// scramble — Scramble Decode 乱码锁定（motion-lab 定稿转原生 Remotion）
// 每个字符先高速随机跳字（种子驱动、可复现），再从左到右逐个"锁定"为真字符，
// 锁定瞬间闪一下高亮辉光。与 typewriter 的顺序打字完全不同的质感——黑客/解密感。
// 设计坐标 480×270（DesignStage 等比放大），参数表数值以此坐标系标定。
import React from 'react';
import { DesignStage, rand, seg, useT } from '../../_fixtures/Motion';

export const SCRAMBLE_DURATION = 96; // 3200ms @30fps

const TEXT = 'TEMPLATE MOTION DEMO';
const POOL = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789#$%&*+=<>/\\';
const CHARS = [...TEXT];

export const Scramble: React.FC = () => {
  const t = useT();
  const frame = Math.floor(t * 96);
  return (
    <DesignStage bg="#07080c">
      <div
        style={{
          position: 'absolute',
          inset: 0,
          display: 'flex',
          alignItems: 'center',
          justifyContent: 'center',
          background: '#07080c',
          fontFamily: '"SF Mono",Menlo,monospace',
          fontSize: 34,
          letterSpacing: 2,
        }}
      >
        {CHARS.map((ch, i) => {
          let content: string = ch;
          let color = '#3d4560';
          let textShadow = 'none';
          if (ch !== ' ') {
            // 锁定时刻：从左到右基础 stagger + 种子微扰
            const lockAt = 0.25 + (i / CHARS.length) * 0.6 + rand(i * 7) * 0.06;
            if (t < 0.06) {
              content = ' '; // 开场短暂空白
            } else if (t < lockAt) {
              // 高速跳字：每 2 帧换一个随机字符
              content = POOL[Math.floor(rand(i * 131 + Math.floor(frame / 2)) * POOL.length)];
            } else {
              // 锁定为真字符，锁定瞬间闪高亮辉光后回落
              const flash = 1 - seg(t, lockAt, lockAt + 0.1);
              color = flash > 0.4 ? '#dff3ff' : '#e8eaf0';
              textShadow = `0 0 ${flash * 18}px rgba(120,200,255,${flash})`;
            }
          }
          return (
            <span
              key={i}
              style={{ minWidth: '0.62em', textAlign: 'center', color, textShadow }}
            >
              {content === ' ' ? ' ' : content}
            </span>
          );
        })}
      </div>
    </DesignStage>
  );
};