Keep track of guild states.

We don't currently bridge anything, but this just keeps everything in sync
with the discord server.

database/guildquery.go

@@ -0,0 +1,83 @@
+package database
+
+import (
+	"fmt"
+
+	log "maunium.net/go/maulogger/v2"
+)
+
+type GuildQuery struct {
+	db  *Database
+	log log.Logger
+}
+
+const (
+	guildSelect = "SELECT discord_id, guild_id, guild_name, bridge FROM guild"
+)
+
+func (gq *GuildQuery) New() *Guild {
+	return &Guild{
+		db:  gq.db,
+		log: gq.log,
+	}
+}
+
+func (gq *GuildQuery) Get(discordID, guildID string) *Guild {
+	query := guildSelect + " WHERE discord_id=$1 AND guild_id=$2"
+
+	row := gq.db.QueryRow(query, discordID, guildID)
+	if row == nil {
+		return nil
+	}
+
+	return gq.New().Scan(row)
+}
+
+func (gq *GuildQuery) GetAll(discordID string) []*Guild {
+	query := guildSelect + " WHERE discord_id=$1"
+
+	rows, err := gq.db.Query(query, discordID)
+	if err != nil || rows == nil {
+		return nil
+	}
+
+	guilds := []*Guild{}
+	for rows.Next() {
+		guilds = append(guilds, gq.New().Scan(rows))
+	}
+
+	return guilds
+}
+
+func (gq *GuildQuery) Prune(discordID string, guilds []string) {
+	// We need this interface slice because a variadic function can't mix
+	// arguements with a `...` expanded slice.
+	args := []interface{}{discordID}
+
+	nGuilds := len(guilds)
+	if nGuilds <= 0 {
+		return
+	}
+
+	gq.log.Debugfln("prunning guilds not in %#v for %s", guilds, discordID)
+
+	// Build the in query
+	inQuery := "$2"
+	for i := 1; i < nGuilds; i++ {
+		inQuery += fmt.Sprintf(", $%d", i+2)
+	}
+
+	// Add the arguements for the build query
+	for _, guildID := range guilds {
+		args = append(args, guildID)
+	}
+
+	// Now remove any guilds that the user has left.
+	query := "DELETE FROM guild WHERE discord_id=$1 AND guild_id NOT IN (" +
+		inQuery + ")"
+
+	_, err := gq.db.Exec(query, args...)
+	if err != nil {
+		gq.log.Warnfln("Failed to remove old guilds for user %s: %v", discordID, err)
+	}
+}