$fn = 64;

// --- Parametric Dimensions ---
rack_width = 180;         // Total width of the rack
rack_depth = 75;          // How far the shelf extends from the wall
thickness = 5;            // General material thickness
backplate_height = 45;    // Height of the wall-mounting plate

num_slots = 6;            // Number of brush slots
slot_length = 55;         // Depth of the slot
slot_front_width = 14;    // Width at the opening (fits thicker handles)
slot_back_width = 6;      // Width at the back (wedges thinner handles)

// Wall rail mount (ArtArsenal / French Cleat style)
cleat_depth = 6;          // Depth of the rail hook
cleat_height = 15;        // Drop height of the hook
cleat_thickness = 4;      // Thickness of the hook material

module brush_drying_rack() {
    union() {
        // 1. Backplate
        cube([rack_width, thickness, backplate_height]);

        // 2. Shelf with slots
        difference() {
            // Solid shelf (overlaps backplate slightly for manifold geometry)
            translate([0, thickness - 0.1, backplate_height - thickness])
            cube([rack_width, rack_depth + 0.1, thickness]);

            // Cut tapered slots
            for(i = [0 : num_slots - 1]) {
                spacing = rack_width / num_slots;
                x_pos = (spacing / 2) + i * spacing;

                translate([x_pos, thickness + rack_depth, backplate_height - thickness])
                v_slot();
            }
        }

        // 3. Gussets (Under-shelf supports)
        translate([0, thickness, 0]) gusset();
        translate([rack_width / 2 - thickness / 2, thickness, 0]) gusset();
        translate([rack_width - thickness, thickness, 0]) gusset();

        // 4. Wall Rail Mount (Top Cleat Hook)
        translate([0, 0, 0])
        rotate([90, 0, 90])
        linear_extrude(rack_width)
        polygon([
            [0.1, backplate_height], // Overlap into backplate
            [-cleat_depth - cleat_thickness, backplate_height],
            [-cleat_depth - cleat_thickness, backplate_height - cleat_height],
            [-cleat_depth, backplate_height - cleat_height],
            [0.1, backplate_height - cleat_height + cleat_depth] // 45-degree engagement
        ]);

        // 5. Bottom Standoff (Keeps rack plumb against the wall)
        translate([0, -cleat_depth - cleat_thickness, 0])
        cube([rack_width, cleat_depth + cleat_thickness + 0.1, thickness]);
    }
}

module v_slot() {
    // Hull creates the tapered V-shape for wedging brush handles
    hull() {
        translate([0, 0, -1]) 
        cylinder(d=slot_front_width, h=thickness + 2);
        
        translate([0, -slot_length, -1]) 
        cylinder(d=slot_back_width, h=thickness + 2);
    }
    // Ensure the front opening is completely clear
    translate([-slot_front_width / 2, 0, -1]) 
    cube([slot_front_width, 10, thickness + 2]);
}

module gusset() {
    // Triangular support profile extruded and rotated into place
    rotate([90, 0, 90])
    linear_extrude(thickness)
    polygon([
        [-0.1, -0.1], // Bottom corner (overlaps backplate)
        [rack_depth - 10, backplate_height - thickness + 0.1], // Front top corner
        [-0.1, backplate_height - thickness + 0.1] // Back top corner
    ]);
}

// Generate the final model
// Note: For optimal support-free 3D printing, rotate the model 90 degrees 
// on the X or Y axis in your slicer so it prints on its side.
brush_drying_rack();