feat: add change detection module

internal/widget/changedetection.go

@@ -0,0 +1,51 @@
+package widget
+
+import (
+	"context"
+	"html/template"
+	"time"
+
+	"github.com/glanceapp/glance/internal/assets"
+	"github.com/glanceapp/glance/internal/feed"
+)
+
+type ChangeDetections struct {
+	widgetBase       `yaml:",inline"`
+	ChangeDetections feed.ChangeWatches  `yaml:"-"`
+	Watches          []string          `yaml:"watches"`
+	Token            OptionalEnvString `yaml:"token"`
+	Limit            int               `yaml:"limit"`
+	CollapseAfter    int               `yaml:"collapse-after"`
+}
+
+func (widget *ChangeDetections) Initialize() error {
+	widget.withTitle("Changes").withCacheDuration(2 * time.Hour)
+
+	if widget.Limit <= 0 {
+		widget.Limit = 10
+	}
+
+	if widget.CollapseAfter == 0 || widget.CollapseAfter < -1 {
+		widget.CollapseAfter = 5
+	}
+
+	return nil
+}
+
+func (widget *ChangeDetections) Update(ctx context.Context) {
+	watches, err := feed.FetchLatestDetectedChanges(widget.Watches, string(widget.Token))
+
+	if !widget.canContinueUpdateAfterHandlingErr(err) {
+		return
+	}
+
+	if len(watches) > widget.Limit {
+		watches = watches[:widget.Limit]
+	}
+
+	widget.ChangeDetections = watches
+}
+
+func (widget *ChangeDetections) Render() template.HTML {
+	return widget.render(widget, assets.ChangesTemplate)
+}