general cleanup - removed old comments, enforced naming conventions etc

backend/internal/notifications/discord.go

@@ -0,0 +1,146 @@
+package notifications
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"log"
+	"net/http"
+	"time"
+)
+
+const (
+	// discordHTTPTimeoutSeconds is the timeout for Discord webhook requests.
+	discordHTTPTimeoutSeconds = 10
+
+	// Alert color codes for Discord embeds.
+	colorGreen  = 0x00ff00
+	colorOrange = 0xff9900
+	colorRed    = 0xff0000
+	colorBlue   = 0x0099ff
+)
+
+var discordHTTPClient = &http.Client{ //nolint:gochecknoglobals
+	Timeout: discordHTTPTimeoutSeconds * time.Second,
+}
+
+//  sends alert notifications via a Discord webhook.
+type DiscordNotifier struct {
+	WebhookURL string
+}
+func (d *DiscordNotifier) Send(_ context.Context, message string, meta AlertMetadata) error {
+	_, err := SendDiscordNotification(d.WebhookURL, message, meta)
+	return err
+}
+
+type discordEmbed struct {
+	Title       string         `json:"title"`
+	Description string         `json:"description"`
+	Color       int            `json:"color"`
+	Fields      []discordField `json:"fields"`
+	Timestamp   string         `json:"timestamp"`
+	Footer      discordFooter  `json:"footer"`
+}
+
+type discordField struct {
+	Name   string `json:"name"`
+	Value  string `json:"value"`
+	Inline bool   `json:"inline"`
+}
+
+type discordFooter struct {
+	Text string `json:"text"`
+}
+
+type discordPayload struct {
+	Content *string        `json:"content"`
+	Embeds  []discordEmbed `json:"embeds,omitempty"`
+}
+
+func SendDiscordNotification(webhookURL, message string, meta AlertMetadata) (bool, error) {
+	fields := []discordField{
+		{Name: "Address", Value: meta.AddressLabel, Inline: true},
+		{Name: "Blockchain Address", Value: fmt.Sprintf("`%s`", meta.Address), Inline: false},
+	}
+
+	if meta.TxHash != "" {
+		fields = append(fields, discordField{
+			Name:   "Transaction",
+			Value:  fmt.Sprintf("[View on Etherscan](https://etherscan.io/tx/%s)", meta.TxHash),
+			Inline: false,
+		})
+	}
+
+	payload := discordPayload{
+		Content: nil,
+		Embeds: []discordEmbed{
+			{
+				Title:       "Koin Ping Alert",
+				Description: message,
+				Color:       colorForAlertType(meta.AlertType),
+				Fields:      fields,
+				Timestamp:   time.Now().UTC().Format(time.RFC3339),
+				Footer:      discordFooter{Text: "Koin Ping"},
+			},
+		},
+	}
+
+	body, err := json.Marshal(payload)
+	if err != nil {
+		return false, fmt.Errorf("marshal discord payload: %w", err)
+	}
+
+	resp, err := discordHTTPClient.Post(
+		webhookURL, "application/json", bytes.NewReader(body),
+	)
+	if err != nil {
+		log.Printf("Failed to send Discord notification: %v", err)
+		return false, err
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
+		log.Printf("Discord webhook failed: HTTP %d", resp.StatusCode)
+		return false, fmt.Errorf("discord webhook failed: HTTP %d", resp.StatusCode)
+	}
+
+	return true, nil
+}
+
+func TestDiscordWebhook(webhookURL string) (bool, error) {
+	payload := map[string]string{
+		"content": "Koin Ping test notification - Your Discord webhook is configured correctly!",
+	}
+
+	body, err := json.Marshal(payload)
+	if err != nil {
+		return false, err
+	}
+
+	resp, err := discordHTTPClient.Post(
+		webhookURL, "application/json", bytes.NewReader(body),
+	)
+	if err != nil {
+		log.Printf("Discord webhook test failed: %v", err)
+		return false, err
+	}
+	defer resp.Body.Close()
+
+	return resp.StatusCode >= 200 && resp.StatusCode < 300, nil
+}
+
+func colorForAlertType(alertType string) int {
+	switch alertType {
+	case "incoming_tx":
+		return colorGreen
+	case "outgoing_tx":
+		return colorOrange
+	case "large_transfer":
+		return colorRed
+	case "balance_below":
+		return colorRed
+	default:
+		return colorBlue
+	}
+}