import { useState, useMemo } from 'react';
import { cn, formatCurrency, formatPercent, formatDate } from '@/lib/utils';
import { PLATFORM_COLORS } from '@/lib/constants';
import {
  CalendarDays,
  ArrowUpDown,
  Filter,
  ChevronDown,
} from 'lucide-react';
import {
  BarChart,
  Bar,
  XAxis,
  YAxis,
  CartesianGrid,
  Tooltip,
  ResponsiveContainer,
} from 'recharts';

// ── Types ──────────────────────────────────────────────────────────────

type ReservationStatus = 'confirmed' | 'completed' | 'cancelled';
type Platform = 'airbnb' | 'vrbo';
type SortField = 'guest' | 'checkin' | 'checkout' | 'nights' | 'rate' | 'total' | 'status';
type SortDir = 'asc' | 'desc';

interface Reservation {
  id: string;
  guest: string;
  platform: Platform;
  checkin: string;
  checkout: string;
  nights: number;
  nightlyRate: number;
  totalPayout: number;
  status: ReservationStatus;
}

// ── Mock Data ──────────────────────────────────────────────────────────

const MOCK_RESERVATIONS: Reservation[] = [
  { id: 'r-01', guest: 'Sarah Mitchell', platform: 'airbnb', checkin: '2025-10-04', checkout: '2025-10-08', nights: 4, nightlyRate: 195, totalPayout: 741, status: 'completed' },
  { id: 'r-02', guest: 'James Park', platform: 'vrbo', checkin: '2025-10-12', checkout: '2025-10-15', nights: 3, nightlyRate: 185, totalPayout: 527, status: 'completed' },
  { id: 'r-03', guest: 'Emily Rodriguez', platform: 'airbnb', checkin: '2025-10-22', checkout: '2025-10-27', nights: 5, nightlyRate: 210, totalPayout: 999, status: 'completed' },
  { id: 'r-04', guest: 'Michael Chen', platform: 'airbnb', checkin: '2025-11-01', checkout: '2025-11-04', nights: 3, nightlyRate: 175, totalPayout: 499, status: 'completed' },
  { id: 'r-05', guest: 'Lisa Thompson', platform: 'vrbo', checkin: '2025-11-10', checkout: '2025-11-17', nights: 7, nightlyRate: 165, totalPayout: 1098, status: 'completed' },
  { id: 'r-06', guest: 'David Kim', platform: 'airbnb', checkin: '2025-11-22', checkout: '2025-11-24', nights: 2, nightlyRate: 220, totalPayout: 418, status: 'cancelled' },
  { id: 'r-07', guest: 'Amanda Foster', platform: 'vrbo', checkin: '2025-12-05', checkout: '2025-12-09', nights: 4, nightlyRate: 230, totalPayout: 874, status: 'completed' },
  { id: 'r-08', guest: 'Robert Johnson', platform: 'airbnb', checkin: '2025-12-18', checkout: '2025-12-25', nights: 7, nightlyRate: 250, totalPayout: 1663, status: 'completed' },
  { id: 'r-09', guest: 'Jennifer Lee', platform: 'airbnb', checkin: '2025-12-28', checkout: '2025-12-31', nights: 3, nightlyRate: 245, totalPayout: 698, status: 'completed' },
  { id: 'r-10', guest: 'Chris Martinez', platform: 'vrbo', checkin: '2026-01-03', checkout: '2026-01-06', nights: 3, nightlyRate: 180, totalPayout: 513, status: 'completed' },
  { id: 'r-11', guest: 'Natalie Wright', platform: 'airbnb', checkin: '2026-01-15', checkout: '2026-01-20', nights: 5, nightlyRate: 190, totalPayout: 903, status: 'completed' },
  { id: 'r-12', guest: 'Kevin Brown', platform: 'vrbo', checkin: '2026-01-28', checkout: '2026-02-01', nights: 4, nightlyRate: 175, totalPayout: 665, status: 'completed' },
  { id: 'r-13', guest: 'Patricia Davis', platform: 'airbnb', checkin: '2026-02-07', checkout: '2026-02-12', nights: 5, nightlyRate: 200, totalPayout: 950, status: 'completed' },
  { id: 'r-14', guest: 'Thomas Wilson', platform: 'airbnb', checkin: '2026-02-20', checkout: '2026-02-22', nights: 2, nightlyRate: 215, totalPayout: 409, status: 'cancelled' },
  { id: 'r-15', guest: 'Rachel Garcia', platform: 'vrbo', checkin: '2026-03-01', checkout: '2026-03-05', nights: 4, nightlyRate: 205, totalPayout: 779, status: 'confirmed' },
  { id: 'r-16', guest: 'Daniel Taylor', platform: 'airbnb', checkin: '2026-03-10', checkout: '2026-03-14', nights: 4, nightlyRate: 210, totalPayout: 798, status: 'confirmed' },
  { id: 'r-17', guest: 'Stephanie Moore', platform: 'vrbo', checkin: '2026-03-20', checkout: '2026-03-26', nights: 6, nightlyRate: 195, totalPayout: 1112, status: 'confirmed' },
  { id: 'r-18', guest: 'Brian Anderson', platform: 'airbnb', checkin: '2026-03-28', checkout: '2026-03-31', nights: 3, nightlyRate: 225, totalPayout: 641, status: 'confirmed' },
];

const STATUS_STYLES: Record<ReservationStatus, string> = {
  confirmed: 'bg-green-500/10 text-green-400',
  completed: 'bg-blue-500/10 text-blue-400',
  cancelled: 'bg-red-500/10 text-red-400',
};

const PLATFORM_DOT: Record<Platform, string> = {
  airbnb: PLATFORM_COLORS.airbnb,
  vrbo: PLATFORM_COLORS.vrbo,
};

// ── Component ──────────────────────────────────────────────────────────

export default function Reservations() {
  const [platformFilter, setPlatformFilter] = useState<Platform | 'all'>('all');
  const [statusFilter, setStatusFilter] = useState<ReservationStatus | 'all'>('all');
  const [sortField, setSortField] = useState<SortField>('checkin');
  const [sortDir, setSortDir] = useState<SortDir>('desc');

  function toggleSort(field: SortField) {
    if (sortField === field) {
      setSortDir((d) => (d === 'asc' ? 'desc' : 'asc'));
    } else {
      setSortField(field);
      setSortDir('asc');
    }
  }

  const filtered = useMemo(() => {
    let list = [...MOCK_RESERVATIONS];
    if (platformFilter !== 'all') list = list.filter((r) => r.platform === platformFilter);
    if (statusFilter !== 'all') list = list.filter((r) => r.status === statusFilter);

    list.sort((a, b) => {
      const dir = sortDir === 'asc' ? 1 : -1;
      switch (sortField) {
        case 'guest': return a.guest.localeCompare(b.guest) * dir;
        case 'checkin': return (new Date(a.checkin).getTime() - new Date(b.checkin).getTime()) * dir;
        case 'checkout': return (new Date(a.checkout).getTime() - new Date(b.checkout).getTime()) * dir;
        case 'nights': return (a.nights - b.nights) * dir;
        case 'rate': return (a.nightlyRate - b.nightlyRate) * dir;
        case 'total': return (a.totalPayout - b.totalPayout) * dir;
        case 'status': return a.status.localeCompare(b.status) * dir;
        default: return 0;
      }
    });
    return list;
  }, [platformFilter, statusFilter, sortField, sortDir]);

  // Monthly revenue chart data
  const monthlyRevenue = useMemo(() => {
    const map = new Map<string, number>();
    MOCK_RESERVATIONS.filter((r) => r.status !== 'cancelled').forEach((r) => {
      const d = new Date(r.checkin);
      const key = `${d.getFullYear()}-${String(d.getMonth() + 1).padStart(2, '0')}`;
      map.set(key, (map.get(key) || 0) + r.totalPayout);
    });
    return Array.from(map.entries())
      .sort(([a], [b]) => a.localeCompare(b))
      .map(([month, revenue]) => {
        const [y, m] = month.split('-');
        const label = new Date(Number(y), Number(m) - 1).toLocaleDateString('en-US', {
          month: 'short',
          year: '2-digit',
        });
        return { month: label, revenue };
      });
  }, []);

  // Monthly occupancy summary
  const monthlyOccupancy = useMemo(() => {
    const map = new Map<string, number>();
    MOCK_RESERVATIONS.filter((r) => r.status !== 'cancelled').forEach((r) => {
      const d = new Date(r.checkin);
      const key = `${d.getFullYear()}-${String(d.getMonth() + 1).padStart(2, '0')}`;
      map.set(key, (map.get(key) || 0) + r.nights);
    });
    return Array.from(map.entries())
      .sort(([a], [b]) => a.localeCompare(b))
      .map(([month, nights]) => {
        const [y, m] = month.split('-');
        const daysInMonth = new Date(Number(y), Number(m), 0).getDate();
        const label = new Date(Number(y), Number(m) - 1).toLocaleDateString('en-US', {
          month: 'short',
          year: '2-digit',
        });
        return { month: label, nights, daysInMonth, occupancy: nights / daysInMonth };
      });
  }, []);

  const totalRevenue = filtered
    .filter((r) => r.status !== 'cancelled')
    .reduce((sum, r) => sum + r.totalPayout, 0);

  const SortHeader = ({ field, label, align }: { field: SortField; label: string; align?: string }) => (
    <th
      className={cn('pb-2 pr-4 font-medium cursor-pointer select-none hover:text-text-primary transition-colors', align)}
      onClick={() => toggleSort(field)}
    >
      <span className="inline-flex items-center gap-1">
        {label}
        {sortField === field && (
          <ArrowUpDown className="w-3 h-3 text-accent" />
        )}
      </span>
    </th>
  );

  return (
    <div className="space-y-6">
      {/* Header */}
      <div className="flex items-center gap-3">
        <CalendarDays className="w-5 h-5 text-accent" />
        <h1 className="text-lg font-semibold text-text-primary">Reservations</h1>
        <span className="text-xs text-text-muted bg-surface border border-border rounded-full px-2 py-0.5">
          {filtered.length} reservations
        </span>
      </div>

      {/* Revenue chart + occupancy summary */}
      <div className="grid grid-cols-1 lg:grid-cols-3 gap-4">
        {/* Bar chart */}
        <div className="lg:col-span-2 bg-surface border border-border rounded-lg p-5">
          <h2 className="text-sm font-medium text-text-primary mb-4">Revenue by Month</h2>
          <div className="h-56">
            <ResponsiveContainer width="100%" height="100%">
              <BarChart data={monthlyRevenue} barCategoryGap="20%">
                <CartesianGrid strokeDasharray="3 3" stroke="#262626" />
                <XAxis
                  dataKey="month"
                  tick={{ fill: '#737373', fontSize: 12 }}
                  axisLine={{ stroke: '#262626' }}
                  tickLine={false}
                />
                <YAxis
                  tick={{ fill: '#737373', fontSize: 12 }}
                  axisLine={{ stroke: '#262626' }}
                  tickLine={false}
                  tickFormatter={(v) => `$${(v / 1000).toFixed(1)}k`}
                />
                <Tooltip
                  contentStyle={{
                    backgroundColor: '#141414',
                    border: '1px solid #262626',
                    borderRadius: 8,
                    fontSize: 13,
                  }}
                  labelStyle={{ color: '#fafafa' }}
                  formatter={(value: number) => [formatCurrency(value), 'Revenue']}
                />
                <Bar dataKey="revenue" fill="#22c55e" radius={[4, 4, 0, 0]} />
              </BarChart>
            </ResponsiveContainer>
          </div>
        </div>

        {/* Occupancy cards */}
        <div className="bg-surface border border-border rounded-lg p-5">
          <h2 className="text-sm font-medium text-text-primary mb-4">Monthly Occupancy</h2>
          <div className="space-y-3">
            {monthlyOccupancy.map((m) => (
              <div key={m.month} className="flex items-center justify-between">
                <span className="text-sm text-text-muted">{m.month}</span>
                <div className="flex items-center gap-3 flex-1 ml-4">
                  <div className="flex-1 h-2 bg-background rounded-full overflow-hidden">
                    <div
                      className="h-full bg-accent rounded-full transition-all"
                      style={{ width: `${Math.min(m.occupancy * 100, 100)}%` }}
                    />
                  </div>
                  <span className="font-mono text-sm text-text-primary w-12 text-right">
                    {formatPercent(m.occupancy)}
                  </span>
                </div>
              </div>
            ))}
          </div>
          <div className="mt-4 pt-3 border-t border-border">
            <div className="flex items-center justify-between text-sm">
              <span className="text-text-muted">Total Revenue</span>
              <span className="font-mono font-semibold text-accent">
                {formatCurrency(totalRevenue)}
              </span>
            </div>
          </div>
        </div>
      </div>

      {/* Filters */}
      <div className="flex flex-wrap items-center gap-3">
        <div className="flex items-center gap-1.5 text-text-muted">
          <Filter className="w-4 h-4" />
          <span className="text-xs uppercase tracking-wide">Filters</span>
        </div>

        {/* Platform filter */}
        <div className="relative">
          <select
            value={platformFilter}
            onChange={(e) => setPlatformFilter(e.target.value as Platform | 'all')}
            className={cn(
              'appearance-none rounded-md bg-surface border border-border pl-3 pr-8 py-1.5 text-sm text-text-primary',
              'focus:outline-none focus:ring-1 focus:ring-accent cursor-pointer'
            )}
          >
            <option value="all">All Platforms</option>
            <option value="airbnb">Airbnb</option>
            <option value="vrbo">VRBO</option>
          </select>
          <ChevronDown className="absolute right-2 top-1/2 -translate-y-1/2 w-3.5 h-3.5 text-text-muted pointer-events-none" />
        </div>

        {/* Status filter */}
        <div className="relative">
          <select
            value={statusFilter}
            onChange={(e) => setStatusFilter(e.target.value as ReservationStatus | 'all')}
            className={cn(
              'appearance-none rounded-md bg-surface border border-border pl-3 pr-8 py-1.5 text-sm text-text-primary',
              'focus:outline-none focus:ring-1 focus:ring-accent cursor-pointer'
            )}
          >
            <option value="all">All Statuses</option>
            <option value="confirmed">Confirmed</option>
            <option value="completed">Completed</option>
            <option value="cancelled">Cancelled</option>
          </select>
          <ChevronDown className="absolute right-2 top-1/2 -translate-y-1/2 w-3.5 h-3.5 text-text-muted pointer-events-none" />
        </div>
      </div>

      {/* Reservations table */}
      <div className="bg-surface border border-border rounded-lg overflow-hidden">
        <div className="overflow-x-auto">
          <table className="w-full text-sm">
            <thead>
              <tr className="text-left text-xs text-text-muted border-b border-border px-5">
                <SortHeader field="guest" label="Guest" />
                <th className="pb-2 pr-4 font-medium">Platform</th>
                <SortHeader field="checkin" label="Check-in" />
                <SortHeader field="checkout" label="Check-out" />
                <SortHeader field="nights" label="Nights" align="text-right" />
                <SortHeader field="rate" label="Nightly Rate" align="text-right" />
                <SortHeader field="total" label="Total Payout" align="text-right" />
                <SortHeader field="status" label="Status" />
              </tr>
            </thead>
            <tbody>
              {filtered.map((r) => (
                <tr
                  key={r.id}
                  className="border-b border-border/50 last:border-0 hover:bg-white/[0.02] transition-colors"
                >
                  <td className="px-5 py-3 font-medium text-text-primary whitespace-nowrap">
                    {r.guest}
                  </td>
                  <td className="py-3 pr-4 whitespace-nowrap">
                    <span className="inline-flex items-center gap-2 text-text-primary capitalize">
                      <span
                        className="w-2 h-2 rounded-full shrink-0"
                        style={{ backgroundColor: PLATFORM_DOT[r.platform] }}
                      />
                      {r.platform === 'vrbo' ? 'VRBO' : 'Airbnb'}
                    </span>
                  </td>
                  <td className="py-3 pr-4 text-text-primary whitespace-nowrap">
                    {formatDate(r.checkin)}
                  </td>
                  <td className="py-3 pr-4 text-text-primary whitespace-nowrap">
                    {formatDate(r.checkout)}
                  </td>
                  <td className="py-3 pr-4 text-right font-mono text-text-primary">
                    {r.nights}
                  </td>
                  <td className="py-3 pr-4 text-right font-mono text-text-primary">
                    {formatCurrency(r.nightlyRate)}
                  </td>
                  <td className="py-3 pr-4 text-right font-mono font-semibold text-text-primary">
                    {formatCurrency(r.totalPayout)}
                  </td>
                  <td className="py-3 pr-5">
                    <span
                      className={cn(
                        'inline-flex items-center rounded-full px-2.5 py-0.5 text-xs font-medium capitalize',
                        STATUS_STYLES[r.status]
                      )}
                    >
                      {r.status}
                    </span>
                  </td>
                </tr>
              ))}
              {filtered.length === 0 && (
                <tr>
                  <td colSpan={8} className="px-5 py-8 text-center text-text-muted text-sm">
                    No reservations match the selected filters.
                  </td>
                </tr>
              )}
            </tbody>
          </table>
        </div>
      </div>
    </div>
  );
}