Find a closest point to another set [closed]

I am trying to create a function to determine which of a set of points (represented as a list of coordinates lists) is closest to another given point. It should return the index in the list where that point appears:

Here is the code I've written so far:

def sq_dist(p1: tuple[int, int], p2: tuple[int, int]) -> int:
    """Square of Euclidean distance between p1 and p2

    >>> sq_dist([2, 3], [3, 5])
    5
    """
    x1, y1 = p1
    x2, y2 = p2
    dx = x2 - x1
    dy = y2 - y1
    return dx*dx + dy*dy



def closest_index(point: tuple[int, int], centroids: list[tuple[int, int]]) -> int:
    count = 0
    soopa_distance = 1000000000000000000000000000000000000000000000000
    
    for p in centroids:
        distance = sq_dist(point,p)
        if distance < soopa_distance:
            soopa_distance = distance
        else:
            count =  count +1
           
    return count

Unfortunately it doesn't return the expected index:

point_set1 = [[4,5],[3,4],[2,3],[1,2],[1,1]]
print(closest_index([0,0], point_set1))
# 0

point_set2 = [[1,2],[2,3],[3,4],[4,5],[1,1]]
print(closest_index([0,0], point_set2))
# 3

# Expected result in both cases: 4

Can you please help me identify and fix the error(s) ?