import { useEffect, useRef, useImperativeHandle, forwardRef } from 'react';
import { STORAGE } from '../lib/storage-keys';
import { WebTerminal } from '../lib/terminal/WebTerminal';
import type { TerminalConfig } from '../lib/terminal/terminal-config';

interface TerminalViewProps {
  sessionId: string;
  adapter?: string;
  style?: React.CSSProperties;
}

export interface TerminalViewHandle {
  closeKeyboard(): void;
}

function buildTerminalWsUrl(sessionId: string, adapter?: string): string {
  const proto = location.protocol === 'https:' ? 'wss' : 'ws';
  const token = localStorage.getItem(STORAGE.TOKEN) ?? '';
  const adapterParam = adapter ? `&adapter=${encodeURIComponent(adapter)}` : '';
  return `${proto}://${location.host}/terminal/${encodeURIComponent(sessionId)}?token=${encodeURIComponent(token)}${adapterParam}`;
}

const TERMINAL_CONFIG: TerminalConfig = {
  fontSize: 14,
};

export const TerminalView = forwardRef<TerminalViewHandle, TerminalViewProps>(
  function TerminalView({ sessionId, adapter, style }, ref) {
    const containerRef = useRef<HTMLDivElement>(null);
    const termRef = useRef<WebTerminal | null>(null);

    useImperativeHandle(ref, () => ({
      closeKeyboard() {
        termRef.current?.closeKeyboard();
      },
    }));

    useEffect(() => {
      const el = containerRef.current;
      if (!el) return;

      const wsUrl = buildTerminalWsUrl(sessionId, adapter);
      let cancelled = false;

      WebTerminal.create(el, wsUrl, TERMINAL_CONFIG).then((t) => {
        if (cancelled) {
          t.dispose();
          return;
        }
        termRef.current = t;
      }).catch((err) => {
        console.error('[TerminalView] Failed to create terminal:', err);
      });

      return () => {
        cancelled = true;
        termRef.current?.dispose();
        termRef.current = null;
      };
    }, [sessionId, adapter]);

    return (
      <div
        ref={containerRef}
        style={{
          width: '100%',
          height: '100%',
          backgroundColor: '#000',
          overflow: 'hidden',
          ...style,
        }}
      />
    );
  }
);