const config = useRuntimeConfig()

export const byuAuthConfig = {
  clientId: config.byuClientId,
  issuer: config.byuIssuer,
  
  authorizationUrl: `${config.byuIssuer}/authorize`,
  tokenUrl: `${config.byuIssuer}/token`,
  userInfoUrl: `${config.byuIssuer}/userinfo`,
  
  redirectUri: config.baseUrl === 'http://localhost:8000'
    ? 'http://localhost:8000/api/auth/callback/byu-pkce'
    : `${config.baseUrl}/api/auth/callback/byu-pkce`,
    
  scopes: ['openid']
}

// PKCE helper functions
export function generateCodeVerifier(): string {
  const array = new Uint8Array(32)
  crypto.getRandomValues(array)
  return base64UrlEncode(array)
}

export async function generateCodeChallenge(verifier: string): Promise<string> {
  const encoder = new TextEncoder()
  const data = encoder.encode(verifier)
  const hash = await crypto.subtle.digest('SHA-256', data)
  return base64UrlEncode(new Uint8Array(hash))
}

function base64UrlEncode(array: Uint8Array): string {
  return btoa(String.fromCharCode(...array))
    .replace(/\+/g, '-')
    .replace(/\//g, '_')
    .replace(/=/g, '')
}