#!/usr/bin/env node
/**
 * PreToolUse Hook: Warn about non-standard documentation files
 *
 * Cross-platform (Windows, macOS, Linux)
 *
 * Runs before Write tool use. If the file is a .md or .txt file that isn't
 * a standard documentation file (README, CLAUDE, AGENTS, etc.) or in an
 * expected directory (docs/, skills/, .claude/plans/), warns the user.
 *
 * Exit code 0 — warn only, does not block.
 */

const path = require('path');

const MAX_STDIN = 1024 * 1024; // 1MB limit
let data = '';
process.stdin.setEncoding('utf8');

process.stdin.on('data', chunk => {
  if (data.length < MAX_STDIN) {
    const remaining = MAX_STDIN - data.length;
    data += chunk.length > remaining ? chunk.slice(0, remaining) : chunk;
  }
});

process.stdin.on('end', () => {
  try {
    const input = JSON.parse(data);
    const filePath = input.tool_input?.file_path || '';

    // Only check .md and .txt files
    if (!/\.(md|txt)$/.test(filePath)) {
      process.stdout.write(data);
      return;
    }

    // Allow standard documentation files
    const basename = path.basename(filePath);
    if (/^(README|CLAUDE|AGENTS|CONTRIBUTING|CHANGELOG|LICENSE|SKILL)\.md$/i.test(basename)) {
      process.stdout.write(data);
      return;
    }

    // Allow files in .claude/plans/, docs/, and skills/ directories
    const normalized = filePath.replace(/\\/g, '/');
    if (/\.claude\/plans\//.test(normalized) || /(^|\/)(docs|skills)\//.test(normalized)) {
      process.stdout.write(data);
      return;
    }

    // Warn about non-standard documentation files
    console.error('[Hook] WARNING: Non-standard documentation file detected');
    console.error('[Hook] File: ' + filePath);
    console.error('[Hook] Consider consolidating into README.md or docs/ directory');
  } catch {
    // Parse error — pass through
  }

  process.stdout.write(data);
});