Add mana curve into statistics

src/serra/helpers.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"math"
 	"strconv"
+	"strings"
 	"time"
 	"unicode"
 
@@ -225,3 +226,48 @@ func getFloat64(unknown interface{}) (float64, error) {
 		return math.NaN(), errors.New("Non-numeric type could not be converted to float")
 	}
 }
+
+// Splits string by multiple occurances of substring
+// needed for calcManaCosts
+func SplitAny(s string, seps string) []string {
+	splitter := func(r rune) bool {
+		return strings.ContainsRune(seps, r)
+	}
+	return strings.FieldsFunc(s, splitter)
+}
+
+// Converts mana encoding to mana costs
+//
+//	calcManaCosts("{2}{B}{B}") -> 4
+//	calcManaCosts("{4}{G}{G}{G}{G}") -> 7
+//	calcManaCosts("{1}{U} // {3}{U}") -> 2 (ignore transform costs)
+func calcManaCosts(costs string) int {
+
+	var count int
+
+	for _, c := range SplitAny(costs, "{}") {
+		if strings.Contains(c, "//") {
+			break
+		}
+
+		i, err := strconv.Atoi(c)
+		if err != nil {
+			count = count + 1
+		} else {
+			count = count + i
+		}
+	}
+
+	return count
+}
+
+func printUniqueValue(arr []int) map[int]int {
+	//Create a dictionary of values for each element
+	dict := make(map[int]int)
+	for _, num := range arr {
+		dict[num] = dict[num] + 1
+	}
+
+	return dict
+
+}

src/serra/stats.go

@@ -2,6 +2,7 @@ package serra
 
 import (
 	"fmt"
+	"sort"
 
 	"github.com/spf13/cobra"
 	"go.mongodb.org/mongo-driver/bson"
@@ -127,6 +128,25 @@ var statsCmd = &cobra.Command{
 			fmt.Printf("%s: %s%d%s\n", artist["_id"].(string), Purple, artist["count"], Reset)
 		}
 
+		// Mana Curve of Collection
+		cards := Cards(rarity, set, sortby, name, oracle, cardType, false, foil)
+		var numCosts []int
+		for _, card := range cards {
+			numCosts = append(numCosts, calcManaCosts(card.ManaCost))
+
+		}
+		dist := printUniqueValue(numCosts)
+		fmt.Printf("\n%sMana Curve%s\n", Green, Reset)
+
+		keys := make([]int, 0, len(dist))
+		for k := range dist {
+			keys = append(keys, k)
+		}
+		sort.Ints(keys)
+		for _, k := range keys {
+			fmt.Printf("%d: %s%d%s\n", k, Purple, dist[k], Reset)
+		}
+
 		// Total Value
 		fmt.Printf("\n%sTotal Value%s\n", Green, Reset)
 		nf_value, err := getFloat64(stats[0]["value"])