import time
from dataclasses import dataclass
from pathlib import Path
from typing import Dict, List, Optional


@dataclass
class ModelInfo:
    model_id: str
    created: int
    size: int
    path: Path


def scan_models(model_dir: str) -> List[ModelInfo]:
    base = Path(model_dir)
    if not base.exists():
        return []
    models: List[ModelInfo] = []
    now = int(time.time())
    for entry in base.iterdir():
        if entry.name.endswith(".partial"):
            continue
        if entry.is_file():
            size = entry.stat().st_size
            models.append(ModelInfo(model_id=entry.name, created=now, size=size, path=entry))
        elif entry.is_dir():
            models.append(ModelInfo(model_id=entry.name, created=now, size=0, path=entry))
    models.sort(key=lambda m: m.model_id.lower())
    return models


def find_model(model_dir: str, model_id: str) -> Optional[ModelInfo]:
    for model in scan_models(model_dir):
        if model.model_id == model_id:
            return model
    return None


def resolve_model(model_dir: str, requested: str, aliases: Dict[str, str]) -> Optional[ModelInfo]:
    if not requested:
        return None
    if requested in aliases:
        requested = aliases[requested]
    return find_model(model_dir, requested)