let currentCaptcha = "";

// =======================
// 🎯 生成验证码
// =======================
function generateCaptcha() {
  const canvas = document.getElementById("captchaCanvas");
  const ctx = canvas.getContext("2d");

  const width = 120;
  const height = 40;

  canvas.width = width;
  canvas.height = height;

  ctx.clearRect(0, 0, width, height);

  // 背景
  ctx.fillStyle = "#f5f5f5";
  ctx.fillRect(0, 0, width, height);

  // 字符
  const chars = "ABCDEFGHJKLMNPQRSTUVWXYZ23456789";
  currentCaptcha = "";

  for (let i = 0; i < 5; i++) {
    const char = chars[Math.floor(Math.random() * chars.length)];
    currentCaptcha += char;

    ctx.font = "bold 20px Arial";
    ctx.fillStyle = "#222";

    const x = 10 + i * 20;
    const y = 25 + Math.random() * 5;
    const angle = (Math.random() - 0.5) * 0.5;

    ctx.save();
    ctx.translate(x, y);
    ctx.rotate(angle);
    ctx.fillText(char, 0, 0);
    ctx.restore();
  }

  // 干扰线
  for (let i = 0; i < 2; i++) {
    ctx.strokeStyle = "#999";
    ctx.beginPath();
    ctx.moveTo(Math.random() * width, Math.random() * height);
    ctx.lineTo(Math.random() * width, Math.random() * height);
    ctx.stroke();
  }

  // 干扰点
  for (let i = 0; i < 15; i++) {
    ctx.fillStyle = "#ccc";
    ctx.fillRect(Math.random() * width, Math.random() * height, 1, 1);
  }
}

// =======================
// 🎯 验证验证码（替代 checking_icaptcha）
// =======================
function checking_icaptcha() {
  const input = document.getElementById("secure").value;

  if (!input) return "empty";

  if (input.toUpperCase() === currentCaptcha) {
    return "ok=True";
  } else {
    generateCaptcha();
    document.getElementById("secure").value = "";
    return "Wrong Code";
  }
}

// =======================
// 🎯 登录提交（保留你原逻辑）
// =======================
async function login_submit() {
  let validate = await checking_icaptcha();

  if (validate.trim() === "ok=True") {
    $('#submit_login').submit();
  } else {
    alert("Secure Code Invalid");
  }
}