"use client";

// ============================================================================
// Channels Analytics Page
// ============================================================================

import { useEffect, useState } from "react";
import { useParams } from "next/navigation";
import {
  Loader2,
  Building2,
  ArrowUpDown,
  ArrowUp,
  ArrowDown,
} from "lucide-react";
import { DashboardHeader } from "@/components/layout/dashboard-header";
import { useWorkspace } from "@/components/providers/workspace-provider";
import { demoAwareAnalyticsApi } from "@/lib/demo";
import {
  Card,
  CardContent,
  CardDescription,
  CardHeader,
  CardTitle,
} from "@/components/ui/card";
import { Button } from "@/components/ui/button";
import {
  Table,
  TableBody,
  TableCell,
  TableHead,
  TableHeader,
  TableRow,
} from "@/components/ui/table";
import type { ChannelAnalyticsItem } from "@/lib/types/api";

// ============================================================================
// Helpers
// ============================================================================

const formatCurrency = (value: number | null) => {
  if (value === null) return "—";
  return new Intl.NumberFormat("ru-RU", {
    style: "currency",
    currency: "RUB",
    minimumFractionDigits: 0,
    maximumFractionDigits: 0,
  }).format(value);
};

const formatNumber = (value: number | null) => {
  if (value === null) return "—";
  return new Intl.NumberFormat("ru-RU").format(value);
};

// ============================================================================
// Types
// ============================================================================

type SortField =
  | "placements"
  | "cost"
  | "subscriptions"
  | "views"
  | "cps"
  | "cpm";
type SortOrder = "asc" | "desc" | null;

// ============================================================================
// Component
// ============================================================================

export default function ChannelsAnalyticsPage() {
  const params = useParams();
  const workspaceId = params?.workspaceId as string;
  const { getProjectFilterId } = useWorkspace();
  const projectFilterId = getProjectFilterId();

  const [channels, setChannels] = useState<ChannelAnalyticsItem[]>([]);
  const [loading, setLoading] = useState(true);
  const [sortField, setSortField] = useState<SortField | null>("cost");
  const [sortOrder, setSortOrder] = useState<SortOrder>("desc");

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

  const loadData = async () => {
    try {
      setLoading(true);
      const response = await demoAwareAnalyticsApi.channels(workspaceId, {
        project_id: projectFilterId,
        size: 100,
      });
      setChannels(response.items);
    } catch (err) {
      console.error("Failed to load channels analytics:", err);
    } finally {
      setLoading(false);
    }
  };

  // Sort handler
  const handleSort = (field: SortField) => {
    if (sortField === field) {
      if (sortOrder === "asc") setSortOrder("desc");
      else if (sortOrder === "desc") {
        setSortField(null);
        setSortOrder(null);
      } else setSortOrder("asc");
    } else {
      setSortField(field);
      setSortOrder("desc");
    }
  };

  const getSortIcon = (field: SortField) => {
    if (sortField !== field) return <ArrowUpDown className="h-4 w-4 ml-1" />;
    if (sortOrder === "asc") return <ArrowUp className="h-4 w-4 ml-1" />;
    if (sortOrder === "desc") return <ArrowDown className="h-4 w-4 ml-1" />;
    return <ArrowUpDown className="h-4 w-4 ml-1" />;
  };

  // Sort data
  const sortedChannels = [...channels].sort((a, b) => {
    if (!sortField || !sortOrder) return 0;

    let aVal = 0;
    let bVal = 0;

    switch (sortField) {
      case "placements":
        aVal = a.placements_count;
        bVal = b.placements_count;
        break;
      case "cost":
        aVal = a.total_cost;
        bVal = b.total_cost;
        break;
      case "subscriptions":
        aVal = a.total_subscriptions;
        bVal = b.total_subscriptions;
        break;
      case "views":
        aVal = a.total_views;
        bVal = b.total_views;
        break;
      case "cps":
        aVal = a.avg_cps ?? 0;
        bVal = b.avg_cps ?? 0;
        break;
      case "cpm":
        aVal = a.avg_cpm ?? 0;
        bVal = b.avg_cpm ?? 0;
        break;
    }

    return sortOrder === "asc" ? aVal - bVal : bVal - aVal;
  });

  return (
    <>
      <DashboardHeader
        breadcrumbs={[
          { label: "Главная", href: `/dashboard/${workspaceId}` },
          { label: "Аналитика", href: `/dashboard/${workspaceId}/analytics` },
          { label: "Каналы" },
        ]}
      />

      <div className="flex flex-1 flex-col gap-4 p-4 pt-0 mt-4">
        <div>
          <h1 className="text-2xl font-bold tracking-tight">
            Аналитика по каналам
          </h1>
          <p className="text-muted-foreground">
            Эффективность каналов размещения
          </p>
        </div>

        {loading ? (
          <div className="flex items-center justify-center py-12">
            <Loader2 className="h-8 w-8 animate-spin text-muted-foreground" />
          </div>
        ) : sortedChannels.length === 0 ? (
          <Card>
            <CardContent className="flex flex-col items-center justify-center py-12">
              <Building2 className="h-12 w-12 text-muted-foreground mb-4" />
              <h3 className="text-lg font-semibold mb-2">Нет данных</h3>
              <p className="text-muted-foreground text-center">
                Создайте размещения для отображения статистики по каналам
              </p>
            </CardContent>
          </Card>
        ) : (
          <Card>
            <CardHeader>
              <CardTitle>Каналы размещения</CardTitle>
              <CardDescription>{sortedChannels.length} каналов</CardDescription>
            </CardHeader>
            <Table>
              <TableHeader>
                <TableRow>
                  <TableHead>Канал</TableHead>
                  <TableHead>
                    <Button
                      variant="ghost"
                      size="sm"
                      className="-ml-3 h-8"
                      onClick={() => handleSort("placements")}
                    >
                      Размещений
                      {getSortIcon("placements")}
                    </Button>
                  </TableHead>
                  <TableHead>
                    <Button
                      variant="ghost"
                      size="sm"
                      className="-ml-3 h-8"
                      onClick={() => handleSort("cost")}
                    >
                      Расходы
                      {getSortIcon("cost")}
                    </Button>
                  </TableHead>
                  <TableHead>
                    <Button
                      variant="ghost"
                      size="sm"
                      className="-ml-3 h-8"
                      onClick={() => handleSort("subscriptions")}
                    >
                      Подписчики
                      {getSortIcon("subscriptions")}
                    </Button>
                  </TableHead>
                  <TableHead>
                    <Button
                      variant="ghost"
                      size="sm"
                      className="-ml-3 h-8"
                      onClick={() => handleSort("views")}
                    >
                      Просмотры
                      {getSortIcon("views")}
                    </Button>
                  </TableHead>
                  <TableHead>
                    <Button
                      variant="ghost"
                      size="sm"
                      className="-ml-3 h-8"
                      onClick={() => handleSort("cps")}
                    >
                      Ср. CPS
                      {getSortIcon("cps")}
                    </Button>
                  </TableHead>
                  <TableHead>
                    <Button
                      variant="ghost"
                      size="sm"
                      className="-ml-3 h-8"
                      onClick={() => handleSort("cpm")}
                    >
                      Ср. CPM
                      {getSortIcon("cpm")}
                    </Button>
                  </TableHead>
                </TableRow>
              </TableHeader>
              <TableBody>
                {sortedChannels.map((channel) => (
                  <TableRow key={channel.channel_id}>
                    <TableCell>
                      <div className="font-medium">{channel.channel_title}</div>
                      {channel.channel_username && (
                        <div className="text-xs text-muted-foreground">
                          @{channel.channel_username}
                        </div>
                      )}
                    </TableCell>
                    <TableCell>{channel.placements_count}</TableCell>
                    <TableCell>{formatCurrency(channel.total_cost)}</TableCell>
                    <TableCell>
                      {formatNumber(channel.total_subscriptions)}
                    </TableCell>
                    <TableCell>{formatNumber(channel.total_views)}</TableCell>
                    <TableCell>{formatCurrency(channel.avg_cps)}</TableCell>
                    <TableCell>{formatCurrency(channel.avg_cpm)}</TableCell>
                  </TableRow>
                ))}
              </TableBody>
            </Table>
          </Card>
        )}
      </div>
    </>
  );
}