add feed package

Move feed type and function to its own package.

1 files changed, 55 insertions, 0 deletions

diff --git a/feed/feed.go b/feed/feed.go
new file mode 100644
index 0000000..13de66d
--- /dev/null
+++ b/feed/feed.go
@@ -0,0 +1,55 @@
+// SPDX-License-Identifier: ISC
+// Copyright © 2021 siddharth <s@ricketyspace.net>
+
+package feed
+
+import (
+	"fmt"
+	"os"
+	"path"
+)
+
+type Feed struct {
+	Id      string `json:"id"`
+	Source  string `json:"source"`
+	Schema  string `json:"schema"`
+	DumpDir string
+}
+
+func (feed *Feed) Validate(baseDumpDir string) error {
+	_, err := os.Stat(baseDumpDir)
+	if err != nil {
+		return err
+	}
+
+	// Check 'id'
+	if len(feed.Id) == 0 {
+		return fmt.Errorf("'id' not set in a feed")
+	}
+
+	// Check 'source'
+	if len(feed.Source) == 0 {
+		return fmt.Errorf("'source' not set in a feed '%s'", feed.Id)
+	}
+
+	// Check 'schema'
+	schemaOK := false
+	for _, schema := range []string{"npr", "youtube"} {
+		if feed.Schema == schema {
+			schemaOK = true
+		}
+	}
+	if !schemaOK {
+		return fmt.Errorf("schema '%s' for feed '%s' is not valid",
+			feed.Schema, feed.Id)
+	}
+
+	// Set dump directory for feed and ensure it exists.
+	feed.DumpDir = path.Join(baseDumpDir, feed.Id)
+	err = os.MkdirAll(feed.DumpDir, 0755)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}