"""Daemon configuration resolution (REQ-005, REQ-010, REQ-012/013)."""
from __future__ import annotations

import os
from dataclasses import dataclass
from typing import Optional


def _load_dotenv() -> None:
    """Best-effort load of a .env file into os.environ (REQ-010).

    Real OS environment variables take precedence over .env (override=False),
    matching 12-factor expectations. If python-dotenv is not installed or no
    .env exists, this is a no-op (no regression).
    """
    try:
        from dotenv import find_dotenv, load_dotenv
    except ImportError:  # pragma: no cover - optional at runtime
        return
    load_dotenv(find_dotenv(usecwd=True), override=False)


@dataclass(frozen=True)
class KISConfig:
    base_url: str
    app_key: str
    app_secret: str
    account_ref: str
    timeout: float
    allow_live: bool
    redis_url: str = ""   # REQ-016: optional token cache backend


@dataclass(frozen=True)
class PortfolioHubConfig:
    """portfolio-hub ledger adapter config (REQ-017)."""

    base_url: str
    token: str = ""
    timeout: float = 5.0


@dataclass(frozen=True)
class RabbitMQConfig:
    """RabbitMQ transport adapter config (REQ-022, dcy-006 OQ-6)."""

    url: str
    timeout: float = 5.0


@dataclass(frozen=True)
class DaemonConfig:
    dsn: str
    total_slots: int
    broker: str                      # 'paper' | 'kis'
    execution_interval_sec: float
    kis: Optional[KISConfig] = None
    # REQ-017/019: ledger writer config (None => in-memory stub ledger,
    # appropriate for slice-1 paper-broker integration tests).
    portfolio_hub: Optional[PortfolioHubConfig] = None
    ledger_interval_sec: float = 1.0
    # REQ-022 (BAT-007): RabbitMQ transport config. Required by the new
    # sync+thread daemon — HTTP API has been removed (REQ-025).
    rabbitmq: Optional[RabbitMQConfig] = None

    @staticmethod
    def from_env() -> "DaemonConfig":
        _load_dotenv()
        dsn = os.environ.get("TREX_POSTGRESQL_DSN")
        if not dsn:
            raise RuntimeError(
                "TREX_POSTGRESQL_DSN is required to start the slot-core daemon."
            )
        broker = os.environ.get("TREX_BROKER", "paper").strip().lower()
        kis: Optional[KISConfig] = None
        if broker == "kis":
            kis = KISConfig(
                base_url=os.environ["TREX_KIS_BROKER_BASE_URL"],
                app_key=os.environ["TREX_KIS_BROKER_APP_KEY"],
                app_secret=os.environ["TREX_KIS_BROKER_APP_SECRET"],
                account_ref=os.environ["TREX_KIS_BROKER_ACCOUNT_REF"],
                timeout=float(os.environ.get("TREX_KIS_BROKER_TIMEOUT", "5")),
                allow_live=os.environ.get("TREX_KIS_ALLOW_LIVE", "").lower() in ("1", "true", "yes"),
                redis_url=os.environ.get("TREX_KIS_REDIS_URL", ""),
            )
        portfolio_hub: Optional[PortfolioHubConfig] = None
        pf_base = os.environ.get("TREX_PORTFOLIO_HUB_BASE_URL", "").strip()
        if pf_base:
            portfolio_hub = PortfolioHubConfig(
                base_url=pf_base,
                token=os.environ.get("TREX_PORTFOLIO_HUB_TOKEN", "").strip(),
                timeout=float(os.environ.get("TREX_PORTFOLIO_HUB_TIMEOUT", "5")),
            )
        rabbitmq: Optional[RabbitMQConfig] = None
        mq_url = os.environ.get("TREX_RABBITMQ_URL", "").strip()
        if mq_url:
            rabbitmq = RabbitMQConfig(
                url=mq_url,
                timeout=float(os.environ.get("TREX_RABBITMQ_TIMEOUT", "5")),
            )
        return DaemonConfig(
            dsn=dsn,
            total_slots=int(os.environ.get("TREX_TOTAL_SLOTS", "10")),
            broker=broker,
            execution_interval_sec=float(os.environ.get("TREX_EXECUTION_INTERVAL_SEC", "1.0")),
            kis=kis,
            portfolio_hub=portfolio_hub,
            ledger_interval_sec=float(os.environ.get("TREX_LEDGER_INTERVAL_SEC", "1.0")),
            rabbitmq=rabbitmq,
        )