"""Persistent storage for draft attachments (proforma files)."""
from datetime import datetime, timezone
import logging
import os
from pathlib import Path
import re
from uuid import UUID, uuid4

logger = logging.getLogger("bot.storage")


def sanitize_filename(filename: str) -> str:
    """Sanitize filename preserving Persian/Arabic/English letters, numbers, and extensions."""
    raw = (filename or "proforma.pdf").strip()
    name = Path(raw).name
    # Remove control characters and path traversal
    clean = re.sub(r'[\/\\:\*\?"<>\|\r\n\t]', "_", name)
    clean = clean.strip(". ")
    return clean or f"proforma_{uuid4().hex[:8]}.pdf"


async def save_proforma_file(
    draft_id: str | UUID,
    file_name: str,
    content: bytes,
    mime_type: str | None = None,
    storage_dir: str = "data/attachments/proformas",
) -> dict:
    """Save proforma bytes permanently to disk.

    Returns dict metadata for persisting in draft payload.
    """
    clean_name = sanitize_filename(file_name)
    target_dir = Path(storage_dir) / str(draft_id)
    target_dir.mkdir(parents=True, exist_ok=True)

    unique_prefix = uuid4().hex[:8]
    saved_filename = f"{unique_prefix}_{clean_name}"
    target_path = target_dir / saved_filename

    # Write bytes to disk
    target_path.write_bytes(content)
    logger.info("Persisted proforma (%d bytes) to %s", len(content), target_path)

    return {
        "file_name": clean_name,
        "saved_filename": saved_filename,
        "saved_path": str(target_path.resolve()),
        "relative_path": str(target_path.as_posix()),
        "size_bytes": len(content),
        "mime_type": mime_type or "application/octet-stream",
        "saved_at": datetime.now(timezone.utc).isoformat(),
    }