$fn=128;

// --- PARAMETERS ---
body_length = 40;
body_width = 26;
body_height = 8;
tail_L = [14, 13, 12, 11, 10];
tail_w = [12, 10, 8, 7, 6, 5];

// --- MAIN ASSEMBLY ---
scorpion();

module scorpion() {
    scorpion_body();
    
    // Tail Assembly
    tail_chain(0);
    
    // Left Claw Assembly
    translate([-body_length + 5, 14, 0]) rotate([0, 0, 110]) {
        flexi_link(15, 10, 12, body_height);
        translate([15, 0, 0]) claw(12, body_height, true);
    }
    
    // Right Claw Assembly
    translate([-body_length + 5, -14, 0]) rotate([0, 0, -110]) {
        flexi_link(15, 10, 12, body_height);
        translate([15, 0, 0]) claw(12, body_height, false);
    }
}

// --- MODULES ---

module scorpion_body() {
    difference() {
        union() {
            // Main Carapace
            hull() {
                translate([-body_length + 5, 0, 0]) cylinder(r=10, h=body_height, center=true);
                translate([-body_length/2, 0, 0]) cylinder(r=body_width/2, h=body_height, center=true);
                translate([-tail_w[0]/2 - 1, 0, 0]) cylinder(r=tail_w[0]/2, h=body_height, center=true);
            }
        }
        // Flat bottom cut for printability
        translate([0, 0, -body_height/2 - 5]) cube([150, 100, 10], center=true);
    }
    
    // Carapace armor ridges
    for (i=[0:4]) {
        translate([-body_length/2 + i*7, 0, body_height/2]) 
            scale([1, 2.5, 0.5]) 
            sphere(r=3);
    }
    
    // Eyes
    translate([-body_length + 8, 3, body_height/2]) sphere(r=1.5);
    translate([-body_length + 8, -3, body_height/2]) sphere(r=1.5);
    
    // Tail male joint (Back)
    male_joint(tail_w[0], body_height);
    
    // Legs (4 pairs)
    for (i=[0:3]) {
        leg_x = -body_length + 10 + i*8;
        translate([leg_x, body_width/2 - 2, 0]) 
            rotate([0, 0, 70 - i*15]) 
            leg();
        translate([leg_x, -body_width/2 + 2, 0]) 
            rotate([0, 0, -70 + i*15]) 
            scale([1, -1, 1]) 
            leg();
    }
    
    // Claw Attachments (Front)
    translate([-body_length + 5, 14, 0]) rotate([0, 0, 110]) male_joint(10, body_height);
    translate([-body_length + 5, -14, 0]) rotate([0, 0, -110]) male_joint(10, body_height);
}

module tail_chain(index=0) {
    if (index < 5) {
        flexi_link(tail_L[index], tail_w[index], tail_w[index+1], body_height);
        translate([tail_L[index], 0, 0]) tail_chain(index+1);
    } else {
        stinger(tail_w[index], body_height);
    }
}

module flexi_link(L, w1, w2, h) {
    // Segment Body
    hull() {
        translate([w1/2 + 1, 0, 0]) cylinder(r=w1/2 - 1, h=h, center=true);
        translate([L, 0, 0]) cylinder(r=w2/2 - 0.5, h=h, center=true);
    }
    
    // Female Hinge (Front)
    difference() {
        cylinder(r=w1/2, h=h, center=true);
        cube([w1+4, w1+4, 2.8], center=true); // Clearance slot
    }
    cylinder(r=1.5, h=h, center=true); // Vertical pivot pin
    
    // Male Hinge (Back)
    difference() {
        union() {
            translate([L, 0, 0]) cylinder(r=w2/2 - 0.5, h=1.6, center=true);
            translate([L - w2/4, 0, 0]) cube([w2/2, w2-1, 1.6], center=true);
        }
        translate([L, 0, 0]) cylinder(r=2.0, h=h+2, center=true); // Pivot hole
    }
}

module male_joint(w, h) {
    difference() {
        union() {
            cylinder(r=w/2 - 0.5, h=1.6, center=true);
            // Extended tab to embed securely into the parent body
            translate([-w/2 - 2, 0, 0]) cube([w + 4, w-1, 1.6], center=true);
        }
        cylinder(r=2.0, h=h+2, center=true);
    }
}

module stinger(w, h) {
    // Base Body
    hull() {
        translate([w/2 + 1, 0, 0]) cylinder(r=w/2 - 1, h=h, center=true);
        translate([w + 2, 0, 0]) cylinder(r=w/2, h=h, center=true);
    }
    
    // Female Hinge
    difference() {
        cylinder(r=w/2, h=h, center=true);
        cube([w+4, w+4, 2.8], center=true);
    }
    cylinder(r=1.5, h=h, center=true);
    
    // Curved Telson/Barb
    hull() {
        translate([w + 2, 0, h/2]) sphere(r=1.5);
        translate([w - 1, 0, h + 2]) sphere(r=0.5);
    }
    hull() {
        translate([w + 2, 0, h/2 - 1.5]) cylinder(r=1.5, h=3, center=true);
        translate([w + 2, 0, h/2]) sphere(r=1.5);
    }
}

module claw(w, h, is_left) {
    dir = is_left ? 1 : -1;
    
    // Claw Body and Pincers
    union() {
        hull() {
            translate([w/2 + 1, 0, 0]) cylinder(r=w/2 - 1, h=h, center=true);
            translate([12, dir*3, 0]) cylinder(r=w/1.5, h=h, center=true);
        }
        // Outer fixed finger
        hull() {
            translate([12, dir*3, 0]) cylinder(r=w/1.5, h=h, center=true);
            translate([25, dir*2, 0]) cylinder(r=1.5, h=h, center=true);
        }
        // Inner fixed finger
        hull() {
            translate([12, -dir*3, 0]) cylinder(r=w/2.5, h=h, center=true);
            translate([22, -dir*5, 0]) cylinder(r=1, h=h, center=true);
        }
    }
    
    // Female Hinge
    difference() {
        cylinder(r=w/2, h=h, center=true);
        cube([w+4, w+4, 2.8], center=true);
    }
    cylinder(r=1.5, h=h, center=true);
}

module leg() {
    translate([0, 0, -2]) {
        hull() {
            cylinder(r=2.5, h=4, center=true);
            translate([0, 15, 0]) cylinder(r=1.5, h=4, center=true);
        }
        hull() {
            translate([0, 15, 0]) cylinder(r=1.5, h=4, center=true);
            translate([5, 25, 0]) cylinder(r=0.5, h=4, center=true);
        }
    }
}