#!/usr/bin/env -S npx tsx
import * as path from "node:path";
import { startClientForFile } from "./src/client.ts";
import { isLspCommand, listCommands, runCommand } from "./src/commands.ts";
import { pickServer } from "./src/root.ts";

// Usage
function usage(): never {
  process.stderr.write(
    `Usage: cli.ts <file> <lsp_command> <req_data_json>\n` +
      `Commands: ${listCommands().join(", ")}\n` +
      `Example:\n` +
      `  cli.ts backend/api/server.go hover '{"position":{"line":223,"character":22}}'\n`,
  );
  process.exit(2);
}

async function main() {
  const [, , fileArg, cmdArg, jsonArg] = process.argv;
  if (!fileArg || !cmdArg || jsonArg === undefined) usage();

  if (!isLspCommand(cmdArg)) {
    process.stderr.write(
      `Unknown command "${cmdArg}". Known: ${listCommands().join(", ")}\n`,
    );
    process.exit(2);
  }

  // Parse Request JSON
  let params: Record<string, unknown>;
  try {
    params = jsonArg.trim() === "" ? {} : JSON.parse(jsonArg);
  } catch (err) {
    process.stderr.write(
      `Invalid JSON for req_data_json: ${(err as Error).message}\n`,
    );
    process.exit(2);
  }

  const filePath = path.resolve(fileArg);
  const server = pickServer(filePath);
  const { client, uri } = await startClientForFile(server, filePath);

  try {
    const result = await runCommand(cmdArg, client, uri, params);
    process.stdout.write(JSON.stringify(result, null, 2) + "\n");
  } finally {
    // Fire-And-Forget Shutdown - With `gopls -remote=auto` (and similar)
    // the spawned process is a thin client to a background daemon; a
    // graceful shutdown can hang the parent. Kick it off but don't wait.
    void client.dispose();
  }
  // Hard Exit - Any lingering handles (LSP stdio, daemon stubs) would keep
  // the event loop alive. For a short-lived CLI we just exit.
  process.exit(0);
}

main().catch((err) => {
  process.stderr.write(`${(err as Error).stack ?? err}\n`);
  process.exit(1);
});