# admin.py
import os
import json
import hmac
import zipfile
import shutil
from typing import List, Tuple

ALLOWED_IMAGE_EXTS = {".jpg", ".jpeg", ".png", ".tif", ".tiff"}
_ADMIN_PASSWORD = os.environ.get("ADMIN_PASSWORD", "")  # Hugging Face Space Secret 권장

def _persistent_base_dir() -> str:
    return os.environ.get("HF_PERSISTENT_DIR", "/data")

def _data_root() -> str:
    return _persistent_base_dir()

def verify_password(input_pw: str) -> bool:
    return bool(_ADMIN_PASSWORD) and hmac.compare_digest(input_pw or "", _ADMIN_PASSWORD)

def list_sessions() -> Tuple[List[str], str]:
    root = _data_root()
    os.makedirs(root, exist_ok=True)
    try:
        items = sorted(
            [d for d in os.listdir(root) if os.path.isdir(os.path.join(root, d))],
            reverse=True
        )
        if not items:
            return [], "Info: No saved sessions found under /data."
        return items, f"Found {len(items)} session folder(s) under /data."
    except Exception as e:
        return [], f"Error: Failed to list sessions. {e}"

def session_info(session: str) -> Tuple[str, List[str]]:
    root = _data_root()
    if not session:
        return "Error: No session selected.", []
    path = os.path.join(root, session)
    if not os.path.isdir(path):
        return "Error: Session folder does not exist.", []

    # meta.json
    meta_text = ""
    meta_path = os.path.join(path, "meta.json")
    if os.path.isfile(meta_path):
        try:
            with open(meta_path, "r", encoding="utf-8") as fp:
                meta = json.load(fp)
            meta_text = json.dumps(meta, ensure_ascii=False, indent=2)
        except Exception as e:
            meta_text = f"(Failed to read meta.json: {e})"

    originals = []
    for name in os.listdir(path):
        p = os.path.join(path, name)
        if os.path.isfile(p) and os.path.splitext(name)[1].lower() in ALLOWED_IMAGE_EXTS:
            originals.append(p)

    total_imgs = len(originals)

    info_md = (
        f"**Session:** `{session}`  \n"
        f"**Path:** `{path}`  \n"
        f"**Images (total):** {total_imgs}  \n"
    )
    if meta_text:
        info_md += "\n\n**meta.json**\n```json\n" + meta_text + "\n```"

    return info_md

def zip_session(session: str) -> str:
    root = _data_root()
    if not session:
        raise ValueError("Error: No session selected.")
    src_dir = os.path.join(root, session)
    if not os.path.isdir(src_dir):
        raise ValueError("Error: Session folder does not exist.")

    zip_path = f"/tmp/{session}.zip"
    try:
        if os.path.exists(zip_path):
            os.remove(zip_path)
        with zipfile.ZipFile(zip_path, "w", compression=zipfile.ZIP_DEFLATED) as zf:
            for rootdir, _, files in os.walk(src_dir):
                for f in files:
                    full = os.path.join(rootdir, f)
                    arc = os.path.relpath(full, src_dir)
                    zf.write(full, arcname=arc)
    except Exception as e:
        raise RuntimeError(f"Error: Failed to create zip. {e}")
    return zip_path

def delete_session(session: str) -> str:
    """
    Delete the entire session folder (and its contents).
    Returns a status message.
    """
    root = _data_root()
    if not session:
        return "Error: No session selected."
    path = os.path.join(root, session)
    if not os.path.isdir(path):
        return "Error: Session folder does not exist."

    try:
        shutil.rmtree(path)
        return f"Success: Deleted session '{session}'."
    except Exception as e:
        return f"Error: Failed to delete session '{session}'. {e}"