"""
config.py — Centralised configuration for VulnForge.

Loads environment variables, defines API endpoints, severity colour maps,
cache TTLs and other tunables. Import `settings` everywhere instead of reading
os.environ directly so configuration stays in one place.
"""

from __future__ import annotations

import os
from dataclasses import dataclass, field
from pathlib import Path

from dotenv import load_dotenv

# Load .env from the project root (the directory this file lives in).
PROJECT_ROOT = Path(__file__).resolve().parent
load_dotenv(PROJECT_ROOT / ".env")


def _get_int(name: str) -> int | None:
    """Parse an optional integer env var, returning None when unset/blank."""
    raw = os.getenv(name, "").strip()
    if not raw:
        return None
    try:
        return int(raw)
    except ValueError:
        return None


@dataclass(frozen=True)
class Settings:
    """Immutable runtime settings sourced from environment + defaults."""

    # ── Discord ──────────────────────────────────────────────
    discord_token: str = os.getenv("DISCORD_TOKEN", "").strip()
    guild_id: int | None = _get_int("GUILD_ID")
    digest_channel_id: int | None = _get_int("DIGEST_CHANNEL_ID")
    notify_role_id: int | None = _get_int("NOTIFY_ROLE_ID")

    # ── External APIs ────────────────────────────────────────
    nvd_api_key: str = os.getenv("NVD_API_KEY", "").strip()
    nvd_base_url: str = "https://services.nvd.nist.gov/rest/json/cves/2.0"
    cisa_kev_url: str = (
        "https://www.cisa.gov/sites/default/files/feeds/"
        "known_exploited_vulnerabilities.json"
    )
    nvd_cve_web: str = "https://nvd.nist.gov/vuln/detail"
    cisa_kev_web: str = "https://www.cisa.gov/known-exploited-vulnerabilities-catalog"

    # ── Paths ────────────────────────────────────────────────
    data_dir: Path = PROJECT_ROOT / "data"
    db_path: Path = PROJECT_ROOT / "data" / "vulnforge.db"
    cache_dir: Path = PROJECT_ROOT / "data" / "cache"

    # ── Behaviour ────────────────────────────────────────────
    log_level: str = os.getenv("LOG_LEVEL", "INFO").strip().upper()
    # Cache TTL (seconds): KEV feed is large + slow-changing.
    kev_cache_ttl: int = 60 * 60 * 6          # 6 hours
    cve_cache_ttl: int = 60 * 30              # 30 minutes
    http_timeout: int = 30                    # seconds per request
    digest_top_n: int = 8                     # CVEs shown in weekly digest
    request_retries: int = 3                  # NVD transient retry attempts

    # ── Cyberpunk / hacker colour palette (hex → int) ─────────
    # Severity-coded so embeds read at a glance on mobile + desktop.
    color_critical: int = 0xFF003C            # neon red
    color_high: int = 0xFF6B00                # hot orange
    color_medium: int = 0xFFB300              # amber
    color_low: int = 0x00E5FF                 # cyan
    color_info: int = 0x0A84FF                # electric blue
    color_kev: int = 0xE0115F                 # ruby (actively exploited)
    color_dark: int = 0x0D1117                # near-black backdrop accent
    color_success: int = 0x00FF9C             # matrix green
    user_agent: str = "VulnForge/1.0 (+https://github.com/your-org/vulnforge)"

    def ensure_dirs(self) -> None:
        """Create data/cache directories if they do not yet exist."""
        self.data_dir.mkdir(parents=True, exist_ok=True)
        self.cache_dir.mkdir(parents=True, exist_ok=True)


settings = Settings()