$fn=64;

// --- Parameters ---
// Outer diameter of the insert body (fits inside the pot ring)
insert_diameter = 100; 
// Outer diameter of the top retaining lip
lip_diameter = 115;    
// Thickness of the top retaining lip
lip_thickness = 3;     
// Total depth of the insert bowl
insert_depth = 20;     
// Thickness of the bottom and side walls
wall_thickness = 2.5;  
// Diameter of the drainage holes
hole_diameter = 6;     
// Center-to-center spacing between drainage holes
hole_spacing = 14;     

module pot_ring_insert() {
    difference() {
        // Main solid body
        union() {
            // Lower bowl section
            cylinder(d=insert_diameter, h=insert_depth);
            // Top retaining lip
            translate([0, 0, insert_depth])
                cylinder(d=lip_diameter, h=lip_thickness);
        }

        // Hollow interior (the bowl cutout)
        translate([0, 0, wall_thickness])
            cylinder(
                d=insert_diameter - (2 * wall_thickness), 
                h=insert_depth + lip_thickness + 1 // +1 to prevent Z-fighting
            );

        // Drainage holes pattern
        // Calculate maximum safe radius to avoid cutting into the side walls
        max_r = (insert_diameter / 2) - wall_thickness - (hole_diameter / 2) - 1;
        grid_steps = floor((insert_diameter / 2) / hole_spacing);
        
        for(i = [-grid_steps : grid_steps]) {
            for(j = [-grid_steps : grid_steps]) {
                // Calculate X and Y positions symmetrically around center
                x_pos = i * hole_spacing;
                y_pos = j * hole_spacing;
                
                // Only place holes that fit within the safe radius
                if (sqrt((x_pos * x_pos) + (y_pos * y_pos)) <= max_r) {
                    translate([x_pos, y_pos, -1])
                        cylinder(d=hole_diameter, h=wall_thickness + 2);
                }
            }
        }
    }
}

// Generate the model
pot_ring_insert();