import os
from fastapi import APIRouter, Depends, HTTPException, Query
from ..dependencies import require_admin
from ..models.user import User

router = APIRouter(prefix="/api/filebrowser", tags=["filebrowser"])


@router.get("")
async def browse(
    path: str = Query("/"),
    _admin: User = Depends(require_admin),
):
    path = os.path.normpath(path)
    if not os.path.isdir(path):
        raise HTTPException(status_code=404, detail="Pfad nicht gefunden")

    try:
        names = sorted(os.listdir(path), key=lambda n: n.lower())
    except PermissionError:
        raise HTTPException(status_code=403, detail="Zugriff verweigert")

    entries = []
    for name in names:
        if name.startswith("."):
            continue
        full = os.path.join(path, name)
        try:
            is_dir = os.path.isdir(full)
        except OSError:
            continue
        entries.append({"name": name, "path": full, "isDir": is_dir})

    parent_path = os.path.dirname(path)
    parent = parent_path if parent_path != path else None

    return {"path": path, "parent": parent, "entries": entries}


@router.get("/diagnose")
async def diagnose(_admin: User = Depends(require_admin)):
    """Zeigt was der Backend-Container sieht: Bind-Mounts und Top-Level-Verzeichnisse."""
    # Aktive Mounts aus /proc/self/mountinfo
    mounts = []
    try:
        with open("/proc/self/mountinfo", "r") as f:
            for line in f:
                parts = line.split()
                # Format: id parent major:minor root mount_point options - fstype source super_options
                if len(parts) < 10 or "-" not in parts:
                    continue
                sep = parts.index("-")
                mount_point = parts[4]
                fstype = parts[sep + 1] if sep + 1 < len(parts) else "?"
                source = parts[sep + 2] if sep + 2 < len(parts) else "?"
                # Interne Kernel-Mounts überspringen
                if any(mount_point.startswith(p) for p in ("/proc", "/sys", "/dev", "/etc/", "/run", "/tmp")):
                    continue
                if mount_point in ("/", "/etc/resolv.conf", "/etc/hostname", "/etc/hosts"):
                    continue
                mounts.append({
                    "mountPoint": mount_point,
                    "fsType": fstype,
                    "source": source,
                })
    except Exception as e:
        mounts_error = str(e)
    else:
        mounts_error = None

    # Top-Level-Verzeichnisse die im Container existieren und für Hörbücher in Frage kommen
    candidates = ["/audiofiles", "/mnt", "/media", "/srv", "/home", "/app/data"]
    roots = []
    for p in candidates:
        if os.path.isdir(p):
            try:
                entries = os.listdir(p)
                roots.append({
                    "path": p,
                    "exists": True,
                    "entryCount": len([e for e in entries if not e.startswith(".")]),
                })
            except PermissionError:
                roots.append({"path": p, "exists": True, "entryCount": None, "permError": True})
        else:
            roots.append({"path": p, "exists": False})

    return {
        "mounts": mounts,
        "mountsError": mounts_error,
        "candidateRoots": roots,
        "hint": (
            "Pfade die hier NICHT in 'mounts' auftauchen, sind im Container nicht sichtbar. "
            "Sie müssen in docker-compose.yml als Volume gemountet werden — "
            "z.B. via EXTRA_AUDIO_PATH=/dein/host/pfad in der .env und dann "
            "'docker-compose down && docker-compose up -d'."
        ),
    }