"""Runtime configuration loaded from environment + secret files.

Secrets are read from files (``*_FILE`` env vars pointing at
``/run/secrets/<name>``) so they never appear in ``docker inspect``
or process environment dumps. Plain ``*`` vars are the fallback for
local development where mounting secret files is overkill.
"""

from __future__ import annotations

from functools import lru_cache
from pathlib import Path
from typing import Optional

from pydantic import Field
from pydantic_settings import BaseSettings, SettingsConfigDict


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

    database_url: str = Field(
        default="postgresql+psycopg://datatools_api@localhost:5432/datatools_licenses",
        validation_alias="DATABASE_URL",
    )

    admin_token: Optional[str] = Field(default=None, validation_alias="DATATOOLS_ADMIN_TOKEN")
    admin_token_file: Optional[Path] = Field(default=None, validation_alias="DATATOOLS_ADMIN_TOKEN_FILE")

    license_privkey_hex: Optional[str] = Field(default=None, validation_alias="DATATOOLS_LICENSE_PRIVKEY")
    license_privkey_file: Optional[Path] = Field(default=None, validation_alias="DATATOOLS_LICENSE_PRIVKEY_FILE")

    license_pubkey_hex: Optional[str] = Field(default=None, validation_alias="DATATOOLS_LICENSE_PUBKEY")

    postmark_token: Optional[str] = Field(default=None, validation_alias="POSTMARK_TOKEN")
    postmark_token_file: Optional[Path] = Field(default=None, validation_alias="POSTMARK_TOKEN_FILE")

    gumroad_secret: Optional[str] = Field(default=None, validation_alias="GUMROAD_WEBHOOK_SECRET")
    gumroad_secret_file: Optional[Path] = Field(default=None, validation_alias="GUMROAD_WEBHOOK_SECRET_FILE")

    def resolve_admin_token(self) -> Optional[str]:
        return _resolve(self.admin_token, self.admin_token_file)

    def resolve_license_privkey(self) -> Optional[str]:
        return _resolve(self.license_privkey_hex, self.license_privkey_file)

    def resolve_postmark_token(self) -> Optional[str]:
        return _resolve(self.postmark_token, self.postmark_token_file)

    def resolve_gumroad_secret(self) -> Optional[str]:
        return _resolve(self.gumroad_secret, self.gumroad_secret_file)


def _resolve(inline: Optional[str], path: Optional[Path]) -> Optional[str]:
    if inline:
        return inline.strip()
    if path and path.exists():
        return path.read_text(encoding="utf-8").strip()
    return None


@lru_cache(maxsize=1)
def get_settings() -> Settings:
    return Settings()
