feat(services): implemented service promises

2 files changed, 104 insertions, 0 deletions

diff --git a/gonf/gonf.go b/gonf/gonf.go
index b5aec4f..363a227 100644
--- a/gonf/gonf.go
+++ b/gonf/gonf.go
@@ -31,6 +31,14 @@ func Resolve() (status Status) {
 			packages_list_function()
 			continue
 		}
+		// ----- Services ----------------------------------------------
+		status = resolveServices()
+		switch status {
+		case BROKEN:
+			return BROKEN
+		case REPAIRED:
+			continue
+		}
 		// ----- Commands ----------------------------------------------
 		status = resolveCommands()
 		switch status {
diff --git a/gonf/services.go b/gonf/services.go
new file mode 100644
index 0000000..58c7383
--- /dev/null
+++ b/gonf/services.go
@@ -0,0 +1,96 @@
+package gonf
+
+import "log/slog"
+
+// ----- Globals ---------------------------------------------------------------
+var services []*ServicePromise
+
+// service management function
+var serviceFunction func(string, string) (Status, error)
+
+// ----- Init ------------------------------------------------------------------
+func init() {
+	services = make([]*ServicePromise, 0)
+}
+
+// ----- Public ----------------------------------------------------------------
+func SetServiceFunction(f func(string, string) (Status, error)) {
+	serviceFunction = f
+}
+
+func Service(names ...string) *ServicePromise {
+	return &ServicePromise{
+		chain:  nil,
+		err:    nil,
+		names:  names,
+		states: nil,
+		status: PROMISED,
+	}
+}
+
+func (s *ServicePromise) State(states ...string) *ServicePromise {
+	s.states = states
+	return s
+}
+
+type ServicePromise struct {
+	chain  []Promise
+	err    error
+	names  []string
+	states []string
+	status Status
+}
+
+func (s *ServicePromise) IfRepaired(ps ...Promise) Promise {
+	s.chain = ps
+	return s
+}
+
+func (s *ServicePromise) Promise() Promise {
+	services = append(services, s)
+	return s
+}
+
+func (s *ServicePromise) Resolve() {
+	for _, name := range s.names {
+		var repaired = false
+		for _, state := range s.states {
+			s.status, s.err = serviceFunction(name, state)
+			if s.status == BROKEN {
+				slog.Error("service", "name", name, "state", state, "status", s.status, "error", s.err)
+				return
+			} else if s.status == REPAIRED {
+				repaired = true
+			}
+		}
+		if repaired {
+			s.status = REPAIRED
+			slog.Info("service", "name", name, "state", s.states, "status", s.status)
+		} else {
+			s.status = KEPT
+			slog.Debug("service", "name", name, "state", s.states, "status", s.status)
+		}
+	}
+	if s.status == REPAIRED {
+		for _, pp := range s.chain {
+			pp.Resolve()
+		}
+	}
+}
+
+// ----- Internal --------------------------------------------------------------
+func resolveServices() (status Status) {
+	status = KEPT
+	for _, c := range services {
+		if c.status == PROMISED {
+			c.Resolve()
+			switch c.status {
+			case BROKEN:
+				return BROKEN
+			case REPAIRED:
+				status = REPAIRED
+			}
+		}
+	}
+	return
+}