terrassumptions/server/app/scoring.py

import math
from typing import Tuple

import haversine

mean_earth_radius_km = (6378 + 6357) / 2

# if you're more than 1/4 of the Earth's circumfrence away, you get 0
max_dist_km = (math.pi * mean_earth_radius_km) / 2 # this is about 10,000 km

# if you're within 1/16 of the Earth's circumfrence away, you get at least 1000 points
quarter_of_max_km = max_dist_km / 4 # this is about 2,500 km

# this is the total of the land area of all continents on Earth except Antarctica
relevant_land_area = sum([
    3.036e7, # https://www.wolframalpha.com/input?i=geographic+area+of+africa+in+km2
    4.981e7, # https://www.wolframalpha.com/input?i=geographic+area+of+asia+in+km2
    2.450e7, # https://www.wolframalpha.com/input?i=geographic+area+of+north+america+in+km2
    1.782e7, # https://www.wolframalpha.com/input?i=geographic+area+of+south+america+in+km2
    5.973e6, # https://www.wolframalpha.com/input?i=geographic+area+of+europe+in+km2
    8.563e6, # https://www.wolframalpha.com/input?i=geographic+area+of+oceania+in+km2
])

# this is the "radius" of an "average" continent
# within this radius, you get at least 2000 points
avg_continental_rad_km = math.sqrt(relevant_land_area / (6 * math.pi))
# this works out to be approx 2700 km

# somewhat arbitrarily, if you're within 1000 km, you get at least 3000 points
one_thousand = 1000.0

# this is the "radius" of the "average" country
# within this radius, you get at least 4000 points
# TODO increment or decrement number of countries as wars develop
avg_country_rad_km = math.sqrt(relevant_land_area / (206 * math.pi))
# this works out to be approx 460 km

# if you're within 150m, you get a perfect score of 5000
min_dist_km = 0.15  


def score_within(raw_dist: float, min_dist: float, max_dist: float) -> int:
    """
    Gives a score between 0 and 1000, with 1000 for the min_dist and 0 for the max_dist
    """
    # scale the distance down to [0.0, 1.0], then multiply it by 2 for easing
    pd2 = 2 * (raw_dist - min_dist) / (max_dist - min_dist)
    # perform a quadratic ease-in-out on pd2
    r = (pd2 ** 2) / 2 if pd2 < 1 else 1 - (((2 - pd2) ** 2) / 2)
    # use this to ease between 1000 and 0
    return int(1000 * (1 - r))


def ramp(dist_km: float) -> float:
    if dist_km <= min_dist_km:
        return 5000
    elif dist_km <= avg_country_rad_km:
        return 4000 + score_within(dist_km, min_dist_km, avg_country_rad_km)
    elif dist_km <= one_thousand:
        return 3000 + score_within(dist_km, avg_country_rad_km, one_thousand)
    elif dist_km <= avg_continental_rad_km:
        return 2000 + score_within(dist_km, one_thousand, avg_continental_rad_km)
    elif dist_km <= quarter_of_max_km:
        return 1000 + score_within(dist_km, avg_continental_rad_km, quarter_of_max_km)
    elif dist_km <= max_dist_km:
        return score_within(dist_km, quarter_of_max_km, max_dist_km)
    else: # dist_km > max_dist_km
        return 0


def score(target: Tuple[float, float], guess: Tuple[float, float]) -> Tuple[int, float]:
    """
    Takes in two (latitude, longitude) pairs and produces an int score.
    Score is in the (inclusive) range [0, 5000]
    Higher scores are closer.

    Returns (score, distance in km)
    """
    dist_km = haversine.haversine(target, guess)
    return ramp(dist_km), dist_km


def score_pow(target: Tuple[float, float], guess: Tuple[float, float]) -> Tuple[int, float]:
    """
    Takes in two (latitude, longitude) pairs and produces an int score.
    Score is in the (inclusive) range [0, 5000]
    Higher scores are closer.
    Uses the same ramp as standard score, but raises the distance to a power first

    Returns (score, distance in km)
    """
    dist_km = haversine.haversine(target, guess)
    return ramp(dist_km ** 1.2), dist_km


def score_country_race(target: str, guess: str, time_remaining: int, time_total: int):
    if target != guess:
        return 0

    time_used = time_total - time_remaining
    if time_used <= 5:
        return 5000
    
    # TODO make this into an interesting curve but for now linear is fine
    return int(5000 * (time_remaining / time_total))


def score_hard(target: Tuple[float, float], guess: Tuple[float, float]) -> Tuple[int, float]:
    """
    Takes in two (latitude, longitude) pairs and produces an int score.
    Score is in the (inclusive) range [0, 5000]
    Higher scores are closer.
    Scoring is much more punishing than standard

    Returns (score, distance in km)
    """
    dist_km = haversine.haversine(target, guess)
    return max(0, 5000 - int(dist_km * 10)), dist_km


def score_nightmare(target: Tuple[float, float], guess: Tuple[float, float]) -> Tuple[int, float]:
    """
    Takes in two (latitude, longitude) pairs and produces an int score.
    Score is in the range (-inf, 5000]
    Higher scores are closer.
    Scoring is much, MUCH more punishing than standard

    Returns (score, distance in km)
    """
    dist_km = haversine.haversine(target, guess)
    return 5000 - int(dist_km * 1000), dist_km