import React, { useState } from "react";
import { base44 } from "@/api/base44Client";
import { useQuery } from "@tanstack/react-query";
import { Link } from "react-router-dom";
import { createPageUrl } from "@/utils";
import { Button } from "@/components/ui/button";
import { Card, CardContent } from "@/components/ui/card";
import { Badge } from "@/components/ui/badge";
import { UserPlus, Users, LayoutGrid, List as ListIcon, Phone, MapPin, Calendar, Star } from "lucide-react";
import FilterBar from "../components/staff/FilterBar";
import StaffCard from "../components/staff/StaffCard";
import EmployeeCard from "../components/staff/EmployeeCard";
import PageHeader from "../components/common/PageHeader";

export default function StaffDirectory() {
  const [searchTerm, setSearchTerm] = useState("");
  const [departmentFilter, setDepartmentFilter] = useState("all");
  const [locationFilter, setLocationFilter] = useState("all");
  const [viewMode, setViewMode] = useState("grid"); // "grid" or "list"

  const { data: user } = useQuery({
    queryKey: ['current-user'],
    queryFn: () => base44.auth.me(),
  });

  const { data: staff, isLoading } = useQuery({
    queryKey: ['staff'],
    queryFn: () => base44.entities.Staff.list('-created_date'),
    initialData: [],
  });

  const { data: events } = useQuery({
    queryKey: ['events-for-staff-filter'],
    queryFn: () => base44.entities.Event.list(),
    initialData: [],
    enabled: !!user
  });

  const visibleStaff = React.useMemo(() => {
    const userRole = user?.user_role || user?.role;
    
    if (['admin', 'procurement'].includes(userRole)) {
      return staff;
    }
    
    if (['operator', 'sector'].includes(userRole)) {
      return staff;
    }
    
    if (userRole === 'vendor') {
      return staff.filter(s => 
        s.vendor_id === user?.id || 
        s.vendor_name === user?.company_name ||
        s.created_by === user?.email
      );
    }
    
    if (userRole === 'client') {
      const clientEvents = events.filter(e => 
        e.client_email === user?.email ||
        e.business_name === user?.company_name ||
        e.created_by === user?.email
      );
      
      const assignedStaffIds = new Set();
      clientEvents.forEach(event => {
        if (event.assigned_staff) {
          event.assigned_staff.forEach(assignment => {
            if (assignment.staff_id) {
              assignedStaffIds.add(assignment.staff_id);
            }
          });
        }
      });
      
      return staff.filter(s => assignedStaffIds.has(s.id));
    }
    
    if (userRole === 'workforce') {
      return staff;
    }
    
    return staff;
  }, [staff, user, events]);

  const uniqueDepartments = [...new Set(visibleStaff.map(s => s.department).filter(Boolean))];
  const uniqueLocations = [...new Set(visibleStaff.map(s => s.hub_location).filter(Boolean))];

  const filteredStaff = visibleStaff.filter(member => {
    const matchesSearch = !searchTerm || 
      member.employee_name?.toLowerCase().includes(searchTerm.toLowerCase()) ||
      member.position?.toLowerCase().includes(searchTerm.toLowerCase()) ||
      member.manager?.toLowerCase().includes(searchTerm.toLowerCase());
    
    const matchesDepartment = departmentFilter === "all" || member.department === departmentFilter;
    const matchesLocation = locationFilter === "all" || member.hub_location === locationFilter;
    
    return matchesSearch && matchesDepartment && matchesLocation;
  });

  const canAddStaff = ['admin', 'procurement', 'operator', 'sector', 'vendor'].includes(user?.user_role || user?.role);

  const getPageTitle = () => {
    const userRole = user?.user_role || user?.role;
    if (userRole === 'vendor') return "My Staff Directory";
    if (userRole === 'client') return "Event Staff Directory";
    if (userRole === 'workforce') return "Team Directory";
    return "Staff Directory";
  };

  const getPageSubtitle = () => {
    const userRole = user?.user_role || user?.role;
    if (userRole === 'vendor') return `${filteredStaff.length} of your staff members`;
    if (userRole === 'client') return `${filteredStaff.length} staff assigned to your events`;
    if (userRole === 'workforce') return `${filteredStaff.length} team members`;
    return `${filteredStaff.length} ${filteredStaff.length === 1 ? 'member' : 'members'} found`;
  };

  const getCoverageColor = (percentage) => {
    if (!percentage) return "bg-red-100 text-red-700";
    if (percentage >= 90) return "bg-green-100 text-green-700";
    if (percentage >= 50) return "bg-yellow-100 text-yellow-700";
    return "bg-red-100 text-red-700";
  };

  return (
    <div className="p-4 md:p-8">
      <div className="max-w-7xl mx-auto">
        <PageHeader 
          title={getPageTitle()}
          subtitle={getPageSubtitle()}
          actions={
            canAddStaff ? (
              <Link to={createPageUrl("AddStaff")}>
                <Button className="bg-gradient-to-r from-blue-600 to-blue-700 hover:from-blue-700 hover:to-blue-800 text-white shadow-lg">
                  <UserPlus className="w-5 h-5 mr-2" />
                  Add New Staff
                </Button>
              </Link>
            ) : null
          }
        />

        <div className="mb-6">
          <Card className="border-slate-200">
            <CardContent className="p-4">
              <div className="flex items-center gap-4 mb-4">
                <div className="flex-1">
                  <FilterBar
                    searchTerm={searchTerm}
                    setSearchTerm={setSearchTerm}
                    departmentFilter={departmentFilter}
                    setDepartmentFilter={setDepartmentFilter}
                    locationFilter={locationFilter}
                    setLocationFilter={setLocationFilter}
                    departments={uniqueDepartments}
                    locations={uniqueLocations}
                  />
                </div>
                
                <div className="flex items-center gap-1 bg-slate-100 p-1 rounded-lg">
                  <Button
                    size="sm"
                    variant={viewMode === "grid" ? "default" : "ghost"}
                    onClick={() => setViewMode("grid")}
                    className={viewMode === "grid" ? "bg-[#0A39DF] hover:bg-[#0A39DF]/90" : "hover:bg-white"}
                  >
                    <LayoutGrid className="w-4 h-4" />
                  </Button>
                  <Button
                    size="sm"
                    variant={viewMode === "list" ? "default" : "ghost"}
                    onClick={() => setViewMode("list")}
                    className={viewMode === "list" ? "bg-[#0A39DF] hover:bg-[#0A39DF]/90" : "hover:bg-white"}
                  >
                    <ListIcon className="w-4 h-4" />
                  </Button>
                </div>
              </div>
            </CardContent>
          </Card>
        </div>

        {isLoading ? (
          <div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-6">
            {[...Array(9)].map((_, i) => (
              <div key={i} className="h-64 bg-slate-100 animate-pulse rounded-xl" />
            ))}
          </div>
        ) : filteredStaff.length > 0 ? (
          <>
            {viewMode === "grid" && (
              <div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-6">
                {filteredStaff.map((member) => (
                  <EmployeeCard key={member.id} staff={member} />
                ))}
              </div>
            )}

            {viewMode === "list" && (
              <Card className="border-slate-200 shadow-lg">
                <CardContent className="p-0">
                  <div className="overflow-x-auto">
                    <table className="w-full">
                      <thead className="bg-slate-50 border-b-2 border-slate-200">
                        <tr>
                          <th className="text-left py-4 px-4 font-semibold text-sm text-slate-700">Employee</th>
                          <th className="text-left py-4 px-4 font-semibold text-sm text-slate-700">Primary Skill</th>
                          <th className="text-left py-4 px-4 font-semibold text-sm text-slate-700">Secondary Skill</th>
                          <th className="text-center py-4 px-4 font-semibold text-sm text-slate-700">Rating</th>
                          <th className="text-center py-4 px-4 font-semibold text-sm text-slate-700">Reliability</th>
                          <th className="text-center py-4 px-4 font-semibold text-sm text-slate-700">Coverage</th>
                          <th className="text-center py-4 px-4 font-semibold text-sm text-slate-700">Cancellations</th>
                          <th className="text-left py-4 px-4 font-semibold text-sm text-slate-700">Manager</th>
                          <th className="text-left py-4 px-4 font-semibold text-sm text-slate-700">Location</th>
                        </tr>
                      </thead>
                      <tbody>
                        {filteredStaff.map((member) => (
                          <tr key={member.id} className="border-b border-slate-100 hover:bg-slate-50 transition-colors">
                            <td className="py-4 px-4">
                              <Link to={createPageUrl(`EditStaff?id=${member.id}`)} className="flex items-center gap-3 hover:text-[#0A39DF]">
                                <div className="w-10 h-10 bg-gradient-to-br from-blue-500 to-blue-700 rounded-full flex items-center justify-center text-white font-bold text-sm">
                                  {member.employee_name?.charAt(0) || '?'}
                                </div>
                                <div>
                                  <p className="font-semibold text-[#1C323E]">{member.employee_name}</p>
                                  {member.contact_number && (
                                    <p className="text-xs text-slate-500 flex items-center gap-1">
                                      <Phone className="w-3 h-3" />
                                      {member.contact_number}
                                    </p>
                                  )}
                                </div>
                              </Link>
                            </td>
                            <td className="py-4 px-4 text-sm text-slate-700">{member.position || '—'}</td>
                            <td className="py-4 px-4 text-sm text-slate-500">{member.position_2 || '—'}</td>
                            <td className="py-4 px-4 text-center">
                              <div className="flex items-center justify-center gap-1">
                                <Star className="w-4 h-4 fill-yellow-400 text-yellow-400" />
                                <span className="font-semibold text-sm">
                                  {member.rating ? member.rating.toFixed(1) : '0.0'}
                                </span>
                              </div>
                            </td>
                            <td className="py-4 px-4 text-center">
                              <Badge className={`${
                                (member.reliability_score || 0) >= 90 ? 'bg-green-100 text-green-700' :
                                (member.reliability_score || 0) >= 70 ? 'bg-yellow-100 text-yellow-700' :
                                (member.reliability_score || 0) >= 50 ? 'bg-orange-100 text-orange-700' :
                                'bg-red-100 text-red-700'
                              } font-semibold`}>
                                {member.reliability_score || 0}%
                              </Badge>
                            </td>
                            <td className="py-4 px-4 text-center">
                              <Badge className={`${getCoverageColor(member.shift_coverage_percentage)} font-semibold`}>
                                {member.shift_coverage_percentage || 0}%
                              </Badge>
                            </td>
                            <td className="py-4 px-4 text-center">
                              <Badge variant="outline" className={member.cancellation_count > 0 ? "text-red-600 border-red-300" : "text-slate-600"}>
                                {member.cancellation_count || 0}
                              </Badge>
                            </td>
                            <td className="py-4 px-4 text-sm text-slate-700">{member.manager || '—'}</td>
                            <td className="py-4 px-4">
                              {member.hub_location && (
                                <div className="flex items-center gap-1 text-sm text-slate-600">
                                  <MapPin className="w-3 h-3" />
                                  {member.hub_location}
                                </div>
                              )}
                            </td>
                          </tr>
                        ))}
                      </tbody>
                    </table>
                  </div>
                </CardContent>
              </Card>
            )}
          </>
        ) : (
          <div className="text-center py-16 bg-white rounded-xl border border-slate-200">
            <Users className="w-16 h-16 mx-auto text-slate-300 mb-4" />
            <h3 className="text-xl font-semibold text-slate-900 mb-2">No Staff Members Found</h3>
            <p className="text-slate-600 mb-6">
              {visibleStaff.length === 0 
                ? "No staff members available to display" 
                : "Try adjusting your filters"}
            </p>
            {canAddStaff && (
              <Link to={createPageUrl("AddStaff")}>
                <Button className="bg-gradient-to-r from-blue-600 to-blue-700 hover:from-blue-700 hover:to-blue-800 text-white">
                  <UserPlus className="w-4 h-4 mr-2" />
                  Add Staff Member
                </Button>
              </Link>
            )}
          </div>
        )}
      </div>
    </div>
  );
}