$fn = 64;

// --- Parameters ---
medallion_radius = 45;
base_thickness = 2;
relief_height = 4.5;

dragon_amp = 16;
dragon_len = 56;
dragon_start_y = -28;

// --- Main Assembly ---
union() {
    // Base plate and raised rim
    difference() {
        cylinder(r=medallion_radius, h=relief_height);
        translate([0, 0, base_thickness])
            cylinder(r=medallion_radius - 2.5, h=relief_height);
    }

    // Hanging loop
    translate([0, medallion_radius + 2, 0])
        difference() {
            cylinder(r=6, h=relief_height);
            translate([0, 0, -1])
                cylinder(r=3, h=relief_height + 2);
        }

    // Lunar New Year Motifs
    dragon();
    flaming_pearl();
    clouds();
}

// --- Modules ---

module dragon() {
    // Dragon Body (Sine wave sweep)
    for(i=[0:10:350]) {
        r1 = 1.5 + (i/360) * 3.5;
        r2 = 1.5 + ((i+10)/360) * 3.5;
        x1 = dragon_amp * sin(i * 1.5);
        y1 = dragon_start_y + (i/360) * dragon_len;
        x2 = dragon_amp * sin((i+10) * 1.5);
        y2 = dragon_start_y + ((i+10)/360) * dragon_len;

        // Body segment
        hull() {
            translate([x1, y1, 0]) cylinder(r=r1, h=relief_height);
            translate([x2, y2, 0]) cylinder(r=r2, h=relief_height);
        }

        // Dorsal spikes
        if (i >= 20 && i <= 340) {
            translate([x1, y1, relief_height - 0.1])
                cylinder(r1=r1*0.7, r2=0, h=2.5);
        }
    }

    // Tail tuft
    translate([0, dragon_start_y, 0]) {
        hull() {
            cylinder(r=1.5, h=relief_height);
            translate([-5, -6, 0]) cylinder(r=0.5, h=relief_height);
        }
        hull() {
            cylinder(r=1.5, h=relief_height);
            translate([5, -5, 0]) cylinder(r=0.5, h=relief_height);
        }
    }

    // Dragon Head
    hx = dragon_amp * sin(360 * 1.5);
    hy = dragon_start_y + dragon_len;
    translate([hx, hy, 0]) {
        // Main head
        cylinder(r=5.5, h=relief_height);

        // Snout
        hull() {
            cylinder(r=5.5, h=relief_height);
            rotate([0, 0, 15]) translate([-9, 4, 0]) cylinder(r=3.5, h=relief_height);
        }

        // Horns
        hull() {
            translate([2, -2, 0]) cylinder(r=1.5, h=relief_height);
            translate([8, -10, 0]) cylinder(r=0.5, h=relief_height);
        }
        hull() {
            translate([-2, -4, 0]) cylinder(r=1.5, h=relief_height);
            translate([-4, -13, 0]) cylinder(r=0.5, h=relief_height);
        }

        // Whiskers
        hull() {
            rotate([0, 0, 15]) translate([-9, 4, 0]) cylinder(r=1.5, h=relief_height);
            translate([-16, 0, 0]) cylinder(r=0.5, h=relief_height);
        }
        hull() {
            rotate([0, 0, 15]) translate([-9, 4, 0]) cylinder(r=1.5, h=relief_height);
            translate([-12, 13, 0]) cylinder(r=0.5, h=relief_height);
        }
    }

    // Legs
    leg(dragon_amp * sin(60 * 1.5), dragon_start_y + (60/360)*dragon_len, -30);
    leg(dragon_amp * sin(160 * 1.5), dragon_start_y + (160/360)*dragon_len, 180);
    leg(dragon_amp * sin(280 * 1.5), dragon_start_y + (280/360)*dragon_len, 30);
    leg(dragon_amp * sin(220 * 1.5), dragon_start_y + (220/360)*dragon_len, 135);
}

module leg(x, y, angle) {
    translate([x, y, 0]) rotate([0, 0, angle]) {
        hull() {
            cylinder(r=2, h=relief_height);
            translate([7, 0, 0]) cylinder(r=1.5, h=relief_height);
        }
        translate([7, 0, 0]) rotate([0, 0, 45]) {
            hull() {
                cylinder(r=1.5, h=relief_height);
                translate([4, 0, 0]) cylinder(r=1.2, h=relief_height);
            }
            // Claws
            translate([4, 0, 0]) {
                rotate([0, 0, 35]) translate([2.5, 0, 0]) cylinder(r1=0.8, r2=0.2, h=relief_height);
                rotate([0, 0, -35]) translate([2.5, 0, 0]) cylinder(r1=0.8, r2=0.2, h=relief_height);
                translate([2.5, 0, 0]) cylinder(r1=0.8, r2=0.2, h=relief_height);
            }
        }
    }
}

module flaming_pearl() {
    translate([-16, 30, 0]) {
        cylinder(r=3.5, h=relief_height);
        for(a=[0:90:270]) {
            rotate([0, 0, a + 45]) 
                translate([0, 3.5, 0]) 
                    cylinder(r1=1.5, r2=0, h=relief_height);
        }
    }
}

module clouds() {
    cloud(24, -18, 0.9);
    cloud(-26, -8, 1);
    cloud(25, 14, 0.85);
    cloud(-20, -25, 0.7);
    cloud(-24, 15, 0.8);
}

module cloud(cx, cy, scale_factor=1) {
    translate([cx, cy, 0]) scale([scale_factor, scale_factor, 1]) {
        cylinder(r=4, h=relief_height);
        translate([5, 0, 0]) cylinder(r=3, h=relief_height);
        translate([-4, 2, 0]) cylinder(r=2.5, h=relief_height);
        translate([1, 4, 0]) cylinder(r=3.5, h=relief_height);
        
        // Stylized swirl tail
        hull() {
            translate([5, 0, 0]) cylinder(r=3, h=relief_height);
            translate([11, -3, 0]) cylinder(r=0.5, h=relief_height);
        }
    }
}