init work of uptime

internal/alert/gotify.go

@@ -0,0 +1,59 @@
+package alert
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"strings"
+	"time"
+)
+
+// GotifyAlerter sends notifications to a Gotify server.
+type GotifyAlerter struct {
+	baseURL  string
+	token    string
+	priority int
+	client   *http.Client
+}
+
+func NewGotifyAlerter(baseURL, token string, priority int) *GotifyAlerter {
+	if priority == 0 {
+		priority = 5
+	}
+	return &GotifyAlerter{
+		baseURL:  strings.TrimRight(baseURL, "/"),
+		token:    token,
+		priority: priority,
+		client:   &http.Client{Timeout: 10 * time.Second},
+	}
+}
+
+type gotifyPayload struct {
+	Title    string `json:"title"`
+	Message  string `json:"message"`
+	Priority int    `json:"priority"`
+}
+
+func (g *GotifyAlerter) Send(subject, body string) error {
+	payload, err := json.Marshal(gotifyPayload{
+		Title:    subject,
+		Message:  body,
+		Priority: g.priority,
+	})
+	if err != nil {
+		return fmt.Errorf("marshal gotify payload: %w", err)
+	}
+
+	url := fmt.Sprintf("%s/message?token=%s", g.baseURL, g.token)
+	resp, err := g.client.Post(url, "application/json", bytes.NewReader(payload))
+	if err != nil {
+		return fmt.Errorf("post gotify: %w", err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode >= 300 {
+		return fmt.Errorf("gotify returned %d", resp.StatusCode)
+	}
+	return nil
+}