import React from 'react';
import { format, differenceInMinutes, parseISO } from 'date-fns';
import { CheckCircle2, Circle, Clock, MapPin, AlertCircle, Zap, Navigation } from 'lucide-react';
import { useTourStore } from './useTourStore.js';

const TimeVariance = ({ planned, actual }: { planned: string, actual: string | null }) => {
  if (!actual) return null;
  
  const diff = differenceInMinutes(parseISO(actual), parseISO(planned));
  const isLate = diff > 0;
  
  return (
    <div className={`flex items-center text-xs font-medium mt-1 ${isLate ? 'text-red-500' : 'text-green-600'}`}>
      {isLate ? <AlertCircle className="w-3 h-3 mr-1" /> : <CheckCircle2 className="w-3 h-3 mr-1" />}
      <span>
        {isLate ? `Trễ ${diff} phút` : diff === 0 ? 'Đúng giờ' : `Sớm ${Math.abs(diff)} phút`}
      </span>
    </div>
  );
};

const calculateDistance = (lat1: number, lon1: number, lat2: number, lon2: number) => {
  const p = 0.017453292519943295; // Math.PI / 180
  const c = Math.cos;
  const a = 0.5 - c((lat2 - lat1) * p) / 2 + 
            c(lat1 * p) * c(lat2 * p) * 
            (1 - c((lon2 - lon1) * p)) / 2;
  return 12742 * Math.asin(Math.sqrt(a)); // 2 * R; R = 6371 km
};

const formatTravelTime = (minutes: number) => {
  if (minutes < 60) return `${minutes} phút`;
  const hours = Math.floor(minutes / 60);
  const mins = minutes % 60;
  return mins > 0 ? `${hours} giờ ${mins} phút` : `${hours} giờ`;
};

export const ItineraryTimeline = () => {
  const { legs, optimizeRouting, userRole } = useTourStore();

  const toggleComplete = async (locationId: string) => {
    // Gọi API PATCH /api/v1/locations/:id để cập nhật trạng thái
    console.log("Toggle status for location:", locationId);
  };

  return (
    <div className="max-w-2xl mx-auto p-4 sm:p-6 bg-gray-50 min-h-screen">
      <h2 className="text-2xl font-bold text-gray-800 mb-8 px-2">Lộ trình chuyến đi</h2>
      
      <div className="space-y-8">
        {legs.map((leg, legIdx) => {
          const totalDwellMinutes = leg.locations.reduce((acc: number, loc: any) => {
            if (loc.plannedStart && loc.plannedEnd) {
              return acc + differenceInMinutes(parseISO(loc.plannedEnd), parseISO(loc.plannedStart));
            }
            return acc;
          }, 0);

          return (
          <div key={leg.id} className="relative">
            {/* Leg Header */}
            <div className="flex items-center mb-4 px-2">
              <div className="bg-blue-600 text-white text-sm font-bold px-3 py-1 rounded-full shadow-sm">
                Chặng {leg.sequence}
              </div>
              {leg.totalDistance !== undefined && (
                <div className="flex flex-wrap items-center gap-2 ml-3">
                  <div className="text-xs font-bold text-blue-600 bg-blue-50 px-2 py-1 rounded-lg border border-blue-100">
                    {leg.totalDistance} km
                  </div>
                  <div className="text-xs font-bold text-gray-500 bg-gray-50 px-2 py-1 rounded-lg border border-gray-100 flex items-center gap-1">
                    <Clock className="w-3 h-3" />
                    ~ {formatTravelTime(Math.round((leg.totalDistance / 35) * 60))}
                  </div>
                  {totalDwellMinutes > 0 && (
                    <div className="text-xs font-bold text-amber-600 bg-amber-50 px-2 py-1 rounded-lg border border-amber-100 flex items-center gap-1">
                      <Clock className="w-3 h-3" />
                      Dừng: {formatTravelTime(totalDwellMinutes)}
                    </div>
                  )}
                </div>
              )}
              {['OWNER', 'MANAGER'].includes(userRole || '') && (
                <button 
                  onClick={() => optimizeRouting(leg.id)}
                  className="ml-auto flex items-center gap-1.5 text-xs font-bold text-indigo-600 hover:text-indigo-700 bg-indigo-50 hover:bg-indigo-100 px-3 py-1.5 rounded-xl transition-all"
                >
                  <Zap className="w-3 h-3" />
                  Tối ưu đường đi
                </button>
              )}
              <div className="ml-4 h-[1px] flex-1 bg-gray-200" />
            </div>

            {/* Vertical Line for the whole leg */}
            <div className="absolute left-6 top-10 bottom-0 w-0.5 bg-gray-200 -z-0" />

            <div className="ml-2">
              {leg.locations.map((location, idx) => {
                const nextLocation = leg.locations[idx + 1];
                const distanceToNext = nextLocation 
                  ? calculateDistance(location.latitude, location.longitude, nextLocation.latitude, nextLocation.longitude)
                  : null;

                const averageSpeed = 35; // km/h (vận tốc trung bình giả định)
                const travelTimeMinutes = distanceToNext ? Math.round((distanceToNext / averageSpeed) * 60) : null;

                const dwellMinutes = (location.plannedStart && location.plannedEnd)
                  ? differenceInMinutes(parseISO(location.plannedEnd), parseISO(location.plannedStart))
                  : null;

                return (
                  <div key={location.id}>
                    <div className="relative flex group mb-6">
                      {/* Timeline Node */}
                      <div className="z-10 mt-1.5 mr-4">
                    <button 
                      onClick={() => toggleComplete(location.id)}
                      className={`transition-colors duration-200 ${location.status === 'COMPLETED' ? 'text-green-500' : 'text-gray-300 hover:text-blue-500'}`}
                    >
                      {location.status === 'COMPLETED' ? (
                        <CheckCircle2 className="w-8 h-8 bg-white rounded-full" />
                      ) : (
                        <Circle className="w-8 h-8 bg-white rounded-full fill-white" />
                      )}
                    </button>
                  </div>

                  {/* Card Content */}
                  <div className={`flex-1 bg-white p-4 rounded-xl border transition-all duration-200 ${
                    location.status === 'COMPLETED' ? 'border-green-100 bg-green-50/30' : 'border-gray-100 shadow-sm hover:shadow-md'
                  }`}>
                    <div className="flex justify-between items-start">
                      <div>
                        <h3 className={`font-semibold text-lg ${location.status === 'COMPLETED' ? 'text-gray-500 line-through' : 'text-gray-800'}`}>
                          {location.name}
                        </h3>
                        <div className="flex items-center text-sm text-gray-500 mt-1">
                          <MapPin className="w-3 h-3 mr-1" />
                          <span className="truncate max-w-[200px] sm:max-w-md">{location.address}</span>
                        </div>
                        {dwellMinutes !== null && (
                          <div className="flex items-center text-xs text-amber-600 font-medium mt-1">
                            <Clock className="w-3 h-3 mr-1" />
                            <span>Thời gian dừng: {formatTravelTime(dwellMinutes)}</span>
                          </div>
                        )}
                      </div>
                      
                      <div className="text-right flex flex-col items-end">
                        <div className="flex items-center text-sm font-medium text-blue-600">
                          <Clock className="w-3 h-3 mr-1" />
                          {location.plannedStart ? format(parseISO(location.plannedStart), 'HH:mm') : '--:--'}
                        </div>
                        {location.status === 'COMPLETED' && location.actualStart && (
                          <div className="text-[10px] text-gray-400 mt-1 italic">
                            Thực tế: {format(parseISO(location.actualStart), 'HH:mm')}
                          </div>
                        )}
                      </div>
                    </div>

                    {/* Logic tính toán độ lệch thời gian */}
                    <TimeVariance planned={location.plannedStart || ''} actual={location.actualStart || null} />
                  </div>
                </div>

                    {distanceToNext !== null && travelTimeMinutes !== null && (
                      <div className="ml-4 -mt-4 mb-2 flex items-center gap-3">
                        <div className="w-8 flex justify-center">
                          <Navigation className="w-3 h-3 text-blue-400 rotate-180" />
                        </div>
                        <div className="flex items-center gap-2">
                          <span className="text-[10px] font-bold text-blue-500 bg-blue-50 px-2 py-0.5 rounded-full border border-blue-100">
                            {distanceToNext.toFixed(2)} km
                          </span>
                          <span className="text-[10px] font-bold text-gray-500 bg-gray-50 px-2 py-0.5 rounded-full border border-gray-100 flex items-center gap-1">
                            <Clock className="w-2.5 h-2.5" />
                            ~ {formatTravelTime(travelTimeMinutes)}
                          </span>
                        </div>
                      </div>
                    )}
                  </div>
                );
              })}
            </div>
            
            {leg.notes && (
              <p className="ml-14 mt-4 text-sm text-gray-400 italic">
                * {leg.notes}
              </p>
            )}
          </div>
          );
        })}
      </div>
    </div>
  );
};