Add filter on recipients

cmd/send.go

@@ -9,6 +9,7 @@ import (
 
 func sendCmd() *cobra.Command {
 	var serverURL string
+	var recipientsFilter string
 
 	cmd := &cobra.Command{
 		Use:     "send [content] [list]",
@@ -24,7 +25,7 @@ func sendCmd() *cobra.Command {
 			}
 
 			if u := serverURL; u == "" {
-				return mail.LoadAndSendCampaign(cfg, args[0], args[1])
+				return mail.LoadAndSendCampaign(cfg, args[0], args[1], recipientsFilter)
 			} else {
 				return client.New(cmd.Context(), u).Send(client.SendArgs{
 					ProjectPath:    ".", // TODO: configurable
@@ -38,6 +39,7 @@ func sendCmd() *cobra.Command {
 
 	// Server to specify remote server
 	cmd.Flags().StringVar(&serverURL, "server", "", "URL of server")
+	cmd.Flags().StringVar(&recipientsFilter, "filter", "", "Recipients filter")
 
 	return cmd
 }

go.mod

@@ -5,6 +5,7 @@ go 1.24.1
 require (
 	github.com/PuerkitoBio/goquery v1.10.3
 	github.com/bep/inflect v0.0.0-20160408190323-b896c45f5af9
+	github.com/casbin/govaluate v1.10.0
 	github.com/cenkalti/backoff/v5 v5.0.3
 	github.com/charmbracelet/glamour v0.10.0
 	github.com/chris-ramon/douceur v0.2.0

go.sum

@@ -16,6 +16,8 @@ github.com/aymerick/douceur v0.2.0 h1:Mv+mAeH1Q+n9Fr+oyamOlAkUNPWPlA8PPGR0QAaYuP
 github.com/aymerick/douceur v0.2.0/go.mod h1:wlT5vV2O3h55X9m7iVYN0TBM0NH/MmbLnd30/FjWUq4=
 github.com/bep/inflect v0.0.0-20160408190323-b896c45f5af9 h1:2ZyfRr6MKtNow0D0AbbVlzrS3OI6a+svlOHrtFYGI9Q=
 github.com/bep/inflect v0.0.0-20160408190323-b896c45f5af9/go.mod h1:/fmCHLLmoBKSfptXUFVJZb7MMt7JCS4vm0vqQmAo3xE=
+github.com/casbin/govaluate v1.10.0 h1:ffGw51/hYH3w3rZcxO/KcaUIDOLP84w7nsidMVgaDG0=
+github.com/casbin/govaluate v1.10.0/go.mod h1:G/UnbIjZk/0uMNaLwZZmFQrR72tYRZWQkO70si/iR7A=
 github.com/cenkalti/backoff/v5 v5.0.3 h1:ZN+IMa753KfX5hd8vVaMixjnqRZ3y8CuJKRKj1xcsSM=
 github.com/cenkalti/backoff/v5 v5.0.3/go.mod h1:rkhZdG3JZukswDf7f0cwqPNk4K0sa+F97BxZthm/crw=
 github.com/charmbracelet/colorprofile v0.3.2 h1:9J27WdztfJQVAQKX2WOlSSRB+5gaKqqITmrvb1uTIiI=

mail/campaign.go

@@ -39,7 +39,7 @@ type tmplContext struct {
 }
 
 type Campaign struct {
-	Recipients []*ctxRecipient
+	Recipients CtxRecipients
 	EmailMeta  *ctxCampaign
 	Email      parser.Email
 

mail/context.go

@@ -44,7 +44,9 @@ func newRecipient(data map[string]any) ctxRecipient {
 
 // Campaign variable
 type ctxCampaign struct {
-	From   string
+	From string
+	// Filter recipients
+	Filter string
 	Params map[string]interface{}
 
 	// Original subject from frontmatter
@@ -73,6 +75,7 @@ func newCampaign(cfg *config.AConfig, data map[string]interface{}) ctxCampaign {
 	if c.From == "" {
 		c.From = cfg.From
 	}
+	c.Filter, _ = c.Params["filter"].(string)
 
 	// This will cast either an array or an invidivual string into an array.
 	// We remove blanks because an empty string will become []string{""}
@@ -86,6 +89,7 @@ func newCampaign(cfg *config.AConfig, data map[string]interface{}) ctxCampaign {
 	delete(c.Params, "subject")
 	delete(c.Params, "from")
 	delete(c.Params, "to")
+	delete(c.Params, "filter")
 	return c
 }
 

mail/ctx_recipients.go

@@ -0,0 +1,41 @@
+package mail
+
+import (
+	"github.com/casbin/govaluate"
+)
+
+type CtxRecipients []*ctxRecipient
+
+// Filter filters the recipients based on the provided filter expression.
+// It evaluates the filter expression against each recipient's parameters
+// and returns a slice of recipients that match the criteria.
+//
+// Parameters:
+//
+//	filter: A string representing the filter expression to evaluate.
+//	         The expression should be in a format compatible with
+//	         the govaluate library.
+//
+// Returns:
+//
+//	A slice of pointers to ctxRecipient that match the filter criteria,
+//	or an error if the evaluation of the expression fails or if any
+//	other error occurs during the filtering process.
+func (cr CtxRecipients) Filter(filter string) ([]*ctxRecipient, error) {
+	expression, err := govaluate.NewEvaluableExpression(filter)
+	if err != nil {
+		return nil, err
+	}
+
+	var filteredRecipients []*ctxRecipient
+	for _, r := range cr {
+		result, err := expression.Evaluate(r.Params)
+		if err != nil {
+			return nil, err
+		}
+		if result == true {
+			filteredRecipients = append(filteredRecipients, r)
+		}
+	}
+	return filteredRecipients, nil
+}

mail/ctx_recipients_test.go

@@ -0,0 +1,29 @@
+package mail
+
+import "testing"
+
+func TestCtxRecipientsFilter(t *testing.T) {
+	var recipients CtxRecipients = []*ctxRecipient{
+		&ctxRecipient{
+			Name:  "Name1",
+			Email: "name1@example.com",
+			Params: map[string]interface{}{
+				"class": "1",
+			},
+		},
+		&ctxRecipient{
+			Name:  "Name2",
+			Email: "name2@example.com",
+			Params: map[string]interface{}{
+				"class": "2",
+			},
+		},
+	}
+	filtered, err := recipients.Filter("class == '1'")
+	if err != nil {
+		t.Errorf("Failed: %s", err)
+	}
+	if len(filtered) != 1 {
+		t.Errorf("Got %d", len(filtered))
+	}
+}

mail/sender.go

@@ -28,13 +28,26 @@ type sendConn interface {
 	Close() error
 }
 
-func LoadAndSendCampaign(cfg *config.AConfig, tmplFile, recipientFile string) error {
+func LoadAndSendCampaign(cfg *config.AConfig, tmplFile, recipientFile string, filter string) error {
 	// Load up template and recipientswith frontmatter
 	c, err := LoadCampaign(cfg, tmplFile, recipientFile)
 	if err != nil {
 		return err
 	}
 
+	if filter == "" {
+		// Argument specified: use the possibly declared in Campaign
+		filter = c.EmailMeta.Filter
+	}
+	if filter != "" {
+		// Filter the recipients
+		filteredRecipients, err := c.Recipients.Filter(filter)
+		if err != nil {
+			return err
+		}
+		c.Recipients = filteredRecipients
+	}
+
 	return SendCampaign(cfg, c)
 }
 

server/send.go

@@ -106,6 +106,6 @@ func (r *Resolver) SendCampaign(ctx context.Context, args SendCampaignArgs) (boo
 	}
 
 	// Load campaign and recipient list, and send it 🚀
-	err = mail.LoadAndSendCampaign(cfg, args.Campaign, args.List)
+	err = mail.LoadAndSendCampaign(cfg, args.Campaign, args.List, "")
 	return err == nil, err
 }