From 1c69ce4b2fedec5607d29a15f434c38c2a4f45ff Mon Sep 17 00:00:00 2001
From: Jeeves <guydoodlesdev@gmail.com>
Date: Tue, 29 Apr 2025 14:47:13 -0600
Subject: [PATCH] add Selector

---
 src/main.zig | 71 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 71 insertions(+)

diff --git a/src/main.zig b/src/main.zig
index 26057fa..75b0654 100644
--- a/src/main.zig
+++ b/src/main.zig
@@ -596,4 +596,75 @@ test "max" {
     try std.testing.expectEqual(-0.5, or1.component.getOutput(0).analog);
 }
 
+pub const Selector = struct {
+    component: Component,
+
+    current_output: usize = 0,
+    invert_output: bool = false,
+
+    pub fn init(allocator: std.mem.Allocator) !*Selector {
+        var self = try allocator.create(Selector);
+        errdefer allocator.destroy(self);
+        self.* = .{ .component = undefined };
+        try Component.init(&self.component, allocator, "Selector", 2, 2, &update, &deinit);
+        return self;
+    }
+
+    pub fn deinit(component: *Component, allocator: std.mem.Allocator) void {
+        const self: *Selector = @fieldParentPtr("component", component);
+        allocator.destroy(self);
+    }
+
+    // TODO check implementation
+    pub fn update(component: *Component) AllocatorError!void {
+        const self: *Selector = @fieldParentPtr("component", component);
+        var last_idx: ?usize = null;
+        for (component.inputs.items, 0..) |input, idx| {
+            if (input.signal) |signal| {
+                if (signal.digital == 1) last_idx = idx;
+            }
+        }
+        if (last_idx) |lidx| {
+            for (component.outputs.items, 0..) |*output, idx| {
+                output.signal = if (if (self.invert_output) idx != lidx else idx == lidx)
+                    .{ .digital = 1, .analog = 1.0 }
+                else
+                    .{ .digital = 0, .analog = 0.0 };
+            }
+        }
+    }
+};
+
+test "selector" {
+    var a = Signal{ .digital = 0 };
+    var b = Signal{ .digital = 1 };
+
+    var selector = try Selector.init(std.testing.allocator);
+    defer selector.component.deinit(std.testing.allocator);
+    selector.component.inputs.items[0].signal = &a;
+    selector.component.inputs.items[1].signal = &b;
+
+    try selector.component.update();
+    try std.testing.expectEqual(Signal{ .digital = 0, .analog = 0.0 }, selector.component.getOutput(0).*);
+    try std.testing.expectEqual(Signal{ .digital = 1, .analog = 1.0 }, selector.component.getOutput(1).*);
+
+    a.digital = 0;
+    b.digital = 0;
+    try selector.component.update();
+    try selector.component.update();
+    try std.testing.expectEqual(Signal{ .digital = 0, .analog = 0.0 }, selector.component.getOutput(0).*);
+    try std.testing.expectEqual(Signal{ .digital = 1, .analog = 1.0 }, selector.component.getOutput(1).*);
+
+    a.digital = 1;
+    b.digital = 0;
+    try selector.component.update();
+    try std.testing.expectEqual(Signal{ .digital = 1, .analog = 1.0 }, selector.component.getOutput(0).*);
+    try std.testing.expectEqual(Signal{ .digital = 0, .analog = 0.0 }, selector.component.getOutput(1).*);
+
+    selector.invert_output = true;
+    try selector.component.update();
+    try std.testing.expectEqual(Signal{ .digital = 0, .analog = 0.0 }, selector.component.getOutput(0).*);
+    try std.testing.expectEqual(Signal{ .digital = 1, .analog = 1.0 }, selector.component.getOutput(1).*);
+}
+
 const AllocatorError = std.mem.Allocator.Error;