const fs = require('fs');
const path = require('path');

const srcAppDir = path.join(__dirname, 'src', 'app');

// 1. Walk through all files and add "use client" and replace react-router-dom
function walkDir(dir, callback) {
  fs.readdirSync(dir).forEach(f => {
    const dirPath = path.join(dir, f);
    const isDirectory = fs.statSync(dirPath).isDirectory();
    if (isDirectory) {
      walkDir(dirPath, callback);
    } else {
      callback(path.join(dir, f));
    }
  });
}

walkDir(srcAppDir, (filePath) => {
  if (filePath.endsWith('.tsx') || filePath.endsWith('.ts')) {
    let content = fs.readFileSync(filePath, 'utf8');
    
    // Add "use client" if it's a React component or hook and doesn't have it
    if (!content.includes('"use client"') && !content.includes("'use client'")) {
        // Just add to all ts/tsx files for now except layout.tsx and page.tsx
        if (!filePath.endsWith('layout.tsx') && filePath !== path.join(srcAppDir, 'page.tsx')) {
            content = '"use client";\n' + content;
        }
    }

    // Replace react-router-dom imports
    if (content.includes('react-router-dom')) {
        // Link
        content = content.replace(/import\s+{[^}]*Link[^}]*}\s+from\s+['"]react-router-dom['"];?/g, "import Link from 'next/link';");
        // useNavigate
        content = content.replace(/useNavigate/g, 'useRouter');
        content = content.replace(/import\s+{[^}]*useRouter[^}]*}\s+from\s+['"]react-router-dom['"];?/g, "import { useRouter } from 'next/navigation';");
        
        // useLocation -> usePathname, useSearchParams
        if (content.includes('useLocation')) {
             content = content.replace(/useLocation/g, 'usePathname'); // naive replacement, will need manual fixing if they use location.search
             content = content.replace(/import\s+{[^}]*usePathname[^}]*}\s+from\s+['"]react-router-dom['"];?/g, "import { usePathname } from 'next/navigation';");
        }
        
        // General fallback if multiple imports were in one line
        content = content.replace(/import\s+{(.*)}\s+from\s+['"]react-router-dom['"];?/g, (match, p1) => {
             let imports = p1.split(',').map(s => s.trim());
             let nextNav = [];
             let hasLink = false;
             imports.forEach(i => {
                 if (i === 'Link') hasLink = true;
                 else if (i === 'useNavigate') nextNav.push('useRouter');
                 else if (i === 'useLocation') nextNav.push('usePathname', 'useSearchParams');
             });
             let res = '';
             if (hasLink) res += "import Link from 'next/link';\n";
             if (nextNav.length > 0) res += `import { ${[...new Set(nextNav)].join(', ')} } from 'next/navigation';\n`;
             return res;
        });
    }

    // Replace <Link to="..."> with <Link href="...">
    content = content.replace(/<Link([^>]+)to=/g, '<Link$1href=');

    // Remove lucide-react if not installed (they are in the old project, let's assume they'll install it)
    
    // Fix asset imports (e.g. import bg from '@/assets/landing/...')
    // We moved assets to public/landing/...
    // Let's replace '@/assets/landing/...' with '/landing/...'
    content = content.replace(/import\s+(\w+)\s+from\s+['"]@\/assets\/landing\/([^'"]+)['"];?/g, 'const $1 = "/landing/$2";');
    // Also replace "../../assets/landing"
    content = content.replace(/import\s+(\w+)\s+from\s+['"]\.\.\/\.\.\/assets\/landing\/([^'"]+)['"];?/g, 'const $1 = "/landing/$2";');
    content = content.replace(/import\s+(\w+)\s+from\s+['"]\.\.\/assets\/landing\/([^'"]+)['"];?/g, 'const $1 = "/landing/$2";');

    fs.writeFileSync(filePath, content, 'utf8');
  }
});

console.log('Migration script completed.');