From f19b2fe5feca5e0f313ca8c9a17e02d251c13cb1 Mon Sep 17 00:00:00 2001
From: Alessio Gottardo <alessio.gottardo@openenergi.com>
Date: Wed, 6 Jun 2018 17:57:56 +0100
Subject: [PATCH] Provide a consumable channel with custom defined execution
 stats

---
 crontab.go      | 22 +++++++++++++++++++---
 example_test.go | 49 +++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 68 insertions(+), 3 deletions(-)

diff --git a/crontab.go b/crontab.go
index 42e811e..4422f6c 100644
--- a/crontab.go
+++ b/crontab.go
@@ -11,10 +11,20 @@ import (
 	"time"
 )
 
+// StatsFunc func representing custom execution statistics
+type StatsFunc func() interface{}
+
+// ExecStats struct representing a standardized wrapper for execution statistics
+type ExecStats struct {
+	JobType string
+	Stats   StatsFunc
+}
+
 // Crontab struct representing cron table
 type Crontab struct {
-	ticker *time.Ticker
-	jobs   []job
+	ticker    *time.Ticker
+	jobs      []job
+	statsChan chan ExecStats
 }
 
 // job in cron table
@@ -46,7 +56,8 @@ func New() *Crontab {
 // new creates new crontab, arg provided for testing purpose
 func new(t time.Duration) *Crontab {
 	c := &Crontab{
-		ticker: time.NewTicker(t),
+		ticker:    time.NewTicker(t),
+		statsChan: make(chan ExecStats),
 	}
 
 	go func() {
@@ -58,6 +69,11 @@ func new(t time.Duration) *Crontab {
 	return c
 }
 
+// StatsChan returns the channel to consume execution statistics
+func (c *Crontab) StatsChan() chan ExecStats {
+	return c.statsChan
+}
+
 // AddJob to cron table
 //
 // Returns error if:
diff --git a/example_test.go b/example_test.go
index 2867ef8..281aaf4 100644
--- a/example_test.go
+++ b/example_test.go
@@ -3,6 +3,8 @@ package crontab_test
 import (
 	"fmt"
 	"log"
+	"testing"
+	"time"
 
 	"github.com/mileusna/crontab"
 )
@@ -38,3 +40,50 @@ func myFunc3() {
 func myFunc2(s string, n int) {
 	fmt.Printf("We have params here, string `%s` and nymber %d\n", s, n)
 }
+
+// go test -v ./... -run TestExampleExecStats
+func TestExampleExecStats(t *testing.T) {
+	ctab := crontab.New()
+
+	ctab.MustAddJob("* * * * *", myFuncWithStats, ctab.StatsChan())
+	log.Println("Waiting a bit for the test to complete...")
+
+	for i := 1; i <= 1; i++ {
+		myExecStats := <-ctab.StatsChan()
+		if myExecStats.JobType != "myFuncWithStats" {
+			t.Errorf("Found an unexpected Job type")
+		}
+		customStuff := myExecStats.Stats().(*myCustomStats)
+		if customStuff.strParam != "foo" {
+			t.Errorf("Found an unexpected string parameter in the stats")
+		}
+		if customStuff.intParam != 42 {
+			t.Errorf("Found an unexpected integer parameter in the stats")
+		}
+		ctab.Shutdown()
+		log.Println("Done with the test, the received stats:", customStuff)
+	}
+}
+
+// custom execution stats depending on the scheduled function
+type myCustomStats struct {
+	strParam string
+	intParam int
+}
+
+func myFuncWithStats(statsChan chan crontab.ExecStats) {
+	// work a bit...
+	time.Sleep(1 * time.Second)
+	// publish the execution stats...
+	statsChan <- crontab.ExecStats{
+		// ID to identify the job
+		JobType: "myFuncWithStats",
+		// custom execution stats
+		Stats: func() interface{} {
+			return &myCustomStats{
+				strParam: "foo",
+				intParam: 42,
+			}
+		},
+	}
+}