initial code (#6)

* initial code commit

rss/job.go

@@ -0,0 +1,88 @@
+package rss
+
+import (
+	"fmt"
+	"github.com/l3uddz/nabarr/cmd/nabarr/pvr"
+	"github.com/robfig/cron/v3"
+	"time"
+)
+
+func (c *Client) AddJob(feed feedItem) error {
+	// prepare job
+	if feed.Cron == "" {
+		feed.Cron = "*/15 * * * *"
+	}
+
+	if feed.CacheDuration == 0 {
+		feed.CacheDuration = (24 * time.Hour) * 28
+	}
+
+	// create job
+	job := &rssJob{
+		name: feed.Name,
+		log:  c.log.With().Str("feed_name", feed.Name).Logger(),
+		url:  feed.URL,
+		pvrs: make(map[string]pvr.PVR, 0),
+
+		attempts: 0,
+		errors:   make([]error, 0),
+
+		cron:             c.cron,
+		cache:            c.cache,
+		cacheDuration:    feed.CacheDuration,
+		cacheFiltersHash: c.cacheFiltersHash,
+	}
+
+	// add pvrs
+	for _, p := range feed.Pvrs {
+		po, exists := c.pvrs[p]
+		if !exists {
+			return fmt.Errorf("pvr object does not exist: %v", p)
+		}
+		job.pvrs[p] = po
+	}
+
+	// schedule job
+	if id, err := c.cron.AddJob(feed.Cron, cron.NewChain(
+		cron.SkipIfStillRunning(cron.DiscardLogger)).Then(job),
+	); err != nil {
+		return fmt.Errorf("add job: %w", err)
+	} else {
+		job.jobID = id
+	}
+
+	job.log.Info().Msg("Initialised")
+	return nil
+}
+
+func (j *rssJob) Run() {
+	// increase attempt counter
+	j.attempts++
+
+	// run job
+	err := j.process()
+
+	// handle job response
+	switch {
+	case err == nil:
+		// job completed successfully
+		j.attempts = 0
+		j.errors = j.errors[:0]
+		return
+
+	default:
+		j.log.Warn().
+			Err(err).
+			Int("attempts", j.attempts).
+			Msg("Unexpected error occurred")
+		j.errors = append(j.errors, err)
+	}
+
+	if j.attempts > 5 {
+		j.log.Error().
+			Errs("error", j.errors).
+			Int("attempts", j.attempts).
+			Msg("Consecutive errors occurred while refreshing rss, job has been stopped...")
+		j.cron.Remove(j.jobID)
+	}
+}