import { NextResponse } from 'next/server'
import { getNowPaymentsConfig } from '@/lib/nowpayments'
import { ALLOWED_PAYMENT_CURRENCIES } from '@/lib/payment-currencies'

// GET /api/payments/currencies - Get available payment currencies from NOWPayments
export async function GET() {
  try {
    const nowPaymentsConfig = getNowPaymentsConfig()

    // Fetch available currencies from NOWPayments
    const response = await fetch(
      `${nowPaymentsConfig.baseUrl}/v1/currencies?fixed_rate=true`,
      {
        method: 'GET',
        headers: {
          'x-api-key': nowPaymentsConfig.apiKey,
        },
      }
    )

    if (!response.ok) {
      const error = await response.json()
      console.error('NOWPayments currencies error:', error)
      return NextResponse.json(
        { error: 'Failed to fetch available currencies', details: error },
        { status: 500 }
      )
    }

    const data = await response.json()
    
    // Filter currencies to only include the selected list
    const currencies = (data.currencies || []).filter((c: any) => {
      let currencyCode: string | null = null
      
      // Handle object format (when fixed_rate=true)
      if (typeof c === 'object' && c !== null && c.currency) {
        currencyCode = String(c.currency).trim().toLowerCase()
      }
      // Handle string format (when fixed_rate=false)
      else if (typeof c === 'string') {
        currencyCode = c.trim().toLowerCase()
      }
      
      // Check if currency is in the allowed list
      return currencyCode && ALLOWED_PAYMENT_CURRENCIES.includes(currencyCode as any)
    })

    // Return the filtered currencies array
    return NextResponse.json({
      currencies: currencies,
    })
  } catch (error) {
    console.error('Error fetching currencies:', error)
    return NextResponse.json(
      { error: 'Failed to fetch currencies' },
      { status: 500 }
    )
  }
}