import { useParams, useNavigate } from 'react-router-dom';
import { Avatar, Box, Button, Chip, Grid, Paper, Stack, Step, StepLabel, Stepper, Typography, useMediaQuery } from '@mui/material';
import { useTheme } from '@mui/material/styles';
import { useQuery, useMutation, useQueryClient } from '@tanstack/react-query';
import {
  MdArrowBack,
  MdLocalShipping,
  MdPerson,
  MdPhone,
  MdLocationOn,
  MdTwoWheeler,
  MdStar,
  MdOutlineSmartToy,
  MdOutlineAssignmentInd,
  MdOutlineCancel
} from 'react-icons/md';
import Loader from 'components/Loader';
import { OpenToast } from 'components/third-party/OpenToast';
import { getorderdetails, autoAssignBooking, cancelOrder } from 'pages/api/api';

const DT = {
  radiusCard: 16,
  textPrimary: '#0f172a',
  textSecondary: '#64748b',
  textMuted: '#94a3b8',
  borderSubtle: '#e2e8f0',
  divider: '#f1f5f9',
  surface: '#ffffff',
  surfaceAlt: '#f8fafc'
};
const a = (c, suffix) => `${c}${suffix}`;
const tint = (c) => a(c, '08');
const soft = (c) => a(c, '18');
const edge = (c) => a(c, '55');
const BRAND = '#C01227';

// Ordered status progression used for the stepper. Doormile's real status
// vocabulary — Assignment_Failed and Cancelled are terminal/off-path states
// shown separately rather than as stepper nodes.
const STATUS_STEPS = ['Pending_Pickup', 'Miler_Assigned', 'Pickup_Scheduled', 'At_Customer', 'Picked_Up', 'At_Hub', 'Delivered'];
const STEP_LABELS = {
  Pending_Pickup: 'Pending Pickup',
  Miler_Assigned: 'Miler Assigned',
  Pickup_Scheduled: 'Pickup Scheduled',
  At_Customer: 'At Customer',
  Picked_Up: 'Picked Up',
  At_Hub: 'At Hub',
  Delivered: 'Delivered'
};

const InfoRow = ({ icon: Icon, label, value, color = BRAND }) => (
  <Stack direction="row" alignItems="flex-start" spacing={1.5}>
    <Avatar sx={{ width: 32, height: 32, bgcolor: soft(color), color }}>
      <Icon size={16} />
    </Avatar>
    <Box sx={{ minWidth: 0 }}>
      <Typography variant="caption" sx={{ color: DT.textMuted, fontWeight: 700, textTransform: 'uppercase', letterSpacing: 0.4 }}>
        {label}
      </Typography>
      <Typography sx={{ fontWeight: 600, color: DT.textPrimary, wordBreak: 'break-word' }}>{value || '—'}</Typography>
    </Box>
  </Stack>
);

const BookingDetail = () => {
  const { id } = useParams();
  const navigate = useNavigate();
  const theme = useTheme();
  const isMobile = useMediaQuery(theme.breakpoints.down('md'));
  const queryClient = useQueryClient();

  const { data, isLoading, isError } = useQuery({
    queryKey: ['bookingDetail', id],
    queryFn: () => getorderdetails(id),
    enabled: Boolean(id)
  });

  // Confirmed shape (booking id 5): bookingid, bookingreference, status,
  // pickupaddress, deliveryaddress, assignedmileruserid, createdat,
  // bookingparcels (nested parcels), serviceoptions, payments.
  const booking = data?.data || data || {};

  const reassignMutation = useMutation({
    mutationFn: () => autoAssignBooking(id),
    onSuccess: () => {
      OpenToast('Reassignment triggered', 'success', 2000);
      queryClient.invalidateQueries({ queryKey: ['bookingDetail', id] });
    },
    onError: (err) => OpenToast(err.response?.data?.message || err.message, 'error', 3000)
  });

  const cancelMutation = useMutation({
    mutationFn: () => cancelOrder(id),
    onSuccess: () => {
      OpenToast('Booking cancelled', 'success', 2000);
      queryClient.invalidateQueries({ queryKey: ['bookingDetail', id] });
    },
    onError: (err) => OpenToast(err.response?.data?.message || err.message, 'error', 3000)
  });

  if (isLoading) return <Loader />;

  const status = booking.status || 'Pending_Pickup';
  const isTerminal = ['cancelled', 'assignment_failed'].includes(String(status).toLowerCase());
  const activeStepIdx = STATUS_STEPS.indexOf(status);
  const parcels = booking.bookingparcels || booking.parcels || [];
  const miler = booking.miler || booking.assignedmiler || null;
  const agentDecision = booking.agent_decision_id ? booking.agentdecision || booking.agent_decision : null;

  return (
    <>
      <Stack direction="row" alignItems="center" spacing={1.5} sx={{ mb: 2 }}>
        <Button startIcon={<MdArrowBack size={16} />} onClick={() => navigate('/nearle/orders')} sx={{ color: DT.textSecondary, textTransform: 'none', fontWeight: 700 }}>
          Back to Bookings
        </Button>
      </Stack>

      <Paper
        elevation={0}
        sx={{
          p: { xs: 2, md: 3 },
          borderRadius: `${DT.radiusCard}px`,
          background: `linear-gradient(135deg, ${tint(BRAND)} 0%, ${tint('#D35968')} 100%)`,
          border: '1px solid',
          borderColor: DT.borderSubtle,
          mb: 2
        }}
      >
        <Stack direction={{ xs: 'column', sm: 'row' }} justifyContent="space-between" alignItems={{ xs: 'flex-start', sm: 'center' }} spacing={2}>
          <Stack direction="row" alignItems="center" spacing={1.5}>
            <Avatar sx={{ width: 48, height: 48, bgcolor: BRAND, color: '#fff' }}>
              <MdLocalShipping size={24} />
            </Avatar>
            <Box>
              <Typography variant="h3">{booking.bookingreference || `Booking #${id}`}</Typography>
              <Typography variant="body2" sx={{ color: DT.textSecondary }}>
                {booking.createdat ? new Date(booking.createdat).toLocaleString() : '—'}
              </Typography>
            </Box>
          </Stack>
          <Chip
            label={STEP_LABELS[status] || status}
            sx={{ fontWeight: 800, bgcolor: isTerminal ? soft('#ef4444') : soft(BRAND), color: isTerminal ? '#ef4444' : BRAND, border: `1px solid ${edge(isTerminal ? '#ef4444' : BRAND)}` }}
          />
        </Stack>
      </Paper>

      {isError && (
        <Paper elevation={0} sx={{ p: 2, mb: 2, borderRadius: 2, border: `1px solid ${edge('#ef4444')}`, bgcolor: tint('#ef4444') }}>
          <Typography sx={{ color: '#ef4444', fontWeight: 600 }}>Could not load full booking details — showing whatever came back.</Typography>
        </Paper>
      )}

      {/* Status timeline */}
      {!isTerminal && (
        <Paper elevation={0} sx={{ p: { xs: 2, md: 3 }, mb: 2, borderRadius: `${DT.radiusCard}px`, border: '1px solid', borderColor: DT.borderSubtle, background: '#fff' }}>
          <Stepper activeStep={activeStepIdx} alternativeLabel={!isMobile} orientation={isMobile ? 'vertical' : 'horizontal'}>
            {STATUS_STEPS.map((s) => (
              <Step key={s}>
                <StepLabel
                  sx={{
                    '& .MuiStepIcon-root.Mui-active': { color: BRAND },
                    '& .MuiStepIcon-root.Mui-completed': { color: BRAND }
                  }}
                >
                  {STEP_LABELS[s]}
                </StepLabel>
              </Step>
            ))}
          </Stepper>
        </Paper>
      )}

      <Grid container spacing={2.5}>
        <Grid item xs={12} md={6}>
          <Paper elevation={0} sx={{ p: { xs: 2, md: 2.5 }, borderRadius: `${DT.radiusCard}px`, border: '1px solid', borderColor: DT.borderSubtle, background: '#fff', height: '100%' }}>
            <Typography variant="subtitle1" sx={{ fontWeight: 800, mb: 2 }}>
              Customer & Pickup
            </Typography>
            <Stack spacing={2}>
              <InfoRow icon={MdPerson} label="Customer" value={booking.customername || booking.customer?.name} />
              <InfoRow icon={MdPhone} label="Phone" value={booking.customerphone || booking.customer?.phone} />
              <InfoRow icon={MdLocationOn} label="Pickup Address" value={booking.pickupaddress} color="#0ea5e9" />
            </Stack>
          </Paper>
        </Grid>
        <Grid item xs={12} md={6}>
          <Paper elevation={0} sx={{ p: { xs: 2, md: 2.5 }, borderRadius: `${DT.radiusCard}px`, border: '1px solid', borderColor: DT.borderSubtle, background: '#fff', height: '100%' }}>
            <Typography variant="subtitle1" sx={{ fontWeight: 800, mb: 2 }}>
              Delivery
            </Typography>
            <Stack spacing={2}>
              <InfoRow icon={MdLocationOn} label="Delivery Address" value={booking.deliveryaddress} color="#10b981" />
            </Stack>
          </Paper>
        </Grid>

        <Grid item xs={12} md={6}>
          <Paper elevation={0} sx={{ p: { xs: 2, md: 2.5 }, borderRadius: `${DT.radiusCard}px`, border: '1px solid', borderColor: DT.borderSubtle, background: '#fff', height: '100%' }}>
            <Typography variant="subtitle1" sx={{ fontWeight: 800, mb: 2 }}>
              Assigned Miler
            </Typography>
            {booking.assignedmileruserid || miler ? (
              <Stack direction="row" alignItems="center" spacing={1.5}>
                <Avatar sx={{ width: 44, height: 44, bgcolor: soft('#8b5cf6'), color: '#8b5cf6' }}>
                  <MdTwoWheeler size={22} />
                </Avatar>
                <Box>
                  <Typography sx={{ fontWeight: 700, color: DT.textPrimary }}>
                    {miler?.displayname || `Miler #${booking.assignedmileruserid}`}
                  </Typography>
                  <Stack direction="row" alignItems="center" spacing={1.5} sx={{ mt: 0.25 }}>
                    {miler?.phone && (
                      <Typography variant="caption" sx={{ color: DT.textSecondary }}>
                        {miler.phone}
                      </Typography>
                    )}
                    {miler?.rating != null && (
                      <Stack direction="row" alignItems="center" spacing={0.25}>
                        <MdStar size={13} style={{ color: '#f59e0b' }} />
                        <Typography variant="caption" sx={{ color: DT.textSecondary }}>
                          {miler.rating}
                        </Typography>
                      </Stack>
                    )}
                  </Stack>
                </Box>
              </Stack>
            ) : (
              <Typography variant="body2" sx={{ color: DT.textMuted }}>
                No miler assigned yet.
              </Typography>
            )}
          </Paper>
        </Grid>

        <Grid item xs={12} md={6}>
          <Paper elevation={0} sx={{ p: { xs: 2, md: 2.5 }, borderRadius: `${DT.radiusCard}px`, border: '1px solid', borderColor: DT.borderSubtle, background: '#fff', height: '100%' }}>
            <Typography variant="subtitle1" sx={{ fontWeight: 800, mb: 2 }}>
              Parcel Details
            </Typography>
            {parcels.length === 0 ? (
              <Typography variant="body2" sx={{ color: DT.textMuted }}>
                No parcel details available.
              </Typography>
            ) : (
              <Stack spacing={1}>
                {parcels.map((p, i) => (
                  <Stack key={i} direction="row" justifyContent="space-between" sx={{ p: 1, borderRadius: 1.5, bgcolor: DT.surfaceAlt }}>
                    <Typography variant="body2">{p.description || p.name || `Parcel ${i + 1}`}</Typography>
                    <Typography variant="body2" sx={{ color: DT.textSecondary }}>
                      {p.weight ? `${p.weight}kg` : ''}
                    </Typography>
                  </Stack>
                ))}
              </Stack>
            )}
          </Paper>
        </Grid>

        {agentDecision && (
          <Grid item xs={12}>
            <Paper elevation={0} sx={{ p: { xs: 2, md: 2.5 }, borderRadius: `${DT.radiusCard}px`, border: `1px solid ${edge('#6366f1')}`, background: tint('#6366f1') }}>
              <Stack direction="row" alignItems="center" spacing={1} sx={{ mb: 1 }}>
                <Avatar sx={{ width: 32, height: 32, bgcolor: soft('#6366f1'), color: '#6366f1' }}>
                  <MdOutlineSmartToy size={16} />
                </Avatar>
                <Typography variant="subtitle1" sx={{ fontWeight: 800, color: '#6366f1' }}>
                  AI Assignment Reasoning
                </Typography>
              </Stack>
              <Typography variant="body2" sx={{ color: DT.textPrimary }}>
                {agentDecision.reasoning || agentDecision.reason || JSON.stringify(agentDecision)}
              </Typography>
            </Paper>
          </Grid>
        )}
      </Grid>

      <Stack direction="row" spacing={1.5} justifyContent="flex-end" sx={{ mt: 2.5 }}>
        {!isTerminal && (
          <Button
            variant="contained"
            startIcon={<MdOutlineAssignmentInd size={16} />}
            disabled={reassignMutation.isLoading}
            onClick={() => reassignMutation.mutate()}
            sx={{ bgcolor: '#6366f1', '&:hover': { bgcolor: '#4f46e5' } }}
          >
            Reassign Miler
          </Button>
        )}
        {!isTerminal && (
          <Button
            variant="outlined"
            color="error"
            startIcon={<MdOutlineCancel size={16} />}
            disabled={cancelMutation.isLoading}
            onClick={() => cancelMutation.mutate()}
          >
            Cancel Booking
          </Button>
        )}
      </Stack>
    </>
  );
};

export default BookingDetail;