import { useEffect, useRef } from "react";
import { Terminal } from "xterm";
import { FitAddon } from "xterm-addon-fit";
import "xterm/css/xterm.css";

export default function XTerm({ onData, output }) {
  const termRef = useRef(null);
  const fitAddon = new FitAddon();

  useEffect(() => {
    const term = new Terminal({
      cursorBlink: true,
      fontSize: 14,
      theme: {
        background: "#1e1e1e",
        foreground: "#ffffff",
      },
    });

    termRef.current = term;
    term.loadAddon(fitAddon);

    term.open(document.getElementById("terminal-container"));
    fitAddon.fit();

    term.onData((data) => {
      // Echo user input (like real terminals)
      term.write(data);

      // When ENTER pressed, send full line to parent
      if (data === "\r") {
        const line = term._core.buffer.xtermBuffer.active.getLine(
          term.buffer.active.cursorY
        ).translateToString().trim();
        onData(line);
      }
    });

    return () => term.dispose();
  }, []);

  // Print backend output into terminal
  useEffect(() => {
    if (output) {
      termRef.current?.writeln("\r\n" + output);
    }
  }, [output]);

  return (
    <div
      id="terminal-container"
      style={{
        width: "100%",
        height: "180px",
        background: "#1e1e1e",
        borderTop: "1px solid #333",
      }}
    ></div>
  );
}