import {
  DndContext,
  DragEndEvent,
  PointerSensor,
  closestCenter,
  useSensor,
  useSensors,
} from '@dnd-kit/core';
import {
  SortableContext,
  arrayMove,
  horizontalListSortingStrategy,
} from '@dnd-kit/sortable';
import { Button } from '@heroui/button';
import { useLocalStorage } from '@uidotdev/usehooks';
import clsx from 'clsx';
import { useEffect, useState } from 'react';
import toast from 'react-hot-toast';
import { IoAdd, IoClose } from 'react-icons/io5';

import key from '@/const/key';
import { TabList, TabPanel, Tabs } from '@/components/tabs';
import { SortableTab } from '@/components/tabs/sortable_tab.tsx';
import { TerminalInstance } from '@/components/terminal/terminal-instance';

import terminalManager from '@/controllers/terminal_manager';

interface TerminalTab {
  id: string;
  title: string;
}

export default function TerminalPage () {
  const [tabs, setTabs] = useState<TerminalTab[]>([]);
  const [selectedTab, setSelectedTab] = useState<string>('');
  const [backgroundImage] = useLocalStorage<string>(key.backgroundImage, '');
  const hasBackground = !!backgroundImage;

  useEffect(() => {
    // 获取已存在的终端列表
    terminalManager.getTerminalList().then((terminals) => {
      if (terminals.length === 0) return;

      const newTabs = terminals.map((terminal) => ({
        id: terminal.id,
        title: terminal.id,
      }));

      setTabs(newTabs);
      setSelectedTab(newTabs[0].id);
    });
  }, []);

  const createNewTerminal = async () => {
    try {
      const { id } = await terminalManager.createTerminal(80, 24);
      const newTab = {
        id,
        title: id,
      };

      setTabs((prev) => [...prev, newTab]);
      setSelectedTab(id);
    } catch (error: unknown) {
      console.error('Failed to create terminal:', error);
      toast.error((error as Error).message);
    }
  };

  const closeTerminal = async (id: string) => {
    try {
      await terminalManager.closeTerminal(id);
      terminalManager.removeTerminal(id);
      if (selectedTab === id) {
        const previousIndex = tabs.findIndex((tab) => tab.id === id) - 1;
        if (previousIndex >= 0) {
          setSelectedTab(tabs[previousIndex].id);
        } else {
          setSelectedTab(tabs[0]?.id || '');
        }
      }
      setTabs((prev) => prev.filter((tab) => tab.id !== id));
    } catch (_error) {
      toast.error('关闭终端失败');
    }
  };

  const handleDragEnd = (event: DragEndEvent) => {
    const { active, over } = event;
    if (active.id !== over?.id) {
      setTabs((items) => {
        const oldIndex = items.findIndex((item) => item.id === active.id);
        const newIndex = items.findIndex((item) => item.id === over?.id);
        return arrayMove(items, oldIndex, newIndex);
      });
    }
  };

  const sensors = useSensors(
    useSensor(PointerSensor, {
      activationConstraint: {
        distance: 8,
      },
    })
  );

  return (
    <div className='flex flex-col gap-2 p-4 h-[calc(100vh-6rem)] md:h-[calc(100vh-4rem)]'>
      <DndContext
        sensors={sensors}
        collisionDetection={closestCenter}
        onDragEnd={handleDragEnd}
      >
        <Tabs
          activeKey={selectedTab}
          onChange={setSelectedTab}
          className='h-full overflow-hidden'
        >
          <div className='flex items-center gap-2 flex-shrink-0 flex-grow-0'>
            {tabs.length > 0 && (
              <TabList className={clsx(
                'flex-1 !overflow-x-auto w-full hide-scrollbar backdrop-blur-sm p-1 rounded-lg border border-white/20',
                hasBackground ? 'bg-white/20 dark:bg-black/10' : 'bg-white/40 dark:bg-black/20'
              )}>
                <SortableContext
                  items={tabs}
                  strategy={horizontalListSortingStrategy}
                >
                  {tabs.map((tab) => (
                    <SortableTab
                      key={tab.id}
                      id={tab.id}
                      value={tab.id}
                      isSelected={selectedTab === tab.id}
                      className='flex gap-2 items-center flex-shrink-0'
                    >
                      {tab.title}
                      <Button
                        isIconOnly
                        radius='full'
                        variant='flat'
                        size='sm'
                        className='min-w-0 w-4 h-4 flex-shrink-0'
                        onPress={() => closeTerminal(tab.id)}
                        color={selectedTab === tab.id ? 'primary' : 'default'}
                      >
                        <IoClose />
                      </Button>
                    </SortableTab>
                  ))}
                </SortableContext>
              </TabList>
            )}
            <Button
              isIconOnly
              color='primary'
              size='sm'
              variant='flat'
              onPress={createNewTerminal}
              startContent={<IoAdd />}
              className='text-xl ml-auto'
            />
          </div>
          <div className='flex-grow overflow-hidden'>
            {tabs.length === 0 && (
              <div className='flex flex-col gap-2 items-center justify-center h-full text-gray-500 py-5'>
                <IoAdd className='text-4xl' />
                <div className='text-sm'>点击右上角按钮创建终端</div>
              </div>
            )}
            {tabs.map((tab) => (
              <TabPanel key={tab.id} value={tab.id} className='h-full'>
                <TerminalInstance id={tab.id} />
              </TabPanel>
            ))}
          </div>
        </Tabs>
      </DndContext>
    </div>
  );
}