"""Application configuration.

Settings are read from environment variables first, then from a `.env` file.
Environment variables always take precedence over the file.
"""

from functools import lru_cache

from pydantic_settings import BaseSettings, SettingsConfigDict


class Settings(BaseSettings):
    model_config = SettingsConfigDict(
        env_file=".env",
        env_file_encoding="utf-8",
        extra="ignore",
        case_sensitive=False,
    )

    # General
    app_name: str = "FastAPI Skeleton"
    debug: bool = False

    # Security / JWT
    secret_key: str = "change-me-please-use-a-long-random-string"
    algorithm: str = "HS256"
    access_token_expire_minutes: int = 15
    refresh_token_expire_days: int = 7

    # Database — single URL drives SQLite or Postgres.
    #   SQLite:   sqlite+aiosqlite:///./app.db
    #   Postgres: postgresql+asyncpg://user:pass@host:5432/dbname
    database_url: str = "sqlite+aiosqlite:///./app.db"
    auto_create_tables: bool = True

    # Web / cookies (the HTMX UI stores the access token in an httpOnly cookie)
    cookie_name: str = "access_token"
    cookie_secure: bool = False

    # CORS
    cors_origins: list[str] = ["*"]

    # --- LDAP / Active Directory (optional) --------------------------------
    # When ``ldap_enabled`` is true, login credentials are validated by binding
    # to the directory. A local ``User`` row is provisioned on first successful
    # login so RBAC, tokens, and the admin UI keep working. Local database auth
    # remains available as a fallback (so the seeded superuser can still log in).
    ldap_enabled: bool = False
    # e.g. "ldap://ldap.example.com:389" or "ldaps://ldap.example.com:636"
    ldap_server_uri: str = ""
    ldap_use_ssl: bool = False
    ldap_start_tls: bool = False
    # Verify the server's TLS certificate (ldaps/StartTLS). Disable only for dev.
    ldap_tls_validate: bool = True
    ldap_ca_certs_file: str = ""

    # Two ways to locate/authenticate the user (direct bind takes precedence):
    #
    # 1. Direct bind — build the user's DN from the login name, then bind as it:
    #      LDAP_BIND_DN_TEMPLATE="uid={username},ou=people,dc=example,dc=com"
    ldap_bind_dn_template: str = ""
    #
    # 2. Search + bind — bind with a service account (or anonymously), search for
    #    the user, then re-bind as the found DN to verify the password:
    ldap_bind_dn: str = ""
    ldap_bind_password: str = ""
    ldap_user_search_base: str = ""
    ldap_user_search_filter: str = "(uid={username})"

    # Attributes read from the directory entry to populate the local user.
    ldap_attr_email: str = "mail"
    ldap_attr_full_name: str = "cn"

    # Roles (by name) granted to a user provisioned from LDAP on first login.
    ldap_default_roles: list[str] = ["user"]

    # Bootstrap superuser (used by scripts/seed.py)
    first_superuser_email: str = "admin@example.com"
    first_superuser_password: str = "changethis"


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


settings = get_settings()