added player lists for secret santa

.gitignore

@@ -17,3 +17,8 @@ cake4everybot
 
 # configuration files for tokens, access keys and other connection data
 *env.yaml
+
+# runtime config files (as described in config.yml)
+modules/secretsanta/players.json
+twitch/prizes.json
+twitch/times.json

config.yaml

@@ -34,6 +34,10 @@ event:
   adventcalendar:
     images: data/images/adventcalendar
 
+  secretsanta:
+    # the filepath for the players
+    players: modules/secretsanta/players.json
+
   twitch_giveaway:
     # The amount of points a single giveaway ticket costs.
     ticket_cost: 1000

data/lang/de.yaml

@@ -131,6 +131,7 @@ discord.command:
 
     msg.setup.no_reactions: Diese Nachricht hat keine Reaktionen. Nur Leute, die mit %s reagiert haben, werden eingeschlossen.
     msg.setup.not_enough_reactions: Nicht genug Reaktionen um zu starten. Es werden mindestens %d Reaktionen benötigt.
+    msg.setup.users: Teilnehmer
 
 module:
   adventcalendar:

data/lang/en.yaml

@@ -131,6 +131,7 @@ discord.command:
 
     msg.setup.no_reactions: This message doesn't have any vote reactions. Only members who reated with %s are included.
     msg.setup.not_enough_reactions: Not enough votes to start a game. At least %d votes are required.
+    msg.setup.users: Members
 
 module:
   adventcalendar:

modules/secretsanta/handlerMessageSetup.go

@@ -3,7 +3,9 @@ package secretsanta
 import (
 	"cake4everybot/data/lang"
 	"cake4everybot/util"
+	"fmt"
 
+	"github.com/bwmarrin/discordgo"
 )
 
 func (cmd MsgCmd) handler() {
@@ -43,4 +45,40 @@ func (cmd MsgCmd) handler() {
 		cmd.ReplyHiddenf(lang.GetDefault(tp+"msg.setup.not_enough_reactions"), 2)
 		return
 	}
+
+	e := &discordgo.MessageEmbed{
+		Title: lang.GetDefault(tp + "title"),
+		Color: 0x690042,
+	}
+
+	var (
+		names   string
+		players []*player = make([]*player, 0, len(users))
+	)
+	for _, u := range users {
+		member, err := cmd.Session.GuildMember(cmd.Interaction.GuildID, u.ID)
+		if member == nil {
+			log.Printf("WARN: Could not get member '%s' from guild '%s': %v", u.ID, cmd.Interaction.GuildID, err)
+			continue
+		}
+		players = append(players, &player{Member: member})
+		names += fmt.Sprintf("%s\n", member.Mention())
+	}
+	if len(players) < 2 {
+		cmd.ReplyHiddenf(lang.GetDefault(tp+"msg.setup.not_enough_reactions"), 2)
+		return
+	}
+	util.AddEmbedField(e, lang.GetDefault(tp+"msg.setup.users"), names, false)
+
+	players = DerangementMatch(players)
+
+	err = cmd.setPlayers(players)
+	if err != nil {
+		log.Printf("Error on set players: %v\n", err)
+		cmd.ReplyError()
+		return
+	}
+
+	util.SetEmbedFooter(cmd.Session, tp+"display", e)
+	cmd.ReplyHiddenEmbed(e)
 }

modules/secretsanta/secretsantabase.go

@@ -2,9 +2,14 @@ package secretsanta
 
 import (
 	"cake4everybot/util"
+	"encoding/json"
+	"fmt"
 	logger "log"
+	"os"
 
 	"github.com/bwmarrin/discordgo"
+	"github.com/spf13/viper"
+	"golang.org/x/exp/rand"
 )
 
 const (
@@ -20,3 +25,150 @@ type secretSantaBase struct {
 	member *discordgo.Member
 	user   *discordgo.User
 }
+
+// getPlayers returns the list of players for the current guild. If it is the first time, it loads
+// the players from the file or creates an empty file.
+func (ssb secretSantaBase) getPlayers() ([]*player, error) {
+	if allPlayers != nil {
+		return allPlayers[ssb.Interaction.GuildID], nil
+	}
+
+	log.Println("First time getting players. Loading from file...")
+	playersPath := viper.GetString("event.secretsanta.players")
+	playersData, err := os.ReadFile(playersPath)
+	if err != nil {
+		if !os.IsNotExist(err) {
+			return nil, fmt.Errorf("read players file: %v", err)
+		}
+		allPlayers = make(AllPlayers)
+		playersData, err = json.Marshal(allPlayers)
+		if err != nil {
+			return nil, fmt.Errorf("marshal players file: %v", err)
+		}
+		err = os.WriteFile(playersPath, playersData, 0644)
+		if err != nil {
+			return nil, fmt.Errorf("write players file: %v", err)
+		}
+		log.Printf("Created players file: %s\n", playersPath)
+		return []*player{}, nil
+	}
+	allPlayersUnresolved := AllPlayersUnresolved{}
+	err = json.Unmarshal(playersData, &allPlayersUnresolved)
+	if err != nil {
+		return nil, fmt.Errorf("unmarshal players file: %v", err)
+	}
+	err = allPlayersUnresolved.Resolve(ssb.Session)
+	if err != nil {
+		return nil, fmt.Errorf("resolve players file: %v", err)
+	}
+	log.Printf("Got %d guilds from file", len(allPlayers))
+
+	return allPlayers[ssb.Interaction.GuildID], nil
+}
+
+// setPlayers sets the players for the current guild.
+func (ssb secretSantaBase) setPlayers(players []*player) (err error) {
+	if _, err = ssb.getPlayers(); err != nil {
+		return err
+	}
+
+	allPlayers[ssb.Interaction.GuildID] = players
+	playersData, err := json.Marshal(allPlayers)
+	if err != nil {
+		return fmt.Errorf("marshal players file: %v", err)
+	}
+	err = os.WriteFile(viper.GetString("event.secretsanta.players"), playersData, 0644)
+	if err != nil {
+		return fmt.Errorf("write players file: %v", err)
+	}
+	return nil
+}
+
+// player is a player in the secret santa game
+type player struct {
+	*discordgo.Member
+
+	// Match is the matched player
+	Match *player
+	// Address is the address of the player
+	Address string
+}
+
+type playerUnresolved struct {
+	ID      string `json:"id"`
+	MatchID string `json:"match"`
+	Address string `json:"address"`
+}
+
+// AllPlayers is a map from guild ID to a list of players
+type AllPlayers map[string][]*player
+
+// allPlayers is the current state of all players.
+// See [AllPlayers]
+var allPlayers AllPlayers
+
+// MarshalJSON implements json.Marshaler
+func (allPlayers AllPlayers) MarshalJSON() ([]byte, error) {
+	m := make(AllPlayersUnresolved)
+	for guildID, players := range allPlayers {
+		for _, player := range players {
+			m[guildID] = append(m[guildID], &playerUnresolved{
+				ID:      player.User.ID,
+				MatchID: player.Match.User.ID,
+				Address: player.Address,
+			})
+		}
+
+	}
+	return json.Marshal(m)
+}
+
+// AllPlayersUnresolved is a map from guild ID to a list of unresolved players.
+// Unresolved players have no member but only an ID
+type AllPlayersUnresolved map[string][]*playerUnresolved
+
+// Resolve resolves allPlayersUnresolved into allPlayers
+func (allPlayersUnresolved AllPlayersUnresolved) Resolve(s *discordgo.Session) (err error) {
+	allPlayers = make(AllPlayers)
+	for guildID, unresolvedPlayers := range allPlayersUnresolved {
+		resolvedPlayers := map[string]*player{}
+		for _, up := range unresolvedPlayers {
+			member, err := s.GuildMember(guildID, up.ID)
+			if err != nil {
+				return fmt.Errorf("failed to get guild member %s/%s: %v", guildID, up.ID, err)
+			}
+			resolvedPlayers[up.ID] = &player{
+				Member:  member,
+				Match:   resolvedPlayers[up.MatchID],
+				Address: up.Address,
+			}
+		}
+		for _, rp := range resolvedPlayers {
+			if rp.Match != nil {
+				continue
+			}
+			rp.Match = resolvedPlayers[rp.User.ID]
+
+			allPlayers[guildID] = append(allPlayers[guildID], rp)
+		}
+	}
+	return nil
+}
+
+// DerangementMatch matches the players in a way that no one gets matched to themselves.
+func DerangementMatch(players []*player) []*player {
+	n := len(players)
+	players2 := make([]*player, n)
+	copy(players2, players)
+
+	for i := 0; i < n-1; i++ {
+		j := i + rand.Intn(n-i-1) + 1
+		players2[i], players2[j] = players2[j], players2[i]
+	}
+
+	for i, item := range players {
+		item.Match = players2[i]
+	}
+
+	return players
+}