already set).")
        return 0
    open(DUMPER_PATH, "w", encoding="utf-8").write(new_txt)
    print(f"Updated {DUMPER_PATH} -> DUMPER_VERSION = {new_version}")
    if commit:
        try:
            subprocess.check_call(["git", "add", DUMPER_PATH], cwd=ROOT)
            subprocess.check_call(["git", "commit", "-m", f"chore: update dumper version to {new_version}"], cwd=ROOT)
            print("Committed change to git.")
        except Exception as e:
            print(f"Failed to commit: {e}")
            return 3
    return 0


def main():
    ap = argparse.ArgumentParser()
    ap.add_argument("--version", help="explicit version to write")
    ap.add_argument("--commit", action="store_true", help="stage and commit the change")
    args = ap.parse_args()

    version = args.version
    if not version:
        version = read_version_from_file()
    if not version:
        version = git_describe_from(ROOT)
    if not version:
        print("Could not determine version from _version.py or git; please pass --version")
        return 10
    return replace_dumper_version(version, commit=args.commit)


if __name__ == "__main__":
    sys.exit(main())