scripts/_ports.py

"""Per-worktree dev port computation.

Single source of truth so the FastAPI launcher, the LangGraph Studio wrapper,
and the kill-ports helper all agree on which two ports this worktree owns.

Conductor exposes ``CONDUCTOR_WORKSPACE_NAME`` for every worktree it manages.
We hash that into a stable 1-99 offset so two worktrees never collide. The
original (non-worktree) checkout has no such env var and keeps the canonical
8000 / 2024 ports.

Override either port at any time by exporting ``PORT`` or ``LANGGRAPH_PORT``
before starting the dev process — these win unconditionally.

CLI:
    uv run python scripts/_ports.py            # human-readable summary
    uv run python scripts/_ports.py server     # server port only
    uv run python scripts/_ports.py studio     # studio port only
    uv run python scripts/_ports.py export     # printable shell exports
"""

from __future__ import annotations

import hashlib
import os
import sys

_BASE_SERVER_PORT = 8000
_BASE_STUDIO_PORT = 2024


def workspace_name() -> str | None:
    """Return the Conductor workspace name, or None outside Conductor."""
    return os.environ.get("CONDUCTOR_WORKSPACE_NAME") or None


def _offset() -> int:
    name = workspace_name()
    if not name:
        return 0
    digest = hashlib.sha1(name.encode("utf-8")).hexdigest()
    return int(digest, 16) % 99 + 1


def server_port() -> int:
    if (override := os.environ.get("PORT")):
        return int(override)
    return _BASE_SERVER_PORT + _offset()


def studio_port() -> int:
    if (override := os.environ.get("LANGGRAPH_PORT")):
        return int(override)
    return _BASE_STUDIO_PORT + _offset()


def main() -> None:
    cmd = sys.argv[1] if len(sys.argv) > 1 else "info"
    if cmd == "server":
        print(server_port())
    elif cmd == "studio":
        print(studio_port())
    elif cmd == "export":
        print(f"export PORT={server_port()}")
        print(f"export LANGGRAPH_PORT={studio_port()}")
    elif cmd == "info":
        name = workspace_name() or "(none — canonical ports)"
        print(f"workspace: {name}")
        print(f"offset:    +{_offset()}")
        print(f"server:    http://127.0.0.1:{server_port()}")
        print(f"studio:    http://127.0.0.1:{studio_port()}")
    else:
        sys.exit(f"unknown command: {cmd}")


if __name__ == "__main__":
    main()