MM_PER_IN = 25.4


# A progression of root depths, decreasing by a constant amount each step.
def linear_depths(start, end, base, increment):
    return {str(depth): base - (depth - start) * increment
            for depth in range(start, end + 1)}


def depths_in_to_mm(depths):
    return {name: depth * MM_PER_IN for name, depth in depths.items()}


# https://www.lockreference.com/wp-content/uploads/2019/03/Yale-Disc-Tumbler.pdf
yale_disc = depths_in_to_mm({
    "1": .250,
    "2": .230,
    "X": .220,  # also called "7"
    "3": .210,
    "4": .190,
    "5": .170,
})

# https://www.lockreference.com/wp-content/uploads/2018/01/Yale-.019.pdf
yale_019 = depths_in_to_mm(linear_depths(0, 9, .320, .019))

# https://www.lockreference.com/wp-content/uploads/2018/01/Yale-.025.pdf
yale_025 = depths_in_to_mm(linear_depths(0, 7, .320, .025))

# https://www.lockreference.com/wp-content/uploads/2018/09/National-Disc-Tumbler-Single-Sided.pdf
national_disc_tumbler = depths_in_to_mm(linear_depths(1, 4, .250, .025))