import json

from django.http import HttpRequest, JsonResponse
from django.views.decorators.csrf import csrf_exempt
from django.views.decorators.http import require_GET, require_POST

from common.auth import get_current_user
from .models import Device, VpnLog
from .services.device_service import issue_connect_token
from .services.netmaker_client import NetmakerApiError, NetmakerClient, NetmakerConfigError


@csrf_exempt
@require_POST
def connect_token(request: HttpRequest) -> JsonResponse:
    user = get_current_user(request)
    if user is None:
        return JsonResponse({"error": "unauthorized"}, status=401)

    body = json.loads(request.body or b"{}")
    device_name = body.get("device_name") or "unknown-device"
    fingerprint = body.get("device_fingerprint") or ""
    try:
        token = issue_connect_token(user, device_name, fingerprint)
    except PermissionError as error:
        return JsonResponse({"error": str(error)}, status=403)
    except NetmakerConfigError as error:
        return JsonResponse({"error": str(error)}, status=503)
    except NetmakerApiError as error:
        return JsonResponse({"error": str(error)}, status=502)
    return JsonResponse({"token": token})


@require_GET
def status(request: HttpRequest) -> JsonResponse:
    user = get_current_user(request)
    if user is None:
        return JsonResponse({"error": "unauthorized"}, status=401)
    devices = list(user.devices.values("id", "device_name", "status", "netmaker_node_id", "updated_at"))
    logs = list(
        VpnLog.objects.filter(user=user)
        .select_related("device")
        .order_by("-created_at")
        .values("id", "device_id", "action", "detail", "created_at")[:20]
    )
    return JsonResponse(
        {
            "user": {
                "id": user.id,
                "name": user.name,
                "email": user.email,
            },
            "devices": devices,
            "logs": logs,
        }
    )


@csrf_exempt
@require_POST
def register_node(request: HttpRequest) -> JsonResponse:
    user = get_current_user(request)
    if user is None:
        return JsonResponse({"error": "unauthorized"}, status=401)

    body = json.loads(request.body or b"{}")
    fingerprint = body.get("device_fingerprint") or ""
    node_id = body.get("netmaker_node_id") or body.get("host_id") or body.get("node_id") or ""
    device_name = body.get("device_name") or "unknown-device"
    if not fingerprint:
        return JsonResponse({"error": "missing_device_fingerprint"}, status=400)
    if not node_id:
        return JsonResponse({"error": "missing_netmaker_node_id"}, status=400)

    device, _created = Device.objects.get_or_create(
        user=user,
        device_fingerprint=fingerprint,
        defaults={"device_name": device_name},
    )
    if device.status == Device.STATUS_REVOKED:
        return JsonResponse({"error": "device_revoked"}, status=403)

    changed_fields = []
    if device.device_name != device_name:
        device.device_name = device_name
        changed_fields.append("device_name")
    if device.netmaker_node_id != node_id:
        device.netmaker_node_id = node_id
        changed_fields.append("netmaker_node_id")
    if changed_fields:
        changed_fields.append("updated_at")
        device.save(update_fields=changed_fields)
        VpnLog.objects.create(
            user=user,
            device=device,
            action="netmaker_node_registered",
            detail={"netmaker_node_id": node_id},
        )

    return JsonResponse({"status": "ok", "device_id": device.id})


@csrf_exempt
@require_POST
def disconnect_log(request: HttpRequest) -> JsonResponse:
    user = get_current_user(request)
    if user is None:
        return JsonResponse({"error": "unauthorized"}, status=401)
    body = json.loads(request.body or b"{}")
    fingerprint = body.get("device_fingerprint") or ""
    device = Device.objects.filter(user=user, device_fingerprint=fingerprint).first()
    VpnLog.objects.create(user=user, device=device, action="disconnect", detail={"device_fingerprint": fingerprint})
    return JsonResponse({"status": "ok"})


@csrf_exempt
@require_POST
def revoke_device(request: HttpRequest) -> JsonResponse:
    user = get_current_user(request)
    if user is None:
        return JsonResponse({"error": "unauthorized"}, status=401)
    body = json.loads(request.body or b"{}")
    device = Device.objects.filter(user=user, id=body.get("device_id")).first()
    if device is None:
        return JsonResponse({"error": "device_not_found"}, status=404)

    netmaker_error = ""
    if device.netmaker_node_id:
        try:
            NetmakerClient().delete_node(device.netmaker_node_id)
        except (NetmakerConfigError, NetmakerApiError) as error:
            netmaker_error = str(error)

    device.status = Device.STATUS_REVOKED
    device.save(update_fields=["status", "updated_at"])
    VpnLog.objects.create(
        user=user,
        device=device,
        action="device_revoked",
        detail={"device_id": device.id, "netmaker_error": netmaker_error},
    )
    return JsonResponse({"status": "ok", "netmaker_error": netmaker_error})