feat: start logging token usage and subscriptions (#2)

### Explanation

_No response_

### Issue

_No response_

### Attestations

- [x] I have read and agree to the [Code of Conduct](https://docs.nhcarrigan.com/community/coc/)
- [x] I have read and agree to the [Community Guidelines](https://docs.nhcarrigan.com/community/guide/).
- [x] My contribution complies with the [Contributor Covenant](https://docs.nhcarrigan.com/dev/covenant/).

### Dependencies

- [x] I have pinned the dependencies to a specific patch version.

### Style

- [x] I have run the linter and resolved any errors.
- [x] My pull request uses an appropriate title, matching the conventional commit standards.
- [x] My scope of feat/fix/chore/etc. correctly matches the nature of changes in my pull request.

### Tests

- [ ] My contribution adds new code, and I have added tests to cover it.
- [ ] My contribution modifies existing code, and I have updated the tests to reflect these changes.
- [x] All new and existing tests pass locally with my changes.
- [x] Code coverage remains at or above the configured threshold.

### Documentation

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### Versioning

Minor - My pull request introduces a new non-breaking feature.

Reviewed-on: nhcarrigan/cordelia-taryne#2
Co-authored-by: Naomi Carrigan <commits@nhcarrigan.com>
Co-committed-by: Naomi Carrigan <commits@nhcarrigan.com>

src/index.ts

@@ -12,7 +12,7 @@ import { proofread } from "./modules/proofread.js";
 import { query } from "./modules/query.js";
 import { summarise } from "./modules/summarise.js";
 import { instantiateServer } from "./server/serve.js";
-import { logHandler } from "./utils/logHandler.js";
+import { logger } from "./utils/logger.js";
 
 const commands: Record<
   string,
@@ -41,8 +41,16 @@ client.on(Events.InteractionCreate, (interaction) => {
   }
 });
 
+client.on(Events.EntitlementCreate, (entitlement) => {
+  void logger.log("info", `User ${entitlement.userId} has subscribed!`);
+});
+
+client.on(Events.EntitlementDelete, (entitlement) => {
+  void logger.log("info", `User ${entitlement.userId} has unsubscribed... :c`);
+});
+
 client.on(Events.ClientReady, () => {
-  logHandler.info("Bot is ready.");
+  void logger.log("debug", "Bot is ready.");
 });
 
 instantiateServer();

src/modules/alt.ts

@@ -6,6 +6,7 @@
 import { MessageFlags, type ChatInputCommandInteraction } from "discord.js";
 import { personality } from "../config/personality.js";
 import { ai } from "../utils/ai.js";
+import { calculateCost } from "../utils/calculateCost.js";
 import { isSubscribed } from "../utils/isSubscribed.js";
 import type { ImageBlockParam } from "@anthropic-ai/sdk/resources/index.js";
 
@@ -109,4 +110,7 @@ export const alt = async(
     response?.text
       ?? "I'm sorry, I don't have an answer for that. Please try again later.",
   );
+
+  const { usage } = messages;
+  await calculateCost(usage, interaction.user.username, "alt-text");
 };

src/modules/evaluate.ts

@@ -6,6 +6,7 @@
 import { MessageFlags, type ChatInputCommandInteraction } from "discord.js";
 import { personality } from "../config/personality.js";
 import { ai } from "../utils/ai.js";
+import { calculateCost } from "../utils/calculateCost.js";
 import { isSubscribed } from "../utils/isSubscribed.js";
 
 /**
@@ -40,4 +41,7 @@ export const evaluate = async(
     response?.text
       ?? "I'm sorry, I don't have an answer for that. Please try again later.",
   );
+
+  const { usage } = messages;
+  await calculateCost(usage, interaction.user.username, "evaluate");
 };

src/modules/mood.ts

@@ -6,6 +6,7 @@
 import { MessageFlags, type ChatInputCommandInteraction } from "discord.js";
 import { personality } from "../config/personality.js";
 import { ai } from "../utils/ai.js";
+import { calculateCost } from "../utils/calculateCost.js";
 import { isSubscribed } from "../utils/isSubscribed.js";
 
 /**
@@ -41,4 +42,7 @@ export const mood = async(
     response?.text
       ?? "I'm sorry, I don't have an answer for that. Please try again later.",
   );
+
+  const { usage } = messages;
+  await calculateCost(usage, interaction.user.username, "mood");
 };

src/modules/proofread.ts

@@ -6,6 +6,7 @@
 import { MessageFlags, type ChatInputCommandInteraction } from "discord.js";
 import { personality } from "../config/personality.js";
 import { ai } from "../utils/ai.js";
+import { calculateCost } from "../utils/calculateCost.js";
 import { isSubscribed } from "../utils/isSubscribed.js";
 
 /**
@@ -41,4 +42,7 @@ export const proofread = async(
     response?.text
       ?? "I'm sorry, I don't have an answer for that. Please try again later.",
   );
+
+  const { usage } = messages;
+  await calculateCost(usage, interaction.user.username, "proofread");
 };

src/modules/query.ts

@@ -6,6 +6,7 @@
 import { MessageFlags, type ChatInputCommandInteraction } from "discord.js";
 import { personality } from "../config/personality.js";
 import { ai } from "../utils/ai.js";
+import { calculateCost } from "../utils/calculateCost.js";
 import { isSubscribed } from "../utils/isSubscribed.js";
 
 /**
@@ -41,4 +42,7 @@ export const query = async(
     response?.text
       ?? "I'm sorry, I don't have an answer for that. Please try again later.",
   );
+
+  const { usage } = messages;
+  await calculateCost(usage, interaction.user.username, "query");
 };

src/modules/summarise.ts

@@ -6,6 +6,7 @@
 import { MessageFlags, type ChatInputCommandInteraction } from "discord.js";
 import { personality } from "../config/personality.js";
 import { ai } from "../utils/ai.js";
+import { calculateCost } from "../utils/calculateCost.js";
 import { isSubscribed } from "../utils/isSubscribed.js";
 
 /**
@@ -41,4 +42,7 @@ export const summarise = async(
     response?.text
       ?? "I'm sorry, I don't have an answer for that. Please try again later.",
   );
+
+  const { usage } = messages;
+  await calculateCost(usage, interaction.user.username, "summarise");
 };

src/server/serve.ts

@@ -5,7 +5,7 @@
  */
 
 import fastify from "fastify";
-import { logHandler } from "../utils/logHandler.js";
+import { logger } from "../utils/logger.js";
 
 const html = `<!DOCTYPE html>
 <html>
@@ -60,12 +60,16 @@ export const instantiateServer = (): void => {
 
     server.listen({ port: 5002 }, (error) => {
       if (error) {
-        logHandler.error(error);
+        void logger.error("instantiate server", error);
         return;
       }
-      logHandler.info("Server listening on port 5002.");
+      void logger.log("debug", "Server listening on port 5002.");
     });
   } catch (error) {
-    logHandler.error(error);
+    if (error instanceof Error) {
+      void logger.error("instantiate server", error);
+      return;
+    }
+    void logger.error("instantiate server", new Error("Unknown error"));
   }
 };

src/utils/calculateCost.ts

@@ -0,0 +1,30 @@
+/**
+ * @copyright nhcarrigan
+ * @license Naomi's Public License
+ * @author Naomi Carrigan
+ */
+import { logger } from "./logger.js";
+import type { Usage } from "@anthropic-ai/sdk/resources/index.js";
+
+/**
+ * Calculates the cost of a command run by a user, and sends to
+ * our logging service.
+ * @param usage -- The usage payload from Anthropic.
+ * @param uuid -- The Discord ID of the user who ran the command.
+ * @param command -- The command that was run.
+ */
+export const calculateCost = async(
+  usage: Usage,
+  uuid: string,
+  command: string,
+): Promise<void> => {
+  const inputCost = usage.input_tokens * (3 / 1_000_000);
+  const outputCost = usage.output_tokens * (15 / 1_000_000);
+  const totalCost = inputCost + outputCost;
+  await logger.log(
+    "info",
+    `User ${uuid} ran \`${command}\` which accepted ${usage.input_tokens.toString()} and generated ${usage.output_tokens.toString()}.
+    
+    Total cost: ${totalCost.toLocaleString("en-GB", { currency: "USD", style: "currency" })}`,
+  );
+};

src/utils/logHandler.ts

@@ -1,31 +0,0 @@
-/**
- * @copyright nhcarrigan
- * @license Naomi's Public License
- * @author Naomi Carrigan
- */
-import { createLogger, format, transports, config } from "winston";
-
-const { combine, timestamp, colorize, printf } = format;
-
-/**
- * Standard log handler, using winston to wrap and format
- * messages. Call with `logHandler.log(level, message)`.
- * @param {string} level - The log level to use.
- * @param {string} message - The message to log.
- */
-export const logHandler = createLogger({
-  exitOnError: false,
-  format:      combine(
-    timestamp({
-      format: "YYYY-MM-DD HH:mm:ss",
-    }),
-    colorize(),
-    printf((info) => {
-      // eslint-disable-next-line @typescript-eslint/restrict-template-expressions -- Winston properties...
-      return `${info.level}: ${info.timestamp}: ${info.message}`;
-    }),
-  ),
-  level:      "silly",
-  levels:     config.npm.levels,
-  transports: [ new transports.Console() ],
-});

src/utils/logger.ts

@@ -0,0 +1,12 @@
+/**
+ * @copyright nhcarrigan
+ * @license Naomi's Public License
+ * @author Naomi Carrigan
+ */
+
+import { Logger } from "@nhcarrigan/logger";
+
+export const logger = new Logger(
+  "Cordelia Taryne",
+  process.env.LOG_TOKEN ?? "",
+);