from __future__ import annotations

from dataclasses import dataclass
from pathlib import Path
import os


def _load_dotenv(path: Path) -> None:
    if not path.exists():
        return

    for raw_line in path.read_text(encoding="utf-8").splitlines():
        line = raw_line.strip()
        if not line or line.startswith("#"):
            continue
        if line.startswith("export "):
            line = line[len("export ") :].strip()
        if "=" not in line:
            continue
        key, value = line.split("=", 1)
        key = key.strip()
        value = value.strip()
        if not key or key in os.environ:
            continue
        if len(value) >= 2 and value[0] == value[-1] and value[0] in {'"', "'"}:
            value = value[1:-1]
        os.environ[key] = value


def _env(name: str, default: str = "") -> str:
    return os.getenv(name, default).strip()


def _int_env(name: str, default: int) -> int:
    value = _env(name)
    if not value:
        return default
    try:
        return int(value)
    except ValueError:
        return default


def _split_csv(value: str, default: tuple[str, ...]) -> tuple[str, ...]:
    if not value:
        return default
    items = tuple(part.strip() for part in value.split(",") if part.strip())
    return items or default


@dataclass(frozen=True, slots=True)
class ArgusConfig:
    app_name: str = "argus-mcp"
    sqlite_path: Path = Path("data/argus_mcp.sqlite3")
    finnhub_token: str = ""
    twelve_data_key: str = ""
    symbols: tuple[str, ...] = ("QQQ", "SPY", "DXY", "HYG", "BTCUSD", "ETHUSD", "VXX")
    interval: str = "1d"
    finnhub_ttl_seconds: int = 60
    twelve_data_ttl_seconds: int = 900
    snapshot_ttl_seconds: int = 60


def load_config() -> ArgusConfig:
    _load_dotenv(Path.cwd() / ".env")
    return ArgusConfig(
        sqlite_path=Path(_env("ARGUS_SQLITE_PATH", "data/argus_mcp.sqlite3")),
        finnhub_token=_env("FINNHUB_TOKEN"),
        twelve_data_key=_env("TWELVE_DATA_KEY"),
        symbols=_split_csv(
            _env("ARGUS_SYMBOLS"),
            ("QQQ", "SPY", "DXY", "HYG", "BTCUSD", "ETHUSD", "VXX"),
        ),
        interval=_env("ARGUS_INTERVAL", "1d"),
        finnhub_ttl_seconds=_int_env("ARGUS_FINNHUB_TTL_SECONDS", 60),
        twelve_data_ttl_seconds=_int_env("ARGUS_TWELVE_DATA_TTL_SECONDS", 900),
        snapshot_ttl_seconds=_int_env("ARGUS_SNAPSHOT_TTL_SECONDS", 60),
    )