"use client";

import React, { useState, useEffect, useRef } from "react";
import {
  Select,
  SelectContent,
  SelectItem,
  SelectTrigger,
  SelectValue,
} from "@/components/ui/select";
import {
  Dialog,
  DialogContent,
  DialogDescription,
  DialogHeader,
  DialogTitle,
} from "@/components/ui/dialog";
import { Button } from "@/components/ui/button";
import { useTargetChannel } from "@/components/providers/target-channel-provider";
import {
  Loader2,
  AlertCircle,
  Plus,
  ExternalLink,
  CheckCircle2,
} from "lucide-react";
import { Alert, AlertDescription } from "@/components/ui/alert";
import { BOT_USERNAME } from "@/lib/utils/constants";
import { channelsApi } from "@/lib/api";

export const TargetChannelSelector: React.FC = () => {
  const { channels, selectedChannel, setSelectedChannel, isLoading, error } =
    useTargetChannel();
  const [isAddDialogOpen, setIsAddDialogOpen] = useState(false);
  const [isSuccess, setIsSuccess] = useState(false);
  const [initialChannelCount, setInitialChannelCount] = useState(0);
  const pollingIntervalRef = useRef<NodeJS.Timeout | null>(null);

  // Очистка интервала при размонтировании
  useEffect(() => {
    return () => {
      if (pollingIntervalRef.current) {
        clearInterval(pollingIntervalRef.current);
      }
    };
  }, []);

  // Автоматический запуск polling при открытии диалога
  useEffect(() => {
    if (isAddDialogOpen && !isSuccess && initialChannelCount > 0) {
      pollingIntervalRef.current = setInterval(() => {
        checkForNewChannels();
      }, 1000);

      return () => {
        if (pollingIntervalRef.current) {
          clearInterval(pollingIntervalRef.current);
          pollingIntervalRef.current = null;
        }
      };
    }
  }, [isAddDialogOpen, isSuccess, initialChannelCount]);

  const checkForNewChannels = async () => {
    try {
      const response = await channelsApi.list();
      const activeChannels = response.target_channels.filter(
        (c) => c.is_active
      );

      if (activeChannels.length > initialChannelCount) {
        setIsSuccess(true);

        if (pollingIntervalRef.current) {
          clearInterval(pollingIntervalRef.current);
          pollingIntervalRef.current = null;
        }
        setTimeout(() => {
          setIsAddDialogOpen(false);
          setIsSuccess(false);
          window.location.reload();
        }, 2000);
      }
    } catch (err) {
      console.error("Error polling channels:", err);
    }
  };

  const handleAddChannel = () => {
    setInitialChannelCount(channels.length);
    setIsSuccess(false);
    setIsAddDialogOpen(true);
  };

  const handleDialogOpenChange = (open: boolean) => {
    if (!open) {
      // Разрешаем закрытие всегда (в том числе через кнопку крестик)
      setIsAddDialogOpen(false);
      setIsSuccess(false);
      if (pollingIntervalRef.current) {
        clearInterval(pollingIntervalRef.current);
        pollingIntervalRef.current = null;
      }
    }
  };

  if (isLoading) {
    return (
      <div className="flex items-center gap-2 text-sm text-muted-foreground">
        <Loader2 className="h-4 w-4 animate-spin" />
        Загрузка каналов...
      </div>
    );
  }

  if (error) {
    return (
      <Alert variant="destructive" className="p-2 h-auto">
        <AlertCircle className="h-4 w-4" />
        <AlertDescription className="text-xs">Ошибка: {error}</AlertDescription>
      </Alert>
    );
  }

  if (channels.length === 0) {
    return (
      <Button variant="outline" size="sm" onClick={handleAddChannel}>
        <Plus className="h-4 w-4 mr-2" />
        Добавить канал
      </Button>
    );
  }

  return (
    <>
      <Select
        value={selectedChannel?.id || "add-new"}
        onValueChange={(value) => {
          if (value === "add-new") {
            handleAddChannel();
          } else {
            const channel = channels.find((c) => c.id === value);
            if (channel) {
              setSelectedChannel(channel);
            }
          }
        }}
      >
        <SelectTrigger className="w-[260px] h-auto min-h-[52px] py-2 rounded-lg">
          <SelectValue placeholder="Выберите канал">
            {selectedChannel && (
              <div className="flex flex-col items-start gap-0.5">
                <span className="font-semibold text-base">
                  {selectedChannel.title}
                </span>
                {selectedChannel.username && (
                  <span className="text-xs text-muted-foreground -mt-1">
                    @{selectedChannel.username}
                  </span>
                )}
              </div>
            )}
          </SelectValue>
        </SelectTrigger>
        <SelectContent>
          {channels.map((channel) => (
            <SelectItem
              key={channel.id}
              value={channel.id}
              className="cursor-pointer py-3"
            >
              <div className="flex items-center justify-between w-full gap-2">
                <div className="flex flex-col items-start flex-1 min-w-0 gap-0.5">
                  <span className="font-semibold text-base truncate w-full">
                    {channel.title}
                  </span>
                  {channel.username && (
                    <span className="text-xs text-muted-foreground flex items-center gap-1">
                      @{channel.username}
                    </span>
                  )}
                </div>
              </div>
            </SelectItem>
          ))}
          <SelectItem
            value="add-new"
            className="cursor-pointer border-t mt-1 py-3"
          >
            <div className="flex items-center gap-2 text-primary">
              <Plus className="h-4 w-4" />
              <span className="font-medium">Добавить канал</span>
            </div>
          </SelectItem>
        </SelectContent>
      </Select>

      <Dialog open={isAddDialogOpen} onOpenChange={handleDialogOpenChange}>
        <DialogContent
          className="sm:max-w-md"
          onInteractOutside={(e) => !isSuccess && e.preventDefault()}
          onEscapeKeyDown={(e) => !isSuccess && e.preventDefault()}
        >
          <DialogHeader>
            <DialogTitle>Добавить целевой канал</DialogTitle>
            <DialogDescription>
              Следуйте инструкциям ниже, чтобы подключить новый канал
            </DialogDescription>
          </DialogHeader>

          {isSuccess ? (
            <div className="flex flex-col items-center justify-center py-8 space-y-4">
              <div className="rounded-full bg-green-100 dark:bg-green-900 p-3">
                <CheckCircle2 className="h-8 w-8 text-green-600 dark:text-green-400" />
              </div>
              <div className="text-center">
                <h3 className="text-lg font-semibold">
                  Канал успешно добавлен!
                </h3>
                <p className="text-sm text-muted-foreground mt-1">
                  Страница обновится автоматически...
                </p>
              </div>
            </div>
          ) : (
            <div className="space-y-4">
              <Alert>
                <AlertDescription className="space-y-2">
                  <p className="font-medium">Шаги для добавления канала:</p>
                  <ol className="list-decimal list-inside space-y-1.5 text-sm">
                    <li>Откройте свой Telegram канал</li>
                    <li>Перейдите в настройки канала → Администраторы</li>
                    <li>
                      Добавьте бота{" "}
                      <a
                        href={`https://t.me/${BOT_USERNAME}`}
                        target="_blank"
                        rel="noopener noreferrer"
                        className="font-mono text-primary hover:underline inline-flex items-center gap-1"
                        tabIndex={0}
                        aria-label={`Открыть бота @${BOT_USERNAME} в Telegram`}
                        onClick={(e) => e.stopPropagation()}
                        onKeyDown={(e) => e.stopPropagation()}
                      >
                        @{BOT_USERNAME}
                        <ExternalLink className="h-3 w-3" />
                      </a>{" "}
                      как администратора
                    </li>
                    <li>
                      Предоставьте боту права:{" "}
                      <span className="font-medium">
                        Публикация сообщений, Удаление сообщений
                      </span>
                    </li>
                  </ol>
                </AlertDescription>
              </Alert>

              <div className="flex flex-col items-center justify-center py-6 space-y-3">
                <Loader2 className="h-10 w-10 animate-spin text-primary" />
                <p className="text-sm text-muted-foreground text-center">
                  Ждем добавления бота...
                  <br />
                  <span className="text-xs">
                    Как только вы добавите бота, канал автоматически появится
                  </span>
                </p>
              </div>
            </div>
          )}
        </DialogContent>
      </Dialog>
    </>
  );
};