import React, { useState } from 'react';
import { useApp } from '../context/AppContext';
import { Kanban, User, Calendar, MapPin, Star, Plus, ArrowRight, Eye } from 'lucide-react';

export const KanbanBoard = () => {
  const { tenders, updateKanbanStatus, setActiveTenderDetail } = useApp();
  const [selectedPersonel, setSelectedPersonel] = useState('');
  const [draggedTenderId, setDraggedTenderId] = useState(null);

  const columns = [
    { id: 'incelenecek', title: 'İncelenecek', color: 'bg-slate-100 border-slate-300 text-slate-800' },
    { id: 'inceleniyor', title: 'İnceleniyor', color: 'bg-blue-50 border-blue-200 text-blue-900' },
    { id: 'teklif_hazirlaniyor', title: 'Teklif Hazırlanıyor', color: 'bg-amber-50 border-amber-200 text-amber-900' },
    { id: 'teklif_verildi', title: 'Teklif Verildi', color: 'bg-purple-50 border-purple-200 text-purple-900' },
    { id: 'kazanildi', title: 'Kazanıldı', color: 'bg-emerald-50 border-emerald-200 text-emerald-900' },
    { id: 'kaybedildi', title: 'Kaybedildi', color: 'bg-rose-50 border-rose-200 text-rose-900' }
  ];

  const personnelList = ['Hikmet Tanrıverdi', 'Ahmet Yılmaz', 'Zeynep Kaya', 'Mehmet Demir'];

  const filteredTenders = tenders.filter(t => {
    if (!t.takipte && !t.kanbanStatus) return false;
    if (selectedPersonel && t.atananPersonel !== selectedPersonel) return false;
    return true;
  });

  const handleDragStart = (e, id) => {
    e.dataTransfer.setData('tenderId', id);
    setDraggedTenderId(id);
  };

  const handleDragOver = (e) => {
    e.preventDefault();
  };

  const handleDrop = (e, columnId) => {
    e.preventDefault();
    const id = e.dataTransfer.getData('tenderId') || draggedTenderId;
    if (id) {
      updateKanbanStatus(id, columnId);
      setDraggedTenderId(null);
    }
  };

  return (
    <div className="space-y-4 my-4 animate-fade-in">
      
      {/* Kanban Header Controls */}
      <div className="bg-white rounded-xl border border-slate-200 p-4 shadow-xs flex flex-col sm:flex-row items-center justify-between gap-4">
        <div className="flex items-center gap-3">
          <div className="w-10 h-10 rounded-xl bg-blue-600 text-white flex items-center justify-center shadow-md">
            <Kanban className="w-6 h-6" />
          </div>
          <div>
            <h1 className="text-xl font-black text-slate-900">Ekip Kanban Takip Panosu</h1>
            <p className="text-xs text-slate-500">Kartları kolonlar arasında sürükleyerek ihale süreçlerinizi yönetin.</p>
          </div>
        </div>

        {/* Personnel Filter & Slack Notification Buttons */}
        <div className="flex items-center gap-3 w-full sm:w-auto">
          <div className="flex items-center gap-2 bg-slate-50 border border-slate-300 rounded-xl px-3 py-1.5 text-xs">
            <User className="w-4 h-4 text-slate-400" />
            <select
              value={selectedPersonel}
              onChange={(e) => setSelectedPersonel(e.target.value)}
              className="bg-transparent font-semibold text-slate-800 outline-none"
            >
              <option value="">Tüm Personeller</option>
              {personnelList.map(p => <option key={p} value={p}>{p}</option>)}
            </select>
          </div>

          <button
            onClick={() => alert('Slack & Teams kanalına Kanban güncel durumu başarıyla gönderildi!')}
            className="bg-slate-900 hover:bg-slate-800 text-white font-bold text-xs px-3.5 py-2 rounded-xl flex items-center gap-1.5 transition-colors shadow-xs shrink-0"
            title="Slack & Teams Ekip Kanalına Bildirim Gönder"
          >
            <span>💬 Slack/Teams'e Gönder</span>
          </button>
        </div>
      </div>

      {/* Kanban Columns Grid */}
      <div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-6 gap-3.5 overflow-x-auto pb-4">
        {columns.map(col => {
          const colTenders = filteredTenders.filter(t => (t.kanbanStatus || 'incelenecek') === col.id);

          return (
            <div
              key={col.id}
              onDragOver={handleDragOver}
              onDrop={(e) => handleDrop(e, col.id)}
              className={`rounded-2xl border ${col.color} p-3 flex flex-col min-h-[550px] shadow-2xs transition-colors`}
            >
              {/* Column Header */}
              <div className="flex items-center justify-between border-b border-black/10 pb-2 mb-3">
                <span className="font-extrabold text-xs uppercase tracking-tight">{col.title}</span>
                <span className="bg-white/80 font-black text-xs px-2 py-0.5 rounded-full border border-black/10 shadow-2xs">
                  {colTenders.length}
                </span>
              </div>

              {/* Column Cards */}
              <div className="space-y-3 flex-1 overflow-y-auto max-h-[650px] pr-0.5">
                {colTenders.length === 0 ? (
                  <div className="py-10 text-center border-2 border-dashed border-black/10 rounded-xl">
                    <p className="text-[11px] font-semibold text-slate-400">İhale yok</p>
                  </div>
                ) : (
                  colTenders.map(t => (
                    <div
                      key={t.id}
                      draggable
                      onDragStart={(e) => handleDragStart(e, t.id)}
                      className="bg-white rounded-xl p-3 border border-slate-200 shadow-xs hover:shadow-md cursor-grab active:cursor-grabbing space-y-2 transition-all group"
                    >
                      <div className="flex items-start justify-between gap-1">
                        <span className="text-[10px] font-extrabold bg-blue-100 text-blue-800 px-2 py-0.5 rounded">
                          #{t.ikn}
                        </span>
                        <button
                          onClick={() => setActiveTenderDetail(t)}
                          className="text-slate-400 hover:text-blue-600 p-0.5"
                          title="Detayı Aç"
                        >
                          <Eye className="w-3.5 h-3.5" />
                        </button>
                      </div>

                      <h4 
                        onClick={() => setActiveTenderDetail(t)}
                        className="font-bold text-xs text-slate-900 line-clamp-2 hover:text-blue-600 cursor-pointer leading-snug"
                      >
                        {t.baslik}
                      </h4>

                      <div className="flex items-center justify-between text-[10px] text-slate-500 font-medium">
                        <span className="flex items-center gap-1">
                          <MapPin className="w-3 h-3 text-rose-500" /> {t.sehir}
                        </span>
                        <span className="flex items-center gap-1 font-bold text-blue-900">
                          <Calendar className="w-3 h-3 text-blue-500" /> {t.tarih}
                        </span>
                      </div>

                      {/* Personnel Select on Card */}
                      <div className="pt-1.5 border-t border-slate-100 flex items-center justify-between text-[10px]">
                        <span className="text-slate-400">Atanan:</span>
                        <select
                          value={t.atananPersonel || ''}
                          onChange={(e) => updateKanbanStatus(t.id, col.id, e.target.value)}
                          className="bg-slate-50 border border-slate-200 rounded px-1.5 py-0.5 text-[10px] font-bold text-slate-800"
                        >
                          <option value="">Atama Yap</option>
                          {personnelList.map(p => (
                            <option key={p} value={p}>{p}</option>
                          ))}
                        </select>
                      </div>

                    </div>
                  ))
                )}
              </div>

            </div>
          );
        })}
      </div>

    </div>
  );
};