import { getQuery, getRouterParam, createError } from 'h3'
import { startOfMonth, endOfMonth } from 'date-fns'
import { prisma } from '../../utils/db'

export default defineEventHandler(async (event) => {
  const token = getRouterParam(event, 'token')!
  const query = getQuery(event)
  const month = typeof query.month === 'string' ? query.month : new Date().toISOString().slice(0, 7)
  const monthStart = startOfMonth(new Date(`${month}-01T00:00:00`))
  const monthEnd = endOfMonth(monthStart)

  const link = await prisma.shareLink.findUnique({
    where: { token },
    include: { user: { select: { id: true, name: true } } }
  })

  if (!link || link.revokedAt || link.expiresAt <= new Date()) {
    throw createError({ statusCode: 404, statusMessage: 'Share link not found' })
  }

  const [transactions, assets] = await Promise.all([
    prisma.transaction.findMany({
      where: {
        userId: link.userId,
        occurredAt: { gte: monthStart, lte: monthEnd }
      },
      include: {
        asset: true,
        category: { include: { parent: true } }
      },
      orderBy: { occurredAt: 'desc' }
    }),
    prisma.asset.findMany({
      where: { userId: link.userId, active: true },
      orderBy: [{ sortOrder: 'asc' }, { createdAt: 'asc' }]
    })
  ])

  await prisma.shareLink.update({
    where: { id: link.id },
    data: { lastViewedAt: new Date() }
  })

  const summary = transactions.reduce((acc, tx) => {
    acc[tx.type] += tx.amount
    acc.diff = acc.income - acc.expense
    return acc
  }, { income: 0, expense: 0, diff: 0 })

  return {
    owner: link.user.name,
    name: link.name,
    expiresAt: link.expiresAt,
    summary,
    assets,
    transactions
  }
})