Add PostgreSQL, user/squad management, remove private domains from docs

internal/db/users.go

@@ -0,0 +1,75 @@
+package db
+
+import (
+	"context"
+	"time"
+
+	"github.com/jackc/pgx/v5"
+)
+
+type VPNUser struct {
+	ID                  int64
+	TelegramID          *int64
+	RemnawaveUUID       string
+	RemnawaveUsername   string
+	ExternalSquadUUID   *string
+	InternalSquadUUIDs  []string
+	ExpireAt            *time.Time
+}
+
+func (d *DB) UpsertTelegramUser(ctx context.Context, telegramID int64, username, firstName string) error {
+	_, err := d.pool.Exec(ctx, `
+		INSERT INTO telegram_users (telegram_id, username, first_name)
+		VALUES ($1, $2, $3)
+		ON CONFLICT (telegram_id) DO UPDATE SET
+			username = EXCLUDED.username,
+			first_name = EXCLUDED.first_name`,
+		telegramID, nullStr(username), nullStr(firstName))
+	return err
+}
+
+func (d *DB) SaveVPNUser(ctx context.Context, u VPNUser) error {
+	_, err := d.pool.Exec(ctx, `
+		INSERT INTO vpn_users (
+			telegram_id, remnawave_uuid, remnawave_username,
+			external_squad_uuid, internal_squad_uuids, expire_at
+		) VALUES ($1, $2, $3, $4, $5, $6)
+		ON CONFLICT (remnawave_uuid) DO UPDATE SET
+			telegram_id = EXCLUDED.telegram_id,
+			remnawave_username = EXCLUDED.remnawave_username,
+			external_squad_uuid = EXCLUDED.external_squad_uuid,
+			internal_squad_uuids = EXCLUDED.internal_squad_uuids,
+			expire_at = EXCLUDED.expire_at,
+			updated_at = NOW()`,
+		u.TelegramID, u.RemnawaveUUID, u.RemnawaveUsername,
+		u.ExternalSquadUUID, u.InternalSquadUUIDs, u.ExpireAt)
+	return err
+}
+
+func (d *DB) GetVPNByUsername(ctx context.Context, username string) (*VPNUser, error) {
+	row := d.pool.QueryRow(ctx, `
+		SELECT id, telegram_id, remnawave_uuid::text, remnawave_username,
+			external_squad_uuid::text, internal_squad_uuids::text[], expire_at
+		FROM vpn_users WHERE remnawave_username = $1`, username)
+
+	var u VPNUser
+	var ext *string
+	var internal []string
+	err := row.Scan(&u.ID, &u.TelegramID, &u.RemnawaveUUID, &u.RemnawaveUsername, &ext, &internal, &u.ExpireAt)
+	if err == pgx.ErrNoRows {
+		return nil, nil
+	}
+	if err != nil {
+		return nil, err
+	}
+	u.ExternalSquadUUID = ext
+	u.InternalSquadUUIDs = internal
+	return &u, nil
+}
+
+func nullStr(s string) *string {
+	if s == "" {
+		return nil
+	}
+	return &s
+}