from __future__ import annotations

import os
from dataclasses import dataclass


@dataclass(frozen=True)
class Settings:
    app_name: str = "TradingView Alert Dispatcher"
    host: str = "0.0.0.0"
    port: int = 8000
    database_path: str = "data/dispatcher.db"
    admin_username: str = "admin"
    admin_password: str = "change-me-now"
    session_secret: str = "change-this-session-secret"
    webhook_token: str = ""
    retention_days: int = 30
    max_delivery_attempts: int = 3
    retry_backoff_seconds: int = 60
    feishu_timeout_seconds: int = 10
    timezone: str = ""
    dispatch_inline: bool = False
    delivery_batch_size: int = 100
    delivery_concurrency: int = 5
    worker_interval_seconds: int = 15


def get_settings() -> Settings:
    return Settings(
        host=os.getenv("APP_HOST", "0.0.0.0"),
        port=int(os.getenv("APP_PORT", "8000")),
        database_path=os.getenv("DATABASE_PATH", "data/dispatcher.db"),
        admin_username=os.getenv("ADMIN_USERNAME", "admin"),
        admin_password=os.getenv("ADMIN_PASSWORD", "change-me-now"),
        session_secret=os.getenv("SESSION_SECRET", "change-this-session-secret"),
        webhook_token=os.getenv("WEBHOOK_TOKEN", ""),
        retention_days=int(os.getenv("RETENTION_DAYS", "30")),
        max_delivery_attempts=int(os.getenv("MAX_DELIVERY_ATTEMPTS", "3")),
        retry_backoff_seconds=int(os.getenv("RETRY_BACKOFF_SECONDS", "60")),
        feishu_timeout_seconds=int(os.getenv("FEISHU_TIMEOUT_SECONDS", "10")),
        timezone=os.getenv("APP_TIMEZONE") or os.getenv("TZ", ""),
        dispatch_inline=os.getenv("DISPATCH_INLINE", "").lower() in {"1", "true", "yes", "on"},
        delivery_batch_size=int(os.getenv("DELIVERY_BATCH_SIZE", "100")),
        delivery_concurrency=int(os.getenv("DELIVERY_CONCURRENCY", "5")),
        worker_interval_seconds=int(os.getenv("WORKER_INTERVAL_SECONDS", "15")),
    )