add get more lottery func, chenge lottery act

model/lottery.go

@@ -17,9 +17,20 @@ type Lottery struct {
 
 // GetRandomLotteryByType -
 func GetRandomLotteryByType(t string) (p *Lottery, err error) {
-	p = &Lottery{}
+	parr, err := GetRandomLotteryByTypeAndLimit(t, 1)
+	if err != nil {
+		return nil, err
+	}
+	if parr == nil {
+		return nil, nil
+	}
+	return parr[0], err
+}
+
+// GetRandomLotteryByTypeAndLimit -
+func GetRandomLotteryByTypeAndLimit(t string, limit int) (p []*Lottery, err error) {
 	offset := rand.Intn(10)
-	err = x.Get(p, `select * from "public"."lottery" where "type" = $1 order by random() offset $2 limit 1`, t, offset)
+	err = x.Select(p, `select * from "public"."lottery" where "type" = $1 order by random() offset $2 limit $3`, t, offset, limit)
 	if err == sql.ErrNoRows {
 		return nil, nil
 	}

module/message-command/line-group.go

@@ -2,6 +2,7 @@ package msgcmd
 
 import (
 	"fmt"
+	"math/rand"
 	"strconv"
 	"strings"
 
@@ -338,10 +339,29 @@ func lottery(sub, txt string, s *lineobj.SourceObject) (res string) {
 	if len(sub) == 0 {
 		return ""
 	}
-	data, err := model.GetRandomLotteryByType(sub)
+	arr, err := model.GetRandomLotteryByTypeAndLimit(sub, 100)
-	if err != nil || data == nil {
+	if err != nil || arr == nil {
-		return
+		return ""
 	}
+
+	// shuffle array
+	dest := make([]*model.Lottery, len(arr))
+	perm := rand.Perm(len(arr))
+	for idx, val := range perm {
+		dest[val] = arr[idx]
+		arr[idx] = nil
+	}
+
+	data := dest[0]
+
+	// set arr to nil
+	for i := range dest {
+		dest[i] = nil
+	}
+	arr = nil
+	dest = nil
+	perm = nil
+
 	conf := config.GetConf()
 	u := conf.URL
 	if last := len(u); last > 0 && u[last-1] == '/' {
@@ -350,7 +370,7 @@ func lottery(sub, txt string, s *lineobj.SourceObject) (res string) {
 	oriURL := "/image/origin"
 	thumbURL := "/image/thumbnail"
 	if len(data.Message) == 0 {
-		return
+		return ""
 	}
 	o := u + oriURL + "/" + data.Message + "?d=" + sub
 	t := u + thumbURL + "/" + data.Message + "?d=" + sub