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

from pathlib import Path
from typing import Any

import yaml

# Config keys for model lists → ComfyUI subdir under models/
MODEL_TYPE_SUBDIRS = {
    "diffusion_models": "diffusion_models",
    "text_encoders": "text_encoders",
    "vaes": "vae",
    "upscale_models": "upscale_models",
    "loras": "loras",
}

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


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 model list types. 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")
    for key in MODEL_TYPE_SUBDIRS:
        val = data.get(key)
        if val is None:
            data[key] = []
        elif not isinstance(val, list):
            raise ValueError(f"'{key}' must be a list of URL strings")
        else:
            for i, item in enumerate(val):
                if not isinstance(item, str):
                    raise ValueError(f"'{key}[{i}]' must be a string")


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."""
    types = only_types if only_types is not None else list(MODEL_TYPE_SUBDIRS)
    tasks: list[tuple[str, str]] = []
    for model_type in types:
        if model_type not in MODEL_TYPE_SUBDIRS:
            continue
        urls = data.get(model_type)
        if not isinstance(urls, list):
            continue
        for url in urls:
            if isinstance(url, str) and url.strip():
                tasks.append((model_type, 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()
    subdir = MODEL_TYPE_SUBDIRS[model_type]
    return base / "models" / subdir