feat: publish standalone worker

Separate worker packaging and service lifecycle from the control plane.

app/models/contact.go

@@ -0,0 +1,86 @@
+package models
+
+import (
+	"gorm.io/datatypes"
+
+	"rsgit.ru/rsmon/rsmon/app/models/concerns"
+)
+
+// Contact represents a notification contact.
+//
+// Ownership / tenancy:
+//
+//   - A Contact belongs to exactly one Account (tenant). AccountID may be
+//     nil for system-level admin contacts (see SystemContacts).
+//   - A Contact may belong to at most one User. UserID is set when the
+//     contact was created on behalf of a specific user (the typical
+//     case for self-service "My email" / "My Telegram" contacts) and is
+//     nil for account-wide contacts.
+//
+// `User` is omitempty because most list payloads don't preload it; the
+// `/settings/users` page loads it server-side via the AccountUserRow
+// payload.
+type Contact struct {
+	concerns.Model
+
+	AccountID          *int64         `json:"account_id" gorm:"type:bigint REFERENCES accounts(id)"`
+	Account            *Account       `json:"-"`
+	UserID             *int64         `gorm:"type:bigint REFERENCES users(id)" json:"user_id"`
+	User               *User          `json:"user,omitempty"`
+	Name               string         `json:"name" gorm:"not null"`
+	Kind               string         `json:"kind" gorm:"not null;index:contact_value"`
+	Value              string         `json:"value" gorm:"index:contact_value"`
+	Enabled            bool           `json:"enabled" gorm:"not null;default:true"`
+	Data               datatypes.JSON `json:"data"`
+	IsSystem           *bool          `json:"is_system" gorm:"default:false"`
+	Notifications      []Notification `json:"-" gorm:"many2many:notification_contacts;"`
+	NotificationsCount int            `gorm:"-:all" json:"notifications_count"`
+	MonitorsCount      int            `gorm:"-:all" json:"monitors_count"`
+	Messages           []Message      `json:"-"`
+
+	concerns.Timestamped
+	concerns.HasToken
+	Audited
+}
+
+// SystemContacts returns all contacts marked as system/admin (is_system=true).
+// These are the contacts distributed workers notify directly when the main
+// API is unreachable (see docs/worker-protocol.md "System Selfcheck").
+func SystemContacts() ([]Contact, error) {
+	var contacts []Contact
+	err := DB().Where("is_system = ? AND enabled = ?", true, true).Find(&contacts).Error
+	return contacts, err
+}
+
+// ContactsCounts fills NotificationsCount and MonitorsCount for each contact.
+func ContactsCounts(contacts *[]Contact) {
+	groupIDs := make(map[int64]bool, 0)
+	groupCount := make(map[int64]int, 0)
+
+	for i, c := range *contacts { //nolint:gocritic // range copy is acceptable here
+		(*contacts)[i].NotificationsCount = len(c.Notifications)
+		for _, n := range c.Notifications { //nolint:gocritic // range copy is acceptable here
+			for _, g := range n.Groups { //nolint:gocritic // range copy is acceptable here
+				groupIDs[g.ID] = true
+				groupCount[g.ID] = 0
+			}
+		}
+	}
+
+	gids := make([]int64, 0, len(groupIDs))
+	for g := range groupIDs {
+		gids = append(gids, g)
+	}
+
+	CountGroups(gids, &groupCount)
+
+	for i, c := range *contacts { //nolint:gocritic // range copy is acceptable here
+		cnt := 0
+		for _, n := range c.Notifications { //nolint:gocritic // range copy is acceptable here
+			for _, g := range n.Groups { //nolint:gocritic // range copy is acceptable here
+				cnt += groupCount[g.ID]
+			}
+		}
+		(*contacts)[i].MonitorsCount = cnt
+	}
+}