-- T0219: Add Profile Slug Generation
-- Add slug column to users table for URL-friendly profile URLs

ALTER TABLE users ADD COLUMN IF NOT EXISTS slug VARCHAR(255);

CREATE UNIQUE INDEX IF NOT EXISTS idx_users_slug ON users(slug);

-- Populate existing users with slugs from their usernames
UPDATE users 
SET slug = LOWER(REGEXP_REPLACE(username, '[^a-zA-Z0-9]', '-', 'g'))
WHERE slug IS NULL OR slug = '';