$fn = 64;

// --- Parameters ---
holder_width = 140;
holder_depth = 110;
holder_height = 90;
wall_thickness = 3;
num_slots = 5;

// Rail mount parameters (Generic / ArtArsenal style)
mount_width = 100;
mount_depth = 14;
mount_height = 25;

// --- Calculated Variables ---
slot_width = (holder_width - (wall_thickness * (num_slots + 1))) / num_slots;

// --- Main Assembly ---
union() {
    // Base plate
    cube([holder_width, holder_depth, wall_thickness]);
    
    // Back plate
    cube([holder_width, wall_thickness, holder_height]);
    
    // Front lip to secure palettes
    translate([0, holder_depth - wall_thickness, 0])
        cube([holder_width, wall_thickness, holder_height * 0.25]);
        
    // Dividers
    for (i = [0 : num_slots]) {
        translate([i * (slot_width + wall_thickness), 0, 0]) {
            rotate([90, 0, 90])
            linear_extrude(wall_thickness) {
                polygon([
                    [0, 0],
                    [holder_depth, 0],
                    [holder_depth, holder_height * 0.25],
                    [wall_thickness, holder_height],
                    [0, holder_height]
                ]);
            }
        }
    }
    
    // Wall Rail Mount (Rear Hook)
    // Shifted slightly into the backplate (+0.1) for a manifold union
    translate([(holder_width - mount_width) / 2, -mount_depth + 0.1, holder_height - mount_height - 10]) {
        difference() {
            // Main mount block
            cube([mount_width, mount_depth, mount_height]);
            
            // Cutout channel for the rail
            translate([-1, 5, -1])
                cube([mount_width + 2, mount_depth, mount_height - 7]);
                
            // Angled entry chamfer for easy hooking
            translate([-1, 5, -1])
                rotate([-45, 0, 0])
                cube([mount_width + 2, 12, 12]);
        }
    }
}