import React, { useEffect, useState } from 'react';
import { useNavigate, useLocation, Link } from 'react-router-dom';
import { useAuth } from '../../context/AuthContext';
import api from '../../utils/api';
import { Card } from '../../components/ui/card';
import { Button } from '../../components/ui/button';
import { Badge } from '../../components/ui/badge';
import { Input } from '../../components/ui/input';
import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from '../../components/ui/select';
import {
  DropdownMenu,
  DropdownMenuContent,
  DropdownMenuItem,
  DropdownMenuTrigger,
} from '../../components/ui/dropdown-menu';
import { toast } from 'sonner';
import { Users, Search, User, CreditCard, Eye, CheckCircle, Calendar, AlertCircle, Clock, Mail, UserPlus, Upload, Download, FileDown, ChevronDown } from 'lucide-react';
import PaymentActivationDialog from '../../components/PaymentActivationDialog';
import ConfirmationDialog from '../../components/ConfirmationDialog';
import CreateMemberDialog from '../../components/CreateMemberDialog';
import InviteStaffDialog from '../../components/InviteStaffDialog';
import WordPressImportWizard from '../../components/WordPressImportWizard';

const AdminMembers = () => {
  const navigate = useNavigate();
  const location = useLocation();
  const { hasPermission } = useAuth();
  const [users, setUsers] = useState([]);
  const [filteredUsers, setFilteredUsers] = useState([]);
  const [loading, setLoading] = useState(true);
  const [searchQuery, setSearchQuery] = useState('');
  const [statusFilter, setStatusFilter] = useState('active');
  const [paymentDialogOpen, setPaymentDialogOpen] = useState(false);
  const [selectedUserForPayment, setSelectedUserForPayment] = useState(null);
  const [statusChanging, setStatusChanging] = useState(null);
  const [confirmDialogOpen, setConfirmDialogOpen] = useState(false);
  const [pendingStatusChange, setPendingStatusChange] = useState(null);
  const [createDialogOpen, setCreateDialogOpen] = useState(false);
  const [inviteDialogOpen, setInviteDialogOpen] = useState(false);
  const [importDialogOpen, setImportDialogOpen] = useState(false);
  const [exporting, setExporting] = useState(false);

  useEffect(() => {
    fetchMembers();
  }, []);

  useEffect(() => {
    filterUsers();
  }, [users, searchQuery, statusFilter]);

  const fetchMembers = async () => {
    try {
      const response = await api.get('/admin/users');
      // Filter to only members
      const members = response.data.filter(user => user.role === 'member');
      setUsers(members);
    } catch (error) {
      toast.error('Failed to fetch members');
    } finally {
      setLoading(false);
    }
  };

  const filterUsers = () => {
    let filtered = users;

    if (statusFilter && statusFilter !== 'all') {
      filtered = filtered.filter(user => user.status === statusFilter);
    }

    if (searchQuery) {
      const query = searchQuery.toLowerCase();
      filtered = filtered.filter(user =>
        user.first_name.toLowerCase().includes(query) ||
        user.last_name.toLowerCase().includes(query) ||
        user.email.toLowerCase().includes(query)
      );
    }

    setFilteredUsers(filtered);
  };

  const handleActivatePayment = (user) => {
    setSelectedUserForPayment(user);
    setPaymentDialogOpen(true);
  };

  const handlePaymentSuccess = () => {
    fetchMembers(); // Refresh list
  };

  const handleStatusChangeRequest = (userId, currentStatus, newStatus, user) => {
    // Skip confirmation if status didn't actually change
    if (currentStatus === newStatus) return;

    setPendingStatusChange({ userId, newStatus, user });
    setConfirmDialogOpen(true);
  };

  const confirmStatusChange = async () => {
    if (!pendingStatusChange) return;

    const { userId, newStatus } = pendingStatusChange;
    setStatusChanging(userId);
    setConfirmDialogOpen(false);

    try {
      await api.put(`/admin/users/${userId}/status`, { status: newStatus });
      toast.success('Member status updated successfully');
      fetchMembers(); // Refresh list
    } catch (error) {
      toast.error(error.response?.data?.detail || 'Failed to update status');
    } finally {
      setStatusChanging(null);
      setPendingStatusChange(null);
    }
  };

  const handleExport = async (filterType) => {
    setExporting(true);
    try {
      let params = {};
      if (filterType === 'current') {
        if (statusFilter && statusFilter !== 'all') {
          params.status = statusFilter;
        }
        if (searchQuery) {
          params.search = searchQuery;
        }
      }
      // filterType === 'all' will export all members without filters

      const response = await api.get('/admin/users/export', {
        params,
        responseType: 'blob'
      });

      // Create download link
      const url = window.URL.createObjectURL(new Blob([response.data]));
      const link = document.createElement('a');
      link.href = url;
      link.setAttribute('download', `members_export_${new Date().toISOString().split('T')[0]}.csv`);
      document.body.appendChild(link);
      link.click();
      link.remove();

      toast.success('Members exported successfully');
    } catch (error) {
      toast.error('Failed to export members');
    } finally {
      setExporting(false);
    }
  };

  const getStatusChangeMessage = () => {
    if (!pendingStatusChange) return {};

    const { newStatus, user } = pendingStatusChange;
    const userName = `${user.first_name} ${user.last_name}`;

    const messages = {
      payment_pending: {
        title: 'Revert to Payment Pending?',
        description: `This will change ${userName}'s status back to Payment Pending. They will need to complete payment again to become active.`,
        variant: 'warning',
        confirmText: 'Yes, Revert Status',
      },
      active: {
        title: 'Activate Member?',
        description: `This will activate ${userName}'s membership. They will gain full access to member features and resources.`,
        variant: 'success',
        confirmText: 'Yes, Activate',
      },
      inactive: {
        title: 'Deactivate Member?',
        description: `This will deactivate ${userName}'s membership. They will lose access to member-only features but their data will be preserved.`,
        variant: 'warning',
        confirmText: 'Yes, Deactivate',
      },
      canceled: {
        title: 'Cancel Membership?',
        description: `This will mark ${userName}'s membership as canceled. This indicates they voluntarily ended their membership. Their subscription will not auto-renew.`,
        variant: 'danger',
        confirmText: 'Yes, Cancel Membership',
      },
      expired: {
        title: 'Mark Membership as Expired?',
        description: `This will mark ${userName}'s membership as expired. This indicates their subscription period has ended without renewal.`,
        variant: 'warning',
        confirmText: 'Yes, Mark as Expired',
      },
    };

    return messages[newStatus] || {
      title: 'Confirm Status Change',
      description: `Are you sure you want to change ${userName}'s status to ${newStatus}?`,
      variant: 'warning',
      confirmText: 'Confirm',
    };
  };

  const getStatusBadge = (status) => {
    const config = {
      pending_email: { label: 'Pending Email', className: 'bg-orange-100 text-orange-700' },
      pending_validation: { label: 'Pending Validation', className: 'bg-gray-200 text-gray-700' },
      pre_validated: { label: 'Pre-Validated', className: 'bg-[#81B29A] text-white' },
      payment_pending: { label: 'Payment Pending', className: 'bg-orange-500 text-white' },
      active: { label: 'Active', className: 'bg-[#81B29A] text-white' },
      inactive: { label: 'Inactive', className: 'bg-gray-400 text-white' },
      canceled: { label: 'Canceled', className: 'bg-red-100 text-red-700' },
      expired: { label: 'Expired', className: 'bg-red-500 text-white' },
      abandoned: { label: 'Abandoned', className: 'bg-gray-300 text-gray-600' }
    };

    const statusConfig = config[status] || config.inactive;
    return (
      <Badge className={`${statusConfig.className} px-3 py-1 rounded-full text-sm`}>
        {statusConfig.label}
      </Badge>
    );
  };

  const getReminderInfo = (user) => {
    const emailReminders = user.email_verification_reminders_sent || 0;
    const eventReminders = user.event_attendance_reminders_sent || 0;
    const paymentReminders = user.payment_reminders_sent || 0;
    const renewalReminders = user.renewal_reminders_sent || 0;
    const totalReminders = emailReminders + eventReminders + paymentReminders + renewalReminders;

    return {
      emailReminders,
      eventReminders,
      paymentReminders,
      renewalReminders,
      totalReminders,
      lastReminderAt: user.last_email_verification_reminder_at ||
                      user.last_event_attendance_reminder_at ||
                      user.last_payment_reminder_at ||
                      user.last_renewal_reminder_at
    };
  };

  return (
    <>
      <div className="mb-8">
        <div className="flex justify-between items-start mb-4">
          <div>
            <h1 className="text-4xl md:text-5xl font-semibold text-[#422268] mb-4" style={{ fontFamily: "'Inter', sans-serif" }}>
              Members Management
            </h1>
            <p className="text-lg text-[#664fa3]" style={{ fontFamily: "'Nunito Sans', sans-serif" }}>
              Manage paying members and their subscriptions.
            </p>
          </div>
          <div className="flex gap-3 flex-wrap">
            {hasPermission('users.export') && (
              <DropdownMenu>
                <DropdownMenuTrigger asChild>
                  <Button
                    className="bg-[#664fa3] hover:bg-[#422268] text-white rounded-xl h-12 px-6"
                    disabled={exporting}
                  >
                    {exporting ? (
                      <>
                        <Download className="h-5 w-5 mr-2 animate-bounce" />
                        Exporting...
                      </>
                    ) : (
                      <>
                        <FileDown className="h-5 w-5 mr-2" />
                        Export
                        <ChevronDown className="h-4 w-4 ml-2" />
                      </>
                    )}
                  </Button>
                </DropdownMenuTrigger>
                <DropdownMenuContent className="rounded-xl">
                  <DropdownMenuItem onClick={() => handleExport('all')} className="cursor-pointer">
                    Export All Members
                  </DropdownMenuItem>
                  <DropdownMenuItem onClick={() => handleExport('current')} className="cursor-pointer">
                    Export Current View
                  </DropdownMenuItem>
                </DropdownMenuContent>
              </DropdownMenu>
            )}

            {hasPermission('users.import') && (
              <Button
                onClick={() => setImportDialogOpen(true)}
                className="bg-[#81B29A] hover:bg-[#6DA085] text-white rounded-xl h-12 px-6"
              >
                <Upload className="h-5 w-5 mr-2" />
                Import
              </Button>
            )}

            {hasPermission('users.invite') && (
              <Button
                onClick={() => setInviteDialogOpen(true)}
                className="bg-[#664fa3] hover:bg-[#422268] text-white rounded-xl h-12 px-6"
              >
                <Mail className="h-5 w-5 mr-2" />
                Invite Member
              </Button>
            )}

            {hasPermission('users.create') && (
              <Button
                onClick={() => setCreateDialogOpen(true)}
                className="bg-[#81B29A] hover:bg-[#6DA085] text-white rounded-xl h-12 px-6"
              >
                <UserPlus className="h-5 w-5 mr-2" />
                Create Member
              </Button>
            )}
          </div>
        </div>
      </div>

      {/* Stats */}
      <div className="grid grid-cols-1 sm:grid-cols-2 md:grid-cols-4 gap-4 mb-8">
        <Card className="p-6 bg-white rounded-2xl border border-[#ddd8eb]">
          <p className="text-sm text-[#664fa3] mb-2" style={{ fontFamily: "'Nunito Sans', sans-serif" }}>Total Members</p>
          <p className="text-3xl font-semibold text-[#422268]" style={{ fontFamily: "'Inter', sans-serif" }}>
            {users.length}
          </p>
        </Card>
        <Card className="p-6 bg-white rounded-2xl border border-[#ddd8eb]">
          <p className="text-sm text-[#664fa3] mb-2" style={{ fontFamily: "'Nunito Sans', sans-serif" }}>Active</p>
          <p className="text-3xl font-semibold text-[#422268]" style={{ fontFamily: "'Inter', sans-serif" }}>
            {users.filter(u => u.status === 'active').length}
          </p>
        </Card>
        <Card className="p-6 bg-white rounded-2xl border border-[#ddd8eb]">
          <p className="text-sm text-[#664fa3] mb-2" style={{ fontFamily: "'Nunito Sans', sans-serif" }}>Payment Pending</p>
          <p className="text-3xl font-semibold text-[#422268]" style={{ fontFamily: "'Inter', sans-serif" }}>
            {users.filter(u => u.status === 'payment_pending').length}
          </p>
        </Card>
        <Card className="p-6 bg-white rounded-2xl border border-[#ddd8eb]">
          <p className="text-sm text-[#664fa3] mb-2" style={{ fontFamily: "'Nunito Sans', sans-serif" }}>Inactive</p>
          <p className="text-3xl font-semibold text-[#422268]" style={{ fontFamily: "'Inter', sans-serif" }}>
            {users.filter(u => u.status === 'inactive').length}
          </p>
        </Card>
      </div>

      {/* Filters */}
      <Card className="p-6 bg-white rounded-2xl border border-[#ddd8eb] mb-8">
        <div className="grid grid-cols-1 md:grid-cols-2 gap-4">
          <div className="relative">
            <Search className="absolute left-4 top-1/2 transform -translate-y-1/2 h-5 w-5 text-[#664fa3]" />
            <Input
              placeholder="Search by name or email..."
              value={searchQuery}
              onChange={(e) => setSearchQuery(e.target.value)}
              className="pl-12 h-14 rounded-xl border-2 border-[#ddd8eb] focus:border-[#664fa3]"
              data-testid="search-members-input"
            />
          </div>
          <Select value={statusFilter} onValueChange={setStatusFilter}>
            <SelectTrigger className="h-14 rounded-xl border-2 border-[#ddd8eb]" data-testid="status-filter-select">
              <SelectValue placeholder="Filter by status" />
            </SelectTrigger>
            <SelectContent>
              <SelectItem value="all">All Statuses</SelectItem>
              <SelectItem value="active">Active</SelectItem>
              <SelectItem value="payment_pending">Payment Pending</SelectItem>
              <SelectItem value="pending_validation">Pending Validation</SelectItem>
              <SelectItem value="pre_validated">Pre-Validated</SelectItem>
              <SelectItem value="inactive">Inactive</SelectItem>
              <SelectItem value="canceled">Canceled</SelectItem>
              <SelectItem value="expired">Expired</SelectItem>
              <SelectItem value="abandoned">Abandoned</SelectItem>
            </SelectContent>
          </Select>
        </div>
      </Card>

      {/* Members List */}
      {loading ? (
        <div className="text-center py-20">
          <p className="text-[#664fa3]" style={{ fontFamily: "'Nunito Sans', sans-serif" }}>Loading members...</p>
        </div>
      ) : filteredUsers.length > 0 ? (
        <div className="space-y-4">
          {filteredUsers.map((user) => (
            <Card
              key={user.id}
              className="p-6 bg-white rounded-2xl border border-[#ddd8eb] hover:shadow-md transition-shadow"
              data-testid={`member-card-${user.id}`}
            >
              <div className="flex justify-between items-start flex-wrap gap-4">
                <div className="flex items-start gap-4 flex-1">
                  {/* Avatar */}
                  <div className="h-14 w-14 rounded-full bg-[#DDD8EB] flex items-center justify-center text-[#422268] font-semibold text-lg flex-shrink-0">
                    {user.first_name?.[0]}{user.last_name?.[0]}
                  </div>

                  {/* Info */}
                  <div className="flex-1 min-w-0">
                    <div className="flex items-center gap-3 mb-2 flex-wrap">
                      <h3 className="text-xl font-semibold text-[#422268]" style={{ fontFamily: "'Inter', sans-serif" }}>
                        {user.first_name} {user.last_name}
                      </h3>
                      {getStatusBadge(user.status)}
                    </div>
                    <div className="grid md:grid-cols-2 gap-2 text-sm text-[#664fa3]" style={{ fontFamily: "'Nunito Sans', sans-serif" }}>
                      <p>Email: {user.email}</p>
                      <p>Phone: {user.phone}</p>
                      <p>Joined: {new Date(user.created_at).toLocaleDateString()}</p>
                      {user.referred_by_member_name && (
                        <p>Referred by: {user.referred_by_member_name}</p>
                      )}
                    </div>

                    {/* Reminder Info */}
                    {(() => {
                      const reminderInfo = getReminderInfo(user);
                      if (reminderInfo.totalReminders > 0) {
                        return (
                          <div className="mt-4 p-3 bg-[#F8F7FB] rounded-lg border border-[#ddd8eb]">
                            <div className="flex items-center gap-2 mb-2">
                              <AlertCircle className="h-4 w-4 text-[#ff9e77]" />
                              <span className="text-sm font-semibold text-[#422268]" style={{ fontFamily: "'Inter', sans-serif" }}>
                                {reminderInfo.totalReminders} reminder{reminderInfo.totalReminders !== 1 ? 's' : ''} sent
                                {reminderInfo.totalReminders >= 3 && (
                                  <Badge className="ml-2 bg-[#ff9e77] text-white px-2 py-0.5 rounded-full text-xs">
                                    Needs attention
                                  </Badge>
                                )}
                              </span>
                            </div>
                            <div className="grid grid-cols-2 md:grid-cols-4 gap-2 text-xs text-[#664fa3]" style={{ fontFamily: "'Nunito Sans', sans-serif" }}>
                              {reminderInfo.emailReminders > 0 && (
                                <p>
                                  <Mail className="inline h-3 w-3 mr-1" />
                                  {reminderInfo.emailReminders} email verification
                                </p>
                              )}
                              {reminderInfo.eventReminders > 0 && (
                                <p>
                                  <Calendar className="inline h-3 w-3 mr-1" />
                                  {reminderInfo.eventReminders} event attendance
                                </p>
                              )}
                              {reminderInfo.paymentReminders > 0 && (
                                <p>
                                  <Clock className="inline h-3 w-3 mr-1" />
                                  {reminderInfo.paymentReminders} payment
                                </p>
                              )}
                              {reminderInfo.renewalReminders > 0 && (
                                <p>
                                  <CheckCircle className="inline h-3 w-3 mr-1" />
                                  {reminderInfo.renewalReminders} renewal
                                </p>
                              )}
                            </div>
                            {reminderInfo.lastReminderAt && (
                              <p className="mt-2 text-xs text-[#664fa3]" style={{ fontFamily: "'Nunito Sans', sans-serif" }}>
                                Last reminder: {new Date(reminderInfo.lastReminderAt).toLocaleDateString()} at {new Date(reminderInfo.lastReminderAt).toLocaleTimeString([], { hour: '2-digit', minute: '2-digit' })}
                              </p>
                            )}
                          </div>
                        );
                      }
                      return null;
                    })()}
                  </div>
                </div>

                {/* Actions */}
                <div className="flex flex-col gap-3">
                  <div className="flex gap-2 flex-wrap">
                    <Link to={`/admin/users/${user.id}`}>
                      <Button
                        variant="outline"
                        size="sm"
                        className="border-[#664fa3] text-[#664fa3] hover:bg-[#664fa3] hover:text-white"
                      >
                        <Eye className="h-4 w-4 mr-1" />
                        View Profile
                      </Button>
                    </Link>

                    {/* Show Activate Payment button for payment_pending users */}
                    {user.status === 'payment_pending' && (
                      <Button
                        onClick={() => handleActivatePayment(user)}
                        size="sm"
                        className="bg-[#DDD8EB] text-[#422268] hover:bg-white"
                      >
                        <CheckCircle className="h-4 w-4 mr-1" />
                        Activate Payment
                      </Button>
                    )}
                  </div>

                  {/* Status Management */}
                  <div className="flex items-center gap-2">
                    <span className="text-sm text-[#664fa3] whitespace-nowrap" style={{ fontFamily: "'Nunito Sans', sans-serif" }}>
                      Change Status:
                    </span>
                    <Select
                      value={user.status}
                      onValueChange={(newStatus) => handleStatusChangeRequest(user.id, user.status, newStatus, user)}
                      disabled={statusChanging === user.id}
                    >
                      <SelectTrigger className="w-[180px] h-9 border-[#ddd8eb]">
                        <SelectValue />
                      </SelectTrigger>
                      <SelectContent>
                        <SelectItem value="payment_pending">Payment Pending</SelectItem>
                        <SelectItem value="active">Active</SelectItem>
                        <SelectItem value="inactive">Inactive</SelectItem>
                        <SelectItem value="canceled">Canceled</SelectItem>
                        <SelectItem value="expired">Expired</SelectItem>
                      </SelectContent>
                    </Select>
                  </div>
                </div>
              </div>
            </Card>
          ))}
        </div>
      ) : (
        <div className="text-center py-20">
          <Users className="h-20 w-20 text-[#ddd8eb] mx-auto mb-6" />
          <h3 className="text-2xl font-semibold text-[#422268] mb-4" style={{ fontFamily: "'Inter', sans-serif" }}>
            No Members Found
          </h3>
          <p className="text-[#664fa3]" style={{ fontFamily: "'Nunito Sans', sans-serif" }}>
            {searchQuery || statusFilter !== 'all'
              ? 'Try adjusting your filters'
              : 'No members yet'}
          </p>
        </div>
      )}

      {/* Payment Activation Dialog */}
      <PaymentActivationDialog
        open={paymentDialogOpen}
        onOpenChange={setPaymentDialogOpen}
        user={selectedUserForPayment}
        onSuccess={handlePaymentSuccess}
      />

      {/* Status Change Confirmation Dialog */}
      <ConfirmationDialog
        open={confirmDialogOpen}
        onOpenChange={setConfirmDialogOpen}
        onConfirm={confirmStatusChange}
        loading={statusChanging !== null}
        {...getStatusChangeMessage()}
      />

      {/* Create/Invite/Import Dialogs */}
      <CreateMemberDialog
        open={createDialogOpen}
        onOpenChange={setCreateDialogOpen}
        onSuccess={fetchMembers}
      />

      <InviteStaffDialog
        open={inviteDialogOpen}
        onOpenChange={setInviteDialogOpen}
        onSuccess={fetchMembers}
      />

      <WordPressImportWizard
        open={importDialogOpen}
        onOpenChange={setImportDialogOpen}
        onSuccess={fetchMembers}
      />
    </>
  );
};

export default AdminMembers;