feat: finish the automations plugin (B17)

src/backend/utils/notification-sender.ts

@@ -140,3 +140,147 @@ export async function sendNotification(
     });
   }
 }
+
+export interface ChannelNotification {
+  title: string;
+  body: string;
+  severity: "info" | "warning" | "critical";
+  context?: {
+    hostId?: number;
+    hostName?: string;
+    sourceId?: number | string;
+    sourceName?: string;
+    triggerType?: string;
+    value?: unknown;
+    threshold?: unknown;
+  };
+}
+
+const NTFY_TAGS: Record<string, string> = {
+  info: "information_source",
+  warning: "warning",
+  critical: "rotating_light",
+};
+
+const DISCORD_COLORS: Record<string, number> = {
+  info: 3066993,
+  warning: 16753920,
+  critical: 15158332,
+};
+
+/**
+ * Sends one notification to one channel and throws on failure, so the caller
+ * can report which channel failed. Private and loopback targets need both the
+ * channel's allowPrivateNetwork opt-in and an exact host in the admin
+ * allowlist.
+ */
+export async function deliverNotification(
+  channel: { id: number; type: string; config: string },
+  notification: ChannelNotification,
+): Promise<void> {
+  let config: Record<string, unknown>;
+  try {
+    config = JSON.parse(channel.config) as Record<string, unknown>;
+  } catch {
+    throw new Error("Channel configuration is not valid JSON");
+  }
+
+  const allowlist =
+    config.allowPrivateNetwork === true
+      ? await readNotificationPrivateAllowlist()
+      : [];
+  const post = async (
+    url: string,
+    init: { method: string; headers: Record<string, string>; body: string },
+  ) => {
+    const controller = new AbortController();
+    const timer = setTimeout(() => controller.abort(), 30_000);
+    try {
+      const response = await safeOutboundFetch(
+        url,
+        { ...init, signal: controller.signal },
+        allowlist,
+      );
+      if (!response.ok) {
+        const detail = await response.text().catch(() => "");
+        throw new Error(
+          `HTTP ${response.status} ${response.statusText}${detail ? `: ${detail.slice(0, 200)}` : ""}`,
+        );
+      }
+    } finally {
+      clearTimeout(timer);
+    }
+  };
+
+  const url = typeof config.url === "string" ? config.url.trim() : "";
+  if (!url) throw new Error("Channel is missing a URL");
+  const context = notification.context ?? {};
+
+  switch (channel.type) {
+    case "webhook": {
+      const headers =
+        config.headers && typeof config.headers === "object"
+          ? (config.headers as Record<string, string>)
+          : {};
+      return post(url, {
+        method: config.method === "PUT" ? "PUT" : "POST",
+        headers: { "Content-Type": "application/json", ...headers },
+        body: JSON.stringify({
+          title: notification.title,
+          hostName: context.hostName,
+          hostId: context.hostId,
+          ruleName: context.sourceName ?? notification.title,
+          ruleId: context.sourceId,
+          triggerType: context.triggerType,
+          value: context.value,
+          threshold: context.threshold,
+          message: notification.body,
+          severity: notification.severity,
+          timestamp: new Date().toISOString(),
+        }),
+      });
+    }
+    case "ntfy": {
+      const topic = typeof config.topic === "string" ? config.topic.trim() : "";
+      if (!topic) throw new Error("ntfy channel is missing a topic");
+      const headers: Record<string, string> = {
+        Title: notification.title || "Termix",
+        Priority: String(NTFY_PRIORITY[notification.severity] ?? 3),
+        Tags: NTFY_TAGS[notification.severity] ?? "information_source",
+      };
+      if (typeof config.token === "string" && config.token) {
+        headers.Authorization = `Bearer ${config.token}`;
+      }
+      return post(`${url.replace(/\/$/, "")}/${topic}`, {
+        method: "POST",
+        headers,
+        body: notification.body || notification.title,
+      });
+    }
+    case "discord": {
+      const payload: Record<string, unknown> = {
+        embeds: [
+          {
+            title: notification.title || "Termix",
+            description: notification.body || undefined,
+            color: DISCORD_COLORS[notification.severity] ?? 3447003,
+            timestamp: new Date().toISOString(),
+          },
+        ],
+      };
+      if (typeof config.username === "string" && config.username) {
+        payload.username = config.username;
+      }
+      if (typeof config.avatar_url === "string" && config.avatar_url) {
+        payload.avatar_url = config.avatar_url;
+      }
+      return post(url, {
+        method: "POST",
+        headers: { "Content-Type": "application/json" },
+        body: JSON.stringify(payload),
+      });
+    }
+    default:
+      throw new Error(`Unsupported channel type: ${channel.type}`);
+  }
+}