// ========================================================
// PARAMETRIC SEEDLING TRAY & PUSHABLE PLATES
// ========================================================

/* [Grid Configuration] */
cols = 3;                 // Number of columns
rows = 2;                 // Number of rows
cell_size = 35;           // Inner width/length of each square cell (mm)
tray_height = 50;         // Total height of the tray (mm)

/* [Wall & Ledge Dimensions] */
wall_thickness = 1.6;     // Thickness of the walls (mm)
bottom_lip = 4.0;         // Width of the bottom ledge holding the plate (mm)
floor_thickness = 2.0;    // Thickness of the bottom lip (mm)

/* [Pusher Plate Settings] */
plate_thickness = 2.0;    // Thickness of the pushable plate (mm)
clearance = 0.4;          // Gap between cell walls and plate for easy sliding (mm)
drain_hole_dia = 4.5;     // Diameter of drainage holes in the pushable plate (mm)

/* [Render Mode] */
// ["both_layout", "assembled", "tray_only", "plates_only"]
render_mode = "both_layout"; 



// --- DERIVED CALCULATIONS ---
pitch = cell_size + wall_thickness;
total_width  = cols * pitch + wall_thickness;
total_length = rows * pitch + wall_thickness;


// --- MAIN DISPLAY ---
if (render_mode == "tray_only") {
    seedling_tray();
} else if (render_mode == "plates_only") {
    plate_grid();
} else if (render_mode == "both_layout") {
    seedling_tray();
    translate([0, total_length + 10, 0])
        plate_grid();
} else if (render_mode == "assembled") {
    // Visual preview
    seedling_tray();
    for (r = [0 : rows - 1]) {
        for (c = [0 : cols - 1]) {
            translate([
                wall_thickness + c * pitch + clearance/2, 
                wall_thickness + r * pitch + clearance/2, 
                floor_thickness
            ])
                pusher_plate();
        }
    }
}


// ========================================================
// MODULES
// ========================================================

// Main seedling tray body
module seedling_tray() {
    difference() {
        // Outer solid volume
        cube([total_width, total_length, tray_height]);

        // Cut out each cell pocket and bottom push hole
        for (r = [0 : rows - 1]) {
            for (c = [0 : cols - 1]) {
                x_pos = wall_thickness + c * pitch;
                y_pos = wall_thickness + r * pitch;

                // 1. Main cell compartment
                translate([x_pos, y_pos, floor_thickness])
                    cube([cell_size, cell_size, tray_height]);

                // 2. Bottom push-through opening
                translate([x_pos + bottom_lip, y_pos + bottom_lip, -1])
                    cube([
                        cell_size - (2 * bottom_lip), 
                        cell_size - (2 * bottom_lip), 
                        floor_thickness + 2
                    ]);
            }
        }
    }
}

// Single pushable bottom plate
module pusher_plate() {
    p_size = cell_size - clearance;
    offset_margin = p_size / 3.5;

    difference() {
        // Plate body
        cube([p_size, p_size, plate_thickness]);

        // 5-points drainage hole pattern
        translate([p_size / 2, p_size / 2, -1])
            cylinder(h = plate_thickness + 2, d = drain_hole_dia, $fn = 20);

        for (dx = [offset_margin, p_size - offset_margin]) {
            for (dy = [offset_margin, p_size - offset_margin]) {
                translate([dx, dy, -1])
                    cylinder(h = plate_thickness + 2, d = drain_hole_dia, $fn = 20);
            }
        }
    }
}

// Plate grid
module plate_grid() {
    p_size = cell_size - clearance;
    spacing = 2;

    for (r = [0 : rows - 1]) {
        for (c = [0 : cols - 1]) {
            translate([c * (p_size + spacing), r * (p_size + spacing), 0])
                pusher_plate();
        }
    }
}