import ipaddress
import logging as _std_logging
import os
from urllib.parse import urlparse

from dotenv import load_dotenv

load_dotenv()


_PRIVATE_IP_RANGES = (
    ipaddress.ip_network("10.0.0.0/8"),
    ipaddress.ip_network("172.16.0.0/12"),
    ipaddress.ip_network("192.168.0.0/16"),
    ipaddress.ip_network("169.254.0.0/16"),
    ipaddress.ip_network("127.0.0.0/8"),
    ipaddress.ip_network("::1/128"),
    ipaddress.ip_network("fc00::/7"),
)


def _validate_custom_api_url(value: str, name: str) -> str:
    if not value:
        return value
    try:
        parsed = urlparse(value)
    except Exception as exc:
        raise RuntimeError(f"Invalid URL for {name}: {exc}") from exc

    if parsed.scheme not in ("http", "https"):
        raise RuntimeError(
            f"Invalid scheme for {name}: {parsed.scheme}. Must be http or https."
        )

    host = (parsed.hostname or "").strip("[]")
    if not host:
        raise RuntimeError(f"No host in {name}: {value}")

    return value


def _validate_cobalt_api_url(value: str, name: str) -> str:
    if not value:
        return value
    try:
        parsed = urlparse(value)
    except Exception as exc:
        raise RuntimeError(f"Invalid URL for {name}: {exc}") from exc

    if parsed.scheme != "https":
        raise RuntimeError(
            f"HTTPS is required for {name}. Found: {parsed.scheme}. "
            f"Use https:// or set {name}_DANGER_ACCEPT_INSECURE=true to bypass."
        )

    host = (parsed.hostname or "").strip("[]")
    if not host:
        raise RuntimeError(f"No host in {name}: {value}")

    try:
        addr = ipaddress.ip_address(host)
        for net in _PRIVATE_IP_RANGES:
            if addr in net:
                raise RuntimeError(
                    f"Host {host} in {name} resolves to a private/internal IP range."
                )
    except ValueError:
        pass

    return value


def _read_env(
    name: str, *, required: bool = False, aliases: tuple[str, ...] = ()
) -> str | None:
    value = os.getenv(name)
    if value is None:
        for alias in aliases:
            value = os.getenv(alias)
            if value is not None:
                break
    if value is not None:
        value = value.strip()
    if not value:
        if required:
            raise RuntimeError(f"Required environment variable {name} is not set.")
        return None
    return value


def _read_int_env(
    name: str, *, required: bool = False, aliases: tuple[str, ...] = ()
) -> int | None:
    value = _read_env(name, required=required, aliases=aliases)
    if value is None:
        return None
    try:
        return int(value)
    except ValueError as exc:
        raise RuntimeError(f"Environment variable {name} must be an integer.") from exc


def _read_float_env(
    name: str, *, required: bool = False, aliases: tuple[str, ...] = ()
) -> float | None:
    value = _read_env(name, required=required, aliases=aliases)
    if value is None:
        return None
    try:
        return float(value)
    except ValueError as exc:
        raise RuntimeError(f"Environment variable {name} must be a float.") from exc


BOT_TOKEN = _read_env("BOT_TOKEN", required=True)
DATABASE_URL = _read_env("DATABASE_URL", required=True)
ADMIN_ID = _read_int_env("ADMIN_ID", required=True, aliases=("admin_id",))
CUSTOM_API_URL = _validate_custom_api_url(
    _read_env("CUSTOM_API_URL", required=True, aliases=("custom_api_url",)) or "",
    "CUSTOM_API_URL",
)
MEASUREMENT_ID = _read_env("MEASUREMENT_ID")
API_SECRET = _read_env("API_SECRET")
CHANNEL_ID = _read_env("CHANNEL_ID")
OUTPUT_DIR = "downloads"
COBALT_API_URL = _read_env("COBALT_API_URL")
if COBALT_API_URL:
    if os.getenv("COBALT_API_URL_DANGER_ACCEPT_INSECURE"):
        _std_logging.warning(
            "COBALT_API_URL_DANGER_ACCEPT_INSECURE is set — HTTPS and private IP validation is disabled for COBALT_API_URL"
        )
    else:
        COBALT_API_URL = _validate_cobalt_api_url(COBALT_API_URL, "COBALT_API_URL")
COBALT_API_KEY = _read_env("COBALT_API_KEY")
SPOTIFY_CLIENT_ID = _read_env("SPOTIFY_CLIENT_ID")
SPOTIFY_CLIENT_SECRET = _read_env("SPOTIFY_CLIENT_SECRET")
SPOTIFY_MARKET = _read_env("SPOTIFY_MARKET") or "UA"
BOT_POLLING_TASKS_CONCURRENCY_LIMIT = (
    _read_int_env("BOT_POLLING_TASKS_CONCURRENCY_LIMIT") or 256
)
BOT_SESSION_CONNECTION_LIMIT = _read_int_env("BOT_SESSION_CONNECTION_LIMIT") or 400
DB_POOL_SIZE = _read_int_env("DB_POOL_SIZE") or 5
DB_MAX_OVERFLOW = _read_int_env("DB_MAX_OVERFLOW") or 10
DB_POOL_TIMEOUT = _read_float_env("DB_POOL_TIMEOUT") or 15.0
ANTIFLOOD_MESSAGE_LIMIT = _read_int_env("ANTIFLOOD_MESSAGE_LIMIT") or 4
ANTIFLOOD_MESSAGE_WINDOW_SECONDS = (
    _read_float_env("ANTIFLOOD_MESSAGE_WINDOW_SECONDS") or 2.0
)
ANTIFLOOD_CALLBACK_LIMIT = _read_int_env("ANTIFLOOD_CALLBACK_LIMIT") or 6
ANTIFLOOD_CALLBACK_WINDOW_SECONDS = (
    _read_float_env("ANTIFLOOD_CALLBACK_WINDOW_SECONDS") or 2.0
)
ANTIFLOOD_INLINE_LIMIT = _read_int_env("ANTIFLOOD_INLINE_LIMIT") or 4
ANTIFLOOD_INLINE_WINDOW_SECONDS = (
    _read_float_env("ANTIFLOOD_INLINE_WINDOW_SECONDS") or 3.0
)
ANTIFLOOD_GUEST_LIMIT = _read_int_env("ANTIFLOOD_GUEST_LIMIT") or 4
ANTIFLOOD_GUEST_WINDOW_SECONDS = (
    _read_float_env("ANTIFLOOD_GUEST_WINDOW_SECONDS") or 3.0
)
ANTIFLOOD_GLOBAL_LIMIT = _read_int_env("ANTIFLOOD_GLOBAL_LIMIT") or 8
ANTIFLOOD_GLOBAL_WINDOW_SECONDS = (
    _read_float_env("ANTIFLOOD_GLOBAL_WINDOW_SECONDS") or 3.0
)
ANTIFLOOD_COOLDOWN_SECONDS = _read_float_env("ANTIFLOOD_COOLDOWN_SECONDS") or 6.0
ANTIFLOOD_USER_TTL_SECONDS = _read_float_env("ANTIFLOOD_USER_TTL_SECONDS") or 180.0
ANTIFLOOD_MAX_TRACKED_USERS = _read_int_env("ANTIFLOOD_MAX_TRACKED_USERS") or 50000
REQUEST_DEDUPE_ACTIVE_TTL_SECONDS = (
    _read_float_env("REQUEST_DEDUPE_ACTIVE_TTL_SECONDS") or 900.0
)
REQUEST_DEDUPE_COMPLETED_TTL_SECONDS = (
    _read_float_env("REQUEST_DEDUPE_COMPLETED_TTL_SECONDS") or 12.0
)
REQUEST_DEDUPE_MAX_ENTRIES = _read_int_env("REQUEST_DEDUPE_MAX_ENTRIES") or 50000
DOWNLOAD_QUEUE_MIN_WORKERS = _read_int_env("DOWNLOAD_QUEUE_MIN_WORKERS") or 3
DOWNLOAD_QUEUE_MAX_WORKERS = _read_int_env("DOWNLOAD_QUEUE_MAX_WORKERS") or 7
DOWNLOAD_QUEUE_MAX_SIZE = _read_int_env("DOWNLOAD_QUEUE_MAX_SIZE") or 250
DOWNLOAD_QUEUE_PER_USER_RATE_LIMIT = (
    _read_int_env("DOWNLOAD_QUEUE_PER_USER_RATE_LIMIT") or 4
)
DOWNLOAD_QUEUE_PER_USER_WINDOW_SECONDS = (
    _read_float_env("DOWNLOAD_QUEUE_PER_USER_WINDOW_SECONDS") or 10.0
)
DOWNLOAD_QUEUE_PER_USER_MAX_PENDING = (
    _read_int_env("DOWNLOAD_QUEUE_PER_USER_MAX_PENDING") or 3
)
DOWNLOAD_QUEUE_PER_USER_PENDING_TIMEOUT_SECONDS = (
    _read_float_env("DOWNLOAD_QUEUE_PER_USER_PENDING_TIMEOUT_SECONDS")
    if _read_float_env("DOWNLOAD_QUEUE_PER_USER_PENDING_TIMEOUT_SECONDS") is not None
    else 20.0
)
DOWNLOAD_QUEUE_SCALE_COOLDOWN_SECONDS = (
    _read_float_env("DOWNLOAD_QUEUE_SCALE_COOLDOWN_SECONDS") or 8.0
)
DOWNLOAD_QUEUE_IDLE_SCALE_DOWN_SECONDS = (
    _read_float_env("DOWNLOAD_QUEUE_IDLE_SCALE_DOWN_SECONDS") or 35.0
)
DOWNLOAD_MAX_WORKERS_CAP = _read_int_env("DOWNLOAD_MAX_WORKERS_CAP") or 6
BATCH_LINKS_MAX_ITEMS = _read_int_env("BATCH_LINKS_MAX_ITEMS") or 6
BATCH_LINKS_MIN_CONCURRENCY = _read_int_env("BATCH_LINKS_MIN_CONCURRENCY") or 1
BATCH_LINKS_MAX_CONCURRENCY = _read_int_env("BATCH_LINKS_MAX_CONCURRENCY") or 4
BATCH_LINKS_PARALLEL_QUEUE_DEPTH_THRESHOLD = (
    _read_int_env("BATCH_LINKS_PARALLEL_QUEUE_DEPTH_THRESHOLD") or 4
)
BATCH_LINKS_PARALLEL_ACTIVE_JOBS_THRESHOLD = (
    _read_int_env("BATCH_LINKS_PARALLEL_ACTIVE_JOBS_THRESHOLD") or 5
)
MAX_FILE_SIZE = _read_int_env("MAX_FILE_SIZE") or int(1.5 * 1024 * 1024 * 1024)

BOT_COMMANDS = [
    {"command": "start", "description": "Get started"},
    {"command": "help", "description": "Supported sites and tips"},
    {"command": "settings", "description": "Settings"},
    {"command": "stats", "description": "Statistics"},
]
ADMINS_UID = [ADMIN_ID]