/**
 * Outbound staff → customer e-mail (lead mail composer, AI-draft send).
 *
 * One place for the branded signature (table layout → renders in Outlook / Gmail /
 * Apple Mail), the plain-text → HTML conversion and the local-MTA transport, so every
 * "send from the lead page" route mails the same way:
 *   From     = info@logyou.de with the sender's display name
 *   Reply-To = the sending user's own AD_User address (answers land with the author)
 *   Body     = the user's text (ends at the greeting) + the server-side signature block.
 * The dev Mac has no MTA → sending fails soft there; never test-send from dev.
 */
import nodemailer from 'nodemailer'
import fetchHelper from '../fetchHelper'
import { isValidEmail } from './leadMailbox'
import { APP_BASE_URL } from '../emailVerification'

export const STAFF_MAIL_FROM = 'info@logyou.de'
export const MAX_SUBJECT = 255
export const MAX_BODY = 20000

const NAVY = '#1c324b'
const ORANGE = '#F15924'
const LOGO_URL = `${APP_BASE_URL}/assets/logyou-logo-color.png`
export const COMPANY = { name: 'LogYou GmbH', street: 'Mühlenweg 4', city: '35510 Butzbach', web: 'logyou.de', mail: STAFF_MAIL_FROM, legal: 'Geschäftsführer: Dennis Montag · Amtsgericht Friedberg, HRB 10595' }

/** `phone` = AD_User.Phone (direct line), `phone2` = AD_User.Phone2 (mobile) — both optional. */
export interface Sender { name: string; title: string; email: string; phone: string; phone2: string }

const escapeHtml = (s: string) => String(s).replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;').replace(/"/g, '&quot;')

/** The signature's sender block from the logged-in user's AD_User record (fail-soft). */
export const loadSender = async (event: any, token: string, userId: number): Promise<Sender> => {
  const sender: Sender = { name: '', title: '', email: '', phone: '', phone2: '' }
  try {
    const me: any = await fetchHelper(event, `models/ad_user/${userId}`, 'GET', token, null)
    sender.name = String(me?.Name || me?.name || '')
    sender.email = String(me?.EMail || me?.eMail || '').trim()
    sender.phone = String(me?.Phone || me?.phone || '').trim()
    sender.phone2 = String(me?.Phone2 || me?.phone2 || '').trim()
    // Only a second number that differs from the first earns its own line.
    if (sender.phone2 && sender.phone2.replace(/[^\d+]/g, '') === sender.phone.replace(/[^\d+]/g, '')) sender.phone2 = ''
    sender.title = String(me?.Title || me?.title || me?.C_Job_ID?.identifier || '').trim()
  } catch { /* signature falls back to the company block */ }
  return sender
}

/** Branded signature: orange rule, navy name, T/M/E/W lines, logo right, legal footer. */
export const signatureHtml = (sender: Sender, lang: string) => {
  const en = lang === 'en'
  const line = (icon: string, html: string) => `<tr><td style="padding:1px 0;font-size:12.5px;color:#334155;line-height:1.5"><span style="color:${ORANGE};font-weight:700;display:inline-block;width:18px">${icon}</span>${html}</td></tr>`
  const rows: string[] = []
  const tel = (n: string) => `<a href="tel:${escapeHtml(n.replace(/[^\d+]/g, ''))}" style="color:#334155;text-decoration:none">${escapeHtml(n)}</a>`
  if (sender.phone) rows.push(line('T', tel(sender.phone)))
  if (sender.phone2) rows.push(line('M', tel(sender.phone2)))
  if (sender.email) rows.push(line('E', `<a href="mailto:${escapeHtml(sender.email)}" style="color:${NAVY};text-decoration:none">${escapeHtml(sender.email)}</a>`))
  rows.push(line('W', `<a href="https://${COMPANY.web}" style="color:${NAVY};text-decoration:none;font-weight:600">${COMPANY.web}</a>`))
  return `
<table role="presentation" cellpadding="0" cellspacing="0" border="0" style="margin-top:28px;border-collapse:collapse;font-family:-apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,Helvetica,Arial,sans-serif">
  <tr><td colspan="2" style="height:3px;background:${ORANGE};font-size:0;line-height:0">&nbsp;</td></tr>
  <tr>
    <td style="padding:14px 18px 12px 0;vertical-align:top;border-right:1px solid #e3e7ec">
      <div style="font-size:15px;font-weight:700;color:${NAVY};letter-spacing:.01em">${escapeHtml(sender.name || COMPANY.name)}</div>
      ${sender.title ? `<div style="font-size:12px;color:#64748b;margin-top:2px">${escapeHtml(sender.title)}</div>` : ''}
      <div style="font-size:12px;color:${ORANGE};font-weight:700;margin-top:2px;text-transform:uppercase;letter-spacing:.06em">${COMPANY.name}</div>
      <table role="presentation" cellpadding="0" cellspacing="0" border="0" style="margin-top:8px;border-collapse:collapse">${rows.join('')}</table>
    </td>
    <td style="padding:14px 0 12px 18px;vertical-align:middle">
      <a href="https://${COMPANY.web}" style="text-decoration:none"><img src="${LOGO_URL}" alt="${COMPANY.name}" width="120" style="display:block;width:120px;max-width:120px;height:auto;border:0"></a>
    </td>
  </tr>
  <tr><td colspan="2" style="padding:10px 0 0;font-size:11px;color:#94a3b8;line-height:1.5;border-top:1px solid #e3e7ec">
    ${COMPANY.name} · ${COMPANY.street} · ${COMPANY.city}${en ? ', Germany' : ''} · ${escapeHtml(COMPANY.legal)}<br>
    ${en ? 'Fulfillment · Warehousing · Shipping for online retailers' : 'Fulfillment · Lagerung · Versand für Online-Händler'}
  </td></tr>
</table>`
}

export const signatureText = (sender: Sender) => [
  '', '--', sender.name || COMPANY.name,
  ...(sender.title ? [sender.title] : []), COMPANY.name,
  ...(sender.phone ? [`T ${sender.phone}`] : []), ...(sender.phone2 ? [`M ${sender.phone2}`] : []), ...(sender.email ? [`E ${sender.email}`] : []), `W https://${COMPANY.web}`,
  '', `${COMPANY.name} · ${COMPANY.street} · ${COMPANY.city} · ${COMPANY.legal}`
].join('\n')

/** Plain text (paragraphs separated by blank lines) → branded HTML mail incl. signature. */
export const textToHtml = (text: string, sender: Sender, lang: string) => `<!doctype html><html><head><meta charset="utf-8"></head><body style="margin:0;padding:24px 20px;background:#ffffff">
<div style="max-width:680px;font-family:-apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,Helvetica,Arial,sans-serif;font-size:14px;line-height:1.6;color:#1f2937">
${text.split(/\n{2,}/).map((p) => `<p style="margin:0 0 12px">${escapeHtml(p).replace(/\n/g, '<br>')}</p>`).join('')}
${signatureHtml(sender, lang)}
</div></body></html>`

export interface StaffMailInput {
  sender: Sender
  to: string
  toName?: string
  cc?: string[]
  subject: string
  text: string
  lang?: string
}

/** Send via the local MTA. Throws on transport errors (callers answer 502). */
export const sendStaffMail = async (input: StaffMailInput) => {
  const senderName = String(input.sender?.name || '').replace(/"/g, '')
  const toName = String(input.toName || '').replace(/"/g, '')
  const cc = (input.cc || []).filter((s) => isValidEmail(s))
  const lang = input.lang === 'en' ? 'en' : 'de'
  const transporter = nodemailer.createTransport({ host: 'localhost', port: 25, secure: false, tls: { rejectUnauthorized: false } })
  await transporter.sendMail({
    from: senderName ? `"${senderName} | LogYou" <${STAFF_MAIL_FROM}>` : STAFF_MAIL_FROM,
    to: toName ? `"${toName}" <${input.to}>` : input.to,
    cc: cc.length ? cc : undefined,
    replyTo: isValidEmail(input.sender?.email) ? input.sender.email : undefined,
    subject: input.subject || (lang === 'en' ? '(no subject)' : '(kein Betreff)'),
    text: input.text + '\n' + signatureText(input.sender),
    html: textToHtml(input.text, input.sender, lang)
  })
  return { cc }
}