Roller v1 done

2020-09-10 11:10:19 -08:00
parent dc86a8c4d8
commit 24b1adf7bf
6 changed files with 222 additions and 1 deletions
@@ -1,5 +1,156 @@
 package roller

-func ParseRollString(s string) int {
+import (
+	"crypto/rand"
+	"errors"
+	"fmt"
+	"math/big"
+	"strconv"
+	"strings"
+)

+func ParseRollString(s string) (int64, string, error) {
+	s = strings.ReplaceAll(s, "-", "+-")
+	parts := strings.Split(s, "+")
+	var out int64
+	var outString string = " <= "
+	for i, part := range parts {
+		adv := false
+		dis := false
+		if strings.HasSuffix(part, "a") {
+			adv = true
+		} else if strings.HasSuffix(part, "d") {
+			dis = true
+		}
+		part = strings.TrimSuffix(part, "a")
+		part = strings.TrimSuffix(part, "d")
+		if c, err := strconv.ParseInt(part, 10, 64); err == nil && i != 0 {
+			out += c
+			if c < 0 {
+				outString += " - " + strconv.FormatInt(-1*c, 10)
+			} else {
+				outString += " + " + strconv.FormatInt(c, 10)
+			}
+		} else {
+			i, s, err := processDie(part, adv, dis)
+			if err != nil {
+				return i, outString, err
+			}
+			out += i
+			outString += s
+		}
+	}
+	return out, strings.Replace(outString, " <=  + ", " <= ", 1), nil
+}
+
+func processDie(part string, adv, dis bool) (int64, string, error) {
+	var mult int64 = 1
+	var size int64
+	var outString string = ""
+	var val int64
+	if strings.HasPrefix(part, "-") {
+		mult = -1
+		part = strings.TrimPrefix(part, "-")
+	}
+	if strings.Contains(part, "d") {
+		ps := strings.Split(part, "d")
+		count, err := strconv.Atoi(ps[0])
+		if err != nil {
+			count = 1
+		}
+		size, err = strconv.ParseInt(ps[1], 10, 64)
+		if err != nil {
+			return -1, outString, errors.New("invalid format")
+		}
+		for i := 0; i < count; i++ {
+			i, s, err := rollDie(size, adv, dis)
+			if err != nil {
+				return i, outString, err
+			}
+			val += i * mult
+			if mult > 0 {
+				outString += " + " + s
+			} else if mult < 0 {
+				outString += " - " + s
+			} else if mult > 0 {
+				outString += s
+			}
+		}
+	} else if strings.Contains(part, "x") {
+		ps := strings.Split(part, "x")
+		if len(ps) < 2 {
+			return -1, outString, errors.New("invalid format")
+		}
+		modifer, err := strconv.ParseInt(ps[0], 10, 64)
+		if err != nil {
+			return -1, outString, errors.New("invalid format")
+		}
+		multiple, err := strconv.ParseInt(ps[1], 10, 64)
+		if err != nil {
+			return -1, outString, errors.New("invalid format")
+		}
+		out := modifer * multiple * mult
+		if out < 0 {
+			outString += " - " + strconv.FormatInt(-1*out, 10)
+		} else {
+			outString += " + " + strconv.FormatInt(out, 10)
+		}
+		val += out
+	} else {
+		size, err := strconv.ParseInt(part, 10, 64)
+		if err != nil {
+			return -1, outString, err
+		}
+		i, s, err := rollDie(size, adv, dis)
+		if err != nil {
+			return i, outString, err
+		}
+		val += i * mult
+		if mult > 0 {
+			outString += " + " + s
+		} else if mult < 0 {
+			outString += " - " + s
+		} else if mult > 0 {
+			outString += s
+		}
+	}
+	return val, outString, nil
+}
+
+func rollDie(i int64, adv, dis bool) (int64, string, error) {
+	if i <= 1 {
+		return -2, "", errors.New("invalid die")
+	}
+	size := big.NewInt(i)
+	one := big.NewInt(1)
+	num, err := rand.Int(rand.Reader, size)
+	if err != nil {
+		return -1, "", errors.New("can't get die roll")
+	}
+	num.Add(num, one)
+	if i == 10 && num.Cmp(big.NewInt(10)) == 0 {
+		num = big.NewInt(0)
+	}
+	if adv {
+		num2, err := rand.Int(rand.Reader, size)
+		if err != nil {
+			return -1, "", errors.New("can't get die roll")
+		}
+		num2.Add(num2, one)
+		if num2.Cmp(num) == 1 {
+			return num2.Int64(), fmt.Sprintf("{ ~~%s~~ %s }", num.String(), num2.String()), nil
+		}
+		return num.Int64(), fmt.Sprintf("{ ~~%s~~ %s }", num2.String(), num.String()), nil
+	} else if dis {
+		num2, err := rand.Int(rand.Reader, size)
+		if err != nil {
+			return -1, "", errors.New("can't get die roll")
+		}
+		num2.Add(num2, one)
+		if num2.Cmp(num) == -1 {
+			return num2.Int64(), fmt.Sprintf("{ ~~%s~~ %s }", num.String(), num2.String()), nil
+		}
+		return num.Int64(), fmt.Sprintf("{ ~~%s~~ %s }", num2.String(), num.String()), nil
+	}
+	return num.Int64(), fmt.Sprintf("{ %s }", num.String()), nil
 }