$fn = 64;

// --- Parameters ---
hex_radius = 16;         // Outer radius of a single hexagon
wall_thickness = 1.2;    // Thickness of the bin walls
floor_thickness = 1.2;   // Thickness of the bottom floor
unit_height = 10;        // Height of one unit
units = 2;               // Number of height units

// --- Calculated Values ---
height = unit_height * units;
F = sqrt(3) * hex_radius; // Flat-to-flat distance

// Centers of the 3 hexagons forming an equilateral triangle
pos1 = [0, 0];
pos2 = [F, 0];
pos3 = [F/2, F * sqrt(3)/2];

// Centroid for centering the final model
cx = (pos1[0] + pos2[0] + pos3[0]) / 3;
cy = (pos1[1] + pos2[1] + pos3[1]) / 3;

// --- Modules ---
module hex_shape(r) {
    // Rotate 30 degrees so flat sides align for adjacent placement
    rotate(30) circle(r = r, $fn = 6);
}

module outer_profile() {
    union() {
        translate(pos1) hex_shape(hex_radius);
        translate(pos2) hex_shape(hex_radius);
        translate(pos3) hex_shape(hex_radius);
    }
}

// --- Main Assembly ---
translate([-cx, -cy, 0]) {
    difference() {
        // Outer solid shape
        linear_extrude(height) {
            outer_profile();
        }
        
        // Inner hollow shape (single continuous compartment)
        translate([0, 0, floor_thickness]) {
            linear_extrude(height + 1) { // Extrude past the top to prevent Z-fighting
                offset(delta = -wall_thickness) outer_profile();
            }
        }
    }
}