from __future__ import annotations

from functools import lru_cache
from ipaddress import IPv4Network, IPv6Network, ip_network
from pathlib import Path
from typing import Literal

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

PROJECT_ROOT = Path(__file__).resolve().parents[2]


class AppSettings(BaseSettings):
    model_config = SettingsConfigDict(
        env_file=PROJECT_ROOT / ".env",
        env_prefix="ROTATOR_",
        extra="ignore",
    )

    app_name: str = "FluxIP"
    environment: Literal["development", "test", "production"] = "development"
    host: str = "127.0.0.1"
    port: int = Field(default=8787, ge=1, le=65535)
    database_path: Path = PROJECT_ROOT / "data" / "fluxip.db"
    master_key_file: Path = PROJECT_ROOT / "data" / "master.key"
    master_key: str | None = None
    bootstrap_token: SecretStr | None = None
    cookie_secure: bool = False
    session_days: int = Field(default=7, ge=1, le=90)
    allowed_origins: str = "http://localhost:8787,http://127.0.0.1:8787"
    trusted_hosts: str = "localhost,127.0.0.1"
    trusted_proxies: str = "127.0.0.1,::1"
    scheduler_enabled: bool = True
    scheduler_tick_seconds: int = Field(default=10, ge=2, le=60)
    log_level: str = "INFO"
    external_timeout_seconds: int = Field(default=20, ge=5, le=60)

    @field_validator("database_path", "master_key_file", mode="before")
    @classmethod
    def resolve_path(cls, value: str | Path) -> Path:
        path = Path(value)
        return path if path.is_absolute() else PROJECT_ROOT / path

    @field_validator("bootstrap_token", mode="before")
    @classmethod
    def normalize_optional_secret(cls, value: object) -> object:
        return None if value is None or not str(value).strip() else value

    @field_validator("trusted_proxies")
    @classmethod
    def validate_trusted_proxies(cls, value: str) -> str:
        for item in value.split(","):
            if item.strip():
                ip_network(item.strip(), strict=False)
        return value

    @property
    def origins(self) -> list[str]:
        return [value.strip() for value in self.allowed_origins.split(",") if value.strip()]

    @property
    def hosts(self) -> list[str]:
        return [value.strip() for value in self.trusted_hosts.split(",") if value.strip()]

    @property
    def proxy_networks(self) -> tuple[IPv4Network | IPv6Network, ...]:
        return tuple(
            ip_network(value.strip(), strict=False)
            for value in self.trusted_proxies.split(",")
            if value.strip()
        )


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