Advent-of-Code-2023/day20/modules.go

package day20

import (
	"fmt"
	"log"
	"regexp"
	"slices"
	"strings"
)

type PulseType int
func (pt PulseType)String() string {
	types := []string{"high", "low"}
	return types[pt]
}

const (
	HighPulse PulseType = iota
	LowPulse
)

type Signal struct {
	To, From string
	PulseType PulseType
}

type Module interface {
	Receive(s Signal) []Signal
	Outputs() []string
	StateSnapshot() string
}

// Modules
type FlipFlop struct {
	Name string
	OutputNames []string
	IsOn bool
}

// ignores HighPulse
// on LowPulse - toggle state and send signal
func (ff *FlipFlop)Receive(s Signal) []Signal {
	if s.PulseType == HighPulse {
		return []Signal{}
	}

	ff.IsOn = !ff.IsOn
	outTemplate := Signal{
		From: ff.Name,
	}
	if ff.IsOn {
		outTemplate.PulseType = HighPulse
	} else {
		outTemplate.PulseType = LowPulse
	}

	result := make([]Signal, len(ff.OutputNames))
	for i, outName := range ff.OutputNames {
		out := outTemplate
		out.To = outName
		result[i] = out
	}

	return result
}

func (ff *FlipFlop)Outputs() []string {
	return ff.OutputNames
}

func (ff *FlipFlop)String() string {
	return fmt.Sprintf("[flip-flop '%s' (on: %t) -> %s]", ff.Name, ff.IsOn, ff.OutputNames)
}

func (ff *FlipFlop)StateSnapshot() string {
	return ff.String()
}

func IsLineFlipFlop(line string) bool {
	return strings.HasPrefix(line, "%")
}

func ParseFlipFlop(line string) (result FlipFlop) {
	re := regexp.MustCompile(`%(?P<NAME>\D+) -> (?P<OUTPUTS>.+)`)
	matches := re.FindStringSubmatch(line)

	log.Printf("matching %s getting '%s' and '%s'\n", line, matches[1], matches[2])
	result.Name = matches[1]
	result.OutputNames = strings.Split(matches[2], ", ")

	return
}

type Broadcast struct {
	OutputNames []string
}

// send same pulse to all outputs
func (b *Broadcast)Receive(s Signal) (result []Signal) {
	signalTemplate := Signal{From: "broadcast", PulseType: s.PulseType}
	for _, out := range b.OutputNames {
		outSignal := signalTemplate
		outSignal.To = out
		result = append(result, outSignal)
	}
	return
}

func (b *Broadcast)Outputs() []string {
	return b.OutputNames
}

func (b *Broadcast)String() string {
	return fmt.Sprintf("[broadcast -> %+v]", b.OutputNames)
}
func (b *Broadcast)StateSnapshot() string {
	return b.String()
}

func IsLineBroadcast(line string) bool {
	return strings.HasPrefix(line, "broadcaster")
}

func ParseBroadcast(line string) (result Broadcast) {
	re := regexp.MustCompile(`broadcaster -> (?P<OUTPUTS>.+)`)
	matches := re.FindStringSubmatch(line)

	result.OutputNames = strings.Split(matches[1], ", ")
	return
}

type Conjunction struct {
	Name string
	OutputNames []string
	MostRecentPulseFromInputIsHigh map[string]bool
}

// remembers last signal type from all inputs (initial default is Low)
// when receiving pulse, first update memory for that input
// then if for all inputs remembered is high - send LowPulse
// otherwise if some remembers are low - send HighPulse
func (c *Conjunction)Receive(s Signal) (result []Signal) {
	c.MostRecentPulseFromInputIsHigh[s.From] = s.PulseType == HighPulse

	allHigh := true
	for _, latestImpulseHight := range c.MostRecentPulseFromInputIsHigh {
		if !latestImpulseHight {
			allHigh = false
			break
		}
	}

	outTemplate := Signal{From: c.Name}
	if allHigh {
		outTemplate.PulseType = LowPulse
	} else {
		outTemplate.PulseType = HighPulse
	}

	for _, outName := range c.OutputNames {
		outSignal := outTemplate
		outSignal.To = outName
		result = append(result, outSignal)
	}

	return
}

func (c *Conjunction)Outputs() []string {
	return c.OutputNames
}

func (c *Conjunction)RegisterInputs(allModules map[string]Module) {
	for name, module := range allModules {
		if slices.Contains( module.Outputs(), c.Name) {
			c.MostRecentPulseFromInputIsHigh[name] = false
		}
	}
}

func (c *Conjunction)String() string {
	return fmt.Sprintf("[conjunction '%s' -> %+v]", c.Name, c.OutputNames)
}

func (c *Conjunction)StateSnapshot() string {
	return fmt.Sprintf("[conjunction '%s' -> %+v]", c.Name, c.MostRecentPulseFromInputIsHigh)
}

func IsLineConjunction(line string) bool {
	return strings.HasPrefix(line, "&")
}

func ParseConjunction(line string) (result Conjunction) {
	re := regexp.MustCompile(`&(?P<NAME>\D+) -> (?P<OUTPUTS>.+)`)
	matches := re.FindStringSubmatch(line)

	log.Printf("matching %s getting '%s' and '%s'\n", line, matches[1], matches[2])
	result.Name = matches[1]
	result.OutputNames = strings.Split(matches[2], ", ")

	result.MostRecentPulseFromInputIsHigh = map[string]bool{}

	return
}

type Button struct {}

func (b *Button)Receive(s Signal) []Signal {
	return []Signal{
		{ To: "broadcast", From: "button", PulseType: LowPulse },
	}
}

func (b *Button)Outputs() []string {
	return []string{"broadcast"}
}

func (b *Button)String() string {
	return "[button]"
}

func (b *Button)StateSnapshot() string {
	return b.String()
}

type Output struct {}

func (o *Output)Receive(s Signal) []Signal {
	log.Print("Outut received signal: ", s)
	return []Signal{}
}

func (o *Output)Outputs() []string {
	return []string{}
}

func (o *Output)String() string {
	return "[output]"
}

func (o *Output)StateSnapshot() string {
	return o.String()
}