import React, { useState } from 'react';
import { Deal, DealStage } from '../../../entities/crm/deal';
import { Contact } from '../../../entities/crm/contact';
import { Company } from '../../../entities/crm/company';
import { Button } from '../../../shared/ui/Button';
import { formatCurrencyMinor } from '../../../shared/lib/currency';
import { DEAL_STAGES } from '../constants';
import { Search, Plus, ArrowRight, Building } from 'lucide-react';

export interface CrmKanbanViewProps {
  deals: Deal[];
  contacts: Contact[];
  companies: Company[];
  search: string;
  onSearchChange: (value: string) => void;
  onAddDeal: () => void;
  onStageChange: (dealId: string, nextStage: DealStage) => Promise<void> | void;
}

export const CrmKanbanView: React.FC<CrmKanbanViewProps> = ({
  deals,
  contacts,
  companies,
  search,
  onSearchChange,
  onAddDeal,
  onStageChange,
}) => {
  const [draggedDealId, setDraggedDealId] = useState<string | null>(null);

  const handleDragStart = (e: React.DragEvent, dealId: string) => {
    e.dataTransfer.setData('text/plain', dealId);
    setDraggedDealId(dealId);
  };

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

  const handleDrop = async (e: React.DragEvent, targetStage: DealStage) => {
    e.preventDefault();
    const dealId = e.dataTransfer.getData('text/plain') || draggedDealId;
    if (dealId) {
      await onStageChange(dealId, targetStage);
    }
    setDraggedDealId(null);
  };

  return (
    <div className="space-y-3">
      <div className="flex items-center justify-between">
        <div className="relative w-64">
          <Search className="w-3.5 h-3.5 absolute left-2.5 top-2.5 text-krona-secondary" />
          <input
            type="text"
            value={search}
            onChange={(e) => onSearchChange(e.target.value)}
            placeholder="Поиск по сделкам..."
            className="w-full pl-8 pr-3 py-1.5 text-xs bg-krona-surface border border-krona-border rounded-lg text-krona-primary focus:outline-none focus:border-krona-green"
          />
        </div>
        <Button variant="primary" size="sm" onClick={onAddDeal}>
          <Plus className="w-3.5 h-3.5 mr-1" /> Новая сделка
        </Button>
      </div>

      <div className="grid grid-cols-1 md:grid-cols-4 lg:grid-cols-7 gap-2.5 overflow-x-auto pb-4">
        {DEAL_STAGES.map((col) => {
          const colDeals = deals.filter(
            (d) =>
              d.stage === col.key &&
              (d.title.toLowerCase().includes(search.toLowerCase()) || !search)
          );
          const colTotalMinor = colDeals.reduce((sum, d) => sum + d.amount.minor, 0);

          return (
            <div
              key={col.key}
              data-testid={`kanban-column-${col.key}`}
              onDragOver={handleDragOver}
              onDrop={(e) => handleDrop(e, col.key)}
              className={`bg-krona-surface/70 border rounded-xl p-2.5 flex flex-col min-w-[200px] max-h-[750px] shadow-krona-soft transition-all ${col.color}`}
            >
              <div className="flex items-center justify-between border-b border-krona-border/60 pb-2 mb-2">
                <div>
                  <div className="text-xs font-bold text-krona-primary">{col.label}</div>
                  <div className="text-[11px] font-medium text-krona-green mt-0.5">
                    {formatCurrencyMinor(colTotalMinor)}
                  </div>
                </div>
                <span className="text-[11px] px-1.5 py-0.5 rounded-full bg-krona-workspace text-krona-secondary font-bold">
                  {colDeals.length}
                </span>
              </div>

              <div className="space-y-2 overflow-y-auto flex-1 pr-0.5">
                {colDeals.map((deal) => {
                  const contact = contacts.find((c) => c.id === deal.contactId);
                  const company = companies.find((c) => c.id === deal.companyId);
                  const nextStageIdx = DEAL_STAGES.findIndex((s) => s.key === deal.stage) + 1;
                  const nextStage = DEAL_STAGES[nextStageIdx]?.key;

                  return (
                    <div
                      key={deal.id}
                      data-testid={`deal-card-${deal.id}`}
                      data-deal-id={deal.id}
                      data-deal-stage={deal.stage}
                      draggable
                      onDragStart={(e) => handleDragStart(e, deal.id)}
                      className="bg-krona-workspace border border-krona-border hover:border-krona-green/60 p-2.5 rounded-lg text-xs space-y-2 shadow-xs cursor-grab active:cursor-grabbing transition-all"
                    >
                      <div className="font-semibold text-krona-primary line-clamp-2">
                        {deal.title}
                      </div>

                      <div className="flex items-center justify-between text-[11px]">
                        <span className="font-bold text-krona-primary">
                          {formatCurrencyMinor(deal.amount.minor)}
                        </span>
                        <span className="px-1.5 py-0.2 bg-emerald-500/10 text-emerald-600 dark:text-emerald-400 rounded font-medium">
                          {deal.probability}% вер.
                        </span>
                      </div>

                      {(contact || company) && (
                        <div className="text-[11px] text-krona-secondary truncate flex items-center gap-1">
                          <Building className="w-3 h-3" />
                          {company?.name || `${contact?.firstName} ${contact?.lastName}`}
                        </div>
                      )}

                      {/* Quick stage transition button */}
                      {nextStage && deal.stage !== 'won' && deal.stage !== 'lost' && (
                        <button
                          type="button"
                          onClick={() => onStageChange(deal.id, nextStage)}
                          className="w-full mt-1 py-1 text-[11px] bg-krona-surface hover:bg-krona-green/10 text-krona-secondary hover:text-krona-green border border-krona-border rounded flex items-center justify-center gap-1 transition-colors"
                        >
                          Далее: {DEAL_STAGES[nextStageIdx]?.label} <ArrowRight className="w-3 h-3" />
                        </button>
                      )}
                    </div>
                  );
                })}

                {colDeals.length === 0 && (
                  <div className="text-center py-6 text-[11px] text-krona-secondary italic">
                    Пусто
                  </div>
                )}
              </div>
            </div>
          );
        })}
      </div>
    </div>
  );
};