From 35dc6043bc455a5adca4900c4d97af7026779aa2 Mon Sep 17 00:00:00 2001
From: Maksym Pavlenko <pavlenko.maksym@gmail.com>
Date: Sat, 7 Mar 2020 18:01:00 -0800
Subject: [PATCH] Support episodes cleanup #44

---
 README.md                 |  1 +
 cmd/podsync/updater.go    | 61 +++++++++++++++++++++++++++++++++++++++
 pkg/config/config.go      |  7 +++++
 pkg/config/config_test.go |  4 +++
 4 files changed, 73 insertions(+)

diff --git a/README.md b/README.md
index 4647aa4..1d68d3e 100644
--- a/README.md
+++ b/README.md
@@ -58,6 +58,7 @@ vimeo = "{VIMEO_API_TOKEN}"
   # max_height = "720" # Optional maximal height of video, example: 720, 1080, 1440, 2160, ...
   # cron_schedule = "@every 12h" # Optional cron expression format. If set then overwrite 'update_period'. See details below
   # filters = { title = "regex for title here" } # Optional Golang regexp format. If set, then only download episodes with matching titles.
+  # clean = { keep_last = 10 } # Keep last 10 episodes (order desc by PubDate)
 ```
 
 Episodes files will be kept at: `/path/to/data/directory/ID1`, feed will be accessible from: `http://localhost/ID1.xml`
diff --git a/cmd/podsync/updater.go b/cmd/podsync/updater.go
index 44d0fe7..3660275 100644
--- a/cmd/podsync/updater.go
+++ b/cmd/podsync/updater.go
@@ -7,8 +7,10 @@ import (
 	"io"
 	"os"
 	"regexp"
+	"sort"
 	"time"
 
+	"github.com/hashicorp/go-multierror"
 	"github.com/pkg/errors"
 	log "github.com/sirupsen/logrus"
 
@@ -61,6 +63,10 @@ func (u *Updater) Update(ctx context.Context, feedConfig *config.Feed) error {
 		return err
 	}
 
+	if err := u.cleanup(ctx, feedConfig); err != nil {
+		log.WithError(err).Error("cleanup failed")
+	}
+
 	elapsed := time.Since(started)
 	nextUpdate := time.Now().Add(feedConfig.UpdatePeriod.Duration)
 	log.Infof("successfully updated feed in %s, next update at %s", elapsed, nextUpdate.Format(time.Kitchen))
@@ -241,3 +247,58 @@ func (u *Updater) buildXML(ctx context.Context, feedConfig *config.Feed) error {
 
 	return nil
 }
+
+func (u *Updater) cleanup(ctx context.Context, feedConfig *config.Feed) error {
+	var (
+		feedID = feedConfig.ID
+		logger = log.WithField("feed_id", feedID)
+		count  = feedConfig.Clean.KeepLast
+		list   []*model.Episode
+		result *multierror.Error
+	)
+
+	if count < 1 {
+		logger.Info("nothing to clean")
+		return nil
+	}
+
+	logger.WithField("count", count).Info("running cleaner")
+	if err := u.db.WalkEpisodes(ctx, feedConfig.ID, func(episode *model.Episode) error {
+		switch episode.Status {
+		case model.EpisodeError, model.EpisodeCleaned:
+			// Skip
+		default:
+			list = append(list, episode)
+		}
+		return nil
+	}); err != nil {
+		return err
+	}
+
+	if count > len(list) {
+		return nil
+	}
+
+	sort.Slice(list, func(i, j int) bool {
+		return list[i].PubDate.After(list[j].PubDate)
+	})
+
+	for _, episode := range list[count:] {
+		logger.WithField("episode_id", episode.ID).Infof("deleting %q", episode.Title)
+
+		if err := u.fs.Delete(ctx, feedConfig.ID, feed.EpisodeName(feedConfig, episode)); err != nil {
+			result = multierror.Append(result, errors.Wrapf(err, "failed to delete episode: %s", episode.ID))
+			continue
+		}
+
+		if err := u.db.UpdateEpisode(feedID, episode.ID, func(episode *model.Episode) error {
+			episode.Status = model.EpisodeCleaned
+			return nil
+		}); err != nil {
+			result = multierror.Append(result, errors.Wrapf(err, "failed to set state for cleaned episode: %s", episode.ID))
+			continue
+		}
+	}
+
+	return result.ErrorOrNil()
+}
diff --git a/pkg/config/config.go b/pkg/config/config.go
index 7cdecd0..bbb57c4 100644
--- a/pkg/config/config.go
+++ b/pkg/config/config.go
@@ -38,6 +38,8 @@ type Feed struct {
 	CoverArt string `toml:"cover_art"`
 	// Only download episodes that match this regexp (defaults to matching anything)
 	Filters Filters `toml:"filters"`
+	// Clean is a cleanup policy to use for this feed
+	Clean Cleanup `toml:"clean"`
 }
 
 type Tokens struct {
@@ -64,6 +66,11 @@ type Database struct {
 	Dir string `toml:"dir"`
 }
 
+type Cleanup struct {
+	// KeepLast defines how many episodes to keep
+	KeepLast int `toml:"keep_last"`
+}
+
 type Config struct {
 	// Server is the web server configuration
 	Server Server `toml:"server"`
diff --git a/pkg/config/config_test.go b/pkg/config/config_test.go
index c29ce61..4cdb8ab 100644
--- a/pkg/config/config_test.go
+++ b/pkg/config/config_test.go
@@ -32,6 +32,8 @@ dir = "/home/user/db/"
   update_period = "5h"
   format = "audio"
   quality = "low"
+  filters = { title = "regex for title here" }
+  clean = { keep_last = 10 }
 `
 
 	f, err := ioutil.TempFile("", "")
@@ -62,6 +64,8 @@ dir = "/home/user/db/"
 	assert.EqualValues(t, Duration{5 * time.Hour}, feed.UpdatePeriod)
 	assert.EqualValues(t, "audio", feed.Format)
 	assert.EqualValues(t, "low", feed.Quality)
+	assert.EqualValues(t, "regex for title here", feed.Filters.Title)
+	assert.EqualValues(t, 10, feed.Clean.KeepLast)
 }
 
 func TestApplyDefaults(t *testing.T) {