'use client';

import { Plus, Trash2, BarChart3 } from 'lucide-react';
import { useState } from 'react';
import { Badge } from '@/components/ui/badge';
import { Button } from '@/components/ui/button';
import {
  Card,
  CardContent,
  CardDescription,
  CardHeader,
  CardTitle,
} from '@/components/ui/card';
import { Input } from '@/components/ui/input';
import { Label } from '@/components/ui/label';
import { Select } from '@/components/ui/select';
import { formatPrice, formatPricePerM2 } from '@/lib/currency';
import { useValuationBatch } from '@/lib/hooks/use-valuation';
import {
  VALUATION_PROPERTY_TYPES,
  CITIES,
} from '@/lib/validations/valuation';
import type { ValuationRequest, ValuationResult } from '@/lib/valuation-api';

interface PropertySlot {
  id: string;
  propertyType: string;
  area: string;
  district: string;
  city: string;
  bedrooms: string;
  label: string;
}

function createEmptySlot(index: number): PropertySlot {
  return {
    id: crypto.randomUUID(),
    propertyType: 'APARTMENT',
    area: '',
    district: '',
    city: 'Ho Chi Minh',
    bedrooms: '',
    label: `BĐS ${index + 1}`,
  };
}

function getConfidenceColor(c: number): string {
  if (c >= 0.8) return 'text-green-600';
  if (c >= 0.5) return 'text-yellow-600';
  return 'text-red-600';
}

function getConfidenceVariant(c: number): 'success' | 'warning' | 'destructive' {
  if (c >= 0.8) return 'success';
  if (c >= 0.5) return 'warning';
  return 'destructive';
}

export function ValuationCompare() {
  const [slots, setSlots] = useState<PropertySlot[]>([
    createEmptySlot(0),
    createEmptySlot(1),
  ]);
  const [results, setResults] = useState<ValuationResult[] | null>(null);

  const batchMutation = useValuationBatch();

  const updateSlot = (id: string, field: keyof PropertySlot, value: string) => {
    setSlots((prev) =>
      prev.map((s) => (s.id === id ? { ...s, [field]: value } : s)),
    );
  };

  const addSlot = () => {
    if (slots.length >= 5) return;
    setSlots((prev) => [...prev, createEmptySlot(prev.length)]);
  };

  const removeSlot = (id: string) => {
    if (slots.length <= 2) return;
    setSlots((prev) => prev.filter((s) => s.id !== id));
  };

  const handleCompare = () => {
    const validSlots = slots.filter((s) => s.area && s.district);
    if (validSlots.length < 2) return;

    const properties: ValuationRequest[] = validSlots.map((s) => ({
      propertyType: s.propertyType,
      area: Number(s.area),
      district: s.district,
      city: s.city,
      bedrooms: s.bedrooms ? Number(s.bedrooms) : undefined,
    }));

    batchMutation.mutate(
      { properties },
      {
        onSuccess: (data) => {
          setResults(data.results);
        },
      },
    );
  };

  const bestValue =
    results && results.length > 0
      ? results.reduce((best, r) =>
          r.pricePerM2 < best.pricePerM2 ? r : best,
        )
      : null;

  return (
    <div className="space-y-6">
      <Card>
        <CardHeader>
          <div className="flex items-center gap-2">
            <BarChart3 className="h-5 w-5 text-primary" />
            <CardTitle>So sánh định giá</CardTitle>
          </div>
          <CardDescription>
            So sánh giá trị ước tính của nhiều bất động sản cùng lúc (2-5 BĐS)
          </CardDescription>
        </CardHeader>
        <CardContent className="space-y-4">
          {slots.map((slot) => (
            <div
              key={slot.id}
              className="rounded-lg border p-4 space-y-3"
            >
              <div className="flex items-center justify-between">
                <Label className="text-sm font-semibold">{slot.label}</Label>
                {slots.length > 2 && (
                  <button
                    type="button"
                    onClick={() => removeSlot(slot.id)}
                    className="text-muted-foreground hover:text-destructive"
                  >
                    <Trash2 className="h-4 w-4" />
                  </button>
                )}
              </div>
              <div className="grid gap-3 sm:grid-cols-2 lg:grid-cols-5">
                <Select
                  value={slot.propertyType}
                  onChange={(e) =>
                    updateSlot(slot.id, 'propertyType', e.target.value)
                  }
                >
                  {VALUATION_PROPERTY_TYPES.map((t) => (
                    <option key={t.value} value={t.value}>
                      {t.label}
                    </option>
                  ))}
                </Select>
                <Input
                  type="number"
                  placeholder="Diện tích (m²)"
                  value={slot.area}
                  onChange={(e) => updateSlot(slot.id, 'area', e.target.value)}
                />
                <Input
                  placeholder="Quận/Huyện"
                  value={slot.district}
                  onChange={(e) =>
                    updateSlot(slot.id, 'district', e.target.value)
                  }
                />
                <Select
                  value={slot.city}
                  onChange={(e) => updateSlot(slot.id, 'city', e.target.value)}
                >
                  {CITIES.map((c) => (
                    <option key={c.value} value={c.value}>
                      {c.label}
                    </option>
                  ))}
                </Select>
                <Input
                  type="number"
                  placeholder="Phòng ngủ"
                  value={slot.bedrooms}
                  onChange={(e) =>
                    updateSlot(slot.id, 'bedrooms', e.target.value)
                  }
                />
              </div>
            </div>
          ))}

          <div className="flex gap-3">
            {slots.length < 5 && (
              <Button type="button" variant="outline" onClick={addSlot}>
                <Plus className="mr-1.5 h-4 w-4" />
                Thêm BĐS
              </Button>
            )}
            <Button
              onClick={handleCompare}
              disabled={
                batchMutation.isPending ||
                slots.filter((s) => s.area && s.district).length < 2
              }
            >
              {batchMutation.isPending
                ? 'Đang so sánh...'
                : 'So sánh ngay'}
            </Button>
          </div>
        </CardContent>
      </Card>

      {/* Comparison results */}
      {results && results.length > 0 && (
        <div className="grid gap-4 sm:grid-cols-2 lg:grid-cols-3">
          {results.map((result, i) => {
            const isBest = bestValue && result.id === bestValue.id;
            return (
              <Card
                key={result.id || i}
                className={isBest ? 'border-primary ring-2 ring-primary/20' : ''}
              >
                <CardHeader className="pb-2">
                  <div className="flex items-center justify-between">
                    <CardTitle className="text-base">
                      {slots[i]?.label ?? `BĐS ${i + 1}`}
                    </CardTitle>
                    {isBest && (
                      <Badge variant="success" className="text-xs">
                        Giá/m² tốt nhất
                      </Badge>
                    )}
                  </div>
                  <CardDescription className="text-xs">
                    {slots[i]?.district}, {slots[i]?.city}
                  </CardDescription>
                </CardHeader>
                <CardContent className="space-y-3">
                  <div>
                    <p className="text-2xl font-bold text-primary">
                      {formatPrice(result.estimatedPriceVND)} VNĐ
                    </p>
                    <p className="text-sm text-muted-foreground">
                      {formatPricePerM2(result.pricePerM2)}/m²
                    </p>
                  </div>

                  <div className="flex items-center justify-between text-sm">
                    <span className="text-muted-foreground">Độ tin cậy</span>
                    <span className={`font-semibold ${getConfidenceColor(result.confidence)}`}>
                      {Math.round(result.confidence * 100)}%
                    </span>
                  </div>

                  <div className="h-1.5 rounded-full bg-muted">
                    <div
                      className={`h-1.5 rounded-full ${
                        result.confidence >= 0.8
                          ? 'bg-green-500'
                          : result.confidence >= 0.5
                            ? 'bg-yellow-500'
                            : 'bg-red-500'
                      }`}
                      style={{ width: `${result.confidence * 100}%` }}
                    />
                  </div>

                  <div className="text-xs text-muted-foreground">
                    Khoảng giá: {formatPrice(result.priceRangeLow)} -{' '}
                    {formatPrice(result.priceRangeHigh)}
                  </div>

                  {result.priceDrivers.length > 0 && (
                    <div className="flex flex-wrap gap-1 pt-1">
                      {result.priceDrivers.slice(0, 3).map((d) => (
                        <Badge
                          key={d.feature}
                          variant={getConfidenceVariant(
                            d.direction === 'positive' ? 1 : 0,
                          )}
                          className="text-[10px]"
                        >
                          {d.direction === 'positive' ? '+' : '-'}
                          {Math.abs(d.impact).toFixed(0)}% {d.feature}
                        </Badge>
                      ))}
                    </div>
                  )}
                </CardContent>
              </Card>
            );
          })}
        </div>
      )}

      {batchMutation.isError && (
        <div className="rounded-lg border border-destructive/50 bg-destructive/10 p-4 text-sm text-destructive">
          Không thể so sánh. Vui lòng thử lại sau.
        </div>
      )}
    </div>
  );
}