"""Credentials loading and Matrix client construction."""

import json
import os
import sys
import time
from pathlib import Path

from nio import AsyncClient, AsyncClientConfig, LoginResponse


def store_dir() -> Path:
    return Path(os.environ.get("STORE_DIR", "/shared/tui-store"))


def load_credentials(retries: int = 10, delay: float = 3.0) -> dict:
    """Read CREDENTIALS_FILE, waiting a bit in case bootstrap is still provisioning."""
    path = Path(os.environ.get("CREDENTIALS_FILE", "/shared/credentials.json"))
    for attempt in range(retries):
        try:
            return json.loads(path.read_text())
        except (OSError, json.JSONDecodeError):
            if attempt < retries - 1:
                print(
                    f"vortex-tui: waiting for {path} (bootstrap still provisioning?)...",
                    file=sys.stderr,
                )
                time.sleep(delay)
    sys.exit(
        f"vortex-tui: credentials file {path} missing or invalid after "
        f"{retries} attempts. Run the bootstrap first, or set CREDENTIALS_FILE."
    )


async def build_client(creds: dict) -> AsyncClient:
    """Return a logged-in AsyncClient with its own persisted E2EE device.

    Order: STORE_DIR/session.json (our own device) -> password login (persist
    new device) -> bootstrap access_token fallback.
    """
    store = store_dir()
    store.mkdir(parents=True, exist_ok=True)
    homeserver = (
        os.environ.get("MATRIX_HOMESERVER")
        or creds.get("homeserver")
        or "http://localhost:8008"
    )
    user_id = creds["user_id"]
    # encryption_enabled defaults to True only when olm is importable,
    # so this works with or without the [e2e] extra installed.
    client = AsyncClient(
        homeserver,
        user_id,
        store_path=str(store),
        config=AsyncClientConfig(store_sync_tokens=True),
    )
    session_file = store / "session.json"
    if session_file.exists():
        s = json.loads(session_file.read_text())
        client.restore_login(s["user_id"], s["device_id"], s["access_token"])
        return client
    if creds.get("password"):
        resp = await client.login(creds["password"], device_name="vortex-tui")
        if isinstance(resp, LoginResponse):
            session_file.write_text(
                json.dumps(
                    {
                        "user_id": resp.user_id,
                        "device_id": resp.device_id,
                        "access_token": resp.access_token,
                    }
                )
            )
            return client
    if creds.get("access_token"):
        # Fall back to the bootstrap token (shares the bootstrap device).
        client.restore_login(
            user_id, creds.get("device_id") or "VORTEXTUI", creds["access_token"]
        )
        return client
    await client.close()
    raise RuntimeError("no usable password or access_token in credentials file")