"use client";

import { useEffect, useRef } from "react";

export function GateScene() {
  const canvasRef = useRef<HTMLCanvasElement>(null);
  const mouse = useRef({ x: -1000, y: -1000 });

  useEffect(() => {
    const canvas = canvasRef.current;
    if (!canvas) return;
    const ctx = canvas.getContext("2d");
    if (!ctx) return;

    const FONT_SIZE = 13;
    const COL_GAP = 18;
    const ROW_GAP = 20;

    interface Cell {
      char: string;
      alpha: number;
      targetAlpha: number;
      speed: number;
      nextChange: number;
    }

    let cells: Cell[][] = [];
    let cols = 0;
    let rows = 0;
    let animId: number;

    const init = () => {
      cols = Math.ceil(canvas.width / COL_GAP);
      rows = Math.ceil(canvas.height / ROW_GAP);
      cells = Array.from({ length: cols }, () =>
        Array.from({ length: rows }, () => ({
          char: Math.random() > 0.5 ? "1" : "0",
          alpha: Math.random() * 0.08,
          targetAlpha: Math.random() * 0.15,
          speed: 0.008 + Math.random() * 0.02,
          nextChange: Math.floor(Math.random() * 80),
        })),
      );
    };

    const onMouseMove = (e: MouseEvent) => {
      mouse.current = { x: e.clientX, y: e.clientY };
    };

    const resize = () => {
      canvas.width = window.innerWidth;
      canvas.height = window.innerHeight;
      init();
    };

    let frame = 0;

    const draw = () => {
      frame++;
      ctx.clearRect(0, 0, canvas.width, canvas.height);
      ctx.font = `${FONT_SIZE}px 'Courier New', monospace`;

      for (let c = 0; c < cols; c++) {
        for (let r = 0; r < rows; r++) {
          const cell = cells[c][r];
          const x = c * COL_GAP;
          const y = r * ROW_GAP + FONT_SIZE;

          // Mouse proximity influence
          const dx = mouse.current.x - x;
          const dy = mouse.current.y - y;
          const distSq = dx * dx + dy * dy;
          const proximity = Math.max(0, 1 - Math.sqrt(distSq) / 250);

          // Nudge alpha toward target
          cell.alpha += (cell.targetAlpha - cell.alpha) * cell.speed;

          // More aggressive random behavior
          if (frame >= cell.nextChange) {
            cell.targetAlpha = Math.random() * 0.25; // Higher max alpha
            cell.speed = 0.01 + Math.random() * 0.03; // Faster transitions
            cell.nextChange = frame + 20 + Math.floor(Math.random() * 80); // More frequent changes

            // Higher flip probability near mouse
            const flipProb = 0.3 + proximity * 0.5;
            if (Math.random() < flipProb) {
              cell.char = cell.char === "0" ? "1" : "0";
            }
          }

          const a = Math.min(0.4, cell.alpha + proximity * 0.35);
          if (a < 0.01) continue;

          // Dark chars on light background
          ctx.fillStyle = `rgba(0, 0, 0, ${a})`;
          ctx.fillText(cell.char, x, y);
        }
      }

      animId = requestAnimationFrame(draw);
    };

    resize();
    window.addEventListener("resize", resize);
    window.addEventListener("mousemove", onMouseMove);
    animId = requestAnimationFrame(draw);

    return () => {
      cancelAnimationFrame(animId);
      window.removeEventListener("resize", resize);
      window.removeEventListener("mousemove", onMouseMove);
    };
  }, []);

  return (
    <div className="absolute inset-0 pointer-events-none z-0 bg-[#f5f5f7]">
      <canvas ref={canvasRef} className="absolute inset-0 w-full h-full" />
      <div
        className="absolute inset-0 pointer-events-none"
        style={{
          background:
            "radial-gradient(ellipse 55% 65% at 50% 50%, rgba(245,245,247,0.7) 0%, transparent 100%)",
        }}
      />
    </div>
  );
}