import React, { useState, useEffect } from 'react';
import { Activity, AlertCircle, Clock, Users, Bell, Heart, Thermometer, Wind, CheckCircle, UserX } from 'lucide-react';

const StaffDashboard = () => {
  const [patients, setPatients] = useState([]);
  const [stats, setStats] = useState({
    total_patients: 0,
    active_patients: 0,
    tier_breakdown: { EMERGENCY: 0, ALERT: 0, NORMAL: 0 },
    average_wait_minutes: 0
  });
  const [selectedPatient, setSelectedPatient] = useState(null);
  const [filter, setFilter] = useState('all');

  useEffect(() => {
    const generateMockPatients = () => {
      const mockPatients = [
        {
          patient_id: 'P100001',
          band_id: 'VitalLink-A1B2',
          name: 'John Smith',
          tier: 'NORMAL',
          priority_score: 15.2,
          wait_time_minutes: 22,
          last_hr: 76,
          last_spo2: 98,
          last_temp: 36.8,
          symptoms: ['Chest Pain', 'Nausea']
        },
        {
          patient_id: 'P100002',
          band_id: 'VitalLink-C3D4',
          name: 'Sarah Johnson',
          tier: 'ALERT',
          priority_score: 68.5,
          wait_time_minutes: 45,
          last_hr: 118,
          last_spo2: 93,
          last_temp: 38.4,
          symptoms: ['Fever', 'Difficulty Breathing']
        },
        {
          patient_id: 'P100003',
          band_id: 'VitalLink-E5F6',
          name: 'Michael Chen',
          tier: 'EMERGENCY',
          priority_score: 142.8,
          wait_time_minutes: 8,
          last_hr: 148,
          last_spo2: 86,
          last_temp: 39.7,
          symptoms: ['Severe Headache', 'Chest Pain']
        },
        {
          patient_id: 'P100004',
          band_id: 'VitalLink-G7H8',
          name: 'Emily Davis',
          tier: 'NORMAL',
          priority_score: 18.0,
          wait_time_minutes: 35,
          last_hr: 82,
          last_spo2: 97,
          last_temp: 37.1,
          symptoms: ['Abdominal Pain']
        },
        {
          patient_id: 'P100005',
          band_id: 'VitalLink-I9J0',
          name: 'Robert Williams',
          tier: 'ALERT',
          priority_score: 72.3,
          wait_time_minutes: 52,
          last_hr: 124,
          last_spo2: 91,
          last_temp: 38.8,
          symptoms: ['Fever', 'Dizziness']
        }
      ];
      
      setPatients(mockPatients);
      setStats({
        total_patients: 5,
        active_patients: 5,
        tier_breakdown: { EMERGENCY: 1, ALERT: 2, NORMAL: 2 },
        average_wait_minutes: 32.4
      });
    };

    generateMockPatients();
    
    const interval = setInterval(() => {
      setPatients(prev => prev.map(p => ({
        ...p,
        wait_time_minutes: p.wait_time_minutes + 1,
        last_hr: Math.max(40, Math.min(180, p.last_hr + Math.floor(Math.random() * 5) - 2)),
        last_spo2: Math.max(70, Math.min(100, p.last_spo2 + Math.floor(Math.random() * 3) - 1)),
        last_temp: Math.max(35, Math.min(41, p.last_temp + (Math.random() * 0.2 - 0.1)))
      })));
    }, 3000);

    return () => clearInterval(interval);
  }, []);

  const getTierColor = (tier) => {
    switch(tier) {
      case 'EMERGENCY': return 'bg-red-100 text-red-800 border-red-300';
      case 'ALERT': return 'bg-yellow-100 text-yellow-800 border-yellow-300';
      case 'NORMAL': return 'bg-green-100 text-green-800 border-green-300';
      default: return 'bg-gray-100 text-gray-800 border-gray-300';
    }
  };

  const getTierIcon = (tier) => {
    switch(tier) {
      case 'EMERGENCY': return <AlertCircle className="w-5 h-5" />;
      case 'ALERT': return <Bell className="w-5 h-5" />;
      case 'NORMAL': return <CheckCircle className="w-5 h-5" />;
      default: return <Activity className="w-5 h-5" />;
    }
  };

  const getVitalStatus = (type, value) => {
    if (type === 'hr') {
      if (value > 110 || value < 50) return 'text-red-600 font-bold';
      if (value > 100 || value < 60) return 'text-yellow-600 font-semibold';
      return 'text-green-600';
    }
    if (type === 'spo2') {
      if (value < 88) return 'text-red-600 font-bold';
      if (value < 92) return 'text-yellow-600 font-semibold';
      return 'text-green-600';
    }
    if (type === 'temp') {
      if (value > 39.5 || value < 35.5) return 'text-red-600 font-bold';
      if (value > 38.3 || value < 36.0) return 'text-yellow-600 font-semibold';
      return 'text-green-600';
    }
    return 'text-gray-700';
  };

  const handleDischarge = (patientId) => {
    setPatients(prev => prev.filter(p => p.patient_id !== patientId));
    setSelectedPatient(null);
  };

  const filteredPatients = patients
    .filter(p => filter === 'all' || p.tier === filter)
    .sort((a, b) => b.priority_score - a.priority_score);

  return (
    <div className="min-h-screen bg-gray-100">
      <div className="bg-gradient-to-r from-blue-600 to-blue-700 text-white p-6 shadow-lg">
        <div className="max-w-7xl mx-auto">
          <div className="flex items-center justify-between">
            <div>
              <h1 className="text-3xl font-bold mb-1">VitalLink Dashboard</h1>
              <p className="text-blue-100">Emergency Department Patient Monitoring</p>
            </div>
            <div className="flex items-center gap-3">
              <div className="bg-white bg-opacity-20 rounded-lg px-4 py-2">
                <p className="text-sm text-blue-100">Last Update</p>
                <p className="text-lg font-semibold">{new Date().toLocaleTimeString()}</p>
              </div>
            </div>
          </div>
        </div>
      </div>

      <div className="bg-white border-b shadow-sm">
        <div className="max-w-7xl mx-auto p-6">
          <div className="grid grid-cols-4 gap-6">
            <div className="flex items-center gap-4">
              <div className="bg-blue-100 p-3 rounded-lg">
                <Users className="w-6 h-6 text-blue-600" />
              </div>
              <div>
                <p className="text-sm text-gray-600">Active Patients</p>
                <p className="text-2xl font-bold text-gray-800">{stats.active_patients}</p>
              </div>
            </div>
            
            <div className="flex items-center gap-4">
              <div className="bg-red-100 p-3 rounded-lg">
                <AlertCircle className="w-6 h-6 text-red-600" />
              </div>
              <div>
                <p className="text-sm text-gray-600">Emergency</p>
                <p className="text-2xl font-bold text-red-600">{stats.tier_breakdown.EMERGENCY}</p>
              </div>
            </div>
            
            <div className="flex items-center gap-4">
              <div className="bg-yellow-100 p-3 rounded-lg">
                <Bell className="w-6 h-6 text-yellow-600" />
              </div>
              <div>
                <p className="text-sm text-gray-600">Alert</p>
                <p className="text-2xl font-bold text-yellow-600">{stats.tier_breakdown.ALERT}</p>
              </div>
            </div>
            
            <div className="flex items-center gap-4">
              <div className="bg-green-100 p-3 rounded-lg">
                <Clock className="w-6 h-6 text-green-600" />
              </div>
              <div>
                <p className="text-sm text-gray-600">Avg Wait Time</p>
                <p className="text-2xl font-bold text-gray-800">{stats.average_wait_minutes} min</p>
              </div>
            </div>
          </div>
        </div>
      </div>

      <div className="max-w-7xl mx-auto p-6">
        <div className="bg-white rounded-lg shadow-sm p-4 mb-6">
          <div className="flex gap-2">
            <button
              onClick={() => setFilter('all')}
              className={`px-6 py-2 rounded-lg font-semibold transition-colors ${
                filter === 'all' 
                  ? 'bg-blue-600 text-white' 
                  : 'bg-gray-100 text-gray-700 hover:bg-gray-200'
              }`}
            >
              All Patients ({patients.length})
            </button>
            <button
              onClick={() => setFilter('EMERGENCY')}
              className={`px-6 py-2 rounded-lg font-semibold transition-colors ${
                filter === 'EMERGENCY' 
                  ? 'bg-red-600 text-white' 
                  : 'bg-gray-100 text-gray-700 hover:bg-gray-200'
              }`}
            >
              Emergency ({stats.tier_breakdown.EMERGENCY})
            </button>
            <button
              onClick={() => setFilter('ALERT')}
              className={`px-6 py-2 rounded-lg font-semibold transition-colors ${
                filter === 'ALERT' 
                  ? 'bg-yellow-600 text-white' 
                  : 'bg-gray-100 text-gray-700 hover:bg-gray-200'
              }`}
            >
              Alert ({stats.tier_breakdown.ALERT})
            </button>
            <button
              onClick={() => setFilter('NORMAL')}
              className={`px-6 py-2 rounded-lg font-semibold transition-colors ${
                filter === 'NORMAL' 
                  ? 'bg-green-600 text-white' 
                  : 'bg-gray-100 text-gray-700 hover:bg-gray-200'
              }`}
            >
              Stable ({stats.tier_breakdown.NORMAL})
            </button>
          </div>
        </div>

        <div className="space-y-4">
          {filteredPatients.map((patient, index) => (
            <div 
              key={patient.patient_id}
              className="bg-white rounded-lg shadow-sm hover:shadow-md transition-shadow"
            >
              <div className="p-6">
                <div className="flex items-start justify-between mb-4">
                  <div className="flex items-start gap-4">
                    <div className="text-2xl font-bold text-gray-400 min-w-12 text-center pt-1">
                      #{index + 1}
                    </div>
                    <div>
                      <h3 className="text-xl font-bold text-gray-800 mb-1">{patient.name}</h3>
                      <div className="flex items-center gap-3 text-sm text-gray-600">
                        <span className="font-mono">{patient.patient_id}</span>
                        <span>•</span>
                        <span className="font-mono">{patient.band_id}</span>
                      </div>
                      <div className="flex flex-wrap gap-2 mt-2">
                        {patient.symptoms.map(symptom => (
                          <span key={symptom} className="bg-gray-100 text-gray-700 px-3 py-1 rounded-full text-xs font-medium">
                            {symptom}
                          </span>
                        ))}
                      </div>
                    </div>
                  </div>
                  
                  <div className="flex items-center gap-3">
                    <div className={`px-4 py-2 rounded-lg border-2 flex items-center gap-2 font-semibold ${getTierColor(patient.tier)}`}>
                      {getTierIcon(patient.tier)}
                      {patient.tier}
                    </div>
                    <button
                      onClick={() => handleDischarge(patient.patient_id)}
                      className="px-4 py-2 bg-gray-600 text-white rounded-lg hover:bg-gray-700 transition-colors flex items-center gap-2 font-semibold"
                    >
                      <UserX className="w-4 h-4" />
                      Discharge
                    </button>
                  </div>
                </div>

                <div className="grid grid-cols-4 gap-4 pt-4 border-t">
                  <div className="bg-gray-50 rounded-lg p-3">
                    <div className="flex items-center gap-2 mb-1">
                      <Heart className="w-4 h-4 text-gray-600" />
                      <span className="text-xs text-gray-600 font-medium">Heart Rate</span>
                    </div>
                    <p className={`text-2xl font-bold ${getVitalStatus('hr', patient.last_hr)}`}>
                      {patient.last_hr}
                    </p>
                    <p className="text-xs text-gray-500 mt-1">bpm</p>
                  </div>

                  <div className="bg-gray-50 rounded-lg p-3">
                    <div className="flex items-center gap-2 mb-1">
                      <Wind className="w-4 h-4 text-gray-600" />
                      <span className="text-xs text-gray-600 font-medium">SpO₂</span>
                    </div>
                    <p className={`text-2xl font-bold ${getVitalStatus('spo2', patient.last_spo2)}`}>
                      {patient.last_spo2}
                    </p>
                    <p className="text-xs text-gray-500 mt-1">%</p>
                  </div>

                  <div className="bg-gray-50 rounded-lg p-3">
                    <div className="flex items-center gap-2 mb-1">
                      <Thermometer className="w-4 h-4 text-gray-600" />
                      <span className="text-xs text-gray-600 font-medium">Temperature</span>
                    </div>
                    <p className={`text-2xl font-bold ${getVitalStatus('temp', patient.last_temp)}`}>
                      {patient.last_temp.toFixed(1)}
                    </p>
                    <p className="text-xs text-gray-500 mt-1">°C</p>
                  </div>

                  <div className="bg-gray-50 rounded-lg p-3">
                    <div className="flex items-center gap-2 mb-1">
                      <Clock className="w-4 h-4 text-gray-600" />
                      <span className="text-xs text-gray-600 font-medium">Wait Time</span>
                    </div>
                    <p className="text-2xl font-bold text-gray-700">
                      {patient.wait_time_minutes}
                    </p>
                    <p className="text-xs text-gray-500 mt-1">minutes</p>
                  </div>
                </div>
              </div>
            </div>
          ))}
        </div>

        {filteredPatients.length === 0 && (
          <div className="bg-white rounded-lg shadow-sm p-12 text-center">
            <Activity className="w-16 h-16 text-gray-300 mx-auto mb-4" />
            <h3 className="text-xl font-semibold text-gray-600 mb-2">No patients in this category</h3>
            <p className="text-gray-500">Patients will appear here as they check in</p>
          </div>
        )}
      </div>
    </div>
  );
};

const root = ReactDOM.createRoot(document.getElementById('root'));
root.render(<StaffDashboard />);