import { NextResponse } from 'next/server'
import { auth } from '@/lib/auth'
import { prisma } from '@/lib/prisma'
import { transactionQuerySchema } from '@/lib/validations/transaction'
import { Prisma } from '@/generated/prisma/client'

export async function GET(req: Request) {
  const session = await auth()
  if (!session?.user?.id) {
    return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
  }

  const { searchParams } = new URL(req.url)
  const parsed = transactionQuerySchema.safeParse(Object.fromEntries(searchParams))
  if (!parsed.success) {
    return NextResponse.json({ error: parsed.error.flatten() }, { status: 400 })
  }

  const { accountId, dateFrom, dateTo, type, search, budgetId, page, limit } = parsed.data

  const where: Prisma.TransactionWhereInput = {
    account: { userId: session.user.id },
    ...(accountId && { accountId }),
    ...(type && { type }),
    ...(budgetId !== undefined && { budgetId: budgetId || null }),
    ...(search && { description: { contains: search, mode: 'insensitive' } }),
    ...((dateFrom || dateTo) && {
      date: {
        ...(dateFrom && { gte: new Date(dateFrom) }),
        ...(dateTo && { lte: new Date(dateTo + 'T23:59:59.999Z') }),
      },
    }),
  }

  const [transactions, total] = await prisma.$transaction([
    prisma.transaction.findMany({
      where,
      include: {
        account: { select: { name: true, type: true } },
        budget: { select: { id: true, name: true, color: true } },
      },
      orderBy: { date: 'desc' },
      skip: (page - 1) * limit,
      take: limit,
    }),
    prisma.transaction.count({ where }),
  ])

  return NextResponse.json({ transactions, total, page, limit, totalPages: Math.ceil(total / limit) })
}