$fn=64;

// --- Parameters ---
dish_length = 120;
dish_width = 80;
dish_height = 18;
wall_thickness = 2.5;
base_thickness = 3;
corner_radius = 12;

ridge_width = 4;
ridge_height = 4;
ridge_spacing = 12;
num_ridges = 9;

hole_diameter = 5;
num_holes_x = 7;
num_holes_y = 3;
hole_spacing_x = 15;
hole_spacing_y = 20;

// --- Modules ---
module rounded_rect(l, w, h, r) {
    hull() {
        translate([-l/2 + r, -w/2 + r, 0]) cylinder(h=h, r=r);
        translate([ l/2 - r, -w/2 + r, 0]) cylinder(h=h, r=r);
        translate([ l/2 - r,  w/2 - r, 0]) cylinder(h=h, r=r);
        translate([-l/2 + r,  w/2 - r, 0]) cylinder(h=h, r=r);
    }
}

// --- Main Model ---
difference() {
    union() {
        // Main tray body
        difference() {
            // Outer shell
            rounded_rect(dish_length, dish_width, dish_height, corner_radius);
            
            // Inner cavity (hollowed out)
            translate([0, 0, base_thickness])
                rounded_rect(
                    dish_length - 2*wall_thickness, 
                    dish_width - 2*wall_thickness, 
                    dish_height + 1, 
                    corner_radius - wall_thickness
                );
        }

        // Drainage ridges
        intersection() {
            // Clip ridges to fit perfectly inside the inner cavity's rounded corners
            translate([0, 0, base_thickness])
                rounded_rect(
                    dish_length - 2*wall_thickness, 
                    dish_width - 2*wall_thickness, 
                    dish_height + 1, 
                    corner_radius - wall_thickness
                );
            
            // Generate the ridges
            union() {
                for (i = [-(num_ridges-1)/2 : (num_ridges-1)/2]) {
                    // Rounded top for the soap to rest on
                    translate([i * ridge_spacing, 0, base_thickness + ridge_height - (ridge_width/2)])
                        rotate([90, 0, 0])
                        cylinder(h=dish_width, d=ridge_width, center=true);
                    
                    // Base of the ridge
                    translate([i * ridge_spacing - ridge_width/2, -dish_width/2, base_thickness])
                        cube([ridge_width, dish_width, ridge_height - (ridge_width/2) + 0.1]);
                }
            }
        }
    }

    // Drainage holes through the base and ridges
    for (i = [-(num_holes_x-1)/2 : (num_holes_x-1)/2]) {
        for (j = [-(num_holes_y-1)/2 : (num_holes_y-1)/2]) {
            translate([i * hole_spacing_x, j * hole_spacing_y, -1])
                cylinder(h=base_thickness + ridge_height + 2, d=hole_diameter);
        }
    }
}