"""Zone registry and loading."""

from __future__ import annotations

import logging
import tomllib
from pathlib import Path

from mudlib.zone import Zone

log = logging.getLogger(__name__)

# Module-level zone registry
zone_registry: dict[str, Zone] = {}


def register_zone(name: str, zone: Zone) -> None:
    """Register a zone by name.

    Args:
        name: Unique name for the zone
        zone: Zone instance to register
    """
    zone_registry[name] = zone


def get_zone(name: str) -> Zone | None:
    """Look up a zone by name.

    Args:
        name: Zone name to look up

    Returns:
        Zone instance if found, None otherwise
    """
    return zone_registry.get(name)


def load_zone(path: Path) -> Zone:
    """Load a zone from a TOML file.

    Args:
        path: Path to TOML file

    Returns:
        Zone instance loaded from file
    """
    with open(path, "rb") as f:
        data = tomllib.load(f)

    # Extract basic properties
    name = data["name"]
    width = data["width"]
    height = data["height"]
    toroidal = data.get("toroidal", True)

    # Parse terrain rows into 2D list
    terrain_rows = data.get("terrain", {}).get("rows", [])
    terrain = []
    for row in terrain_rows:
        terrain.append(list(row))

    # Parse impassable tiles
    impassable_list = data.get("terrain", {}).get("impassable", {}).get("tiles", [])
    impassable = set(impassable_list) if impassable_list else {"^", "~"}

    zone = Zone(
        name=name,
        width=width,
        height=height,
        toroidal=toroidal,
        terrain=terrain,
        impassable=impassable,
    )

    return zone


def load_zones(directory: Path) -> dict[str, Zone]:
    """Load all zones from a directory.

    Args:
        directory: Path to directory containing zone TOML files

    Returns:
        Dict mapping zone names to Zone instances
    """
    zones = {}

    if not directory.exists():
        log.warning("zones directory does not exist: %s", directory)
        return zones

    for toml_file in directory.glob("*.toml"):
        try:
            zone = load_zone(toml_file)
            zones[zone.name] = zone
            log.debug("loaded zone '%s' from %s", zone.name, toml_file)
        except Exception as e:
            log.error("failed to load zone from %s: %s", toml_file, e, exc_info=True)

    return zones