context-warn/index.ts

/**
 * Context Warn + Voice Extension
 *
 * 1. Emits a sound alert when the context window reaches 100k tokens.
 * 2. Registers a /speak command so the agent can vocalize conclusions.
 *
 * Usage:
 *   pi install git:git.enne2.net/enne2/context-warn@main
 *
 * Commands:
 *   /context-warn-status — Show current context usage
 *   /context-warn-alert  — Manually test the alert sound
 *   /speak <text>        — Speak the text aloud (for the agent to use)
 */

import type { ExtensionAPI } from "@earendil-works/pi-coding-agent";
import { execFileSync } from "node:child_process";
import { existsSync } from "node:fs";
import { join, dirname } from "node:path";
import { fileURLToPath } from "node:url";

// ---------------------------------------------------------------------------
// Configuration
// ---------------------------------------------------------------------------

const WARNING_TOKEN_THRESHOLD = 100_000;
const CHECK_INTERVAL_MS = 15_000;
const WARNING_COOLDOWN_MS = 60_000;

const EXT_DIR = dirname(fileURLToPath(import.meta.url));
const ALERT_WAV = join(EXT_DIR, "alert.wav");

// ---------------------------------------------------------------------------
// Sound: play bundled alert.wav
// ---------------------------------------------------------------------------

function playAlert(): void {
  if (!existsSync(ALERT_WAV)) {
    console.error(`[context-warn] alert.wav not found at ${ALERT_WAV}`);
    return;
  }
  try {
    execFileSync("aplay", ["-q", ALERT_WAV], { stdio: "ignore" });
  } catch (err) {
    console.error(`[context-warn] Audio play failed: ${err instanceof Error ? err.message : String(err)}`);
  }
}

// ---------------------------------------------------------------------------
// Voice: speak text aloud via test_tts.py (blocking, one at a time)
// ---------------------------------------------------------------------------

const TTS_SCRIPT = "/home/enne2/.pi/agent/test_tts.py";

/**
 * Speak text aloud using the local TTS script.
 * This is a BLOCKING call — must wait for completion before speaking again.
 */
function speak(text: string): void {
  if (!existsSync(TTS_SCRIPT)) {
    console.error(`[voice] TTS script not found at ${TTS_SCRIPT}`);
    return;
  }
  try {
    // execFileSync is synchronous — waits for completion
    execFileSync("python3", [TTS_SCRIPT, text], { stdio: "ignore" });
  } catch (err) {
    console.error(`[voice] TTS failed: ${err instanceof Error ? err.message : String(err)}`);
  }
}

// ---------------------------------------------------------------------------
// Extension
// ---------------------------------------------------------------------------

export default function (pi: ExtensionAPI) {
  let lastAlertTimestamp: number | null = null;
  let alertedAtThreshold: boolean = false;

  const checkContext = (_event: unknown, ctx: any) => {
    const usage = ctx.getContextUsage();
    if (!usage || usage.tokens === null || usage.tokens === undefined) return;

    const currentTokens = usage.tokens;
    const crossedThreshold = !alertedAtThreshold && currentTokens >= WARNING_TOKEN_THRESHOLD;
    alertedAtThreshold = alertedAtThreshold || crossedThreshold;

    if (crossedThreshold) {
      const now = Date.now();
      if (lastAlertTimestamp && (now - lastAlertTimestamp) < WARNING_COOLDOWN_MS) return;
      lastAlertTimestamp = now;

      if (ctx.hasUI) {
        ctx.ui.notify(
          "⚠️ Context Warning",
          `Context reached ${currentTokens.toLocaleString()} tokens (>${WARNING_TOKEN_THRESHOLD.toLocaleString()}). Consider compacting.`,
          "warning"
        );
        ctx.ui.setStatus("context-warn", `${(currentTokens / 1000).toFixed(0)}k / ${usage.contextWindow ? `${usage.contextWindow / 1000}k` : "?"}`);
      }

      playAlert();
      console.log(`[context-warn] Context: ${currentTokens.toLocaleString()} tokens (threshold: ${WARNING_TOKEN_THRESHOLD.toLocaleString()})`);
    }
  };

  pi.on("turn_end", (_event, ctx) => checkContext(_event, ctx));
  pi.on("agent_end", (_event, ctx) => checkContext(_event, ctx));

  pi.on("session_start", (_event, ctx) => {
    alertedAtThreshold = false;
    lastAlertTimestamp = null;
    if (ctx.hasUI) {
      ctx.ui.notify("🔊 Context monitor active", `Alerts at ≥ ${WARNING_TOKEN_THRESHOLD.toLocaleString()} tokens`, "info");
      ctx.ui.setStatus("context-warn", "monitoring…");
    }
  });

  pi.on("session_compact", (_event, ctx) => {
    alertedAtThreshold = false;
    lastAlertTimestamp = Date.now();
    if (ctx.hasUI) ctx.ui.setStatus("context-warn", "compact ✓");
  });

  // /context-warn-status
  pi.registerCommand("context-warn-status", {
    description: "Show current context token usage and warning status",
    handler: async (_args, ctx) => {
      const usage = ctx.getContextUsage();
      if (!usage || usage.tokens === null || usage.tokens === undefined) {
        ctx.ui.notify("Context", "No usage data available yet.", "info");
        return;
      }
      const pct = usage.percent !== null && usage.percent !== undefined ? `${usage.percent.toFixed(1)}%` : "?";
      ctx.ui.notify(
        "Context Status",
        `${usage.tokens.toLocaleString()} tokens / ${usage.contextWindow?.toLocaleString()} (${pct})\nThreshold: ${WARNING_TOKEN_THRESHOLD.toLocaleString()}\nAlerted: ${alertedAtThreshold ? "yes" : "no"}`,
        "info"
      );
    },
  });

  // /context-warn-alert
  pi.registerCommand("context-warn-alert", {
    description: "Play the alert sound immediately (test)",
    handler: async (_args, ctx) => {
      playAlert();
      ctx.ui.notify("🔔 Alert", "Sound played.", "info");
    },
  });

  // /speak <text> — voice the agent's conclusion
  pi.registerCommand("speak", {
    description: "Speak the provided text aloud via TTS (for vocalizing conclusions)",
    handler: async ([text], ctx) => {
      if (!text || typeof text !== "string" || text.trim().length === 0) {
        ctx.ui.notify("Speak", "Usage: /speak <text>", "info");
        return;
      }
      speak(text.trim());
      ctx.ui.notify("🔊 Speaking", `"${text.trim().substring(0, 60)}${text.trim().length > 60 ? "..." : ""}"`, "info");
    },
  });
}