from mpoint import MPoint


def create_point_store():
    """ creates a new point_store """
    point_store = {'kept': 0, 'removed': 0}
    return point_store


def unify_polygons(polygons, point_store, precision=None):
    out = []
    for polygon in polygons:
        out.append(unify_polygon(polygon, point_store, precision))
    return out


def unify_polygon(polygon, point_store, precision=None):
    """
    Replaces duplicate points with an instance of the
    same point
    """
    new_points = []
    lptid = ''
    for pt in polygon:
        if 'deleted' not in pt:
            pt = MPoint(pt[0], pt[1])  # eventually convert to MPoint
        if precision is not None:
            fmt = '%' + precision + 'f-%' + precision + 'f'
        else:
            fmt = '%f-%f'
        pid = fmt % (pt.x, pt.y)
        if pid == lptid:
            continue  # skip double points
        lptid = pid
        if pid in point_store:
            point = point_store[pid]
            if point.three:
                point.deleted = True
            if point.two:
                point.three = True
            else:
                point.two = True
            point_store['removed'] += 1
        else:
            point = pt
            point_store['kept'] += 1
            point_store[pid] = pt
        new_points.append(point)
    return new_points