RewriteEngine On
SetEnvIf Authorization "(.*)" HTTP_AUTHORIZATION=$1

# --- API routing: /api/* → backend/ ---
# 3 levels
RewriteRule ^api/([^/]+)/([^/]+)/([^/]+)\.php/?$ backend/$1/$2/$3.php [L,QSA]
RewriteRule ^api/([^/]+)/([^/]+)/([^/]+)/?$ backend/$1/$2/$3.php [L,QSA]

# 2 levels
RewriteRule ^api/([^/]+)/([^/]+)\.php/?$ backend/$1/$2.php [L,QSA]
RewriteRule ^api/([^/]+)/([^/]+)/?$ backend/$1/$2.php [L,QSA]

# 1 level
RewriteRule ^api/([^/]+)\.php/?$ backend/$1.php [L,QSA]
RewriteRule ^api/([^/]+)/?$ backend/$1.php [L,QSA]

# Auto-append .php for direct /backend/ access
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_URI} !\.php$
RewriteRule ^backend/(.*)$ backend/$1.php [L,QSA]

# --- SPA fallback ---
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.html [L]