import { NextRequest, NextResponse } from 'next/server'
import { z } from 'zod'
import { authMiddleware } from '@/lib/auth-middleware'
import connectDB from '@/lib/mongodb'
import { User as UserModel } from '@/models/user'

// Schema for balance response
const BalanceResponseSchema = z.object({
  success: z.boolean(),
  data: z.object({
    balance: z.number(),
    currency: z.string().default('INR'),
    lastUpdated: z.string(),
  }),
})

// Get user's current balance
export async function GET(request: NextRequest) {
  try {
    // Authenticate user
    const user = await authMiddleware(request)
    if (!user) {
      return NextResponse.json(
        {
          success: false,
          error: { message: 'Authentication required', code: 'UNAUTHORIZED' },
        },
        { status: 401 }
      )
    }

    await connectDB()

    // Get user's current balance from database
    const userData = await UserModel.findOne({ email: user.email })
    if (!userData) {
      return NextResponse.json(
        {
          success: false,
          error: { message: 'User not found', code: 'USER_NOT_FOUND' },
        },
        { status: 404 }
      )
    }

    const responseData = {
      success: true,
      data: {
        balance: userData.balance || 0,
        currency: 'INR',
        lastUpdated: userData.updatedAt?.toISOString() || new Date().toISOString(),
      },
    }

    // Validate response format
    const validatedResponse = BalanceResponseSchema.parse(responseData)
    return NextResponse.json(validatedResponse, { status: 200 })
  } catch (error) {
    console.error('Balance API error:', error)

    if (error instanceof z.ZodError) {
      return NextResponse.json(
        {
          success: false,
          error: { message: 'Invalid response format', code: 'VALIDATION_ERROR' },
        },
        { status: 500 }
      )
    }

    return NextResponse.json(
      {
        success: false,
        error: { message: 'Failed to fetch balance', code: 'INTERNAL_ERROR' },
      },
      { status: 500 }
    )
  }
}