from __future__ import division  # Use floating point for math calculations

import math

from CTFd.models import Solves
from CTFd.utils.modes import get_model


def get_solve_count(challenge):
    Model = get_model()

    solve_count = (
        Solves.query.join(Model, Solves.account_id == Model.id)
        .filter(
            Solves.challenge_id == challenge.id,
            Model.hidden == False,
            Model.banned == False,
        )
        .count()
    )
    return solve_count


def linear(challenge):
    solve_count = get_solve_count(challenge)

    # If the solve count is 0 we shouldn't manipulate the solve count to
    # let the math update back to normal
    if solve_count != 0:
        # We subtract -1 to allow the first solver to get max point value
        solve_count -= 1

    value = challenge.initial - (challenge.decay * solve_count)

    value = math.ceil(value)

    if value < challenge.minimum:
        value = challenge.minimum

    return value


def logarithmic(challenge):
    solve_count = get_solve_count(challenge)

    # If the solve count is 0 we shouldn't manipulate the solve count to
    # let the math update back to normal
    if solve_count != 0:
        # We subtract -1 to allow the first solver to get max point value
        solve_count -= 1

    # Handle situations where admins have entered a 0 decay
    # This is invalid as it can cause a division by zero
    if challenge.decay == 0:
        challenge.decay = 1

    # It is important that this calculation takes into account floats.
    # Hence this file uses from __future__ import division
    value = (
        ((challenge.minimum - challenge.initial) / (challenge.decay ** 2))
        * (solve_count ** 2)
    ) + challenge.initial

    value = math.ceil(value)

    if value < challenge.minimum:
        value = challenge.minimum

    return value


DECAY_FUNCTIONS = {
    "linear": linear,
    "logarithmic": logarithmic,
}