import { createEffect, createResource, createSignal, For, Show } from "solid-js"
import QRCode from "qrcode"
import Modal from "@/components/Modal"
import PaymentSetup from "@/components/PaymentSetup"
import { getInvoice, getInvoiceBolt11, listInvoiceItems, type Invoice } from "@/lib/api"
import { billingTenant } from "@/lib/state"

type PayStatus = "idle" | "loading" | "success" | "error"
type Bolt11Status = "idle" | "loading" | "ready" | "error"

type PaymentInvoice = Pick<Invoice, "id" | "amount"> &
  Partial<Pick<Invoice, "period_start" | "period_end">>

type PaymentDialogProps = {
  invoice: PaymentInvoice
  open: boolean
  onClose: () => void
}

export default function PaymentDialog(props: PaymentDialogProps) {
  const [bolt11, setBolt11] = createSignal("")
  const [qrDataUrl, setQrDataUrl] = createSignal("")
  const [bolt11Status, setBolt11Status] = createSignal<Bolt11Status>("idle")
  const [bolt11Error, setBolt11Error] = createSignal("")
  const [payStatus, setPayStatus] = createSignal<PayStatus>("idle")
  const [payError, setPayError] = createSignal("")
  const [showPaymentSetup, setShowPaymentSetup] = createSignal(false)
  const [setupSaved, setSetupSaved] = createSignal(false)
  const [items] = createResource(
    () => (props.open ? props.invoice.id : undefined),
    listInvoiceItems,
  )

  const autopayConfigured = () => {
    const t = billingTenant()
    return Boolean(t?.nwc_is_set || t?.stripe_payment_method_id)
  }

  async function loadBolt11() {
    if (!props.invoice.id) return
    setBolt11Status("loading")
    setBolt11Error("")
    setBolt11("")
    setQrDataUrl("")

    try {
      const { lnbc } = await getInvoiceBolt11(props.invoice.id)
      setBolt11(lnbc)
      setQrDataUrl(await QRCode.toDataURL(lnbc, { width: 256, margin: 2 }))
      setBolt11Status("ready")
    } catch (e) {
      setBolt11Status("error")
      setBolt11Error(e instanceof Error ? e.message : "Failed to generate Lightning invoice")
    }
  }

  createEffect(() => {
    if (!props.open || !props.invoice.id) return
    void loadBolt11()
  })

  function copyBolt11() {
    void navigator.clipboard.writeText(bolt11())
  }

  async function checkPayment() {
    setPayStatus("loading")
    setPayError("")
    try {
      const invoice = await getInvoice(props.invoice.id)
      if (invoice.paid_at != null) {
        setPayStatus("success")
      } else {
        setPayStatus("error")
        setPayError("Payment not yet confirmed. Please try again after sending.")
      }
    } catch (e) {
      setPayStatus("error")
      setPayError(e instanceof Error ? e.message : "Failed to check payment status")
    }
  }

  function handleClose() {
    setPayStatus("idle")
    setPayError("")
    setBolt11Status("idle")
    setBolt11Error("")
    setBolt11("")
    setQrDataUrl("")
    props.onClose()
  }

  const amountLabel = () => `$${(props.invoice.amount / 100).toFixed(2)}`

  const periodLabel = () => {
    const { period_start, period_end } = props.invoice
    if (!period_start || !period_end) return ""
    const start = new Date(period_start * 1000).toLocaleDateString()
    const end = new Date(period_end * 1000).toLocaleDateString()
    return `${start} – ${end}`
  }

  return (
    <>
    <Modal
      open={props.open}
      onClose={handleClose}
      wrapperClass="fixed inset-0 z-50 flex items-center justify-center bg-black/50 p-4"
      panelClass="w-full max-w-md rounded-2xl bg-white shadow-xl overflow-hidden"
    >
      {/* Header */}
      <div class="px-6 pt-6 pb-4 border-b border-gray-100">
        <div class="flex items-start justify-between gap-3">
          <div>
            <h2 class="text-lg font-semibold text-gray-900">Pay Invoice</h2>
            <p class="text-2xl font-bold text-gray-900 mt-1">{amountLabel()}</p>
            <Show when={periodLabel()}>
              <p class="text-xs text-gray-500 mt-0.5">Billing period {periodLabel()}</p>
            </Show>
          </div>
          <button
            type="button"
            onClick={handleClose}
            class="text-gray-400 hover:text-gray-700 rounded p-1 hover:bg-gray-100 flex-shrink-0"
            aria-label="Close"
          >
            <svg class="w-5 h-5" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
              <path d="M18 6L6 18M6 6l12 12" />
            </svg>
          </button>
        </div>
      </div>

      {/* Content */}
      <div class="px-6 py-4 min-h-[240px] flex flex-col items-center justify-center">
        <Show
          when={payStatus() === "success"}
          fallback={
            <div class="w-full space-y-4">
              {/* What's being paid for — the invoice's actual line items */}
              <Show when={(items() ?? []).length > 0}>
                <div class="rounded-lg border border-gray-200 bg-gray-50 p-3">
                  <p class="text-xs font-medium text-gray-500 uppercase tracking-wide mb-2">On this invoice</p>
                  <ul class="space-y-1.5">
                    <For each={items()}>
                      {(item) => (
                        <li class="flex items-center justify-between gap-3 text-sm">
                          <span class="truncate text-gray-900">{item.description}</span>
                          <span class="flex-shrink-0 text-xs text-gray-500">${(item.amount / 100).toFixed(2)}</span>
                        </li>
                      )}
                    </For>
                  </ul>
                </div>
              </Show>

              <p class="text-xs font-medium text-gray-500 uppercase tracking-wide text-center">Pay with Lightning</p>
              <Show when={bolt11Status() === "idle" || bolt11Status() === "loading"}>
                <div class="flex items-center justify-center py-12 text-sm text-gray-400">Generating invoice...</div>
              </Show>
              <Show when={bolt11Status() === "error"}>
                <div class="rounded-lg border border-red-200 bg-red-50 p-4">
                  <p class="text-sm font-medium text-red-700">Unable to generate invoice</p>
                  <p class="mt-1 text-xs text-red-600 wrap-break-word">{bolt11Error()}</p>
                  <button
                    type="button"
                    onClick={() => void loadBolt11()}
                    class="mt-3 inline-flex items-center rounded-lg bg-red-600 px-3 py-1.5 text-sm font-medium text-white hover:bg-red-700"
                  >
                    Retry
                  </button>
                </div>
              </Show>
              <Show when={bolt11Status() === "ready"}>
                <img src={qrDataUrl()} alt="Lightning invoice QR code" class="mx-auto rounded-lg" />
                <Show when={bolt11()}>
                  <div class="flex rounded-lg border border-gray-300">
                    <input
                      type="text"
                      readOnly
                      value={bolt11()}
                      class="min-w-0 flex-1 rounded-l-lg border-0 px-3 py-2 text-xs text-gray-500 bg-transparent focus:outline-none"
                    />
                    <button
                      type="button"
                      class="flex items-center px-3 text-gray-400 hover:text-gray-700"
                      onClick={copyBolt11}
                      title="Copy invoice"
                    >
                      <svg class="w-4 h-4" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
                        <rect x="9" y="9" width="13" height="13" rx="2" />
                        <path d="M5 15H4a2 2 0 01-2-2V4a2 2 0 012-2h9a2 2 0 012 2v1" />
                      </svg>
                    </button>
                  </div>
                </Show>
              </Show>

              {/* Card / automatic payment alternative */}
              <div class="border-t border-gray-100 pt-3 text-center">
                <p class="text-xs text-gray-500 mb-1">Prefer to pay with a card?</p>
                <button
                  type="button"
                  onClick={() => setShowPaymentSetup(true)}
                  class="text-sm font-medium text-blue-600 hover:text-blue-700"
                >
                  Pay with card or set up automatic payments
                </button>
              </div>
            </div>
          }
        >
          <div class="text-center space-y-3">
            <div class="mx-auto mb-3 flex h-12 w-12 items-center justify-center rounded-full bg-green-100">
              <svg class="w-6 h-6 text-green-600" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
                <polyline points="20 6 9 17 4 12" />
              </svg>
            </div>
            <p class="text-sm font-medium text-gray-900">Payment confirmed!</p>
            <p class="text-xs text-gray-500">Thank you. Your account is up to date.</p>
            <Show when={!autopayConfigured()}>
              <button
                type="button"
                onClick={() => setShowPaymentSetup(true)}
                class="mt-2 text-sm font-medium text-blue-600 hover:text-blue-700"
              >
                Set up automatic payments
              </button>
            </Show>
          </div>
        </Show>
      </div>

      {/* Error */}
      <Show when={payError()}>
        <div class="px-6 pb-2">
          <p class="text-xs text-red-600">{payError()}</p>
        </div>
      </Show>

      {/* Footer */}
      <div class="px-6 py-4 flex justify-between gap-3 border-t border-gray-100">
        <Show
          when={payStatus() !== "success"}
          fallback={
            <div class="flex justify-end w-full">
              <button
                type="button"
                onClick={handleClose}
                class="py-2 px-4 bg-blue-600 text-white text-sm font-medium rounded-lg hover:bg-blue-700"
              >
                Done
              </button>
            </div>
          }
        >
          <button
            type="button"
            onClick={handleClose}
            class="py-2 px-4 border border-gray-300 text-gray-700 text-sm rounded-lg hover:bg-gray-50 transition-colors"
          >
            Pay Later
          </button>
          <button
            type="button"
            onClick={checkPayment}
            disabled={payStatus() === "loading" || bolt11Status() !== "ready"}
            class="py-2 px-4 bg-blue-600 text-white text-sm font-medium rounded-lg hover:bg-blue-700 disabled:opacity-50 transition-colors"
          >
            {payStatus() === "loading" ? "Checking..." : "Complete Payment"}
          </button>
        </Show>
      </div>
    </Modal>
    <PaymentSetup
      open={showPaymentSetup()}
      onClose={() => {
        setShowPaymentSetup(false)
        if (setupSaved()) {
          setSetupSaved(false)
          props.onClose()
        }
      }}
      onSaved={() => setSetupSaved(true)}
    />
    </>
  )
}