agent-toolkit

import { type ChatMessage, type PromptPreprocessorController } from "@lmstudio/sdk";
import { loadPermissions } from "./permissions";

export function currentTimeString(): string {
  return new Date().toLocaleString("en-US", {
    weekday: "short", year: "numeric", month: "short", day: "numeric",
    hour: "2-digit", minute: "2-digit", second: "2-digit", timeZoneName: "short",
  });
}

/** Fetch display name, size in GB, and param string for the current model. */
async function getModelLine(ctl: PromptPreprocessorController): Promise<string> {
  try {
    const model = await ctl.client.llm.model();
    const info  = await model.getModelInfo();
    if (!info) return "";
    const gb     = (info.sizeBytes / 1_073_741_824).toFixed(1) + " GB";
    const params = info.paramsString ? ` · ${info.paramsString} params` : "";
    return `${info.displayName} · ${gb}${params}`;
  } catch {
    return "";
  }
}

function buildFullGuide(time: string, modelLine: string): string {
  const perms = loadPermissions();

  const readWrite: string[] = [];
  const readOnly:  string[] = [];
  const denied:    string[] = [];
  for (const [path, rule] of Object.entries(perms.rules)) {
    if (rule === "read_write") readWrite.push(path);
    else if (rule === "read")  readOnly.push(path);
    else                       denied.push(path);
  }
  const scopeLines: string[] = [];
  if (readWrite.length) scopeLines.push(`  read_write : ${readWrite.join(", ")}`);
  if (readOnly.length)  scopeLines.push(`  read       : ${readOnly.join(", ")}`);
  if (denied.length)    scopeLines.push(`  deny       : ${denied.join(", ")}`);
  scopeLines.push(`  default    : ${perms.default}`);

  const cmdStatus = perms.command_executor.enabled ? "enabled" : "disabled";
  const modelStr  = modelLine ? `\nModel: ${modelLine}` : "";

  return `\
[agent-toolkit]
Time: ${time}${modelStr}

Tools:
  web_search <query> [page_size] [page]    — DuckDuckGo web search → [title, URL] list
  image_search <query> [count]             — DuckDuckGo image search → inline images
  visit_website <url> [find_in_page]       — fetch page: title, links, images, text
  view_images <urls[]>                     — download & display images inline
  get_current_time                         — current date/time
  get_model_info                           — name, size, context length, capabilities
  open_control_panel                       — open the permissions/settings GUI
  media_control <action> [level]           — play/pause/toggle/next/previous/volume/mute/status
  run_javascript <code> [timeout_s]        — Deno sandbox: maths, logic, data (no net/env/subprocess)
  read_file <path>                         — whole file
  read_file_lines <path> <start> <end>     — line range (prefer for large files)
  write_file <path> <content>              — create / overwrite
  edit_file <path> <old> <new>             — substring replace (prefer for edits)
  edit_file_lines <path> <start> <end> <c> — line-range replace
  list_directory <path> [recursive]        — list folder
  create_directory <path>
  delete_path <path> [recursive]
  move_path <src> <dst>
  run_command <cmd> [working_directory]    — shell (${cmdStatus})
  get_permissions                          — show full policy

Permission tiers (files and commands share the same rules):
  read_write → full access; write commands allowed
  read       → read-only: ls/cat/grep/find/…; no write commands
  deny       → invisible; no commands

Accessible paths:
${scopeLines.join("\n")}

Notes: ~ is expanded · deny list always wins · write-impact commands verify path perms
When showing file edits to the user, always wrap the diff output in a \`\`\`diff code block so changes are rendered with green/red highlighting.`;
}

export async function promptPreprocessor(
  ctl: PromptPreprocessorController,
  userMessage: ChatMessage,
): Promise<string> {
  const original = userMessage.getText();
  const time = currentTimeString();

  // pullHistory() excludes the current user message.
  // LM Studio may pre-populate a system message even on turn 1, so we check
  // for the absence of any user or assistant message rather than total length.
  const history = await ctl.pullHistory();
  const isFirst = !history.getMessagesArray().some(
    (m) => m.getRole() === "user" || m.getRole() === "assistant",
  );

  if (isFirst) {
    const [modelLine, perms] = await Promise.all([
      getModelLine(ctl),
      Promise.resolve(loadPermissions()),
    ]);
    const systemPromptBlock = perms.custom_system_prompt.trim()
      ? `[System instructions]\n${perms.custom_system_prompt.trim()}\n\n`
      : "";
    return `${systemPromptBlock}${buildFullGuide(time, modelLine)}\n\n${original}`;
  }

  // Subsequent messages: time + model name (lightweight, no extra API call needed
  // since model rarely changes mid-conversation — fetch async, don't block).
  const modelLine = await getModelLine(ctl).catch(() => "");
  const modelStr  = modelLine ? ` | ${modelLine}` : "";
  return `[agent-toolkit] Time: ${time}${modelStr}\n\n${original}`;
}