#!/usr/bin/env python3
# type: ignore

# *************************************************************************
#   Copyright (C) 2025, Paul Lutus                                        *
#                                                                         *
#   This program is free software; you can redistribute it and/or modify  *
#   it under the terms of the GNU General Public License as published by  *
#   the Free Software Foundation; either version 2 of the License, or     *
#   (at your option) any later version.                                   *
#                                                                         *
#   This program is distributed in the hope that it will be useful,       *
#   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
#   GNU General Public License for more details.                          *
#                                                                         *
#   You should have received a copy of the GNU General Public License     *
#   along with this program; if not, write to the                         *
#   Free Software Foundation, Inc.,                                       *
#   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
# *************************************************************************

import cadquery as cq
import copy

import math, sys

# a classic interpolation algorithm


def ntrp(x, xa, xb, ya, yb):
    return (x - xa) * (yb - ya) / (xb - xa) + ya


def show_results(item):
    try:
        show_object(item)
    except:
        None
        # print("  The show_object() function only works in CQ-Editor.")


def generate_tensioner(testing=False):

    # external arc
    disc_a = cq.Workplane("YZ").circle(5.0).extrude(1.75).translate((-0.875, 12, 15))
    # shoulder
    disc_b = cq.Workplane("YZ").circle(2.75).extrude(3).translate((-1.5, 12, 15))
    # pulley axle port
    perf_a = cq.Workplane("YZ").circle(1.35).extrude(24).translate((-12, 12, 15))
    # tensioner adjustment brass insert port
    perf_b = cq.Workplane("XZ").circle(2).extrude(24).translate((0, 20, 4))

    # pulley for testing
    pulley = cq.Workplane("YZ").circle(8.5).extrude(9).translate((-4.5, 12, 15))

    insert = cq.Workplane("XZ").circle(2).extrude(8).translate((0, 8.5, 4))

    # see solvespace source file for dimension numbers
    edge_points_A = (
        (0.5, 0.0),
        (0.0, 0.5),
        (0.0, 8.0),
        (3.050, 11.814),
        (4.205, 9.570),
        (6.169, 7.5),
        (7.653, 6.553),
        (17.0, 3.0),
        (17.0, 1.0),
        (16.0, 0.0),
        (0.5, 0.0),
    )
    edge_points_B = (
        (0.5, 0.0),
        (0.0, 0.5),
        (0.0, 8.0),
        (8.1, 18.12),
        # arc fills in here
        (17.0, 15.0),
        (17.0, 1.0),
        (16.0, 0.0),
        (0.5, 0, 0),
    )
    edge_points_C = (
        (0.0, 6.75),
        (0.0, 8.0),
        (8.1, 18.123),
        # arc fills in here
        (17.0, 15.0),
        (17.0, 6.75),
        (0.0, 6.75),
    )
    body_a = (
        cq.Workplane("YZ")
        .polyline(edge_points_A)
        .close()
        .extrude(11)
        .edges("X")
        .fillet(0.8)
        .translate((-5.5, 0, 0))
    )
    body_b = (
        cq.Workplane("YZ")
        .polyline(edge_points_B)
        .close()
        .extrude(1.75)
        .edges("X")
        .fillet(0.8)
        .translate((-0.875, 0, 0))
    )
    body_c = (
        cq.Workplane("YZ")
        .polyline(edge_points_C)
        .close()
        .extrude(1.75)
        .edges("X")
        .fillet(0.8)
        .translate((-0.875, 0, 0))
    )
    body_b1 = (body_b + disc_a + disc_b).translate((6.25, 0, 0))
    body_b2 = (body_b + disc_a + disc_b).translate((-6.25, 0, 0))
    body_c1 = (body_c + disc_a + disc_b).translate((8, 0, 0))
    body_c2 = (body_c + disc_a + disc_b).translate((-8, 0, 0))

    body = body_a + body_b1 + body_b2 + body_c1 + body_c2 - (perf_a + perf_b)

    if testing:
        body += pulley
        body += insert

    show_results(body)
    return body


def dispatch(testing):
    ts = ("", "_testing")[testing]
    body = generate_tensioner(testing)
    fn = f"belt_tensioner_cadquery{ts}.stl"
    body.export(fn)
    print(f"wrote {fn}.")


def main():
    dispatch(True)
    dispatch(False)


if __name__ == "__main__":
    main()