import { useState } from "react";
import { Banknote, Pencil, Receipt } from "lucide-react";
import {
  Button,
  Divider,
  Group,
  NumberInput,
  Paper,
  Stack,
  Text,
  Textarea,
} from "@mantine/core";
import { useMutation, useQueryClient } from "@tanstack/react-query";
import toast from "react-hot-toast";

import type { BookingDetail } from "@/types/booking";
import { bookingsService } from "@/services/bookings.service";

import { SectionCard } from "./detail/SectionCard";
import { detailStyles } from "./detail/booking-detail.styles";

export function BookingPricingSummary({ booking }: { booking: BookingDetail }) {
  const qc = useQueryClient();
  const computed = Number(booking.totalAmount);
  const isAdjusted =
    booking.adjustedTotalAmount !== null &&
    booking.adjustedTotalAmount !== undefined;
  const effective = isAdjusted ? Number(booking.adjustedTotalAmount) : computed;

  const lineItems = booking.pricingBreakdown?.lineItems ?? [];

  const [editing, setEditing] = useState(false);
  const [amount, setAmount] = useState<number | "">(effective);
  const [reason, setReason] = useState("");

  const adjustMutation = useMutation({
    mutationFn: (payload: { amount: number | null; reason?: string }) =>
      bookingsService.adjustPrice(booking.id, payload.amount, payload.reason),
    onSuccess: () => {
      toast.success("Price updated");
      setEditing(false);
      qc.invalidateQueries({ queryKey: ["bookings"] });
    },
    onError: () => toast.error("Could not update price"),
  });

  const fmt = (n: number) =>
    `${booking.paymentCurrency} ${n.toLocaleString(undefined, { minimumFractionDigits: 2 })}`;

  return (
    <SectionCard icon={Banknote} title="Pricing & payment">
      <Stack gap="md">
        <Paper radius="md" withBorder p="md" style={detailStyles.highlightCard}>
          <Group justify="space-between" align="flex-start">
            <div>
              <Text size="xs" c="dimmed" fw={500} tt="uppercase" lts="0.04em">
                {isAdjusted ? "Adjusted total" : "Total amount"}
              </Text>
              <Text
                size="xl"
                fw={700}
                c="edr-green.9"
                mt={4}
                style={{ fontVariantNumeric: "tabular-nums", letterSpacing: "-0.5px" }}
              >
                {fmt(effective)}
              </Text>
              {isAdjusted && (
                <Text size="xs" c="dimmed" mt={2}>
                  Computed: {fmt(computed)}
                  {booking.adjustmentReason ? ` · ${booking.adjustmentReason}` : ""}
                </Text>
              )}
            </div>
            {!editing && (
              <Button
                size="compact-xs"
                variant="light"
                leftSection={<Pencil size={13} />}
                onClick={() => {
                  setAmount(effective);
                  setEditing(true);
                }}
              >
                Adjust
              </Button>
            )}
          </Group>

          {editing && (
            <Stack gap="xs" mt="md">
              <NumberInput
                label="New total"
                value={amount}
                onChange={(v) => setAmount(v === "" ? "" : Number(v))}
                min={0}
                radius="md"
                prefix={`${booking.paymentCurrency} `}
                thousandSeparator=","
              />
              <Textarea
                label="Reason (optional)"
                value={reason}
                onChange={(e) => setReason(e.currentTarget.value)}
                autosize
                minRows={2}
                radius="md"
              />
              <Group justify="space-between" mt={4}>
                {isAdjusted ? (
                  <Button
                    size="compact-sm"
                    variant="subtle"
                    color="red"
                    loading={adjustMutation.isPending}
                    onClick={() =>
                      adjustMutation.mutate({ amount: null })
                    }
                  >
                    Clear adjustment
                  </Button>
                ) : (
                  <span />
                )}
                <Group gap="xs">
                  <Button
                    size="compact-sm"
                    variant="default"
                    onClick={() => setEditing(false)}
                  >
                    Cancel
                  </Button>
                  <Button
                    size="compact-sm"
                    color="edr-green"
                    loading={adjustMutation.isPending}
                    disabled={amount === ""}
                    onClick={() =>
                      adjustMutation.mutate({
                        amount: Number(amount),
                        reason: reason.trim() || undefined,
                      })
                    }
                  >
                    Save
                  </Button>
                </Group>
              </Group>
            </Stack>
          )}
        </Paper>

        <Row label="Payment status" value={booking.paymentStatus} />
        {booking.pnrCode && <Row label="PNR code" value={booking.pnrCode} mono />}

        {lineItems.length > 0 && (
          <>
            <Divider color="var(--mantine-color-gray-2)" />
            <Group gap={6}>
              <Receipt size={13} color="var(--mantine-color-gray-5)" />
              <Text size="xs" c="dimmed" fw={500} tt="uppercase" lts="0.04em">
                Price breakdown
              </Text>
            </Group>
            <Stack gap="xs">
              {lineItems.map((li, i) => (
                <Group
                  key={`${li.code}-${i}`}
                  justify="space-between"
                  px="sm"
                  py={6}
                  style={{
                    borderRadius: 8,
                    border: "1px solid var(--mantine-color-gray-2)",
                    background: "var(--mantine-color-gray-0)",
                  }}
                >
                  <Text size="sm" c="dimmed">
                    {li.description}
                  </Text>
                  <Text size="sm" fw={600} style={{ fontVariantNumeric: "tabular-nums" }}>
                    {Number(li.amount).toLocaleString()} {li.currency}
                  </Text>
                </Group>
              ))}
            </Stack>
          </>
        )}
      </Stack>
    </SectionCard>
  );
}

function Row({ label, value, mono }: { label: string; value: string; mono?: boolean }) {
  return (
    <Group
      justify="space-between"
      px="sm"
      py="xs"
      style={{
        borderRadius: 8,
        border: "1px solid var(--mantine-color-gray-2)",
        background: "var(--mantine-color-gray-0)",
      }}
    >
      <Text size="sm" c="dimmed">
        {label}
      </Text>
      <Text size="sm" fw={600} ff={mono ? "monospace" : undefined}>
        {value}
      </Text>
    </Group>
  );
}