From 04ce10fec39c085f36ae11e52635f3b9a7922cea Mon Sep 17 00:00:00 2001
From: Chakib Benziane <chakib.benz@gmail.com>
Date: Fri, 7 Dec 2018 16:50:29 +0100
Subject: [PATCH] manager

---
 manager.go | 109 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 109 insertions(+)
 create mode 100644 manager.go

diff --git a/manager.go b/manager.go
new file mode 100644
index 0000000..bd3e7a3
--- /dev/null
+++ b/manager.go
@@ -0,0 +1,109 @@
+package gum
+
+import (
+	"log"
+	"os"
+	"os/signal"
+	"reflect"
+	"strings"
+)
+
+type WorkUnit interface {
+	Spawn(UnitManager)
+	Shutdown()
+}
+
+type UnitManager interface {
+	ShouldStop() <-chan bool
+	Done()
+}
+
+type WorkUnitManager struct {
+	stop       chan bool
+	workerQuit chan bool
+	unit       WorkUnit
+}
+
+func (w *WorkUnitManager) ShouldStop() <-chan bool {
+	return w.stop
+}
+
+func (w *WorkUnitManager) Done() {
+	w.workerQuit <- true
+}
+
+type Manager struct {
+	signal chan os.Signal
+
+	workers map[string]*WorkUnitManager
+
+	quit chan bool
+}
+
+func (m *Manager) Start() {
+	log.Println("Starting manager ...")
+
+	for unitName, w := range m.workers {
+		log.Printf("Starting <%s>\n", unitName)
+		go w.unit.Spawn(w)
+	}
+
+	for {
+		select {
+		case sig := <-m.signal:
+			if sig != os.Interrupt {
+				break
+			}
+
+			log.Println("shutting event received ... ")
+
+			// send shutdown event to all worker units
+			for name, w := range m.workers {
+				log.Printf("shuting down <%s>\n", name)
+				w.stop <- true
+			}
+
+			// Wait for all units to quit
+			for name, w := range m.workers {
+				<-w.workerQuit
+				log.Printf("<%s> down", name)
+			}
+
+			// All workers have shutdown
+			log.Println("All workers have shutdown, shutting down manager ...")
+
+			DB.Handle.Close()
+			m.quit <- true
+
+		}
+	}
+}
+
+func (m *Manager) SubscribeTo(sig os.Signal) {
+	signal.Notify(m.signal, sig)
+}
+
+func (m *Manager) AddUnit(unit WorkUnit) {
+
+	workUnitManager := &WorkUnitManager{
+		workerQuit: make(chan bool, 1),
+		stop:       make(chan bool, 1),
+		unit:       unit,
+	}
+
+	unitType := reflect.TypeOf(unit)
+	unitName := strings.Split(unitType.String(), ".")[1]
+
+	log.Println("Adding unit ", unitName)
+
+	m.workers[unitName] = workUnitManager
+	log.Println(m.workers)
+}
+
+func NewManager() *Manager {
+	return &Manager{
+		signal:  make(chan os.Signal, 1),
+		quit:    make(chan bool),
+		workers: make(map[string]*WorkUnitManager),
+	}
+}