thickness = 3;

hook_width = 15;
hook_height = 20;
hook_dist = 125;
ledge_width = 220;
fraction = 0.7;

module hook(w, h, t){
    polygon(
        [
            [0, 0],
            [t, 0],
            [t, h],
            [t+w, h],
            [t+w, 0],
            [2*t+w, 0],
            [2*t+w, h+t],
            [0, h+t],
            [0, 0]
        ]
    );
}

module enforcement(diff, pos_frac){
    polygon(
        [
            [-(pos_frac+diff)*ledge_width, (pos_frac+diff)*fraction*(hook_dist)+hook_height-1.5],
            [-(pos_frac-diff)*ledge_width, (pos_frac-diff)*fraction*(hook_dist)+hook_height-1.5],
            [-(pos_frac-diff)*ledge_width, fraction*(hook_dist+hook_height)],
            [-(pos_frac+diff)*ledge_width, fraction*(hook_dist+hook_height)],
        ]
    );
}

linear_extrude(10){
    hook(hook_width, hook_height, thickness);
    translate([0,hook_dist,0]){
        hook(hook_width, hook_height, thickness);
    }
    // Connect hooks
    polygon(
        [
            [0,0],
            [thickness,0],
            [thickness,hook_dist+hook_height],
            [0,hook_dist+hook_height],
            [0,0]
        ]
    );


    translate([-ledge_width, fraction*(hook_dist+hook_height), 0]){
        square([ledge_width, thickness]);
    }

    // Enforce ledge
    polygon(
        [
            [-ledge_width, fraction*(hook_dist+hook_height)],
            [-ledge_width+2*thickness, fraction*(hook_dist+hook_height)],
            [0, thickness+hook_height],
            [0, 0+hook_height],
            [-ledge_width, fraction*(hook_dist+hook_height)],
        ]
    );

    enforcement(0.005, 0.3);
    enforcement(0.005, 0.6);

    // Add little bump
    polygon(
        [
            [-ledge_width, fraction*(hook_dist+hook_height)+thickness],
            [-ledge_width+thickness, fraction*(hook_dist+hook_height)+thickness],
            [-ledge_width+thickness, fraction*(hook_dist+hook_height)+2*thickness],
            [-ledge_width, fraction*(hook_dist+hook_height)+2*thickness],
        ]
    );
}