"use client";

// ============================================================================
// External Channel Detail Page
// ============================================================================

import React, { useEffect, useState } from "react";
import { use } from "react";
import Link from "next/link";
import { useRouter } from "next/navigation";
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 { Alert, AlertDescription } from "@/components/ui/alert";
import {
  Table,
  TableBody,
  TableCell,
  TableHead,
  TableHeader,
  TableRow,
} from "@/components/ui/table";
import { externalChannelsApi } from "@/lib/api";
import {
  formatNumber,
  formatMetric,
  formatCurrency,
  formatUsername,
  formatDate,
  formatCompactNumber,
} from "@/lib/utils/format";
import {
  ExternalLink as ExternalLinkIcon,
  Users,
  TrendingUp,
  ArrowLeft,
  Loader2,
  AlertCircle,
  BarChart3,
  Pencil,
  Trash2,
} from "lucide-react";
import type { ExternalChannelDetail } from "@/lib/types/api";

interface PageProps {
  params: Promise<{ id: string }>;
}

export default function ExternalChannelDetailPage({ params }: PageProps) {
  const resolvedParams = use(params);
  const router = useRouter();
  const [channel, setChannel] = useState<ExternalChannelDetail | null>(null);
  const [loading, setLoading] = useState(true);
  const [error, setError] = useState<string | null>(null);

  useEffect(() => {
    const loadChannel = async () => {
      try {
        setLoading(true);
        const data = await externalChannelsApi.get(resolvedParams.id);
        setChannel(data);
      } catch (err: any) {
        setError(err?.error?.message || "Ошибка загрузки канала");
      } finally {
        setLoading(false);
      }
    };

    loadChannel();
  }, [resolvedParams.id]);

  const handleDelete = async () => {
    if (!channel) return;
    if (!confirm(`Удалить канал "${channel.title}"?`)) return;

    try {
      await externalChannelsApi.delete(channel.id);
      router.push("/external-channels");
    } catch (err: any) {
      alert(err?.error?.message || "Ошибка удаления канала");
    }
  };

  if (loading) {
    return (
      <>
        <DashboardHeader
          breadcrumbs={[
            { label: "Внешние каналы", href: "/external-channels" },
            { label: "Загрузка..." },
          ]}
        />
        <div className="flex flex-1 items-center justify-center">
          <Loader2 className="h-8 w-8 animate-spin text-muted-foreground" />
        </div>
      </>
    );
  }

  if (error || !channel) {
    return (
      <>
        <DashboardHeader
          breadcrumbs={[
            { label: "Внешние каналы", href: "/external-channels" },
            { label: "Ошибка" },
          ]}
        />
        <div className="flex flex-1 flex-col gap-4 p-4 pt-0 mt-4">
          <Alert variant="destructive">
            <AlertCircle className="h-4 w-4" />
            <AlertDescription>{error || "Канал не найден"}</AlertDescription>
          </Alert>
          <Button asChild variant="outline">
            <Link href="/external-channels">
              <ArrowLeft className="mr-2 h-4 w-4" />
              Вернуться к каналам
            </Link>
          </Button>
        </div>
      </>
    );
  }

  return (
    <>
      <DashboardHeader
        breadcrumbs={[
          { label: "Главная", href: "/" },
          { label: "Внешние каналы", href: "/external-channels" },
          { label: channel.title },
        ]}
      />
      <div className="flex flex-1 flex-col gap-4 p-4 pt-0 mt-4">
        <div className="flex items-start justify-between">
          <div className="flex-1">
            <div className="flex items-center gap-2 mb-2">
              <ExternalLinkIcon className="h-6 w-6" />
              <h1 className="text-3xl font-bold tracking-tight">
                {channel.title}
              </h1>
            </div>
            <div className="flex items-center gap-4 text-sm text-muted-foreground">
              {channel.username ? (
                <a
                  href={channel.link}
                  target="_blank"
                  rel="noopener noreferrer"
                  className="hover:underline flex items-center gap-1"
                >
                  {formatUsername(channel.username)}
                  <ExternalLinkIcon className="h-3 w-3" />
                </a>
              ) : (
                <a
                  href={channel.link}
                  target="_blank"
                  rel="noopener noreferrer"
                  className="hover:underline flex items-center gap-1"
                >
                  {channel.link}
                  <ExternalLinkIcon className="h-3 w-3" />
                </a>
              )}
              <span>•</span>
              <span>Добавлен {formatDate(channel.created_at)}</span>
            </div>
          </div>
          <div className="flex gap-2">
            <Button variant="outline" onClick={handleDelete}>
              <Trash2 className="mr-2 h-4 w-4" />
              Удалить
            </Button>
          </div>
        </div>

        {channel.description && (
          <Card>
            <CardHeader>
              <CardTitle>Описание</CardTitle>
            </CardHeader>
            <CardContent>
              <p className="text-muted-foreground">{channel.description}</p>
            </CardContent>
          </Card>
        )}

        <div className="grid gap-4 md:grid-cols-4">
          <Card>
            <CardHeader className="flex flex-row items-center justify-between space-y-0 pb-2">
              <CardTitle className="text-sm font-medium">Подписчиков</CardTitle>
              <Users className="h-4 w-4 text-muted-foreground" />
            </CardHeader>
            <CardContent>
              <div className="text-2xl font-bold">
                {channel.subscribers_count
                  ? formatCompactNumber(channel.subscribers_count)
                  : "—"}
              </div>
              <p className="text-xs text-muted-foreground mt-1">В канале</p>
            </CardContent>
          </Card>

          <Card>
            <CardHeader className="flex flex-row items-center justify-between space-y-0 pb-2">
              <CardTitle className="text-sm font-medium">
                Всего закупов
              </CardTitle>
              <BarChart3 className="h-4 w-4 text-muted-foreground" />
            </CardHeader>
            <CardContent>
              <div className="text-2xl font-bold">
                {formatNumber(channel.total_purchases)}
              </div>
              <p className="text-xs text-muted-foreground mt-1">
                В этом канале
              </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>
              <TrendingUp className="h-4 w-4 text-muted-foreground" />
            </CardHeader>
            <CardContent>
              <div className="text-2xl font-bold">
                ₽{formatMetric(channel.avg_cpf)}
              </div>
              <p className="text-xs text-muted-foreground mt-1">
                По всем закупам
              </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 CPM</CardTitle>
              <TrendingUp className="h-4 w-4 text-muted-foreground" />
            </CardHeader>
            <CardContent>
              <div className="text-2xl font-bold">
                ₽{formatMetric(channel.avg_cpm)}
              </div>
              <p className="text-xs text-muted-foreground mt-1">
                Стоимость 1000 просмотров
              </p>
            </CardContent>
          </Card>
        </div>

        <Card>
          <CardHeader>
            <CardTitle>История закупов</CardTitle>
            <CardDescription>
              Все рекламные размещения в этом канале
            </CardDescription>
          </CardHeader>
          <CardContent>
            {channel.purchases.length === 0 ? (
              <p className="text-center text-muted-foreground py-8">
                Закупов в этом канале пока нет
              </p>
            ) : (
              <Table>
                <TableHeader>
                  <TableRow>
                    <TableHead>Целевой канал</TableHead>
                    <TableHead>Дата</TableHead>
                    <TableHead className="text-right">Стоимость</TableHead>
                    <TableHead className="text-right">Подписчики</TableHead>
                    <TableHead className="text-right">CPF</TableHead>
                    <TableHead></TableHead>
                  </TableRow>
                </TableHeader>
                <TableBody>
                  {channel.purchases.map((purchase) => (
                    <TableRow key={purchase.id}>
                      <TableCell className="font-medium">
                        {purchase.target_channel.title}
                      </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">
                        ₽{formatMetric(purchase.cpf)}
                      </TableCell>
                      <TableCell className="text-right">
                        <Button asChild variant="ghost" size="sm">
                          <Link href={`/purchases/${purchase.id}`}>
                            Открыть
                          </Link>
                        </Button>
                      </TableCell>
                    </TableRow>
                  ))}
                </TableBody>
              </Table>
            )}
          </CardContent>
        </Card>
      </div>
    </>
  );
}