from __future__ import annotations

import os
from dataclasses import dataclass, field
from pathlib import Path

from dotenv import load_dotenv


def _load_env() -> None:
    root = Path(__file__).resolve().parents[2]
    for candidate in (root / ".env", root.parent / ".env"):
        if candidate.exists():
            load_dotenv(candidate, override=False)
            return


def _bool(val: str | None, default: bool = False) -> bool:
    if val is None:
        return default
    return val.strip().lower() in {"1", "true", "yes", "y", "on"}


def _float(val: str | None, default: float) -> float:
    try:
        return float(val) if val is not None else default
    except ValueError:
        return default


def _int(val: str | None, default: int) -> int:
    try:
        return int(val) if val is not None else default
    except ValueError:
        return default


@dataclass(frozen=True)
class AlpacaConfig:
    key: str
    secret: str
    base_url: str
    env: str  # "paper" or "live"

    @property
    def is_paper(self) -> bool:
        return self.env.lower() != "live"


@dataclass(frozen=True)
class WheelConfig:
    universe: tuple[str, ...]
    put_dte_min: int
    put_dte_max: int
    put_target_delta: float
    put_otm_pct: float
    call_otm_pct: float
    min_annual_yield: float
    max_short_puts_per_symbol: int


@dataclass(frozen=True)
class RiskConfig:
    max_position_pct: float
    min_cash_buffer_pct: float
    trailing_stop_enabled: bool
    trailing_stop_pct: float


@dataclass(frozen=True)
class Config:
    mode: str  # "dry" or "live"
    alpaca: AlpacaConfig
    wheel: WheelConfig
    risk: RiskConfig
    tick_interval: int
    data_dir: Path
    log_dir: Path
    discord_webhook: str | None = None

    @property
    def dry_run(self) -> bool:
        return self.mode.lower() != "live"


def load_config() -> Config:
    _load_env()
    env = os.environ

    alpaca = AlpacaConfig(
        key=env.get("ALPACA_API_KEY", ""),
        secret=env.get("ALPACA_API_SECRET", ""),
        base_url=env.get("ALPACA_BASE_URL", "https://paper-api.alpaca.markets"),
        env=env.get("ALPACA_ENV", "paper"),
    )

    universe = tuple(
        s.strip().upper() for s in env.get("WHEEL_UNIVERSE", "TSLA").split(",") if s.strip()
    )

    wheel = WheelConfig(
        universe=universe,
        put_dte_min=_int(env.get("WHEEL_PUT_DTE_MIN"), 14),
        put_dte_max=_int(env.get("WHEEL_PUT_DTE_MAX"), 28),
        put_target_delta=_float(env.get("WHEEL_PUT_TARGET_DELTA"), 0.30),
        put_otm_pct=_float(env.get("WHEEL_PUT_OTM_PCT"), 0.10),
        call_otm_pct=_float(env.get("WHEEL_CALL_OTM_PCT"), 0.10),
        min_annual_yield=_float(env.get("WHEEL_MIN_ANNUAL_YIELD"), 0.15),
        max_short_puts_per_symbol=_int(env.get("WHEEL_MAX_SHORT_PUTS_PER_SYMBOL"), 1),
    )

    risk = RiskConfig(
        max_position_pct=_float(env.get("MAX_POSITION_PCT"), 0.25),
        min_cash_buffer_pct=_float(env.get("MIN_CASH_BUFFER_PCT"), 0.05),
        trailing_stop_enabled=_bool(env.get("TRAILING_STOP_ENABLED"), True),
        trailing_stop_pct=_float(env.get("TRAILING_STOP_PCT"), 0.08),
    )

    root = Path(__file__).resolve().parents[2]
    data_dir = Path(env.get("DATA_DIR") or (root / "data")).expanduser().resolve()
    log_dir = Path(env.get("LOG_DIR") or (root / "logs")).expanduser().resolve()
    data_dir.mkdir(parents=True, exist_ok=True)
    log_dir.mkdir(parents=True, exist_ok=True)

    return Config(
        mode=env.get("BOT_MODE", "dry"),
        alpaca=alpaca,
        wheel=wheel,
        risk=risk,
        tick_interval=_int(env.get("TICK_INTERVAL_SECONDS"), 900),
        data_dir=data_dir,
        log_dir=log_dir,
        discord_webhook=env.get("DISCORD_WEBHOOK_URL") or None,
    )