Refactor RPS/RPSLS

lib/rps/rps.go

@@ -2,6 +2,9 @@ package rps
 
 import (
 	"fmt"
+	"strings"
+
+	"git.kill0.net/chill9/beepboop/lib"
 )
 
 type (
@@ -11,6 +14,14 @@ type (
 	}
 )
 
+type InvalidChoiceError struct {
+	s string
+}
+
+func (e InvalidChoiceError) Error() string {
+	return fmt.Sprintf("%q is an invalid choice", e.s)
+}
+
 var (
 	RulesRps [][]string = [][]string{
 		{"rock", "scissors", "crushes"},
@@ -46,6 +57,51 @@ var (
 	}
 )
 
+func NewGame(rules [][]string, emojiMap map[string]string) *Game {
+	return &Game{rules: rules, emojiMap: emojiMap}
+}
+
+func (g *Game) Rand() string {
+	return lib.MapRandKey(g.emojiMap)
+}
+
+func (g *Game) Play(c1, c2 string) (string, error) {
+	var b strings.Builder
+
+	if !g.Valid(c1) {
+		return "", InvalidChoiceError{s: c1}
+	}
+	if !g.Valid(c2) {
+		return "", InvalidChoiceError{s: c2}
+	}
+
+	fmt.Fprintf(&b, "%s v %s: ", g.emojiMap[c1], g.emojiMap[c2])
+
+	for _, rule := range g.rules {
+		verb := rule[2]
+
+		if c1 == c2 {
+			fmt.Fprintf(&b, "draw")
+			return b.String(), nil
+		}
+
+		if c1 == rule[0] && c2 == rule[1] {
+			fmt.Fprintf(&b, "%s %s %s", c1, verb, c2)
+			return b.String(), nil
+		} else if c2 == rule[0] && c1 == rule[1] {
+			fmt.Fprintf(&b, "%s %s %s", c2, verb, c1)
+			return b.String(), nil
+		}
+	}
+
+	return b.String(), nil
+}
+
+func (g *Game) Valid(c string) bool {
+	_, ok := g.emojiMap[c]
+	return ok
+}
+
 func Play(rules [][]string, c1, c2 string) string {
 	for _, rule := range rules {
 		if c1 == c2 {