import os
from datetime import datetime


def scan_files(root_path: str) -> dict:
    """
    Projde celý adresářový strom a vrátí dict všech souborů.
    Nehasuje obsah — to se dělá až pro změněné soubory.

    Returns:
        {relative_path: {full_path, file_name, directory, size, mtime}}
    """
    result = {}
    for root, _, files in os.walk(root_path):
        for name in files:
            full_path = os.path.join(root, name)
            try:
                stat = os.stat(full_path)
            except (FileNotFoundError, PermissionError):
                continue
            rel_path = os.path.relpath(full_path, root_path).replace("\\", "/")
            rel_dir = os.path.relpath(root, root_path).replace("\\", "/")
            # Truncate microseconds — MySQL DATETIME rounds to whole seconds,
            # which causes false "modified" detections on every run.
            mtime = datetime.fromtimestamp(stat.st_mtime).replace(microsecond=0)
            result[rel_path] = {
                "full_path": full_path,
                "file_name": name,
                "directory": rel_dir,
                "size": stat.st_size,
                "mtime": mtime,
            }
    return result