From 00e60657fa6f31a835f6a166242d74211716fd4d Mon Sep 17 00:00:00 2001
From: efim <efim.nefedov@nordigy.ru>
Date: Wed, 20 Dec 2023 09:45:52 +0000
Subject: [PATCH] day20, example 2 first four steps pass

---
 day20/modules.go          |  4 +++
 day20/propagation_test.go | 76 +++++++++++++++++++++++++++++++++++++++
 day20/pulsePropagation.go | 51 ++++++++++++++++++++++++++
 3 files changed, 131 insertions(+)
 create mode 100644 day20/propagation_test.go

diff --git a/day20/modules.go b/day20/modules.go
index 06b02eb..65171e6 100644
--- a/day20/modules.go
+++ b/day20/modules.go
@@ -9,6 +9,10 @@ import (
 )
 
 type PulseType int
+func (pt PulseType)String() string {
+	types := []string{"high", "low"}
+	return types[pt]
+}
 
 const (
 	HighPulse PulseType = iota
diff --git a/day20/propagation_test.go b/day20/propagation_test.go
new file mode 100644
index 0000000..4a8baa4
--- /dev/null
+++ b/day20/propagation_test.go
@@ -0,0 +1,76 @@
+package day20
+
+import (
+	"testing"
+)
+
+func TestPropagateButtonPressExample1(t *testing.T) {
+	filename := "example1"
+	modules := ReadModules(filename)
+	t.Log("got modules:\n", modules)
+
+	low, high := PropagateButtonPress(modules)
+	t.Logf("got low %d and high %d\n", low, high)
+	t.Log("modules after single button press:\n", modules)
+
+	success := low == 8 && high == 4
+	if !success {
+		t.Errorf("expected low 8 got %d, high 4 got %d", low, high)
+	}
+}
+
+func TestPropagateButtonPressExample2(t *testing.T) {
+	filename := "example2"
+	modules := ReadModules(filename)
+	t.Log("got modules:\n", modules)
+	InitStuffs(modules)
+
+	low, high := PropagateButtonPress(modules)
+	t.Logf("got low %d and high %d\n", low, high)
+	t.Log("modules after single button press:\n", modules)
+
+	success := low == 4 && high == 4
+	if !success {
+		t.Errorf("expected low 4 got %d, high 4 got %d", low, high)
+	}
+}
+
+func TestPropagateButtonPressExample2FourSteps(t *testing.T) {
+	filename := "example2"
+	modules := ReadModules(filename)
+	t.Log("got modules:\n", modules)
+	InitStuffs(modules)
+
+	low, high := PropagateButtonPress(modules)
+	t.Logf("got low %d and high %d\n", low, high)
+	t.Log("#1 button press:\n", modules)
+	success := low == 4 && high == 4
+	if !success {
+		t.Errorf("expected low 4 got %d, high 4 got %d", low, high)
+	}
+
+	low, high = PropagateButtonPress(modules)
+	t.Logf("got low %d and high %d\n", low, high)
+	t.Log("#2 button press:\n", modules)
+	success = low == 4 && high == 2
+	if !success {
+		t.Errorf("expected low 4 got %d, high 2 got %d", low, high)
+	}
+
+	low, high = PropagateButtonPress(modules)
+	t.Logf("got low %d and high %d\n", low, high)
+	t.Log("#3 button press:\n", modules)
+	success = low == 5 && high == 3
+	if !success {
+		t.Errorf("expected low 5 got %d, high 3 got %d", low, high)
+	}
+
+	low, high = PropagateButtonPress(modules)
+	t.Logf("got low %d and high %d\n", low, high)
+	t.Log("#4 button press:\n", modules)
+	success = low == 4 && high == 2
+	if !success {
+		t.Errorf("expected low 4 got %d, high 2 got %d", low, high)
+	}
+
+}
diff --git a/day20/pulsePropagation.go b/day20/pulsePropagation.go
index 6ebb715..7c7f85f 100644
--- a/day20/pulsePropagation.go
+++ b/day20/pulsePropagation.go
@@ -10,8 +10,50 @@ import (
 func Run() int {
 	fmt.Println("hello from dya 20")
 
+	filename := "day20/example2"
+	modules := ReadModules(filename)
+	log.Print("got modules:\n", modules)
+
+	low, high := PropagateButtonPress(modules)
+	log.Printf("got low %d and high %d\n", low, high)
+	log.Print("modules after single button press:\n", modules)
+
 	return 0
 }
+
+func PropagateButtonPress(modules map[string]Module) (lowSignalsCount, highSignalsCount int) {
+	signals := []Signal{{From: "button", To: "broadcast", PulseType: LowPulse}}
+	lowSignalsCount += 1
+
+	for len(signals) > 0 {
+		curSignal := signals[0]
+		signals = signals[1:]
+
+		log.Printf("%s -%s-> %s", curSignal.From, curSignal.PulseType, curSignal.To)
+
+		receivingModule, found := modules[curSignal.To]
+		if !found {
+			panic(fmt.Sprintf("signal %+v can't find it's recepient\n", curSignal))
+		}
+
+		newSignals := receivingModule.Receive(curSignal)
+
+		// all newSignals will have same type
+		newSignalsAmount := len(newSignals)
+		if newSignalsAmount > 0 {
+			signals = append(signals, newSignals...)
+			someNewSignal := newSignals[0]
+			if someNewSignal.PulseType == HighPulse {
+				highSignalsCount += newSignalsAmount
+			} else {
+				lowSignalsCount += newSignalsAmount
+			}
+		}
+	}
+
+	return
+}
+
 // process sends single `low pulse` directly to "broadcast"
 
 func ReadModules(filename string) map[string]Module {
@@ -46,3 +88,12 @@ func ReadModules(filename string) map[string]Module {
 
 	return result
 }
+
+func InitStuffs(allModules map[string]Module) {
+	for _, module := range allModules {
+		if conjunction, ok := module.(*Conjunction); ok {
+			conjunction.RegisterInputs(allModules)
+		}
+	}
+
+}