import logging
from typing import Any, Dict, get_type_hints, get_args, get_origin

from fastapi import Request
from transformers.hf_argparser import string_to_bool

from gpustack.config.config import Config


WHITELIST_CONFIG_FIELDS = {
    "debug",
    "system_default_container_registry",
}

READ_ONLY_CONFIG_FIELDS = WHITELIST_CONFIG_FIELDS.union(
    {
        "server_external_url",
        "grafana_url",
        "disable_builtin_observability",
        "grafana_worker_dashboard_uid",
        "grafana_model_dashboard_uid",
    }
)
logger = logging.getLogger(__name__)


def _unwrap_optional(tp):
    origin = get_origin(tp)
    if origin is None:
        return tp
    args = get_args(tp)
    non_none = [a for a in args if a is not type(None)]
    return non_none[0] if non_none else tp


def coerce_value_by_field(field: str, v):
    hints = get_type_hints(Config)
    tp = hints.get(field)
    if tp is None:
        return v
    tp = _unwrap_optional(tp)
    origin = get_origin(tp)
    if tp is bool:
        return string_to_bool(v)
    if tp is int:
        return int(v)
    if tp is float:
        return float(v)
    if tp is str:
        return str(v)
    if origin is list:
        if isinstance(v, str):
            return [item.strip() for item in v.split(',') if item.strip()]
        return list(v)
    if tp is dict or origin is dict:
        if isinstance(v, str):
            import json

            return json.loads(v)
        return dict(v)
    return v


def filter_whitelisted_yaml_config(config_data: Dict[str, Any]) -> Dict[str, Any]:
    if not config_data:
        return config_data
    filtered_data = {}
    for key, value in config_data.items():
        config_key = key.replace('-', '_')
        if config_key in WHITELIST_CONFIG_FIELDS:
            filtered_data[config_key] = value
    return filtered_data


def is_local_request(request: Request) -> bool:
    host = request.client.host
    if host in ("127.0.0.1", "::1"):
        return True
    return False


def apply_registry_override_to_image(
    _config: Config, image: str, fallback_registry: str
) -> str:
    """
    1) If the image has an explicit registry, return it as is.
    2) If the image does not have an explicit registry and a system default registry is configured,
       prefix the image with the system default registry in config.
    3) If the image does not have an explicit registry and no system default registry is configured,
       using docker.io as default if image without "gpustack" prefix.
    4) If the image does not have an explicit registry and no system default registry is configured,
       and with "gpustack" prefix, using docker.io as default if docker.io is reachable.
       Otherwise, using quay.io.
    """
    registry_cfg = (_config.system_default_container_registry or "").strip()

    parts = image.split("/", 1)
    # 1) If the image has an explicit registry, return it as is.
    has_explicit = len(parts) >= 2 and (
        "." in parts[0] or ":" in parts[0] or parts[0] == "localhost"
    )
    if has_explicit:
        return image
    # 2) If the image does not have an explicit registry and a system default registry is configured,
    #    prefix the image with the system default registry in config.
    if registry_cfg:
        registry = registry_cfg.rstrip("/")
        final = f"{registry}/{image}"
        logger.info(
            f"Using system default registry '{registry}'; image resolved to: {final}"
        )
        return final

    # 3) no explicit or configured, and not start with "gpustack" using "docker.io" as default.
    if not image.startswith("gpustack"):
        logger.info(
            f"Using Docker Hub for non-gpustack image; image resolved to: {image}"
        )
        return image

    # 4) Otherwise, use fallback registry if configured.
    #    The fallback registry is Docker Hub or Quay.io depending on reachability.
    #    If both are not reachable, use docker.io as default.
    prefix = fallback_registry + "/" if fallback_registry else ""
    return f"{prefix}{image}"