"""Load and validate YAML config; build ComfyUI paths."""

from pathlib import Path
from typing import Any

import yaml

REQUIRED_KEYS = {"comfyui_base_dir"}
TOKEN_KEYS = {"huggingface_token", "civitai_token"}


def _is_safe_type(t: str) -> bool:
    """Reject type values that could escape models/ (path traversal)."""
    if not t or not isinstance(t, str):
        return False
    if ".." in t or "/" in t or "\\" in t:
        return False
    return True


def load_config(path: str | Path) -> dict[str, Any]:
    """Load YAML config from path. Raises FileNotFoundError or yaml error."""
    p = Path(path)
    if not p.exists():
        raise FileNotFoundError(f"Config not found: {p}")
    with open(p, encoding="utf-8") as f:
        data = yaml.safe_load(f)
    if not isinstance(data, dict):
        raise ValueError("Config must be a YAML object")
    return data


def validate_config(data: dict[str, Any]) -> None:
    """Validate required keys and models list. Raises ValueError on failure."""
    if "comfyui_base_dir" not in data:
        raise ValueError("Config must contain 'comfyui_base_dir'")
    base = data["comfyui_base_dir"]
    if not base or not isinstance(base, str):
        raise ValueError("comfyui_base_dir must be a non-empty string")
    if "models" not in data:
        data["models"] = []
    models = data["models"]
    if not isinstance(models, list):
        raise ValueError("'models' must be a list")
    for i, item in enumerate(models):
        if not isinstance(item, dict):
            raise ValueError(f"models[{i}] must be an object with url and type")
        url = item.get("url")
        if not isinstance(url, str) or not url.strip():
            raise ValueError(f"models[{i}] must have a non-empty 'url' string")
        t = item.get("type")
        if not isinstance(t, str) or not t.strip():
            raise ValueError(f"models[{i}] must have a non-empty 'type' string")
        if not _is_safe_type(t):
            raise ValueError(f"models[{i}] 'type' must not contain /, \\, or ..")


def get_model_tasks(
    data: dict[str, Any], only_types: list[str] | None = None
) -> list[tuple[str, str]]:
    """Return list of (model_type, url) for all configured model URLs."""
    models = data.get("models")
    if not isinstance(models, list):
        return []
    tasks: list[tuple[str, str]] = []
    for item in models:
        if not isinstance(item, dict):
            continue
        url = item.get("url")
        t = item.get("type")
        if not isinstance(url, str) or not url.strip():
            continue
        if not isinstance(t, str) or not t.strip() or not _is_safe_type(t):
            continue
        if only_types is not None and t not in only_types:
            continue
        tasks.append((t.strip(), url.strip()))
    return tasks


def get_download_dir(data: dict[str, Any], model_type: str) -> Path:
    """Return the absolute directory path for a model type under ComfyUI base."""
    base = Path(data["comfyui_base_dir"]).expanduser().resolve()
    return base / "models" / model_type