"""Configuration resolution for the opencode-bridge extension.

All connection fields (URL / user / password / request timeout) are resolved
exclusively from environment variables + built-in defaults at server startup.
They are NOT stored in the JupyterLab plugin settings.

Env vars:
  OPENCODE_BRIDGE_URL       — OpenCode Serve base URL (default http://127.0.0.1:4096)
  OPENCODE_BRIDGE_USER      — HTTP Basic Auth username (default 'opencode')
  OPENCODE_BRIDGE_PASSWORD  — HTTP Basic Auth password (default '' = no auth)
  OPENCODE_BRIDGE_TIMEOUT   — request timeout in seconds (default 120)
"""
from __future__ import annotations

import os
from typing import NamedTuple, Optional, Tuple


ENV_URL = "OPENCODE_BRIDGE_URL"
ENV_USER = "OPENCODE_BRIDGE_USER"
ENV_PASSWORD = "OPENCODE_BRIDGE_PASSWORD"
ENV_TIMEOUT = "OPENCODE_BRIDGE_TIMEOUT"

DEFAULT_URL = "http://127.0.0.1:4096"
DEFAULT_USER = "opencode"
DEFAULT_REQUEST_TIMEOUT = 120


class OpenCodeConfig(NamedTuple):
    url: str
    user: str
    password: str
    request_timeout_seconds: int

    @property
    def auth(self) -> Optional[Tuple[str, str]]:
        """Return (user, password) for HTTP Basic Auth, or None if no password set."""
        if not self.password:
            return None
        return (self.user, self.password)


def resolve_config(jupyter_settings: dict) -> OpenCodeConfig:
    """Resolve OpenCode connection config from environment variables + defaults.

    The `jupyter_settings` argument is accepted for API compatibility but no
    fields are read from it — all connection config is now startup-only
    (environment variables).
    """
    _ = jupyter_settings  # intentionally unused; see module docstring
    return OpenCodeConfig(
        url=os.environ.get(ENV_URL) or DEFAULT_URL,
        user=os.environ.get(ENV_USER) or DEFAULT_USER,
        password=os.environ.get(ENV_PASSWORD) or "",
        request_timeout_seconds=int(
            os.environ.get(ENV_TIMEOUT) or DEFAULT_REQUEST_TIMEOUT
        )
    )