/**
 * Default Tools Extension
 *
 * Reads a `tools` object from settings.json and applies explicitly configured tool states.
 * Only applies when --tools is not passed on the CLI.
 *
 * ~/.pi/agent/settings.json:
 *   { "tools": { "read": true, "bash": true, "grep": true, "find": true, "ls": true } }
 *
 * .pi/settings.json (project override, merged with global):
 *   { "tools": { "ls": false } }
 */

import type { ExtensionAPI } from "@earendil-works/pi-coding-agent";
import { loadSettings } from "../_char_common/settings";

function readToolsConfig(cwd: string): Record<string, boolean> {
  const tools = loadSettings(cwd).tools;
  if (!tools || typeof tools !== "object" || Array.isArray(tools)) return {};

  return Object.fromEntries(
    Object.entries(tools).filter(
      (entry): entry is [string, boolean] => typeof entry[1] === "boolean",
    ),
  );
}

export default function (pi: ExtensionAPI) {
  pi.on("session_start", async (_event, ctx) => {
    // Skip if --tools was provided on CLI
    if (pi.getFlag("--tools") !== undefined) return;

    const configured = Object.entries(readToolsConfig(ctx.cwd));
    if (configured.length === 0) return;

    const active = new Set(pi.getActiveTools());
    for (const [tool, enabled] of configured) {
      if (enabled) active.add(tool);
      else active.delete(tool);
    }
    pi.setActiveTools([...active]);
  });
}