From 53c9a8aba0b5b6e52a76d2c383dad9f0edf497f7 Mon Sep 17 00:00:00 2001
From: Johannes Theiner <j.theiner@live.de>
Date: Tue, 12 May 2020 17:21:13 +0200
Subject: [PATCH] A3: Anfang

---
 go/TrafficLights/TrafficLight.go | 89 ++++++++++++++++++++++++++++++++
 1 file changed, 89 insertions(+)
 create mode 100644 go/TrafficLights/TrafficLight.go

diff --git a/go/TrafficLights/TrafficLight.go b/go/TrafficLights/TrafficLight.go
new file mode 100644
index 0000000..cd7cf5e
--- /dev/null
+++ b/go/TrafficLights/TrafficLight.go
@@ -0,0 +1,89 @@
+package main
+
+type CardinalDirection string
+
+const (
+	north = CardinalDirection("North")
+	south = CardinalDirection("South")
+	east  = CardinalDirection("East")
+	west  = CardinalDirection("West")
+)
+
+var Directions = []CardinalDirection{
+	north, south, east, west,
+}
+
+func nextDirection(currentDirection CardinalDirection) CardinalDirection {
+	switch currentDirection {
+	case north:
+		return east
+	case south:
+		return west
+	case east:
+		return south
+	case west:
+		return north
+	default:
+		return north
+		//TODO: dont return this here, return nil instead
+	}
+}
+
+type Colour string
+
+const (
+	red    = Colour("Red")
+	green  = Colour("Green")
+	yellow = Colour("Yellow")
+)
+
+var Colours = []Colour{
+	red, green, yellow,
+}
+
+func nextColour(currentColour Colour) Colour {
+	switch currentColour {
+	case red:
+		return green
+	case green:
+		return yellow
+	case yellow:
+		return red
+	default:
+		return red
+	}
+}
+
+func main() {
+	var directionChannel = make(chan CardinalDirection)
+	var colourChannel = make(chan Colour)
+	var waitChannel = make(chan string)
+
+	for _, direction := range Directions {
+		go TrafficLight(direction, directionChannel, colourChannel, waitChannel)
+	}
+
+	directionChannel <- north
+	directionChannel <- south
+
+}
+
+func TrafficLight(direction CardinalDirection, directionChannel chan CardinalDirection, colourChannel chan Colour, waitChannel chan string) {
+	var colour Colour
+	for {
+		switch msg := <-waitChannel; {
+		case msg == "proceed":
+			directionChannel <- nextDirection(direction)
+
+		}
+		switch msg := <-directionChannel; {
+		case msg == direction:
+
+		}
+		colourChannel <- nextColour(colour)
+		switch msg := <-colourChannel; {
+		case msg == nextColour(colour):
+
+		}
+	}
+}