// note: ESM imports broken in xterm-headless - use a require instead.
//import { Terminal } from 'xterm-headless';
//         ^^^^^^^^
//SyntaxError: Named export 'Terminal' not found. The requested module 'xterm-headless' is a CommonJS module, which may not support all module.exports as named exports.

const Terminal = require("xterm-headless").Terminal;

async function write(term, str) {
  return new Promise((resolve, reject) => {
    term.write(str, resolve);
  });
}

function dump_ascii(term, showCursor) {
  const rows = term.rows;
  const cols = term.cols;

  const buffer = term.buffer.active;
  const cursorX = buffer.cursorX;
  const cursorY = buffer.cursorY;

  console.log(
    `rows: ${rows}, cols: ${cols} cursorX: ${cursorX}, cursorY: ${cursorY}`
  );

  console.log("+" + "-".repeat(cols) + "+");

  for (let row = 0; row < rows; row++) {
    const line = buffer.getLine(row);
    let charCount = 0;
    let str = "";
    for (let col = 0; col < cols; col++) {
      const cursorIsThisCell = row === cursorY && col === cursorX;
      const chars = line?.getCell(col)?.getChars() || " ";
      if (cursorIsThisCell && showCursor) {
        str += "@";
        charCount++;
      } else {
        if (cursorIsThisCell) {
          // add invert colors
          str += "\x1b[7m";
        }
        str += chars;
        charCount++;
        if (cursorIsThisCell) {
          // reset colors
          str += "\x1b[0m";
        }
      }
    }
    console.log("|" + str + "|");
  }
  console.log("+" + "-".repeat(cols) + "+");
}

(async () => {
  const term = new Terminal({ rows: 5, cols: 5, allowProposedApi: true });
  await write(term, "ABCD");
  dump_ascii(term, true);
  //   rows: 5, cols: 5 cursorX: 4, cursorY: 0
  //   +-----+
  //   |ABCD@|
  //   |     |
  //   |     |
  //   |     |
  //   |     |
  //   +-----+

  term.resize(4, 5);
  dump_ascii(term, true);
  //   rows: 5, cols: 4 cursorX: 3, cursorY: 0
  //   +----+
  //   |ABC@| // NOTE: I believe we expect the cursor to have moved to row 2
  //   |    | // Under the cursor, the 'D' still remains
  //   |    |
  //   |    |
  //   |    |
  //   +----+

  term.resize(3, 5);
  dump_ascii(term, true);
  //   rows: 5, cols: 3 cursorX: 2, cursorY: 0
  //   +---+
  //   |AB@|
  //   |   |
  //   |   |
  //   |   |
  //   |   |
  //   +---+

  term.resize(5, 5);
  dump_ascii(term, true);
  //   rows: 5, cols: 5 cursorX: 2, cursorY: 0
  //   +-----+
  //   |AB@  | // The 'D' is lost, and the 'C' remains under the cursor.
  //   |     |
  //   |     |
  //   |     |
  //   |     |
  //   +-----+
})();