"use client";

// ============================================================================
// Purchases List Page
// ============================================================================

import React, { useEffect, useState } from "react";
import Link from "next/link";
import { DashboardHeader } from "@/components/layout/dashboard-header";
import {
  Card,
  CardContent,
  CardDescription,
  CardHeader,
  CardTitle,
} from "@/components/ui/card";
import { Button } from "@/components/ui/button";
import { Badge } from "@/components/ui/badge";
import { Input } from "@/components/ui/input";
import {
  Select,
  SelectContent,
  SelectItem,
  SelectTrigger,
  SelectValue,
} from "@/components/ui/select";
import {
  Table,
  TableBody,
  TableCell,
  TableHead,
  TableHeader,
  TableRow,
} from "@/components/ui/table";
import { purchasesApi, channelsApi } from "@/lib/api";
import {
  formatNumber,
  formatMetric,
  formatCurrency,
  formatDate,
  formatPercent,
} from "@/lib/utils/format";
import {
  ShoppingCart,
  Loader2,
  AlertCircle,
  Plus,
  Search,
  Filter,
  Eye,
  CheckCircle,
  Clock,
  Archive,
} from "lucide-react";
import type { Purchase, TargetChannel } from "@/lib/types/api";
import { Alert, AlertDescription } from "@/components/ui/alert";

export default function PurchasesPage() {
  const [purchases, setPurchases] = useState<Purchase[]>([]);
  const [channels, setChannels] = useState<TargetChannel[]>([]);
  const [loading, setLoading] = useState(true);
  const [error, setError] = useState<string | null>(null);
  const [searchQuery, setSearchQuery] = useState("");
  const [filterChannel, setFilterChannel] = useState<string>("all");
  const [filterStatus, setFilterStatus] = useState<string>("all");

  useEffect(() => {
    loadData();
  }, []);

  const loadData = async () => {
    try {
      setLoading(true);
      const [purchasesRes, channelsRes] = await Promise.all([
        purchasesApi.list(),
        channelsApi.list({}),
      ]);
      setPurchases(purchasesRes.data);
      setChannels(channelsRes.data);
    } catch (err: any) {
      setError(err?.error?.message || "Ошибка загрузки данных");
    } finally {
      setLoading(false);
    }
  };

  const filteredPurchases = purchases.filter((purchase) => {
    // Поиск
    const matchesSearch =
      purchase.external_channel.title
        .toLowerCase()
        .includes(searchQuery.toLowerCase()) ||
      purchase.target_channel.title
        .toLowerCase()
        .includes(searchQuery.toLowerCase()) ||
      purchase.creative.name.toLowerCase().includes(searchQuery.toLowerCase());

    // Фильтр по каналу
    const matchesChannel =
      filterChannel === "all" || purchase.target_channel.id === filterChannel;

    // Фильтр по статусу
    let matchesStatus = true;
    if (filterStatus === "completed") {
      matchesStatus = !!purchase.actual_date;
    } else if (filterStatus === "scheduled") {
      matchesStatus = !purchase.actual_date;
    } else if (filterStatus === "archived") {
      matchesStatus = purchase.is_archived;
    }

    return matchesSearch && matchesChannel && matchesStatus;
  });

  // Статистика
  const stats = {
    total: purchases.length,
    completed: purchases.filter((p) => p.actual_date).length,
    scheduled: purchases.filter((p) => !p.actual_date).length,
    totalCost: purchases.reduce((sum, p) => sum + (p.cost || 0), 0),
    totalSubscriptions: purchases.reduce(
      (sum, p) => sum + p.subscriptions_count,
      0
    ),
    avgCpf:
      purchases.length > 0
        ? purchases.reduce((sum, p) => sum + (p.cpf || 0), 0) / purchases.length
        : 0,
  };

  return (
    <>
      <DashboardHeader
        breadcrumbs={[{ label: "Главная", href: "/" }, { label: "Закупы" }]}
      />
      <div className="flex flex-1 flex-col gap-4 p-4 pt-0 mt-4">
        <div className="flex items-center justify-between">
          <div>
            <h1 className="text-3xl font-bold tracking-tight">Закупы</h1>
            <p className="text-muted-foreground mt-1">
              Рекламные размещения во внешних каналах
            </p>
          </div>
          <Button asChild>
            <Link href="/purchases/new">
              <Plus className="mr-2 h-4 w-4" />
              Создать закуп
            </Link>
          </Button>
        </div>

        {error && (
          <Alert variant="destructive">
            <AlertCircle className="h-4 w-4" />
            <AlertDescription>{error}</AlertDescription>
          </Alert>
        )}

        <div className="grid gap-4 md:grid-cols-2 lg:grid-cols-4">
          <Card>
            <CardHeader className="flex flex-row items-center justify-between space-y-0 pb-2">
              <CardTitle className="text-sm font-medium">
                Всего закупов
              </CardTitle>
              <ShoppingCart className="h-4 w-4 text-muted-foreground" />
            </CardHeader>
            <CardContent>
              <div className="text-2xl font-bold">
                {formatNumber(stats.total)}
              </div>
              <p className="text-xs text-muted-foreground mt-1">
                {stats.completed} завершено, {stats.scheduled} запланировано
              </p>
            </CardContent>
          </Card>

          <Card>
            <CardHeader className="flex flex-row items-center justify-between space-y-0 pb-2">
              <CardTitle className="text-sm font-medium">
                Общие затраты
              </CardTitle>
            </CardHeader>
            <CardContent>
              <div className="text-2xl font-bold">
                {formatCurrency(stats.totalCost)}
              </div>
              <p className="text-xs text-muted-foreground mt-1">
                За все закупы
              </p>
            </CardContent>
          </Card>

          <Card>
            <CardHeader className="flex flex-row items-center justify-between space-y-0 pb-2">
              <CardTitle className="text-sm font-medium">
                Подписчиков привлечено
              </CardTitle>
            </CardHeader>
            <CardContent>
              <div className="text-2xl font-bold">
                {formatNumber(stats.totalSubscriptions)}
              </div>
              <p className="text-xs text-muted-foreground mt-1">Всего</p>
            </CardContent>
          </Card>

          <Card>
            <CardHeader className="flex flex-row items-center justify-between space-y-0 pb-2">
              <CardTitle className="text-sm font-medium">Средний CPF</CardTitle>
            </CardHeader>
            <CardContent>
              <div className="text-2xl font-bold">
                ₽{formatMetric(stats.avgCpf)}
              </div>
              <p className="text-xs text-muted-foreground mt-1">
                По всем закупам
              </p>
            </CardContent>
          </Card>
        </div>

        <Card>
          <CardHeader>
            <CardTitle>Фильтры</CardTitle>
          </CardHeader>
          <CardContent className="space-y-4">
            <div className="grid gap-4 md:grid-cols-3">
              <div className="relative">
                <Search className="absolute left-2.5 top-2.5 h-4 w-4 text-muted-foreground" />
                <Input
                  placeholder="Поиск по названию..."
                  value={searchQuery}
                  onChange={(e) => setSearchQuery(e.target.value)}
                  className="pl-8"
                />
              </div>

              <Select value={filterChannel} onValueChange={setFilterChannel}>
                <SelectTrigger>
                  <SelectValue placeholder="Целевой канал" />
                </SelectTrigger>
                <SelectContent>
                  <SelectItem value="all">Все каналы</SelectItem>
                  {channels.map((channel) => (
                    <SelectItem key={channel.id} value={channel.id}>
                      {channel.title}
                    </SelectItem>
                  ))}
                </SelectContent>
              </Select>

              <Select value={filterStatus} onValueChange={setFilterStatus}>
                <SelectTrigger>
                  <SelectValue placeholder="Статус" />
                </SelectTrigger>
                <SelectContent>
                  <SelectItem value="all">Все статусы</SelectItem>
                  <SelectItem value="completed">Завершено</SelectItem>
                  <SelectItem value="scheduled">Запланировано</SelectItem>
                  <SelectItem value="archived">Архив</SelectItem>
                </SelectContent>
              </Select>
            </div>

            <div className="flex items-center gap-2">
              <Badge variant="secondary">
                Найдено: {formatNumber(filteredPurchases.length)}
              </Badge>
            </div>
          </CardContent>
        </Card>

        <Card>
          <CardHeader>
            <CardTitle>Список закупов</CardTitle>
            <CardDescription>Все рекламные размещения</CardDescription>
          </CardHeader>
          <CardContent>
            {loading ? (
              <div className="flex items-center justify-center p-12">
                <Loader2 className="h-8 w-8 animate-spin text-muted-foreground" />
              </div>
            ) : filteredPurchases.length === 0 ? (
              <div className="text-center py-12">
                <ShoppingCart className="h-12 w-12 text-muted-foreground mx-auto mb-4" />
                <p className="text-lg font-medium text-muted-foreground">
                  {searchQuery ||
                  filterChannel !== "all" ||
                  filterStatus !== "all"
                    ? "Закупы не найдены"
                    : "Нет закупов"}
                </p>
                <p className="text-sm text-muted-foreground mt-1">
                  {searchQuery ||
                  filterChannel !== "all" ||
                  filterStatus !== "all"
                    ? "Попробуйте изменить фильтры"
                    : "Создайте первый закуп"}
                </p>
              </div>
            ) : (
              <Table>
                <TableHeader>
                  <TableRow>
                    <TableHead>Статус</TableHead>
                    <TableHead>Целевой канал</TableHead>
                    <TableHead>Внешний канал</TableHead>
                    <TableHead>Креатив</TableHead>
                    <TableHead>Дата</TableHead>
                    <TableHead className="text-right">Стоимость</TableHead>
                    <TableHead className="text-right">Подписчики</TableHead>
                    <TableHead className="text-right">CPF</TableHead>
                    <TableHead className="text-right">Конверсия</TableHead>
                    <TableHead></TableHead>
                  </TableRow>
                </TableHeader>
                <TableBody>
                  {filteredPurchases.map((purchase) => (
                    <TableRow key={purchase.id}>
                      <TableCell>
                        {purchase.is_archived ? (
                          <Badge variant="secondary">
                            <Archive className="h-3 w-3 mr-1" />
                            Архив
                          </Badge>
                        ) : purchase.actual_date ? (
                          <Badge variant="default">
                            <CheckCircle className="h-3 w-3 mr-1" />
                            Завершено
                          </Badge>
                        ) : (
                          <Badge variant="outline">
                            <Clock className="h-3 w-3 mr-1" />
                            Запланировано
                          </Badge>
                        )}
                      </TableCell>
                      <TableCell className="font-medium">
                        {purchase.target_channel.title}
                      </TableCell>
                      <TableCell>{purchase.external_channel.title}</TableCell>
                      <TableCell className="max-w-[200px] truncate">
                        {purchase.creative.name}
                      </TableCell>
                      <TableCell>
                        {formatDate(
                          purchase.actual_date || purchase.scheduled_date
                        )}
                      </TableCell>
                      <TableCell className="text-right">
                        {formatCurrency(purchase.cost)}
                      </TableCell>
                      <TableCell className="text-right">
                        {formatNumber(purchase.subscriptions_count)}
                      </TableCell>
                      <TableCell className="text-right">
                        {purchase.cpf ? `₽${formatMetric(purchase.cpf)}` : "—"}
                      </TableCell>
                      <TableCell className="text-right">
                        {purchase.conversion_rate
                          ? formatPercent(purchase.conversion_rate)
                          : "—"}
                      </TableCell>
                      <TableCell className="text-right">
                        <Button asChild variant="ghost" size="sm">
                          <Link href={`/purchases/${purchase.id}`}>
                            <Eye className="h-4 w-4" />
                          </Link>
                        </Button>
                      </TableCell>
                    </TableRow>
                  ))}
                </TableBody>
              </Table>
            )}
          </CardContent>
        </Card>
      </div>
    </>
  );
}