$fn = 20;

round_corner_r = 1;

length_long = 70;
length_short = 20;
door_thickness = 40;
width = 8; // thickness = 8
surface_width = width - round_corner_r * 2; // 6

hook_pos = 46;
hook_gap = 12;
hook_length = 12;
hook_surface_width = surface_width - round_corner_r * 2; // 4

strength_cube_width = width;

union() {
    minkowski() {
        union() {
            cube([length_long, surface_width, surface_width]);
            cube([surface_width, door_thickness + surface_width + round_corner_r * 2, surface_width]);
            translate([0, surface_width + round_corner_r * 2 + door_thickness, 0])
                cube([length_short, surface_width, surface_width]);
        }
        sphere(r = round_corner_r);
    }

    minkowski() {
        union() {
            translate([hook_pos, - hook_gap - round_corner_r, round_corner_r])
                cube([hook_surface_width, hook_gap + width *0.7, hook_surface_width]);
            translate([hook_pos - hook_length, - hook_gap - round_corner_r, round_corner_r])
                cube([hook_length, hook_surface_width, hook_surface_width]);
            translate([hook_pos + surface_width - round_corner_r * 2, -round_corner_r, round_corner_r])
                linear_extrude(height=hook_surface_width)
                    polygon([
                        [0, 0],
                        [0, -12],
                        [12, 0],
                    ]);
            translate([hook_pos - hook_surface_width * 2 - round_corner_r * 2, -round_corner_r, round_corner_r])
                linear_extrude(height=hook_surface_width)
                    polygon([
                        [12, -12],
                        [0, -12],
                        [12, 0],
                    ]);
            
        }
        sphere(r = round_corner_r);
    }
}