Adding upstream version 0.8.9.

Signed-off-by: Daniel Baumann <daniel@debian.org>

pkg/services/mattermost/mattermost_json.go

@@ -0,0 +1,63 @@
+package mattermost
+
+import (
+	"encoding/json"
+	"fmt" // Add this import
+	"regexp"
+
+	"github.com/nicholas-fedor/shoutrrr/pkg/types"
+)
+
+// iconURLPattern matches URLs starting with http or https for icon detection.
+var iconURLPattern = regexp.MustCompile(`https?://`)
+
+// JSON represents the payload structure for Mattermost notifications.
+type JSON struct {
+	Text      string `json:"text"`
+	UserName  string `json:"username,omitempty"`
+	Channel   string `json:"channel,omitempty"`
+	IconEmoji string `json:"icon_emoji,omitempty"`
+	IconURL   string `json:"icon_url,omitempty"`
+}
+
+// SetIcon sets the appropriate icon field in the payload based on whether the input is a URL or not.
+func (j *JSON) SetIcon(icon string) {
+	j.IconURL = ""
+	j.IconEmoji = ""
+
+	if icon != "" {
+		if iconURLPattern.MatchString(icon) {
+			j.IconURL = icon
+		} else {
+			j.IconEmoji = icon
+		}
+	}
+}
+
+// CreateJSONPayload generates a JSON payload for the Mattermost service.
+func CreateJSONPayload(config *Config, message string, params *types.Params) ([]byte, error) {
+	payload := JSON{
+		Text:     message,
+		UserName: config.UserName,
+		Channel:  config.Channel,
+	}
+
+	if params != nil {
+		if value, found := (*params)["username"]; found {
+			payload.UserName = value
+		}
+
+		if value, found := (*params)["channel"]; found {
+			payload.Channel = value
+		}
+	}
+
+	payload.SetIcon(config.Icon)
+
+	payloadBytes, err := json.Marshal(payload)
+	if err != nil {
+		return nil, fmt.Errorf("marshaling Mattermost payload to JSON: %w", err)
+	}
+
+	return payloadBytes, nil
+}