import { getPayload } from 'payload'
import config from '@payload-config'
import { NextRequest, NextResponse } from 'next/server'

/**
 * Admin Management API
 * Combined endpoint for data clearing, stats, and diagnostics
 */

/**
 * GET /api/admin?action=stats
 * Get Payload collection statistics
 */
async function getStats() {
  const payload = await getPayload({ config })

  const [products, preorderProducts] = await Promise.all([
    payload.find({ collection: 'products', limit: 0 }),
    payload.find({ collection: 'preorder-products', limit: 0 }),
  ])

  return {
    products: products.totalDocs,
    preorderProducts: preorderProducts.totalDocs,
    total: products.totalDocs + preorderProducts.totalDocs,
  }
}

/**
 * DELETE /api/admin
 * Clear Payload data (preserves Users and Media)
 * Query params: ?collections=products,preorderProducts,announcements,articles
 */
async function clearData(searchParams: URLSearchParams) {
  const payload = await getPayload({ config })
  
  const collectionsParam = searchParams.get('collections')
  const collections = collectionsParam 
    ? collectionsParam.split(',')
    : ['products', 'preorder-products', 'announcements', 'articles']

  const results: Record<string, number> = {}
  const errors: string[] = []

  for (const collection of collections) {
    // Protect critical collections
    if (['users', 'media'].includes(collection)) {
      errors.push(`Skipped protected collection: ${collection}`)
      continue
    }

    try {
      const deleted = await payload.delete({
        collection: collection as any,
        where: {},
      })
      results[collection] = deleted.docs?.length || 0
      console.log(`✅ Cleared ${results[collection]} documents from ${collection}`)
    } catch (error) {
      const errorMsg = `Failed to clear ${collection}: ${error instanceof Error ? error.message : 'Unknown error'}`
      console.error('❌', errorMsg)
      errors.push(errorMsg)
    }
  }

  return {
    success: true,
    message: 'Data cleared successfully',
    results,
    errors: errors.length > 0 ? errors : undefined,
  }
}

export async function GET(request: NextRequest) {
  try {
    const { searchParams } = new URL(request.url)
    const action = searchParams.get('action')

    if (action === 'stats') {
      const stats = await getStats()
      return NextResponse.json({ success: true, ...stats })
    }

    return NextResponse.json({
      success: false,
      error: 'Invalid action. Valid actions: stats',
    }, { status: 400 })
  } catch (error) {
    console.error('[admin] GET error:', error)
    return NextResponse.json({
      success: false,
      error: error instanceof Error ? error.message : 'Unknown error',
    }, { status: 500 })
  }
}

export async function DELETE(request: NextRequest) {
  try {
    const { searchParams } = new URL(request.url)
    const result = await clearData(searchParams)
    return NextResponse.json(result)
  } catch (error) {
    console.error('[admin] DELETE error:', error)
    return NextResponse.json({
      success: false,
      error: error instanceof Error ? error.message : 'Unknown error',
    }, { status: 500 })
  }
}