gitlab: refactor the iterator, fix bugs

Notably, properly reset sub iterators when changing to the next issue

1 files changed, 138 insertions, 0 deletions

diff --git a/bridge/gitlab/iterator/iterator.go b/bridge/gitlab/iterator/iterator.go
new file mode 100644
index 00000000..ee2090b0
--- /dev/null
+++ b/bridge/gitlab/iterator/iterator.go
@@ -0,0 +1,138 @@
+package iterator
+
+import (
+	"context"
+	"time"
+
+	"github.com/xanzy/go-gitlab"
+)
+
+type Iterator struct {
+	// shared context
+	ctx context.Context
+
+	// to pass to sub-iterators
+	conf config
+
+	// sticky error
+	err error
+
+	// issues iterator
+	issue *issueIterator
+
+	// notes iterator
+	note *noteIterator
+
+	// labelEvent iterator
+	labelEvent *labelEventIterator
+}
+
+type config struct {
+	// gitlab api v4 client
+	gc *gitlab.Client
+
+	timeout time.Duration
+
+	// if since is given the iterator will query only the issues
+	// updated after this date
+	since time.Time
+
+	// project id
+	project string
+
+	// number of issues and notes to query at once
+	capacity int
+}
+
+// NewIterator create a new iterator
+func NewIterator(ctx context.Context, client *gitlab.Client, capacity int, projectID string, since time.Time) *Iterator {
+	return &Iterator{
+		ctx: ctx,
+		conf: config{
+			gc:       client,
+			timeout:  60 * time.Second,
+			since:    since,
+			project:  projectID,
+			capacity: capacity,
+		},
+		issue:      newIssueIterator(),
+		note:       newNoteIterator(),
+		labelEvent: newLabelEventIterator(),
+	}
+}
+
+// Error return last encountered error
+func (i *Iterator) Error() error {
+	return i.err
+}
+
+func (i *Iterator) NextIssue() bool {
+	if i.err != nil {
+		return false
+	}
+
+	if i.ctx.Err() != nil {
+		return false
+	}
+
+	more, err := i.issue.Next(i.ctx, i.conf)
+	if err != nil {
+		i.err = err
+		return false
+	}
+
+	// Also reset the other sub iterators as they would
+	// no longer be valid
+	i.note.Reset(i.issue.Value().IID)
+	i.labelEvent.Reset(i.issue.Value().IID)
+
+	return more
+}
+
+func (i *Iterator) IssueValue() *gitlab.Issue {
+	return i.issue.Value()
+}
+
+func (i *Iterator) NextNote() bool {
+	if i.err != nil {
+		return false
+	}
+
+	if i.ctx.Err() != nil {
+		return false
+	}
+
+	more, err := i.note.Next(i.ctx, i.conf)
+	if err != nil {
+		i.err = err
+		return false
+	}
+
+	return more
+}
+
+func (i *Iterator) NoteValue() *gitlab.Note {
+	return i.note.Value()
+}
+
+func (i *Iterator) NextLabelEvent() bool {
+	if i.err != nil {
+		return false
+	}
+
+	if i.ctx.Err() != nil {
+		return false
+	}
+
+	more, err := i.labelEvent.Next(i.ctx, i.conf)
+	if err != nil {
+		i.err = err
+		return false
+	}
+
+	return more
+}
+
+func (i *Iterator) LabelEventValue() *gitlab.LabelEvent {
+	return i.labelEvent.Value()
+}