"""Runtime configuration (environment-injected; never log secrets)."""

from __future__ import annotations

from functools import lru_cache
from typing import Annotated, Literal

from pydantic import Field, field_validator
from pydantic_settings import BaseSettings, NoDecode, SettingsConfigDict

TradingMode = Literal["offline", "paper", "live"]


class Settings(BaseSettings):
    model_config = SettingsConfigDict(env_prefix="KTRADE_", env_file=".env", extra="ignore")

    env: str = "dev"
    app_base_url: str = "http://127.0.0.1:8471"
    api_host: str = "127.0.0.1"
    api_port: int = 8470
    log_level: str = "INFO"
    log_json: bool = True

    database_url: str = "postgresql+asyncpg://ktrade:ktrade@127.0.0.1:5432/ktrade"
    redis_url: str = "redis://127.0.0.1:6379/3"

    # Session / auth
    secret_key: str = Field(default="dev-insecure-change-me", description="Signs session cookies")
    owner_password_hash: str = Field(default="", description="bcrypt hash of the owner password")
    session_ttl_seconds: int = 12 * 3600
    cookie_secure: bool = False

    # Kraken — three least-privilege key pairs. Data/account keys must NOT have trade permission;
    # the trade key is only read when live mode is armed. Withdrawal permission is never used.
    kraken_rest_url: str = "https://api.kraken.com"
    kraken_ws_url: str = "wss://ws.kraken.com/v2"
    kraken_ws_auth_url: str = "wss://ws-auth.kraken.com/v2"
    kraken_api_key: str = ""
    kraken_api_secret: str = ""
    kraken_trade_api_key: str = ""
    kraken_trade_api_secret: str = ""
    kraken_tier: Literal["starter", "intermediate", "pro"] = "starter"

    # Universe & ingestion
    universe: Annotated[list[str], NoDecode] = Field(default_factory=lambda: ["BTC/USD", "ETH/USD", "SOL/USD", "XRP/USD", "ADA/USD", "LINK/USD", "DOT/USD", "LTC/USD"])
    candle_intervals: Annotated[list[int], NoDecode] = Field(default_factory=lambda: [1, 5, 60, 1440])
    backfill_poll_seconds: int = 60
    book_depth: int = 25
    stale_data_seconds: int = 120

    # Trading mode gates
    trading_mode: TradingMode = "offline"
    live_trading_enabled: bool = False  # feature flag; UI activation also required (Phase 5)

    # Observability
    metrics_enabled: bool = True

    @field_validator("universe", "candle_intervals", mode="before")
    @classmethod
    def _split_csv(cls, v):  # noqa: ANN001
        if isinstance(v, str):
            parts = [p.strip() for p in v.split(",") if p.strip()]
            return [int(p) if p.isdigit() else p for p in parts]
        return v

    @property
    def sync_database_url(self) -> str:
        return self.database_url.replace("+asyncpg", "")

    def has_data_key(self) -> bool:
        return bool(self.kraken_api_key and self.kraken_api_secret)

    def has_trade_key(self) -> bool:
        return bool(self.kraken_trade_api_key and self.kraken_trade_api_secret)


@lru_cache
def get_settings() -> Settings:
    return Settings()