1// SPDX-FileCopyrightText: Amolith <amolith@secluded.site>
 2//
 3// SPDX-License-Identifier: GPL-3.0-or-later
 4
 5import type { AgentEvent } from "@mariozechner/pi-agent-core";
 6
 7const MAX_OUTPUT_LINES = 20;
 8
 9export interface OutputOptions {
10  verbose: boolean;
11}
12
13export function formatToolOutput(output: string): string {
14  const lines = output.split(/\r?\n/);
15  if (lines.length <= MAX_OUTPUT_LINES) {
16    return output;
17  }
18
19  const truncated = lines.slice(0, MAX_OUTPUT_LINES).join("\n");
20  return `${truncated}\n(+${lines.length - MAX_OUTPUT_LINES} more lines)`;
21}
22
23export function createEventLogger(options: OutputOptions) {
24  return (event: AgentEvent) => {
25    if (!options.verbose) return;
26
27    if (event.type === "tool_execution_start") {
28      console.error(`\n[tool] ${event.toolName}`);
29      console.error(JSON.stringify(event.args, null, 2));
30    }
31
32    if (event.type === "tool_execution_end") {
33      if (event.isError) {
34        console.error("[tool error]");
35        console.error(String(event.result));
36        return;
37      }
38
39      const text = (event.result?.content ?? [])
40        .filter((content: { type: string }) => content.type === "text")
41        .map((content: { text?: string }) => content.text ?? "")
42        .join("");
43
44      if (text) {
45        console.error(formatToolOutput(text));
46      }
47    }
48  };
49}
50
51export function printUsageSummary(
52  usage: { cost?: { total?: number }; totalTokens?: number; output?: number; input?: number } | undefined,
53  requestCount?: number,
54) {
55  if (!usage) return;
56
57  const tokens = usage.totalTokens ?? (usage.output ?? 0) + (usage.input ?? 0);
58  const rawCost = usage.cost?.total;
59  const cost = typeof rawCost === "number" && !isNaN(rawCost) && rawCost > 0 ? rawCost : undefined;
60
61  let line = `\nusage: ${tokens} tokens`;
62  if (requestCount !== undefined && requestCount > 0) {
63    line += ` across ${requestCount} ${requestCount === 1 ? "request" : "requests"}`;
64  }
65  if (cost !== undefined) {
66    line += `, cost $${cost.toFixed(4)}`;
67  }
68  console.error(line);
69}