import { db, schema } from '@pascal-app/db'
import { betterAuth } from 'better-auth'
import { drizzleAdapter } from 'better-auth/adapters/drizzle'
import { magicLink } from 'better-auth/plugins'
import { Resend } from 'resend'

let _auth: ReturnType<typeof betterAuth> | null = null

function getAuth() {
  if (!_auth) {
    const betterAuthSecret = process.env.BETTER_AUTH_SECRET
    const betterAuthUrl = process.env.BETTER_AUTH_URL

    if (!betterAuthSecret) {
      throw new Error(
        'Missing BETTER_AUTH_SECRET environment variable. Please configure it in your deployment settings or .env.local file. Generate one with: openssl rand -base64 32',
      )
    }

    if (!betterAuthUrl) {
      throw new Error(
        'Missing BETTER_AUTH_URL environment variable. Please configure it in your deployment settings or .env.local file. Set it to your app URL (e.g., http://localhost:3000 or https://yourdomain.com)',
      )
    }

    // Initialize Resend for email sending
    const resend = process.env.RESEND_API_KEY ? new Resend(process.env.RESEND_API_KEY) : null

    _auth = betterAuth({
      database: drizzleAdapter(db, {
        provider: 'pg',
        usePlural: true,
        schema,
      }),
      advanced: {
        database: {
          generateId: false, // Use our prefixed nanoid IDs from schema
        },
      },
      secret: betterAuthSecret,
      baseURL: betterAuthUrl,
      plugins: [
        magicLink({
          sendMagicLink: async ({ email, url }) => {
            if (!resend) {
              console.log(`[DEV] Magic link for ${email}: ${url}`)
              return
            }

            try {
              await resend.emails.send({
                from: 'Pascal <noreply@pascal.app>',
                to: email,
                subject: 'Sign in to Pascal Editor',
                html: `
              <div style="font-family: Arial, sans-serif; max-width: 600px; margin: 0 auto;">
                <h2>Sign in to Pascal Editor</h2>
                <p>Click the button below to sign in to your account:</p>
                <a href="${url}" style="display: inline-block; background-color: #000; color: #fff; padding: 12px 24px; text-decoration: none; border-radius: 6px; margin: 20px 0;">
                  Sign In
                </a>
                <p style="color: #666; font-size: 14px;">This link will expire in 5 minutes.</p>
                <p style="color: #666; font-size: 14px;">If you didn't request this email, you can safely ignore it.</p>
              </div>
            `,
              })
              console.log(`✓ Magic link email sent to ${email}`)
            } catch (error) {
              console.error('Failed to send magic link email:', error)
              throw error
            }
          },
        }),
      ],
      session: {
        expiresIn: 60 * 60 * 24 * 7, // 7 days
        updateAge: 60 * 60 * 24, // 1 day
        cookieCache: {
          enabled: true,
          maxAge: 5 * 60, // 5 minutes
        },
        additionalFields: {
          activePropertyId: {
            type: 'string',
          },
        },
      },
    })
  }
  return _auth
}

/**
 * Better Auth server instance
 * Configured with PostgreSQL database (Supabase) and magic link authentication
 *
 * Initialized lazily to avoid requiring env vars at build time
 */
export const auth = new Proxy({} as ReturnType<typeof betterAuth>, {
  get(_target, prop) {
    return Reflect.get(getAuth(), prop)
  },
})

/**
 * Type helpers for better-auth session
 */
export type Session = typeof auth.$Infer.Session.session
export type User = typeof auth.$Infer.Session.user