$fn=32*2;
thickness=1.6;
width=208.5;
depth=70.5;
height=8;

// outer display frame
difference(){
  cube([width+(thickness*2), depth+(thickness*2), height]);
  translate([thickness, thickness, 0])
    cube([width, depth, height]);
}

// inner display catch
translate([thickness, thickness, 1.5]){
  padding=5;
  ledge=0.8;
  difference(){
    translate([padding, 0, 0])
      cube([width-(padding*2), depth, thickness]);
    translate([0, ledge, 0])
      cube([width, depth-(ledge*2), thickness]);
  }
}

// usb compartment
usb_compartment();

// battery compartment
translate([146.6, 0, 0])
  battery_compartment();

// raspberry pi 4 cover
rpi4_cover();

// display hinge
translate([(width+thickness*2)/2, -9, 6.57])
  rotate([90, 270, 0])
    male_hinge();

module usb_compartment(){
  usb_tray_width=31;
  usb_tray_height=4;
  usb_step_width=10;
  usb_step_height=2;
  hole=6;
  hole_x=usb_tray_width+(usb_step_width/2)+thickness;
  hole_y=5.6+thickness;

  // usb tray
  difference(){
    translate([0, 0, height])
      cube([usb_tray_width+thickness, depth+(thickness*2), usb_tray_height+thickness]);

    translate([thickness, thickness, height+thickness])
      cube([usb_tray_width, depth, usb_tray_height]);
  }

  // usb step
  difference(){
    translate([usb_tray_width, 0, height])
      cube([usb_step_width+thickness, depth+(thickness*2), usb_step_height+thickness]);

    translate([usb_tray_width+thickness, thickness, height])
      cube([usb_step_width, depth, usb_step_height]);

    translate([hole_x, hole_y, height+usb_step_height])
      cylinder(h=thickness, d=hole);

    translate([hole_x, depth+(thickness*2)-hole_y, height+usb_step_height])
      cylinder(h=thickness, d=hole);
  }
}

module battery_compartment(){
    battery_width=63.5;
    battery_height=4;
    hole=6;
    hole_x=5;
    hole_y=5.6+thickness;

    difference(){
      translate([0, 0, height])
        cube([battery_width+thickness, depth+(thickness*2), battery_height+thickness]);

      translate([0, thickness, height])
        cube([battery_width, depth, battery_height]);

      translate([hole_x, hole_y, height+4])
        cylinder(h=thickness, d=hole);

      translate([hole_x, depth+(thickness*2)-hole_y, height+battery_height])
        cylinder(h=thickness, d=hole);
    }

    // rails
    translate([19, thickness+0.1, height+battery_height+thickness])
      female_rail(battery_width-19);

    translate([19, depth+thickness-0.1, height+battery_height+thickness])
      mirror([0, 1, 0])
        female_rail(battery_width-19);
}

module rpi4_cover(){
    difference(){
      translate([31+thickness+10, 0, height])
        cube([104, depth+(thickness*2), 25+thickness]);

      translate([31+thickness+10, thickness, height])
        cube([104, depth, 25]);

      translate([31+thickness+62, (depth+(thickness*2))/2, height+25])
        cylinder(h=thickness, d=41.5);
    }

    // left slope
    translate([19+thickness, 0, height+thickness])
      sloped_walls(22, depth+(thickness*2), 23.4, thickness);

    // right slope
    translate([145+thickness+22, 0, height+thickness])
      mirror([1,0,0])
        sloped_walls(22, depth+(thickness*2), 23.4, thickness);

    // logo
    translate([31+thickness+62, (depth+(thickness*2))/2, height+25])
      linear_extrude(height=1.6)
        resize([42, 42, 0])
          import(file="mk-logo.svg", center=true);
}

module prism(width, depth, height){
  polyhedron(
    points=[[0, depth, 0],
            [0, 0, 0],
            [width, 0, 0],
            [width, depth, 0],
            [width, depth, height],
            [width, 0, height]],
    faces=[[0,1,2,3],[5,4,3,2],[0,4,5,1],[0,3,4],[5,2,1]]);
}

module sloped_walls(width, depth, height, thickness){
  difference(){
    prism(width, depth, height);

    translate([0, thickness, 0])
      prism(width, depth-(thickness*2), height);
  }
}

module tab(length, thickness){
  difference(){
    union(){
      translate([0,0,-5])
        cube([length, thickness, 10], center=true);

        rotate([90,0,0])
          cylinder(h=thickness, d=length, center=true);
      }

      rotate([90,0,0])
        cylinder(h=20, d=5, center=true);
    }
}

module male_hinge(){
  th=2.90;  //Thickness of solid tabs
  sp=3.10;  //Width of seperation gap
  w=15.14;  //Width of base
  l=13.14;  //length of base

  translate([0, 0, -10+th/2])
    hull(){
      cube([l, w, th], center=true);

      translate([-l/2, -w/2-4, -2])
        cube([l+4, w+8, 0.1]);
    }

  //generating 2 tabs with sp spacing
  translate([0, -sp, 0])
    tab(l, th);
  translate([0, sp, 0])
    tab(l, th);
}

module female_rail(length){
  difference(){
    cube([length, 2.4, 3]);

    translate([0, -0.12, 0.09])
      rotate([45, 0, 0])
        cube([length, 2, 2]);
  }
}

module male_rail(length){
  difference(){
    translate([0, -0.12, 0.09])
      rotate([45, 0, 0])
        cube([length, 2, 2]);

    translate([0, -1, 0])
      cube([length, 1, 3]);
  }
}