Add apprise convenience wrapper

apprise/notify.go

@@ -0,0 +1,167 @@
+package apprise
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"sync"
+
+	"github.com/safing/portbase/utils"
+)
+
+// Notifier sends messsages to an Apprise API.
+type Notifier struct {
+	// URL defines the Apprise API endpoint.
+	URL string
+
+	// DefaultType defines the default message type.
+	DefaultType MsgType
+
+	// DefaultTag defines the default message tag.
+	DefaultTag string
+
+	// DefaultFormat defines the default message format.
+	DefaultFormat MsgFormat
+
+	// AllowUntagged defines if untagged messages are allowed,
+	// which are sent to all configured apprise endpoints.
+	AllowUntagged bool
+
+	client     *http.Client
+	clientLock sync.Mutex
+}
+
+// Message represents the message to be sent to the Apprise API.
+type Message struct {
+	// Title is an optional title to go along with the body.
+	Title string `json:"title,omitempty"`
+
+	// Body is the main message content. This is the only required field.
+	Body string `json:"body"`
+
+	// Type defines the message type you want to send as.
+	// The valid options are info, success, warning, and failure.
+	// If no type is specified then info is the default value used.
+	Type MsgType `json:"type,omitempty"`
+
+	// Tag is used to notify only those tagged accordingly.
+	// Use a comma (,) to OR your tags and a space ( ) to AND them.
+	Tag string `json:"tag,omitempty"`
+
+	// Format optionally identifies the text format of the data you're feeding Apprise.
+	// The valid options are text, markdown, html.
+	// The default value if nothing is specified is text.
+	Format MsgFormat `json:"format,omitempty"`
+}
+
+// MsgType defines the message type.
+type MsgType string
+
+// Message Types.
+const (
+	TypeInfo    MsgType = "info"
+	TypeSuccess MsgType = "success"
+	TypeWarning MsgType = "warning"
+	TypeFailure MsgType = "failure"
+)
+
+// MsgFormat defines the message format.
+type MsgFormat string
+
+// Message Formats.
+const (
+	FormatText     MsgFormat = "text"
+	FormatMarkdown MsgFormat = "markdown"
+	FormatHTML     MsgFormat = "html"
+)
+
+type errorResponse struct {
+	Error string `json:"error"`
+}
+
+// Send sends a message to the Apprise API.
+func (n *Notifier) Send(ctx context.Context, m *Message) error {
+	// Check if the message has a body.
+	if m.Body == "" {
+		return errors.New("the message must have a body")
+	}
+
+	// Apply notifier defaults.
+	n.applyDefaults(m)
+
+	// Check if the message is tagged.
+	if m.Tag == "" && !n.AllowUntagged {
+		return errors.New("the message must have a tag")
+	}
+
+	// Marshal the message to JSON.
+	payload, err := json.Marshal(m)
+	if err != nil {
+		return fmt.Errorf("failed to marshal message: %w", err)
+	}
+
+	// Create request.
+	request, err := http.NewRequestWithContext(ctx, http.MethodPost, n.URL, bytes.NewReader(payload))
+	if err != nil {
+		return fmt.Errorf("failed to create request: %w", err)
+	}
+	request.Header.Set("Content-Type", "application/json")
+
+	// Send message to API.
+	resp, err := n.getClient().Do(request)
+	if err != nil {
+		return fmt.Errorf("failed to send message: %w", err)
+	}
+	defer resp.Body.Close() //nolint:errcheck
+	switch resp.StatusCode {
+	case http.StatusOK, http.StatusCreated, http.StatusNoContent, http.StatusAccepted:
+		return nil
+	default:
+		// Try to tease body contents.
+		if body, err := io.ReadAll(resp.Body); err == nil && len(body) > 0 {
+			// Try to parse json response.
+			errorResponse := &errorResponse{}
+			if err := json.Unmarshal(body, errorResponse); err == nil && errorResponse.Error != "" {
+				return fmt.Errorf("failed to send message: apprise returned %q with an error message: %s", resp.Status, errorResponse.Error)
+			}
+			return fmt.Errorf("failed to send message: %s (body teaser: %s)", resp.Status, utils.SafeFirst16Bytes(body))
+		}
+		return fmt.Errorf("failed to send message: %s", resp.Status)
+	}
+}
+
+func (n *Notifier) applyDefaults(m *Message) {
+	if m.Type == "" {
+		m.Type = n.DefaultType
+	}
+	if m.Tag == "" {
+		m.Tag = n.DefaultTag
+	}
+	if m.Format == "" {
+		m.Format = n.DefaultFormat
+	}
+}
+
+// SetClient sets a custom http client for accessing the Apprise API.
+func (n *Notifier) SetClient(client *http.Client) {
+	n.clientLock.Lock()
+	defer n.clientLock.Unlock()
+
+	n.client = client
+}
+
+func (n *Notifier) getClient() *http.Client {
+	n.clientLock.Lock()
+	defer n.clientLock.Unlock()
+
+	// Create client if needed.
+	if n.client == nil {
+		n.client = &http.Client{}
+	}
+
+	return n.client
+}