import { useState, useRef, useEffect } from 'react';
import {
  Dialog,
  DialogContent,
  DialogDescription,
  DialogTitle,
} from '@/components/ui/dialog';
import { Terminal as XTerm } from 'xterm';
import { FitAddon } from 'xterm-addon-fit';
import 'xterm/css/xterm.css';
import { Maximize2, Minimize2, X } from 'lucide-react';
import { cn } from '@/lib/utils';
import { useUserStore } from '@/store';

interface TerminalDialogProps {
  open: boolean;
  onOpenChange: (open: boolean) => void;
  serverId: number | null;
  serverName: string;
  serverIp: string;
}

/**
 * 终端 Dialog — WebSocket SSH 终端 // Logan.Li
 * 打开时自动连接，关闭时自动断开
 */
export function TerminalDialog({
  open,
  onOpenChange,
  serverId,
  serverName,
  serverIp,
}: TerminalDialogProps) {
  const containerRef = useRef<HTMLDivElement>(null);
  const termRef = useRef<XTerm | null>(null);
  const wsRef = useRef<WebSocket | null>(null);
  const fitRef = useRef<FitAddon | null>(null);
  const [connected, setConnected] = useState(false);
  const [fullscreen, setFullscreen] = useState(false);

  // 连接终端
  useEffect(() => {
    if (!open || !serverId) return;

    // 创建终端
    const term = new XTerm({
      cursorBlink: true,
      fontSize: 13,
      fontFamily: 'Menlo, Monaco, "Courier New", monospace',
      allowProposedApi: true,
      theme: {
        background: '#0a0e14',
        foreground: '#d6d6d6',
        cursor: '#d6d6d6',
        selectionBackground: 'rgba(255,255,255,0.2)',
      },
    });
    const fit = new FitAddon();
    term.loadAddon(fit);
    termRef.current = term;
    fitRef.current = fit;

    // WebSocket 连接
    const proto = location.protocol === 'https:' ? 'wss' : 'ws';
    const token = useUserStore.getState().token || '';
    const wsUrl = `${proto}://${location.host}/ws/terminal?id=${serverId}&cols=80&rows=24&token=${encodeURIComponent(token)}`;
    const ws = new WebSocket(wsUrl);
    wsRef.current = ws;

    term.onData((data) => {
      if (ws.readyState === WebSocket.OPEN) {
        ws.send(JSON.stringify({ status: 0, data }));
      }
    });

    ws.onmessage = (event) => {
      try {
        const msg = JSON.parse(event.data);
        if (msg.status === 0 && typeof msg.data === 'string') {
          term.write(msg.data);
        }
      } catch {
        term.write(typeof event.data === 'string' ? event.data : '');
      }
    };

    ws.onopen = () => {
      setConnected(true);
      // 挂载终端到容器
      if (containerRef.current) {
        term.open(containerRef.current);
        requestAnimationFrame(() => {
          try {
            fit.fit();
            term.focus();
          } catch { /* noop */ }
        });
      }
    };

    ws.onclose = () => {
      setConnected(false);
      term.write('\r\n\x1b[31m[连接已关闭]\x1b[0m\r\n');
    };

    ws.onerror = () => {
      term.write('\r\n\x1b[31m[连接发生错误]\x1b[0m\r\n');
    };

    // resize 监听
    const handleResize = () => {
      if (fitRef.current && termRef.current) {
        try {
          fit.fit();
          const { cols, rows } = termRef.current;
          if (ws.readyState === WebSocket.OPEN) {
            ws.send(JSON.stringify({ status: 1, cols, rows }));
          }
        } catch { /* noop */ }
      }
    };
    window.addEventListener('resize', handleResize);

    return () => {
      window.removeEventListener('resize', handleResize);
      try {
        ws.close();
        term.dispose();
      } catch { /* noop */ }
      termRef.current = null;
      wsRef.current = null;
      setConnected(false);
    };
  }, [open, serverId]);

  // fullscreen 切换时重新 fit
  useEffect(() => {
    if (open && fitRef.current) {
      requestAnimationFrame(() => {
        try {
          fitRef.current?.fit();
          termRef.current?.focus();
        } catch { /* noop */ }
      });
    }
  }, [fullscreen, open]);

  return (
    <Dialog open={open} onOpenChange={onOpenChange}>
      <DialogContent
        className={cn(
          'bg-[var(--dg-bg-secondary)] border-[var(--dg-border)] p-0 gap-0',
          fullscreen && '!max-w-none !w-screen !h-screen !rounded-none !translate-x-0 !translate-y-0 !left-0 !top-0'
        )}
        style={fullscreen ? { maxWidth: '100vw', width: '100vw', height: '100vh' } : { maxWidth: '900px', width: '90vw' }}
      >
        <DialogTitle className="sr-only">终端 - {serverName}</DialogTitle>
        <DialogDescription className="sr-only">SSH 终端连接</DialogDescription>
        {/* 终端头部 */}
        <div className="flex items-center justify-between px-4 py-2 border-b border-[var(--dg-border)]">
          <div className="flex items-center gap-2 text-sm">
            <div className={cn('w-2 h-2 rounded-full', connected ? 'bg-emerald-400' : 'bg-red-400')} />
            <span className="text-[var(--dg-text-primary)] font-medium">{serverName}</span>
            <span className="text-[var(--dg-text-muted)]">({serverIp})</span>
          </div>
          <div className="flex items-center gap-1">
            <button
              onClick={() => setFullscreen(!fullscreen)}
              className="p-1.5 rounded hover:bg-[var(--dg-bg-hover)] text-[var(--dg-text-secondary)]"
            >
              {fullscreen ? <Minimize2 className="h-4 w-4" /> : <Maximize2 className="h-4 w-4" />}
            </button>
            <button
              onClick={() => onOpenChange(false)}
              className="p-1.5 rounded hover:bg-[var(--dg-bg-hover)] text-[var(--dg-text-secondary)]"
            >
              <X className="h-4 w-4" />
            </button>
          </div>
        </div>
        {/* 终端容器 */}
        <div
          ref={containerRef}
          className="bg-[#0a0e14]"
          style={{ height: fullscreen ? 'calc(100vh - 49px)' : '480px' }}
        />
      </DialogContent>
    </Dialog>
  );
}