#!/usr/bin/env node
/**
 * Generates stub packages for all workspace:* dependencies.
 * Scans web/src for imports from @szl-holdings/*, @workspace/*, @szl/*
 * and creates minimal stub packages under stubs/ directory.
 */

import { readFileSync, writeFileSync, mkdirSync, readdirSync, statSync } from 'fs';
import { join, dirname, resolve } from 'path';

const ROOT = resolve(dirname(new URL(import.meta.url).pathname), '..');
const SRC_DIR = join(ROOT, 'web', 'src');

// Collect all .ts/.tsx files recursively
function collectFiles(dir, exts = ['.ts', '.tsx']) {
  const results = [];
  for (const entry of readdirSync(dir, { withFileTypes: true })) {
    const full = join(dir, entry.name);
    if (entry.isDirectory()) {
      results.push(...collectFiles(full, exts));
    } else if (exts.some(ext => entry.name.endsWith(ext))) {
      results.push(full);
    }
  }
  return results;
}

// Also scan index.css for CSS imports
const cssFile = join(ROOT, 'web', 'src', 'index.css');

// Parse imports from a TypeScript/TSX file
function parseImports(content) {
  const imports = [];
  // Match: import { X, Y } from 'pkg'; import X from 'pkg'; import 'pkg';
  const importRegex = /import\s+(?:(?:type\s+)?(?:\{([^}]*)\}|(\w+))\s+from\s+)?['"](@szl-holdings\/[^'"]+|@workspace\/[^'"]+|@szl\/[^'"]+)['"]/g;
  let m;
  while ((m = importRegex.exec(content)) !== null) {
    const namedStr = m[1] || '';
    const defaultImport = m[2] || null;
    const modulePath = m[3];

    const named = namedStr
      .split(',')
      .map(s => s.trim())
      .filter(Boolean)
      .map(s => {
        // Handle "X as Y" -> extract X
        const asMatch = s.match(/^(?:type\s+)?(\w+)(?:\s+as\s+\w+)?$/);
        return asMatch ? asMatch[1] : s.replace(/^type\s+/, '');
      })
      .filter(s => /^\w+$/.test(s));

    imports.push({ modulePath, named, defaultImport });
  }
  return imports;
}

// Collect all imports
const allFiles = collectFiles(SRC_DIR);
const importMap = new Map(); // pkgName -> Map<subpath, Set<exportName>>

for (const file of allFiles) {
  const content = readFileSync(file, 'utf-8');
  const imports = parseImports(content);
  for (const { modulePath, named, defaultImport } of imports) {
    // Split: @szl-holdings/shared-ui/utils -> pkg=@szl-holdings/shared-ui, sub=utils
    const parts = modulePath.split('/');
    let pkgName, subpath;
    if (parts[0].startsWith('@')) {
      pkgName = parts.slice(0, 2).join('/');
      subpath = parts.slice(2).join('/') || '.';
    } else {
      pkgName = parts[0];
      subpath = parts.slice(1).join('/') || '.';
    }

    if (!importMap.has(pkgName)) {
      importMap.set(pkgName, new Map());
    }
    const subMap = importMap.get(pkgName);
    if (!subMap.has(subpath)) {
      subMap.set(subpath, new Set());
    }
    const exports = subMap.get(subpath);
    for (const n of named) exports.add(n);
    if (defaultImport) exports.add('__default__:' + defaultImport);
  }
}

// Also handle CSS imports
try {
  const cssContent = readFileSync(cssFile, 'utf-8');
  const cssImportRegex = /@import\s+['"](@szl-holdings\/[^'"]+|@workspace\/[^'"]+|@szl\/[^'"]+)['"]/g;
  let m;
  while ((m = cssImportRegex.exec(cssContent)) !== null) {
    const modulePath = m[1];
    const parts = modulePath.split('/');
    let pkgName, subpath;
    if (parts[0].startsWith('@')) {
      pkgName = parts.slice(0, 2).join('/');
      subpath = parts.slice(2).join('/') || '.';
    } else {
      pkgName = parts[0];
      subpath = parts.slice(1).join('/') || '.';
    }
    if (!importMap.has(pkgName)) importMap.set(pkgName, new Map());
    const subMap = importMap.get(pkgName);
    if (!subMap.has(subpath)) subMap.set(subpath, new Set());
    subMap.get(subpath).add('__css__');
  }
} catch (e) { /* ignore */ }

// React component stub generator
function generateStubCode(exportNames) {
  const lines = ["import React from 'react';"];
  const hasCSS = exportNames.has('__css__');
  const jsExports = [...exportNames].filter(n => !n.startsWith('__'));
  const defaultExports = [...exportNames].filter(n => n.startsWith('__default__:'));

  // Known type-only exports that should be exported as types
  const typeOnlyNames = new Set(['AuthTokens', 'CommandModeSignal', 'SidebarNavSection',
    'KeyboardShortcut', 'OnboardingConfig', 'CommandItem', 'ActivationStep',
    'DataProvenanceInfo', 'StatusVariant', 'AuditTrailEntry', 'PolicyDecisionRecord',
    'ProofPanelData', 'RecommendationAction', 'AutonomyMode', 'AmbientSignal',
    'DocumentPipelineResult', 'OwnershipNode']);

  // Generate a React component stub
  const componentStub = `(props) => React.createElement('div', { 'data-stub': true, ...props }, props?.children || null)`;
  const fnStub = `(...args) => {}`;

  for (const name of jsExports) {
    if (typeOnlyNames.has(name)) {
      // Skip type-only exports in JS (they're just types)
      continue;
    }
    // Heuristic: PascalCase = React component, camelCase/UPPER = function/constant
    if (/^[A-Z]/.test(name)) {
      lines.push(`export const ${name} = ${componentStub};`);
    } else if (name === 'cn') {
      lines.push(`export function cn(...args) { return args.filter(Boolean).join(' '); }`);
    } else if (name === 'toAlpha') {
      lines.push(`export function toAlpha(hex, alpha) { return hex + Math.round(alpha * 255).toString(16).padStart(2, '0'); }`);

    } else if (name === 'color') {
      lines.push(`export const color = new Proxy({}, { get: (t, k) => '#888888' });`);
    } else if (name === 'toast') {
      lines.push(`export const toast = Object.assign((...a) => {}, { success: () => {}, error: () => {}, info: () => {}, warning: () => {}, dismiss: () => {} });`);
    } else if (name === 'analytics') {
      lines.push(`export const analytics = { track: () => {}, identify: () => {}, page: () => {}, reset: () => {} };`);
    } else {
      lines.push(`export const ${name} = ${fnStub};`);
    }
  }

  // Default export
  if (defaultExports.length > 0) {
    lines.push(`export default ${componentStub};`);
  } else if (jsExports.length === 0 && !hasCSS) {
    lines.push(`export default {};`);
  }

  if (hasCSS) {
    return '/* stub CSS */';
  }

  return lines.join('\n') + '\n';
}

// Generate stub packages
const STUBS_DIR = join(ROOT, 'stubs');
mkdirSync(STUBS_DIR, { recursive: true });

for (const [pkgName, subMap] of importMap) {
  const safeDirName = pkgName.replace(/^@/, '').replace(/\//g, '__');
  const pkgDir = join(STUBS_DIR, safeDirName);
  mkdirSync(pkgDir, { recursive: true });

  // Build exports map for package.json
  const exportsMap = {};
  const subpaths = [...subMap.keys()];

  for (const sub of subpaths) {
    const exportNames = subMap.get(sub);
    const hasCSS = exportNames.has('__css__');
    const fileName = sub === '.' ? 'index' : sub.replace(/\//g, '__');
    const ext = hasCSS ? '.css' : '.js';
    const filePath = `./${fileName}${ext}`;

    // Write the stub file
    const stubContent = generateStubCode(exportNames);
    writeFileSync(join(pkgDir, `${fileName}${ext}`), stubContent);

    // Add to exports map
    const exportKey = sub === '.' ? '.' : `./${sub}`;
    if (hasCSS) {
      exportsMap[exportKey] = filePath;
    } else {
      exportsMap[exportKey] = { import: filePath, default: filePath };
    }
  }

  // Add a wildcard catch-all export
  exportsMap['./*'] = { import: './catch-all.js', default: './catch-all.js' };

  // Write catch-all stub
  writeFileSync(join(pkgDir, 'catch-all.js'), `
import React from 'react';
const Stub = (props) => React.createElement('div', { 'data-stub': true, ...props }, props?.children || null);
export default Stub;
export { Stub };
export const noop = () => {};
`);

  // Write package.json
  const pkgJson = {
    name: pkgName,
    version: '0.0.0-stub',
    type: 'module',
    exports: exportsMap,
    main: './index.js',
  };

  // Write index.js if not already created
  if (!subMap.has('.')) {
    writeFileSync(join(pkgDir, 'index.js'), `
import React from 'react';
const Stub = (props) => React.createElement('div', { 'data-stub': true, ...props }, props?.children || null);
export default Stub;
export { Stub };
`);
    pkgJson.exports['.'] = { import: './index.js', default: './index.js' };
  }

  writeFileSync(join(pkgDir, 'package.json'), JSON.stringify(pkgJson, null, 2) + '\n');
  console.log(`✓ ${pkgName} (${subpaths.length} subpaths)`);
}

console.log(`\nGenerated ${importMap.size} stub packages in stubs/`);