from celery import shared_task
from celery.exceptions import SoftTimeLimitExceeded


@shared_task(name="users_cleansing", time_limit=600)
def users_cleansing():
    """
    Deletes users never used 12 hours after creation
    """
    from datetime import timedelta

    from django.contrib.auth.models import User
    from django.db.models import Q
    from django.utils import timezone

    from api.logics import Logics

    # Users who's last login has not been in the last 6 hours
    active_time_range = (timezone.now() - timedelta(hours=6), timezone.now())
    queryset = User.objects.filter(~Q(last_login__range=active_time_range))
    queryset = queryset.filter(is_staff=False)  # Do not delete staff users

    # And do not have an active trade, any past contract or any reward.
    deleted_users = []
    for user in queryset:
        # Try an except, due to unknown cause for users lacking robots.
        try:
            if (
                user.robot.earned_rewards > 0
                or user.robot.claimed_rewards > 0
                or user.robot.telegram_enabled is True
            ):
                continue
            if not user.robot.total_contracts == 0:
                continue
            valid, _, _ = Logics.validate_already_maker_or_taker(user)
            if valid:
                deleted_users.append(str(user))
                user.delete()
        except Exception:
            pass

    results = {
        "num_deleted": len(deleted_users),
        "deleted_users": deleted_users,
    }
    return results


@shared_task(name="follow_send_payment", time_limit=180, soft_time_limit=175)
def follow_send_payment(hash):
    """Sends sats to buyer, continuous update"""

    from datetime import timedelta

    from decouple import config
    from django.utils import timezone

    from api.lightning.node import LNNode
    from api.models import LNPayment

    if config("DEBUG_PERMISSIONED_PAYOUTS", cast=bool, default=False):
        return

    lnpayment = LNPayment.objects.get(payment_hash=hash)
    lnpayment.last_routing_time = timezone.now()
    lnpayment.save(update_fields=["last_routing_time"])

    # Default is 0ppm. Set by the user over API. Client's default is 1000 ppm.
    fee_limit_sat = int(
        float(lnpayment.num_satoshis) * float(lnpayment.routing_budget_ppm) / 1_000_000
    )
    timeout_seconds = config("PAYOUT_TIMEOUT_SECONDS", cast=int, default=90)
    try:
        results = LNNode.follow_send_payment(lnpayment, fee_limit_sat, timeout_seconds)

    except SoftTimeLimitExceeded:
        # If the 175 seconds have been consumed without follow_send_payment()
        # returning, we set the last routing time as 'in 10 minutes'
        # so the next check happens in 10 minutes, instead of right now.
        lnpayment.last_routing_time = timezone.now() + timedelta(minutes=10)
        lnpayment.save(update_fields=["last_routing_time"])
        print(
            f"Order: {lnpayment.order_paid_LN.id} SOFT TIME LIMIT REACHED. Hash: {hash}"
        )
        results = {}

    return results


@shared_task(name="payments_cleansing", time_limit=600)
def payments_cleansing():
    """
    Deletes cancelled payments (hodl invoices never locked) that
    belong to orders expired more than 3 days ago.
    Deletes 'cancelled' or 'create' onchain_payments
    """

    from datetime import timedelta

    from django.db.models import Q
    from django.utils import timezone

    from api.models import LNPayment, OnchainPayment

    # Orders that have expired more than -3 days ago
    # Usually expiry is 1 day for every finished order. So ~4 days until
    # a never locked hodl invoice is removed.
    finished_time = timezone.now() - timedelta(days=3)
    queryset = LNPayment.objects.filter(
        Q(status=LNPayment.Status.CANCEL),
        Q(order_made__expires_at__lt=finished_time)
        | Q(order_taken__expires_at__lt=finished_time),
    )

    # And do not have an active trade, any past contract or any reward.
    deleted_lnpayments = []
    for lnpayment in queryset:
        # Try and except. In case some payment is already missing.
        try:
            name = str(lnpayment)
            lnpayment.delete()
            deleted_lnpayments.append(name)
        except Exception:
            pass

    # same for onchain payments
    queryset = OnchainPayment.objects.filter(
        Q(status__in=[OnchainPayment.Status.CANCE, OnchainPayment.Status.CREAT]),
        Q(order_paid_TX__expires_at__lt=finished_time) | Q(order_paid_TX__isnull=True),
    )

    # And do not have an active trade, any past contract or any reward.
    deleted_onchainpayments = []
    for onchainpayment in queryset:
        # Try and except. In case some payment is already missing.
        try:
            name = str(onchainpayment)
            onchainpayment.delete()
            deleted_onchainpayments.append(name)
        except Exception:
            pass

    results = {
        "num_lnpayments_deleted": len(deleted_lnpayments),
        "deleted_lnpayments": deleted_lnpayments,
        "num_onchainpayments_deleted": len(deleted_onchainpayments),
        "deleted_onchainpayments": deleted_onchainpayments,
    }
    return results


@shared_task(
    name="cache_external_market_prices",
    ignore_result=True,
    time_limit=120,
    soft_time_limit=115,
)
def cache_market():

    import math

    from django.utils import timezone

    from .models import Currency
    from .utils import get_exchange_rates

    currency_codes = list(Currency.currency_dict.values())

    try:
        exchange_rates = get_exchange_rates(currency_codes)

        if not exchange_rates:
            return

        results = {}
        for i in range(
            len(Currency.currency_dict.values())
        ):  # currencies are indexed starting at 1 (USD)

            rate = exchange_rates[i]
            results[i] = {currency_codes[i], rate}

            # Do not update if no new rate was found
            if math.isnan(rate):
                continue

            # Create / Update database cached prices
            currency_key = list(Currency.currency_dict.keys())[i]
            Currency.objects.update_or_create(
                id=int(currency_key),
                currency=int(currency_key),
                # if there is a Cached market prices matching that id, it updates it with defaults below
                defaults={
                    "exchange_rate": float(rate),
                    "timestamp": timezone.now(),
                },
            )

        return results

    except SoftTimeLimitExceeded:
        print("SOFT LIMIT REACHED. Could not fetch current external market prices.")
        return


@shared_task(name="send_notification", ignore_result=True, time_limit=120)
def send_notification(order_id=None, chat_message_id=None, message=None):

    if order_id:
        from api.models import Order

        order = Order.objects.get(id=order_id)
    elif chat_message_id:
        from chat.models import Message

        chat_message = Message.objects.get(id=chat_message_id)
        order = chat_message.order

    taker_enabled = False if order.taker is None else order.taker.robot.telegram_enabled
    if not (order.maker.robot.telegram_enabled or taker_enabled):
        return

    from api.notifications import Telegram

    telegram = Telegram()

    if message == "welcome":
        telegram.welcome(order)

    elif message == "order_expired_untaken":
        telegram.order_expired_untaken(order)

    elif message == "trade_successful":
        telegram.trade_successful(order)

    elif message == "public_order_cancelled":
        telegram.public_order_cancelled(order)

    elif message == "taker_expired_b4bond":
        telegram.taker_expired_b4bond(order)

    elif message == "order_published":
        telegram.order_published(order)

    elif message == "order_taken_confirmed":
        telegram.order_taken_confirmed(order)

    elif message == "fiat_exchange_starts":
        telegram.fiat_exchange_starts(order)

    elif message == "dispute_opened":
        telegram.dispute_opened(order)

    elif message == "collaborative_cancelled":
        telegram.collaborative_cancelled(order)

    elif message == "new_chat_message":
        telegram.new_chat_message(order, chat_message)

    return