$fn = 50;
threshold = 0.1;
half_threshold = threshold / 2;

wire_radius = 1;

wall_thickness = 2;
cutout_threshold = 1;

battery_length = 71;
battery_width = 18.75;

cell_holder_length = battery_length + wall_thickness * 2;
cell_holder_width = battery_width + wall_thickness * 2;
cell_holder_height = battery_width + wall_thickness;

battery_contact_thickness = .6;
// battery_contact_thickness = 1;
battery_contact_width = 11;
battery_contact_length = 12.8;
battery_contact_spring_height = 10.5;
battery_contact_flange_height = 1.9;

converter_width = 11.25;
converter_length = 22.25;
converter_height = 4.25;

module box(length, width, height, wall_thickness) {
    center_width = width - wall_thickness;
    center_height = height - wall_thickness;
    center_length = length - wall_thickness;

    union() {
        hull() {
            translate([-center_width / 2, -center_length / 2, -center_height / 2]) sphere(r = wall_thickness);
            translate([-center_width / 2, -center_length / 2, center_height / 2]) sphere(r = wall_thickness);
            translate([center_width / 2, -center_length / 2, -center_height / 2]) sphere(r = wall_thickness);
            translate([center_width / 2, -center_length / 2, center_height / 2]) sphere(r = wall_thickness);
        }
        hull() {
            translate([-center_width / 2, center_length / 2, -center_height / 2]) sphere(r = wall_thickness);
            translate([-center_width / 2, center_length / 2, center_height / 2]) sphere(r = wall_thickness);
            translate([center_width / 2, center_length / 2, -center_height / 2]) sphere(r = wall_thickness);
            translate([center_width / 2, center_length / 2, center_height / 2]) sphere(r = wall_thickness);
        }
        hull() {
            translate([-center_width / 2, -center_length / 2, -center_height / 2]) sphere(r = wall_thickness);
            translate([-center_width / 2, -center_length / 2, center_height / 2]) sphere(r = wall_thickness);
            translate([-center_width / 2, center_length / 2, -center_height / 2]) sphere(r = wall_thickness);
            translate([-center_width / 2, center_length / 2, center_height / 2]) sphere(r = wall_thickness);
        }
        hull() {
            translate([center_width / 2, -center_length / 2, -center_height / 2]) sphere(r = wall_thickness);
            translate([center_width / 2, -center_length / 2, center_height / 2]) sphere(r = wall_thickness);
            translate([center_width / 2, center_length / 2, -center_height / 2]) sphere(r = wall_thickness);
            translate([center_width / 2, center_length / 2, center_height / 2]) sphere(r = wall_thickness);
        }
        hull() {
            translate([-center_width / 2, -center_length / 2, -center_height / 2]) sphere(r = wall_thickness);
            translate([-center_width / 2, center_length / 2, -center_height / 2]) sphere(r = wall_thickness);
            translate([center_width / 2, -center_length / 2, -center_height / 2]) sphere(r = wall_thickness);
            translate([center_width / 2, center_length / 2, -center_height / 2]) sphere(r = wall_thickness);
        }
    }

    /*
    difference() {
        cube([width,
              length,
              height],
              center = true);
        translate([0, 0, wall_thickness])
            cube([width - wall_thickness * 2,
                  length - wall_thickness * 2,
                  height + threshold],
                 center = true);
    }
    */
}

module channel(length, width, height, wall_thickness) {
    center_width = width - wall_thickness;
    center_height = height - wall_thickness;
    center_length = length - wall_thickness;

    union() {
        hull() {
            translate([-center_width / 2, -center_length / 2, -center_height / 2]) sphere(r = wall_thickness);
            translate([-center_width / 2, -center_length / 2, center_height / 2]) sphere(r = wall_thickness);
            translate([-center_width / 2, center_length / 2, -center_height / 2]) sphere(r = wall_thickness);
            translate([-center_width / 2, center_length / 2, center_height / 2]) sphere(r = wall_thickness);
        }
        hull() {
            translate([center_width / 2, -center_length / 2, -center_height / 2]) sphere(r = wall_thickness);
            translate([center_width / 2, -center_length / 2, center_height / 2]) sphere(r = wall_thickness);
            translate([center_width / 2, center_length / 2, -center_height / 2]) sphere(r = wall_thickness);
            translate([center_width / 2, center_length / 2, center_height / 2]) sphere(r = wall_thickness);
        }
        hull() {
            translate([-center_width / 2, -center_length / 2, -center_height / 2]) sphere(r = wall_thickness);
            translate([-center_width / 2, center_length / 2, -center_height / 2]) sphere(r = wall_thickness);
            translate([center_width / 2, -center_length / 2, -center_height / 2]) sphere(r = wall_thickness);
            translate([center_width / 2, center_length / 2, -center_height / 2]) sphere(r = wall_thickness);
        }
    }

    /*
    difference() {
        cube([width,
              length,
              height],
              center = true);
        translate([0, 0, wall_thickness])
            cube([width - wall_thickness * 2,
                  length + threshold,
                  height + threshold],
                 center = true);
    }
    */
}

module cell_cradle(length, width) {
    translate([0, 0, -width / 4]) difference() {
        cube([width + wall_thickness * 2,
              wall_thickness,
              width / 2],
             center = true);
        translate([0, 0, width / 2])
            rotate([90, 0, 0])
            cylinder(h = wall_thickness + cutout_threshold,
                      r = width / 2,
                      center = true);
    }
}

module cell_box() {
    union() {
        channel(cell_holder_length, cell_holder_width, cell_holder_height, wall_thickness);
        translate([0, -battery_length / 6, 0]) cell_cradle(cell_holder_length, battery_width);
        translate([0, battery_length / 6, 0]) cell_cradle(cell_holder_length, battery_width);
    }
}


module contact_box(width, contact_width, contact_height, contact_thickness) {
    contact_thickness_ = contact_thickness * .75;
    cutout_width = contact_width * .8;
    box_width = width + wall_thickness * 2;
    box_thickness = contact_thickness_ + wall_thickness * 2;
    box_height = width + wall_thickness;

    union() {
        color("red", 1) cube([box_width,
              box_thickness,
              width + wall_thickness],
              center = true);

        translate([0,
                   0,
                   wall_thickness * 2])
            cube([contact_width,
                  contact_thickness_,
                  contact_height + cutout_threshold],
                 center = true);

        /*
        translate([box_width / 2 - (contact_width * .8) / 2,
                   wall_thickness,
                   box_height - contact_height])
            cube([contact_width * .8,
                  wall_thickness + contact_thickness_ + cutout_threshold,
                  contact_height + cutout_threshold]);

        translate([width / 2 + wall_thickness,
                   0,
                   width + wire_radius * 2])
                   rotate([-90, 0, 0])
                   cylinder(h=wall_thickness * 4, r=wire_radius, center = true);

        rotate([0, 180, 0])
            translate([-cutout_threshold / 2,
                       box_thickness,
                       width + wire_radius * 2])
            cylinder(h = width + wall_thickness * 2 + cutout_threshold, r = 1, center = true);
            */
    }
}

module battery_slot(length, width) {
    union() {
        translate([width + wall_thickness * 2, wall_thickness, 0])
            contact_box(battery_width,
                        battery_contact_width,
                        battery_contact_length,
                        battery_contact_flange_height);
        translate([0, wall_thickness, 0]) cell_box();
        translate([0, wall_thickness + length, 0])
            rotate([0, 0, 180])
            contact_box(battery_width,
                        battery_contact_width,
                        battery_contact_length,
                        battery_contact_flange_height);
    }
}

module battery_case() {
    union() {
        battery_slot(battery_length, battery_width);
        translate([battery_width + wall_thickness, 0, 0]) battery_slot(battery_length, battery_width);
    }
}

battery_case();

translate([-50, 0, 0])
    contact_box(battery_width,
                battery_contact_width,
                battery_contact_length,
                battery_contact_flange_height);

/*
rotate([0, 90, 0])
    translate([0, 5, 0])
    cylinder(h=battery_width + wall_thickness * 2 + cutout_threshold, r=1, center = true);

translate([0, -5, 0])
    rotate([0, 90, 0])
    cylinder(h=battery_width + wall_thickness * 2 + cutout_threshold, r=1, center = true);
*/