$fn=64;

// --- Parameters ---
cols = 4;               // Number of cell columns
rows = 3;               // Number of cell rows
cell_size = 35;         // Inner size of each square cell (mm)
cell_h = 40;            // Height of the cells (mm)
res_h = 15;             // Height of the bottom water reservoir (mm)
wall = 1.6;             // Wall thickness (mm)
drain_d = 6;            // Diameter of drainage holes (mm)
lid_h = 50;             // Height of the humidity lid (mm)
clearance = 0.6;        // Clearance for the lid to fit over the base (mm)

// --- Calculated Dimensions ---
W = cols * cell_size + (cols + 1) * wall;
D = rows * cell_size + (rows + 1) * wall;
H = cell_h + res_h;

lid_W = W + 2 * clearance;
lid_D = D + 2 * clearance;

// --- Main Layout ---
// Base unit
base();

// Lid (rotated 180 degrees to print flat without supports)
translate([0, D + 20 + lid_D + 2 * wall, lid_h]) 
    rotate([180, 0, 0]) 
    lid();

// --- Modules ---

module base() {
    union() {
        // Main body and reservoir
        difference() {
            cube([W, D, H]);
            // Hollow out the entire inside
            translate([wall, wall, wall])
                cube([W - 2 * wall, D - 2 * wall, H]);
        }

        // False bottom (floor of the cells)
        difference() {
            translate([wall, wall, res_h])
                cube([W - 2 * wall, D - 2 * wall, wall]);
            
            // Drainage holes
            for(c = [0 : cols - 1]) {
                for(r = [0 : rows - 1]) {
                    cx = wall + c * (cell_size + wall) + cell_size / 2;
                    cy = wall + r * (cell_size + wall) + cell_size / 2;
                    translate([cx, cy, res_h - 1])
                        cylinder(d=drain_d, h=wall + 2);
                }
            }
        }

        // Internal cell grid (X-axis walls)
        for(c = [1 : cols - 1]) {
            translate([c * (cell_size + wall), wall, res_h])
                cube([wall, D - 2 * wall, cell_h]);
        }
        
        // Internal cell grid (Y-axis walls)
        for(r = [1 : rows - 1]) {
            translate([wall, r * (cell_size + wall), res_h])
                cube([W - 2 * wall, wall, cell_h]);
        }

        // Pot rings (support under cells directing water to reservoir)
        for(c = [0 : cols - 1]) {
            for(r = [0 : rows - 1]) {
                cx = wall + c * (cell_size + wall) + cell_size / 2;
                cy = wall + r * (cell_size + wall) + cell_size / 2;
                
                difference() {
                    // Ring body
                    translate([cx, cy, wall])
                        cylinder(d=drain_d + 8, h=res_h - wall);
                    // Inner hole
                    translate([cx, cy, wall - 1])
                        cylinder(d=drain_d + 2, h=res_h + 2);
                    // Water escape slots at the base of the ring
                    translate([cx, cy, wall + 2])
                        cube([drain_d + 10, 2.5, 6], center=true);
                    translate([cx, cy, wall + 2])
                        cube([2.5, drain_d + 10, 6], center=true);
                }
            }
        }

        // Outer lip for the lid to rest upon
        translate([0, 0, H - 10])
            difference() {
                translate([-(clearance + wall), -(clearance + wall), 0])
                    cube([W + 2 * (clearance + wall), D + 2 * (clearance + wall), wall]);
                translate([-0.1, -0.1, -0.1])
                    cube([W + 0.2, D + 0.2, wall + 0.2]);
            }
    }
}

module lid() {
    difference() {
        // Outer shell
        cube([lid_W + 2 * wall, lid_D + 2 * wall, lid_h]);
        
        // Inner hollow
        translate([wall, wall, -1])
            cube([lid_W, lid_D, lid_h - wall + 1]);

        // Top ventilation holes
        for(cx = [lid_W / 3, lid_W * 2 / 3]) {
            for(cy = [lid_D / 3, lid_D * 2 / 3]) {
                translate([cx + wall, cy + wall, lid_h - wall - 1])
                    cylinder(d=8, h=wall + 2);
            }
        }
    }
}