$fn = 64;

// Parametric Variables
jaw_width = 28;
jaw_thick = 4;
hinge_len = 14;
b_jaw_len = 90;
t_jaw_len = 88;
hole_offset = 45;

spout_r = 13;
spout_h = 16;
ring_r = 10;
ring_h = 5;
thread_pitch = 4;
thread_depth = 1.2;

// Main Assembly
bag_clip();
translate([0, 45, 0]) bag_cap();

// --- Modules ---

module bag_clip() {
    union() {
        bottom_jaw();
        living_hinge();
        top_jaw();
    }
}

module bottom_jaw() {
    difference() {
        union() {
            // Main bottom body
            translate([hinge_len/2, -jaw_width/2, 0]) 
                cube([b_jaw_len, jaw_width, jaw_thick]);
            
            // Inner sealing ring
            translate([hinge_len/2 + hole_offset, 0, jaw_thick - 0.1]) 
                cylinder(r1=ring_r, r2=ring_r-0.5, h=ring_h + 0.1);
            
            // Latch base
            translate([hinge_len/2 + b_jaw_len - 2, -8, 0]) 
                cube([2, 16, jaw_thick + 7]);
            
            // Latch snap hook
            translate([hinge_len/2 + b_jaw_len - 2, 0, jaw_thick + 4.5]) 
                rotate([90, 0, 0]) 
                cylinder(r=1.2, h=16, center=true);
        }
        // Hole through the ring for the bag
        translate([hinge_len/2 + hole_offset, 0, -1]) 
            cylinder(r=ring_r - 2, h=jaw_thick + ring_h + 2);
    }
}

module top_jaw() {
    difference() {
        union() {
            // Main top body
            translate([-hinge_len/2 - t_jaw_len, -jaw_width/2, 0]) 
                cube([t_jaw_len, jaw_width, jaw_thick]);
            
            // Threaded spout base
            translate([-hinge_len/2 - hole_offset, 0, jaw_thick - 0.1]) 
                cylinder(r1=spout_r, r2=spout_r-0.5, h=spout_h + 0.1);
            
            // Spout threads
            translate([-hinge_len/2 - hole_offset, 0, jaw_thick]) 
                helical_thread(r=spout_r, h=spout_h - 1.5, pitch=thread_pitch, depth=thread_depth);
        }
        // Clearance hole for the sealing ring and bag
        translate([-hinge_len/2 - hole_offset, 0, -1]) 
            cylinder(r=ring_r + 0.6, h=jaw_thick + spout_h + 2);
    }
}

module living_hinge() {
    // Thin flexible bridge connecting the jaws
    translate([-hinge_len/2, -jaw_width/2, 0]) 
        cube([hinge_len, jaw_width, 0.8]);
}

module bag_cap() {
    difference() {
        // Outer cap body
        cylinder(r=spout_r + 5, h=spout_h + 3);
        
        // Internal cavity
        translate([0, 0, 2.5]) 
            cylinder(r=spout_r + 0.6, h=spout_h + 1);
        
        // Internal female threads
        translate([0, 0, 2.5]) 
            helical_thread(r=spout_r + 0.6, h=spout_h, pitch=thread_pitch, depth=thread_depth);
        
        // Outer knurling for grip
        for(i = [0 : 15]) {
            rotate([0, 0, i * (360/16)]) 
                translate([spout_r + 5.5, 0, -1]) 
                cylinder(r=2, h=spout_h + 5);
        }
    }
}

module helical_thread(r, h, pitch, depth, starts=3) {
    for(i = [0 : starts - 1]) {
        rotate([0, 0, i * (360/starts)])
            linear_extrude(height=h, twist=-360*(h/pitch), slices=round(h*12))
                translate([r, 0, 0])
                circle(r=depth, $fn=16);
    }
}