from functools import lru_cache
from pathlib import Path

from pydantic import Field
from pydantic_settings import BaseSettings, SettingsConfigDict


def _read_version() -> str:
    version_file = Path(__file__).resolve().parent.parent.parent / "VERSION"
    try:
        return version_file.read_text(encoding="utf-8").strip()
    except (FileNotFoundError, OSError):
        return "1.0.0"


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

    # Project
    project_name: str = Field(default="VoIdeaAI", description="Project name")
    project_version: str = Field(default_factory=_read_version, description="Project version (from VERSION file)")
    project_env: str = Field(default="local", description="Environment")
    project_owner: str = Field(default="Owner", description="Project owner name")
    project_license: str = Field(default="AGPL-3.0", description="License type")

    # Server
    server_host: str = Field(default="0.0.0.0", description="Server host")
    server_port: int = Field(default=8020, description="Server port")
    server_external_url: str = Field(default="http://localhost:8020", description="External URL")

    # Database
    database_url: str = Field(
        default="postgresql+asyncpg://voidea:password@localhost:5432/voidea",
        description="Database URL (async, PostgreSQL with asyncpg)",
    )
    db_echo: bool = Field(default=False, description="Echo SQL queries")

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

    # Redis
    redis_host: str = Field(default="localhost", description="Redis host")
    redis_port: int = Field(default=6379, description="Redis port")
    redis_url: str = Field(default="redis://localhost:6379/0", description="Redis URL")

    # JWT
    jwt_secret_key: str = Field(default="", description="JWT secret key")
    jwt_reset_secret_key: str = Field(default="", description="JWT secret for password reset tokens (separate from access)")
    jwt_algorithm: str = Field(default="HS256", description="JWT algorithm")
    jwt_access_token_expire_minutes: int = Field(default=60, description="Access token TTL")
    jwt_refresh_token_expire_days: int = Field(default=30, description="Refresh token TTL")

    # AI Providers
    openai_api_key: str = Field(default="", description="OpenAI API key (Whisper, GPT)")
    ai_yandex_key: str = Field(default="", description="Yandex GPT API key or IAM token")
    ai_yandex_url: str = Field(default="https://llm.api.cloud.yandex.net", description="Yandex API URL")
    ai_yandex_folder_id: str = Field(default="", description="Yandex Cloud folder ID")
    ai_gigachat_client_id: str = Field(default="", description="GigaChat OAuth client ID")
    ai_gigachat_secret: str = Field(default="", description="GigaChat OAuth client secret")
    ai_gigachat_url: str = Field(default="https://gigachat.devices.sber.ru", description="GigaChat API URL")
    ai_fallback_model: str = Field(default="yandex_gpt", description="Default AI model")
    ai_timeout: int = Field(default=10, description="AI request timeout")
    ai_max_retries: int = Field(default=3, description="Max retries for AI requests")

    # OAuth
    oauth_yandex_id: str = Field(default="", description="Yandex OAuth client ID")
    oauth_yandex_secret: str = Field(default="", description="Yandex OAuth client secret")
    oauth_yandex_redirect_uri: str = Field(default="http://localhost:3000/oauth/callback")
    oauth_google_id: str = Field(default="", description="Google OAuth client ID")
    oauth_google_secret: str = Field(default="", description="Google OAuth client secret")
    oauth_google_redirect_uri: str = Field(default="http://localhost:8020/auth/google/callback")
    oauth_apple_id: str = Field(default="", description="Apple OAuth client ID")
    oauth_apple_secret: str = Field(default="", description="Apple OAuth client secret")
    oauth_apple_redirect_uri: str = Field(default="http://localhost:8020/auth/apple/callback")

    @property
    def google_oauth_enabled(self) -> bool:
        return bool(self.oauth_google_id)

    @property
    def apple_oauth_enabled(self) -> bool:
        return bool(self.oauth_apple_id)

    # Telegram Bot
    telegram_bot_token: str = Field(default="", description="Telegram bot token")

    # Email (SMTP)
    smtp_host: str = Field(default="", description="SMTP server host")
    smtp_port: int = Field(default=587, description="SMTP server port")
    smtp_user: str = Field(default="", description="SMTP username")
    smtp_pass: str = Field(default="", description="SMTP password")
    smtp_from: str = Field(default="VoIdea <notifications@voidea.ru>")
    smtp_tls: bool = Field(default=True)

    # Security
    enable_2fa: bool = Field(default=False)
    accepted_terms_version: str = Field(
        default="2026-05-11",
        description="Current version of Terms of Service / Privacy Policy",
    )

    # System Owner
    system_owner_email: str = Field(
        default="",
        description="Email of the system owner (set on VPS deploy, protected from deletion/suspension)",
    )

    # Social Networks (empty = hidden)
    social_telegram: str = Field(default="voideaai", description="Telegram account name")
    social_vk: str = Field(default="voideaai", description="VK account name")
    social_youtube: str = Field(default="voideaai", description="YouTube account name")
    social_tiktok: str = Field(default="voideaai", description="TikTok account name")
    project_slogan: str = Field(
        default="VoIdeaAI — идеи рождаются вслух, решения приходят мгновенно!",
        description="Project slogan",
    )

    # Analytics (empty = disabled)
    yandex_metrika_id: str = Field(default="", description="Yandex Metrika counter ID")
    google_analytics_id: str = Field(default="", description="Google Analytics tracking ID")

    # Tariffs
    tariffs_enabled: bool = Field(default=False, description="Enable tariff system (false = promo free-for-all)")
    tariffs_free_code: str = Field(default="free", description="Code of the default free tariff plan")

    # Push Notifications (mobile-ready stubs)
    fcm_server_key: str = Field(default="", description="Firebase Cloud Messaging server key (mobile push)")
    apns_key_id: str = Field(default="", description="Apple Push Notification Service key ID (iOS push)")

    # Logging
    log_level: str = Field(default="INFO")
    log_format: str = Field(default="json")
    log_file_path: str = Field(default="logs/app.log")
    log_max_bytes: int = Field(default=10485760)
    log_backup_count: int = Field(default=5)

    # CORS
    cors_origins: str = Field(default="http://localhost:3000,http://localhost:8020")

    @property
    def cors_origins_list(self) -> list[str]:
        return [origin.strip() for origin in self.cors_origins.split(",")]

    # Celery
    celery_broker_url: str = Field(default="redis://localhost:6379/0")
    celery_result_backend: str = Field(default="redis://localhost:6379/0")
    celery_task_track_started: bool = Field(default=True)
    celery_task_time_limit: int = Field(default=300)

    # Observer Agent
    observer_enabled: bool = Field(default=True)
    observer_sample_rate: float = Field(default=0.1)
    observer_store_raw_data: bool = Field(default=False)

    # Rate Limiting
    rate_limit_enabled: bool = Field(default=True, description="Enable rate limiting")
    rate_limit_default: str = Field(default="60/minute", description="Default rate limit")
    rate_limit_auth: str = Field(default="10/minute", description="Auth endpoints rate limit")

    # Crypto
    encryption_key: str = Field(default="", description="AES-256 encryption key (Fernet)")

    # Development
    debug: bool = Field(default=False)
    reload: bool = Field(default=True)

    def is_production(self) -> bool:
        return self.project_env == "production"

    def is_development(self) -> bool:
        return self.project_env in ("development", "local")

    @property
    def public_config(self) -> dict:
        """Non-sensitive settings exposed via GET /api/v1/config/public."""
        return {
            "project_name": self.project_name,
            "project_version": self.project_version,
            "project_env": self.project_env,
            "project_slogan": self.project_slogan,
            "social_telegram": self.social_telegram,
            "social_vk": self.social_vk,
            "social_youtube": self.social_youtube,
            "social_tiktok": self.social_tiktok,
            "yandex_metrika_id": self.yandex_metrika_id,
            "google_analytics_id": self.google_analytics_id,
            "tariffs_enabled": self.tariffs_enabled,
            "tariffs_free_code": self.tariffs_free_code,
            "accepted_terms_version": self.accepted_terms_version,
        }


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


settings = get_settings()