$fn=64;

// --- Parameters ---
w = 110;           // Total width of the base
d = 35;            // Total depth
h_base = 15;       // Base height
w_arch = 50;       // Arch inner width (cable passage)
pw = 25;           // Pillar width
h_pillars = 35;    // Pillar height to start of arch
block_h = 10;      // Height of individual stone blocks
gap = 1.5;         // Mortar gap width
groove_depth = 2;  // Depth of the mortar grooves

// --- Main Assembly ---
union() {
    // 1. Base with cable guide slots
    difference() {
        // Main base block
        translate([0, 0, h_base/2])
            cube([w, d, h_base], center=true);
        
        // Base horizontal decorative groove
        translate([0, 0, h_base/2])
        difference() {
            cube([w+2, d+2, gap], center=true);
            cube([w-groove_depth*2, d-groove_depth*2, gap+2], center=true);
        }
        
        // Cable guide U-slots
        for(x=[-18 : 12 : 18]) {
            translate([x, 0, h_base - 4.5])
                rotate([90, 0, 0])
                cylinder(r=4.5, h=d+2, center=true);
            translate([x, 0, h_base - 2.25])
                cube([9, d+2, 4.5], center=true);
        }
    }

    // 2. Pillar bases (flared for stability and medieval look)
    pillar_base(-(w_arch+pw)/2);
    pillar_base((w_arch+pw)/2);

    // 3. Stone Pillars
    stone_pillar(-(w_arch+pw)/2);
    stone_pillar((w_arch+pw)/2);

    // 4. Stone Arch
    translate([0, 0, h_base + h_pillars])
    rotate([90, 0, 0])
    difference() {
        // Main arch body
        cylinder(r=w_arch/2 + pw, h=d, center=true);
        // Inner cutout
        cylinder(r=w_arch/2, h=d+2, center=true);
        
        // Cut bottom half to make it a semicircle
        translate([0, -(w_arch/2 + pw + 1)/2, 0])
            cube([w_arch + pw*2 + 2, w_arch/2 + pw + 1, d+2], center=true);
        
        // Radial mortar grooves for voussoirs (arch stones)
        for(a=[0 : 180/7 : 180]) {
            rotate([0, 0, a])
            translate([w_arch/2 + pw/2, 0, 0])
            difference() {
                cube([pw+2, gap, d+2], center=true);
                cube([pw-groove_depth*2, gap+2, d-groove_depth*2], center=true);
            }
        }
    }

    // 5. Keystone
    translate([0, 0, h_base + h_pillars + w_arch/2 + pw/2])
    rotate([90, 0, 0])
    hull() {
        translate([0, pw/2 + 2, 0]) cube([18, 1, d+2], center=true);
        translate([0, -pw/2 - 2, 0]) cube([12, 1, d+2], center=true);
    }
}

// --- Modules ---

// Creates a flared base for the pillars
module pillar_base(x_pos) {
    translate([x_pos, 0, h_base + 2])
    hull() {
        translate([0, 0, 2]) cube([pw, d, 0.1], center=true);
        translate([0, 0, -2]) cube([pw+4, d+4, 4], center=true);
    }
}

// Creates a pillar with simulated stone blocks using surface grooves
module stone_pillar(x_pos) {
    translate([x_pos, 0, h_base + h_pillars/2])
    difference() {
        // Solid core
        cube([pw, d, h_pillars], center=true);
        
        // Horizontal mortar grooves
        for(z=[-h_pillars/2 + block_h : block_h : h_pillars/2 - 1]) {
            translate([0, 0, z])
            difference() {
                cube([pw+2, d+2, gap], center=true);
                cube([pw-groove_depth*2, d-groove_depth*2, gap+2], center=true);
            }
        }
        
        // Vertical staggered mortar grooves
        for(i=[0 : h_pillars/block_h - 1]) {
            z = -h_pillars/2 + block_h/2 + i*block_h;
            x_offset = (i%2 == 0) ? 0 : pw/4;
            
            translate([0, 0, z])
            difference() {
                union() {
                    translate([x_offset, 0, 0]) cube([gap, d+2, block_h+2], center=true);
                    translate([0, x_offset, 0]) cube([pw+2, gap, block_h+2], center=true);
                }
                // Protect the core so the cuts are only on the surface
                cube([pw-groove_depth*2, d-groove_depth*2, block_h+4], center=true);
            }
        }
    }
}