/**
 * Discovers cele2e commands by parsing --help output.
 * Used by completion coverage tests to verify registry ↔ help sync.
 */

import { execSync } from 'node:child_process';
import { resolve } from 'node:path';

const CLI = resolve(import.meta.dir, '../..', 'src/cli/index.ts');

function runHelp(args = ''): string {
  try {
    return execSync(`bun ${CLI} ${args} --help 2>&1`, { encoding: 'utf-8' });
  } catch (e: unknown) {
    return (e as { stdout?: string }).stdout?.toString() ?? '';
  }
}

export function parseCommandsFromHelp(text: string): string[] {
  const commands: string[] = [];
  let inCommandsSection = false;

  for (const line of text.split('\n')) {
    if (/^\s*Commands?:\s*$/i.test(line)) {
      inCommandsSection = true;
      continue;
    }
    // Any UNINDENTED heading ends the list. This used to name three headings
    // literally (`Options:`, `Examples:`, `Usage:`), none of which the help
    // actually prints — it writes `Options for \`run\`:` — so the section never
    // closed and every 2-space-indented word after it was read as a command.
    // Nothing showed that, because option lines start with `-` and the only
    // other candidate block happened to sit after `Examples:`. It surfaced the
    // day a command grew a verb list: `reset` was reported as a top-level
    // command that the registry was missing. Keying on the help's real
    // structure fixes the class rather than that instance.
    if (inCommandsSection && /^\S.*:\s*$/.test(line)) {
      inCommandsSection = false;
      continue;
    }
    if (!inCommandsSection) continue;

    // Match "  command-name" at 2-3 spaces indent, followed by space/bracket/end
    const match = line.match(/^ {2,3}([a-z][a-z0-9-]+)(\s|$)/);
    if (match) commands.push(match[1]);
  }

  return commands;
}

export interface CommandNode {
  name: string;
  subcommands: string[];
}

/**
 * Discovers top-level commands from --help output.
 * cele2e doesn't implement per-command --help pages, so subcommand
 * discovery is not attempted — use the COMMANDS registry for that.
 */
export function discoverCommands(): Map<string, CommandNode> {
  const tree = new Map<string, CommandNode>();
  for (const name of parseCommandsFromHelp(runHelp())) {
    tree.set(name, { name, subcommands: [] });
  }
  return tree;
}