Writing a Text Adventure Game in Go - Part 1 (uses a *Location for Game.CurrentLocation)

text_adv-part-1.go

package main

import (
	"fmt"
	"math/rand"
	"time"
)

type Game struct {
	Welcome         string
	Health          int
	CurrentLocation *Location
}

func (g *Game) Play() {
	fmt.Println(g.Welcome)
	for {
		fmt.Println(g.CurrentLocation.Description)

		g.ProcessEvents(g.CurrentLocation.Events)
		if g.Health <= 0 {
			fmt.Println("You are dead, game over!!!")
			return
		}

		fmt.Printf("Health: %d\n", g.Health)
		fmt.Println("You can go to these places:")
		for index, loc := range g.CurrentLocation.Transitions {
			fmt.Printf("\t%s - %s\n", index, loc.Name)
		}
		var name string
		fmt.Print("Where do you want to go? (0 - to quit) ")
		_, err := fmt.Scan(&name)
		if err != nil { fmt.Println(err); return }
		var newLoc *Location
		if v, ok := g.CurrentLocation.Transitions[name]; ok {
			newLoc = v
		} else if name == "0" { return }
		if newLoc != nil {
			g.CurrentLocation = newLoc
		}
	}
}

func (g *Game) ProcessEvents(events []string) {
	for _, evtName := range events {
		g.Health += evts[evtName].ProcessEvent()
	}
}

type Event struct {
	Type        string
	Chance      int
	Description string
	Health      int
	Evt         string
}

func (e *Event) ProcessEvent() int {
	s1 := rand.NewSource(time.Now().UnixNano())
	r1 := rand.New(s1)
	if e.Chance >= r1.Intn(100) {
		hp := e.Health
		if e.Type == "Combat" {
			fmt.Println("Combat Event")
		}
		fmt.Printf("\t%s\n", e.Description)
		if e.Evt != "" {
			hp = hp + evts[e.Evt].ProcessEvent()
		}
		return hp
	}
	return 0
}

type Location struct {
	Name string
	Description string
	Transitions map[string]*Location
	Events      []string
}

var evts = map[string]*Event{
	"alienAttack":     {Type: "Combat", Chance: 20, Description: "An alien beams in front of you and shoots you with a ray gun.", Health: -50, Evt: "doctorTreatment"},
	"doctorTreatment": {Type: "Story", Chance: 10, Description: "The doctor rushes in and inject you with a health boost.", Health: +30, Evt: ""},
	"android":         {Type: "Story", Chance: 50, Description: "Data is in the turbo lift and says hi to you", Health: 0, Evt: ""},
	"relaxing":        {Type: "Story", Chance: 100, Description: "In the lounge you are so relaxed that your health improves.", Health: +10, Evt: ""},
}

var bridge *Location

func init() {
	bridge = &Location{
		Name: "Bridge",
		Description: "You are on the bridge of a spaceship sitting in the Captain's chair.",
		Events: []string{"alienAttack"},
	}
	rr := &Location{
		Name: "Ready Room",
		Description: "The Captain's ready room.",
		Transitions: map[string]*Location{"bridge": bridge},
		Events: []string{"doctorTreatment"}}
	bridge.Transitions = map[string]*Location{"ready": rr}
	bridge.Transitions["lift"] = &Location{
		Name: "Turbo Lift",
		Description: "A Turbo Lift that takes you anywhere in the ship.",
		Events: []string{"android"},
	}
	bridge.Transitions["lift"].Transitions = map[string]*Location{
		"bridge": bridge,
		"engineering": {
			Name: "Engineering",
			Description: "You are in engineering where you see the star drive",
			Events: []string{"alienAttack"},
			Transitions: map[string]*Location{"lift": bridge.Transitions["lift"]},
		},
		"lounge":      {
			Name: "Lounge",
			Description: "You are in the lounge, you feel very relaxed",
			Events: []string{"relaxing"},
			Transitions: map[string]*Location{"lift": bridge.Transitions["lift"]},
		},
	}
}

func main() {
	g := &Game{
		Health:          100,
		Welcome:         "Welcome to the Starship Enterprise\n\n",
		CurrentLocation: bridge,
	}
	g.Play()
}