import * as React from "react"

interface InvoiceAddress {
  name: string
  address: string[]
  phone: string
  email: string
}

interface InvoicePaymentRow {
  label: string
  amount: number
}

interface InvoicePayment {
  subtotal: number
  /**
   * Empty when the plan is not split into installments.
   * If populated, split-payment rows will be shown.
   */
  payments: InvoicePaymentRow[]
  totalPaid: number
  balanceDue: number
}

interface GymInvoiceProps {
  invoiceNo: string
  invoiceDate: string
  dueDate: string
  /** Retained for API compatibility; the invoice no longer renders a logo. */
  logoSrc?: string
  logoAlt?: string
  from: InvoiceAddress
  billTo: InvoiceAddress
  plan: {
    gymPlanName: string
    type: string
    memberName: string
    validityPeriod: string
  }
  payment: InvoicePayment
  paymentMethod: string
  preparedBy: string
  notes: string[]
  footerItems: string[]
  className?: string
  formatAmount: (amount: number) => string

  /**
   * This ref now captures the full A4 invoice page.
   * The PDF download uses this exact node.
   */
  bodyRef?: React.Ref<HTMLDivElement>

  /**
   * Kept for compatibility with existing caller.
   * The footer is still inside the same invoice page.
   */
  footerRef?: React.Ref<HTMLDivElement>
}

function GymInvoice({
  invoiceNo,
  invoiceDate,
  dueDate,
  from,
  billTo,
  plan,
  payment,
  paymentMethod,
  preparedBy,
  notes,
  footerItems,
  formatAmount,
  bodyRef,
  footerRef,
  className = "",
}: GymInvoiceProps) {
  return (
    <div className={`mx-auto flex flex-col overflow-hidden bg-[#f4f4f4] px-6 py-6 font-sans ${className}`}>
      <div
        className="
        mx-auto
        h-[calc(1123px*var(--invoice-preview-scale))]
        w-[calc(794px*var(--invoice-preview-scale))]
        [--invoice-preview-scale:0.46]
        sm:[--invoice-preview-scale:0.62]
        md:[--invoice-preview-scale:1]
      "
      >
        <div
          className="
          origin-top-left
          transform-[scale(var(--invoice-preview-scale))]
        "
        >
          <div
            ref={bodyRef}
            className="mx-auto flex h-280.75 w-198.5 flex-col overflow-hidden bg-white px-13 pt-10 pb-8 text-[#111111] font-sans"
          >
            {/* Header */}
            <div className="flex items-start justify-between gap-4">
              <h1 className="text-[40px] leading-none font-extrabold tracking-[2px] uppercase">
                Invoice
              </h1>
            </div>

            {/* Invoice meta */}
            <div className="mt-7 grid gap-3">
              <MetaRow label="Invoice No." value={invoiceNo} />
              <MetaRow label="Invoice Date" value={invoiceDate} />
              <MetaRow label="Due Date" value={dueDate} />
            </div>

            <Divider className="mt-7" />

            {/* From / Bill To */}
            <div className="mt-8 grid grid-cols-2 gap-16">
              <InfoBlock title="From" data={from} />
              <InfoBlock title="Bill To" data={billTo} />
            </div>

            {/* Membership / Service Details */}
            <div className="mt-8">
              <SectionTitle title="Membership / Service Details" />

              <div className="mt-6 border-t-2 border-b border-t-[#111111] border-b-[#d1d1d1]">
                <div className="grid grid-cols-[30%_18%_26%_26%] border-b-[1.5px] border-b-[#111111] [&>div:not(:last-child)]:border-r [&>div:not(:last-child)]:border-r-[#d8d8d8]">
                  <TableHeadCell>Gym Plan Name</TableHeadCell>
                  <TableHeadCell>Type</TableHeadCell>
                  <TableHeadCell>Name of Member(s)</TableHeadCell>
                  <TableHeadCell>Expiry Date / Validity Period</TableHeadCell>
                </div>

                <div className="grid grid-cols-[30%_18%_26%_26%] [&>div:not(:last-child)]:border-r [&>div:not(:last-child)]:border-r-[#d8d8d8]">
                  <TableCell>{plan.gymPlanName}</TableCell>
                  <TableCell>{plan.type}</TableCell>
                  <TableCell>{plan.memberName}</TableCell>
                  <TableCell>{plan.validityPeriod}</TableCell>
                </div>
              </div>
            </div>

            {/* Notes / Terms + Payment Summary */}
            <div className="mt-8 grid grid-cols-[1fr_300px] items-start gap-10">
              <div>
                <SectionTitle title="Notes / Terms" />

                <div className="mt-6 [&>p+p]:mt-4 [&>p:last-child]:border-b-0 [&>p:last-child]:pb-0">
                  {notes.map((note, i) => (
                    <p
                      key={i}
                      className="m-0 border-b border-b-[#d1d1d1] pb-3 text-[13px] leading-[1.45]"
                    >
                      {note}
                    </p>
                  ))}
                </div>
              </div>

              <PaymentSummary payment={payment} formatAmount={formatAmount} />
            </div>

            {/* Payment Method / Prepared By */}
            <div className="mt-8 grid grid-cols-2 gap-16">
              <div>
                <SectionTitle title="Payment Method" />
                <p className="mt-5 text-[14px]">{paymentMethod || "-"}</p>
              </div>

              <div>
                <SectionTitle title="Prepared By" />
                <p className="mt-5 text-[14px]">{preparedBy || "-"}</p>
              </div>
            </div>

            {/* Footer stays inside the same one-page A4 receipt */}
            <div ref={footerRef} className="mt-auto bg-white pt-6">
              <Divider />

              <div className="mt-5 flex flex-wrap items-center justify-center gap-5 text-[13px] text-[#555555]">
                {footerItems.map((item, i) => (
                  <span key={i} className="flex items-center gap-5">
                    {i > 0 && <span aria-hidden>|</span>}
                    {item}
                  </span>
                ))}
              </div>
            </div>
          </div>
        </div>
      </div>
    </div>
  )
}

function Divider({ className = "" }: { className?: string }) {
  return (
    <div
      className={`h-1.5 border-t-2 border-b-[3px] border-t-[#111111] border-b-[#8e1821] ${className}`}
    />
  )
}

function MetaRow({ label, value }: { label: string; value: string }) {
  return (
    <div className="grid grid-cols-[130px_16px_1fr] items-center gap-x-3">
      <span className="text-[13px] font-extrabold uppercase">{label}</span>
      <span className="text-[13px]">:</span>
      <p className="m-0 text-[14px]">{value}</p>
    </div>
  )
}

function SectionTitle({ title }: { title: string }) {
  return (
    <div>
      <h2 className="m-0 text-[16px] font-extrabold tracking-[0.2px]">
        {title}
      </h2>
      <span className="mt-1 block h-0.75 w-12 bg-[#8e1821]" />
    </div>
  )
}

function InfoBlock({ title, data }: { title: string; data: InvoiceAddress }) {
  return (
    <div className="min-w-0">
      <SectionTitle title={title} />

      <div className="mt-6">
        <h3 className="m-0 mb-1.75 text-[14px] font-extrabold">
          {data.name}
        </h3>

        {data.address.map((line, i) => (
          <p
            key={i}
            className="m-0 mb-1.75 wrap-break-word text-[14px] leading-tight"
          >
            {line}
          </p>
        ))}

        <div className="mt-5">
          <p className="m-0 mb-1.75 text-[14px] leading-tight">
            {data.phone}
          </p>
          <p className="m-0 mb-1.75 wrap-break-word text-[14px] leading-tight">
            {data.email}
          </p>
        </div>
      </div>
    </div>
  )
}

function TableHeadCell({ children }: { children: React.ReactNode }) {
  return (
    <div className="box-border flex min-h-14 items-center justify-center px-3 py-3.5 text-center text-[12px] leading-tight font-extrabold">
      {children}
    </div>
  )
}

function TableCell({ children }: { children: React.ReactNode }) {
  return (
    <div className="box-border flex min-h-13.5 items-center justify-center wrap-break-word px-3 py-3.5 text-center text-[13px] leading-[1.35]">
      {children}
    </div>
  )
}

function PaymentSummary({
  payment,
  formatAmount,
}: {
  payment: InvoicePayment
  formatAmount: (amount: number) => string
}) {
  const hasBreakdown = payment.payments.length > 0

  return (
    <div className="border border-[#111111]">
      <SummaryRow label="Subtotal" amount={formatAmount(payment.subtotal)} />

      {hasBreakdown ? (
        <>
          {payment.payments.map((row, i) => (
            <SummaryRow
              key={i}
              label={row.label}
              amount={formatAmount(row.amount)}
            />
          ))}

          <SummaryRow
            label="Total Paid"
            amount={formatAmount(payment.totalPaid)}
          />

          <SummaryRow
            label="Balance Due"
            amount={formatAmount(payment.balanceDue)}
            highlight
          />
        </>
      ) : (
        <SummaryRow
          label="Total"
          amount={formatAmount(payment.subtotal)}
          highlight
        />
      )}
    </div>
  )
}

function SummaryRow({
  label,
  amount,
  highlight = false,
}: {
  label: string
  amount: string
  highlight?: boolean
}) {
  return (
    <div
      className={`grid min-h-12 grid-cols-[1fr_auto] items-center gap-5 border-b border-b-[#d1d1d1] px-5 last:border-b-0 ${highlight
          ? "border-t-[1.5px] border-t-[#111111] bg-[#f7f7f7]"
          : ""
        }`}
    >
      <span
        className={`font-extrabold uppercase ${highlight ? "text-[15px] font-black" : "text-[13px]"
          }`}
      >
        {label}
      </span>

      <strong
        className={`font-bold ${highlight ? "text-[15px] font-black" : "text-[13px]"
          }`}
      >
        {amount}
      </strong>
    </div>
  )
}

export { GymInvoice }
export type {
  GymInvoiceProps,
  InvoiceAddress,
  InvoicePayment,
  InvoicePaymentRow,
}