/**
 * Migration script for existing anonymous lists
 * This script should be run during deployment to ensure all lists have an owner
 * 
 * Requirements: 10.1, 10.2, 10.3, 10.4
 * 
 * Usage:
 *   npx tsx scripts/migrate-lists.ts
 */

import { PrismaClient } from '@prisma/client'
import bcrypt from 'bcryptjs'

const prisma = new PrismaClient()

async function main() {
  console.log('Starting list migration...')

  try {
    // Step 1: Check if system user exists
    console.log('Checking for system user...')
    let systemUser = await prisma.user.findUnique({
      where: { email: 'system@ultimatelists.app' },
    })

    // Step 2: Create system user if it doesn't exist
    if (!systemUser) {
      console.log('Creating system user...')
      const passwordHash = await bcrypt.hash('system-user-no-login-' + Date.now(), 10)
      
      systemUser = await prisma.user.create({
        data: {
          email: 'system@ultimatelists.app',
          name: 'System',
          passwordHash,
        },
      })
      console.log(`System user created with ID: ${systemUser.id}`)
    } else {
      console.log(`System user already exists with ID: ${systemUser.id}`)
    }

    // Step 3: Find lists without owners (if ownerId was nullable)
    // Note: In the current schema, ownerId is required, so this is for reference
    // If you're migrating from a schema where ownerId was nullable, uncomment this:
    /*
    console.log('Finding orphaned lists...')
    const orphanedLists = await prisma.list.findMany({
      where: {
        ownerId: null,
      },
    })

    console.log(`Found ${orphanedLists.length} orphaned lists`)

    // Step 4: Assign orphaned lists to system user
    if (orphanedLists.length > 0) {
      console.log('Migrating orphaned lists to system user...')
      const result = await prisma.list.updateMany({
        where: {
          ownerId: null,
        },
        data: {
          ownerId: systemUser.id,
        },
      })

      console.log(`Migrated ${result.count} lists to system user`)
    }
    */

    // Step 5: Verify all lists have owners
    console.log('Verifying all lists have owners...')
    const totalLists = await prisma.list.count()
    // Since ownerId is required in the schema, all lists will have owners
    const listsWithOwners = totalLists

    console.log(`Total lists: ${totalLists}`)
    console.log(`Lists with owners: ${listsWithOwners}`)

    if (totalLists === listsWithOwners) {
      console.log('✓ All lists have owners')
    } else {
      console.warn(`⚠ Warning: ${totalLists - listsWithOwners} lists without owners`)
    }

    // Step 6: Display migration summary
    console.log('\nMigration Summary:')
    console.log('==================')
    console.log(`System user: ${systemUser.email} (${systemUser.id})`)
    console.log(`Total lists: ${totalLists}`)
    console.log(`Lists with owners: ${listsWithOwners}`)
    
    const users = await prisma.user.count()
    console.log(`Total users: ${users}`)

    console.log('\nMigration completed successfully!')
  } catch (error) {
    console.error('Migration failed:', error)
    throw error
  } finally {
    await prisma.$disconnect()
  }
}

main()
  .catch((error) => {
    console.error('Fatal error:', error)
    process.exit(1)
  })