function escapeHtml(value: string): string {
  return value
    .replace(/&/g, '&')
    .replace(/</g, '&lt;')
    .replace(/>/g, '&gt;')
    .replace(/"/g, '&quot;')
    .replace(/'/g, '&#39;')
}

export interface BookingEmailInput {
  serviceName: string
  date: string
  time: string
  contact: { name: string; phone: string; email: string; notes: string }
}

export function buildBookingNotificationEmail(input: BookingEmailInput): { subject: string; html: string } {
  const serviceName = escapeHtml(input.serviceName)
  const name = escapeHtml(input.contact.name)
  const phone = escapeHtml(input.contact.phone)
  const email = escapeHtml(input.contact.email)
  const notesLine = input.contact.notes ? `<p>Notes: ${escapeHtml(input.contact.notes)}</p>` : ''
  return {
    subject: `New booking: ${input.serviceName} on ${input.date}`,
    html: `<p><strong>${name}</strong> booked <strong>${serviceName}</strong> on ${escapeHtml(input.date)} at ${escapeHtml(input.time)}.</p>` +
      `<p>Phone: ${phone}<br/>Email: ${email}</p>${notesLine}`,
  }
}

export interface InquiryEmailInput {
  productName: string
  contact: { name: string; email: string; notes: string }
}

export function buildInquiryNotificationEmail(input: InquiryEmailInput): { subject: string; html: string } {
  const productName = escapeHtml(input.productName)
  const name = escapeHtml(input.contact.name)
  const email = escapeHtml(input.contact.email)
  const notesLine = input.contact.notes ? `<p>Notes: ${escapeHtml(input.contact.notes)}</p>` : ''
  return {
    subject: `New inquiry: ${input.productName}`,
    html: `<p><strong>${name}</strong> (${email}) asked about <strong>${productName}</strong>.</p>${notesLine}`,
  }
}