import { config } from '../config.js'

function getPrimaryContact(client) {
  const contacts = client?.contacts || []
  return contacts.find((c) => c.is_primary) || contacts[0] || {}
}

export function sanitizeInvoiceClient(client) {
  const contact = getPrimaryContact(client)
  const baseUrl = config.invoiceNinja.url

  return {
    id: client.id,
    number: client.number || '',
    displayName: client.display_name || client.name || '',
    companyName: client.name || '',
    website: client.website || '',
    phone: contact.phone || client.phone || '',
    email: contact.email || '',
    contactFirstName: contact.first_name || '',
    contactLastName: contact.last_name || '',
    address1: client.address1 || '',
    address2: client.address2 || '',
    city: client.city || '',
    state: client.state || '',
    postalCode: client.postal_code || '',
    countryId: client.country_id || '',
    vatNumber: client.vat_number || '',
    idNumber: client.id_number || '',
    balance: Number(client.balance ?? 0),
    paidToDate: Number(client.paid_to_date ?? 0),
    publicNotes: client.public_notes || '',
    privateNotes: client.private_notes || '',
    editUrl: `${baseUrl}/clients/${client.id}/edit`,
  }
}

const INVOICE_STATUS_LABELS = {
  1: 'Entwurf',
  2: 'Offen',
  3: 'Teilzahlung',
  4: 'Bezahlt',
  5: 'Storniert',
  6: 'Storniert',
}

export function sanitizeInvoice(inv) {
  const today = new Date().toISOString().slice(0, 10)
  const balance = Number(inv.balance ?? 0)
  const statusId = Number(inv.status_id ?? 0)
  const overdue = balance > 0 && Boolean(inv.due_date) && inv.due_date < today && statusId !== 5
  const invitationKey = inv.invitations?.[0]?.key || ''

  return {
    id: inv.id,
    number: inv.number || '',
    date: inv.date || '',
    dueDate: inv.due_date || '',
    amount: Number(inv.amount ?? 0),
    balance,
    statusId,
    status: overdue ? 'Überfällig' : INVOICE_STATUS_LABELS[statusId] || 'Offen',
    overdue,
    poNumber: inv.po_number || '',
    publicNotes: inv.public_notes || '',
    // Link ins InvoiceNinja-Kundenportal (Rechnung ansehen/zahlen)
    portalUrl: invitationKey ? `${config.invoiceNinja.url}/client/invoice/${invitationKey}` : '',
  }
}

/** Rohe Rechnung inkl. Invitations (fuer PDF-Download + Ownership-Pruefung). */
export async function getInvoiceRaw(invoiceId) {
  const token = config.invoiceNinja.apiToken
  if (!token) {
    const error = new Error('INVOICE_NINJA_API_TOKEN ist nicht konfiguriert')
    error.status = 503
    throw error
  }
  const response = await fetch(
    `${config.invoiceNinja.url}/api/v1/invoices/${encodeURIComponent(invoiceId)}?include=invitations`,
    {
      headers: {
        'X-API-TOKEN': token,
        'X-Requested-With': 'XMLHttpRequest',
        Accept: 'application/json',
      },
    }
  )
  const data = await response.json().catch(() => ({}))
  if (!response.ok) {
    const error = new Error(data.message || 'Rechnung nicht gefunden')
    error.status = response.status === 401 ? 502 : response.status
    throw error
  }
  return data.data
}

/** PDF einer Rechnung ueber den Client-Portal-Invitation-Link streamen. */
export async function fetchInvoicePdf(invitationKey) {
  const token = config.invoiceNinja.apiToken
  const response = await fetch(
    `${config.invoiceNinja.url}/client/invoice/${encodeURIComponent(invitationKey)}/download_pdf`,
    {
      headers: {
        'X-Api-Token': token,
        'X-Requested-With': 'XMLHttpRequest',
      },
    }
  )
  if (!response.ok) {
    const error = new Error('PDF-Download fehlgeschlagen')
    error.status = response.status
    throw error
  }
  return Buffer.from(await response.arrayBuffer())
}

/** Rechnungen eines InvoiceNinja-Clients (fuer Kundenportal + Admin-Ansicht). */
export async function listInvoicesForClient(clientId, { includeDrafts = false } = {}) {
  const token = config.invoiceNinja.apiToken
  if (!token) {
    const error = new Error('INVOICE_NINJA_API_TOKEN ist nicht konfiguriert')
    error.status = 503
    throw error
  }
  if (!clientId) return []

  const url = new URL(`${config.invoiceNinja.url}/api/v1/invoices`)
  url.searchParams.set('client_id', String(clientId))
  url.searchParams.set('per_page', '100')
  url.searchParams.set('sort', 'date|desc')

  const response = await fetch(url, {
    headers: {
      'X-API-TOKEN': token,
      'X-Requested-With': 'XMLHttpRequest',
      Accept: 'application/json',
    },
  })

  const data = await response.json().catch(() => ({}))
  if (!response.ok) {
    const error = new Error(data.message || 'Invoice Ninja API Fehler')
    error.status = response.status === 401 ? 502 : response.status
    throw error
  }

  return (data.data || [])
    .filter((inv) => !inv.is_deleted)
    .map(sanitizeInvoice)
    .filter((inv) => includeDrafts || inv.statusId !== 1)
}

export async function listInvoiceNinjaClients() {
  const token = config.invoiceNinja.apiToken
  if (!token) {
    const error = new Error('INVOICE_NINJA_API_TOKEN ist nicht konfiguriert')
    error.status = 503
    throw error
  }

  const clients = []
  let page = 1
  let totalPages = 1

  while (page <= totalPages) {
    const url = new URL(`${config.invoiceNinja.url}/api/v1/clients`)
    url.searchParams.set('per_page', '100')
    url.searchParams.set('page', String(page))
    url.searchParams.set('include', 'contacts')

    const response = await fetch(url, {
      headers: {
        'X-API-TOKEN': token,
        'X-Requested-With': 'XMLHttpRequest',
        Accept: 'application/json',
      },
    })

    const data = await response.json().catch(() => ({}))
    if (!response.ok) {
      const error = new Error(data.message || 'Invoice Ninja API Fehler')
      error.status = response.status === 401 ? 502 : response.status
      throw error
    }

    const batch = (data.data || []).filter((c) => !c.is_deleted)
    clients.push(...batch.map(sanitizeInvoiceClient))

    totalPages = Number(data.meta?.pagination?.total_pages || 1)
    page += 1
  }

  return clients.sort((a, b) =>
    (a.displayName || a.companyName).localeCompare(b.displayName || b.companyName, 'de')
  )
}