Deletion implemented

src/infrastructure/node.zig

@@ -6,10 +6,14 @@ const e = @import("../errors.zig");
 const Road = @import("road.zig").Road;
 
 pub const Node = struct {
+    /// Possibly unnecessary, but for now it's good as a secondary mean of identification
     id: usize,
+    /// Node's position on the simulation 'field'
     pos: rl.Vector2,
+    /// Contains references of all the roads this node is connected to
     roads: std.ArrayList(*Road),
 
+    /// Simple constructor
     pub fn init(new_id: usize, new_pos: rl.Vector2) Node {
         return .{
             .id = new_id,
@@ -18,20 +22,31 @@ pub const Node = struct {
         };
     }
 
-    pub fn deinit(self: *Node, allocator: std.mem.Allocator) void {
+    /// This function frees the list that holds road references that are connected to this node
+    ///
+    /// Next it invalidates itself (the pointer), making it invalid
+    pub fn deinit(self: *Node, allocator: std.mem.Allocator) !void {
+        if (self.roads.items.len != 0) return e.Entity.AlreadyReferenced;
+
         self.roads.deinit(allocator);
+        allocator.destroy(self);
     }
 
+    /// Simple function which draws the node
     pub fn draw(self: *const Node, direct_colour: ?rl.Color) void {
         const colour = if (direct_colour) |clr| clr else c.NODE_COLOUR;
 
         rl.drawCircleV(self.pos, c.NODE_RADIUS, colour);
     }
 
+    /// Identifies whether the pos (location) is within the snapping radius of the node
     pub fn posWithinRadius(self: *const Node, pos: rl.Vector2) bool {
         return rl.checkCollisionPointCircle(pos, self.pos, c.NODE_SNAP_RADIUS);
     }
 
+    /// Tries to reference the passed road to self
+    ///
+    /// Returns an error if the passed road cannot be appended to the list or if said road is already in the list
     pub fn referenceRoad(self: *Node, allocator: std.mem.Allocator, road_to_add: *Road) !void {
         // Note the road_to_add pointer must be one from the roads list as otherwise the pointer is dangling one
         for (self.roads.items) |road| {
@@ -40,6 +55,22 @@ pub const Node = struct {
 
         try self.roads.append(allocator, road_to_add);
     }
+
+    /// Attempts to unreference the passed road from self (node)
+    ///
+    /// Returns whether the node still has node references (true) or not (false)
+    ///
+    /// Returns an error if the road is not referenced to self in the first place
+    pub fn unreferenceRoad(self: *Node, road_to_remove: *const Road) !void {
+        for (0..self.roads.items.len) |i| {
+            if (self.roads.items[i] != road_to_remove) continue;
+
+            _ = self.roads.swapRemove(i);
+            return;
+        }
+
+        return e.Entity.NotFound;
+    }
 };
 
 // TODO tests