Split client part to client.go

1 files changed, 128 insertions, 0 deletions

diff --git a/internal/imap/client.go b/internal/imap/client.go
new file mode 100644
index 0000000..7440ed7
--- /dev/null
+++ b/internal/imap/client.go
@@ -0,0 +1,128 @@
+package imap
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/emersion/go-imap"
+	imapClient "github.com/emersion/go-imap/client"
+
+	"github.com/Necoro/feed2imap-go/internal/log"
+)
+
+type Client struct {
+	c         *imapClient.Client
+	host      string
+	folders   folders
+	delimiter string
+	toplevel  string
+}
+
+type folders map[string]*imap.MailboxInfo
+
+func (f folders) contains(elem string) bool {
+	_, ok := f[elem]
+	return ok
+}
+
+func (f folders) add(elem *imap.MailboxInfo) {
+	name := elem.Name
+	f[name] = elem
+}
+
+func (client *Client) Disconnect() {
+	if client != nil {
+		connected := (client.c.State() & imap.ConnectedState) != 0
+		_ = client.c.Logout()
+
+		if connected {
+			log.Print("Disconnected from ", client.host)
+		}
+	}
+}
+
+func (client *Client) FolderName(path []string) string {
+	return strings.Join(path, client.delimiter)
+}
+
+func (client *Client) createFolder(folder string) error {
+	err := client.c.Create(folder)
+	if err != nil {
+		return fmt.Errorf("creating folder '%s': %w", folder, err)
+	}
+
+	err = client.c.Subscribe(folder)
+	if err != nil {
+		return fmt.Errorf("subscribing to folder '%s': %w", folder, err)
+	}
+
+	log.Printf("Created folder '%s'", folder)
+
+	return nil
+}
+
+func (client *Client) list(folder string) (*imap.MailboxInfo, int, error) {
+	mailboxes := make(chan *imap.MailboxInfo, 10)
+	done := make(chan error, 1)
+	go func() {
+		done <- client.c.List("", folder, mailboxes)
+	}()
+
+	found := 0
+	var mbox *imap.MailboxInfo
+	for m := range mailboxes {
+		if found == 0 {
+			mbox = m
+		}
+		found++
+	}
+
+	if err := <-done; err != nil {
+		return nil, 0, fmt.Errorf("while listing '%s': %w", folder, err)
+	}
+
+	return mbox, found, nil
+}
+
+func (client *Client) selectToplevel() (err error) {
+	err = client.EnsureFolder(client.toplevel)
+
+	if err == nil {
+		_, err = client.c.Select(client.toplevel, false)
+	}
+
+	return
+}
+
+func (client *Client) fetchDelimiter() error {
+	mbox, _, err := client.list("")
+	if err != nil {
+		return err
+	}
+
+	client.delimiter = mbox.Delimiter
+	return nil
+}
+
+func (client *Client) EnsureFolder(folder string) error {
+
+	if client.folders.contains(folder) {
+		return nil
+	}
+
+	log.Printf("Checking for folder '%s'", folder)
+
+	mbox, found, err := client.list(folder)
+
+	switch {
+	case err != nil:
+		return err
+	case found == 0:
+		return client.createFolder(folder)
+	case found == 1:
+		client.folders.add(mbox)
+		return nil
+	default:
+		return fmt.Errorf("Found multiple folders matching '%s'.", folder)
+	}
+}