<template>
  <div ref="containerRef" class="beams-container w-full h-full relative" />
</template>

<script setup lang="ts">
import { ref, onMounted, onUnmounted, watch, computed } from 'vue';
import * as THREE from 'three';
import { degToRad } from 'three/src/math/MathUtils.js';

interface BeamsProps {
  beamWidth?: number;
  beamHeight?: number;
  beamNumber?: number;
  lightColor?: string;
  speed?: number;
  noiseIntensity?: number;
  scale?: number;
  rotation?: number;
}

const props = withDefaults(defineProps<BeamsProps>(), {
  beamWidth: 2,
  beamHeight: 15,
  beamNumber: 12,
  lightColor: '#ffffff',
  speed: 2,
  noiseIntensity: 1.75,
  scale: 0.2,
  rotation: 0
});

const containerRef = ref<HTMLDivElement>();

let renderer: THREE.WebGLRenderer | null = null;
let scene: THREE.Scene | null = null;
let camera: THREE.PerspectiveCamera | null = null;
let beamMesh: THREE.Mesh<THREE.BufferGeometry, THREE.ShaderMaterial> | null = null;
let directionalLight: THREE.DirectionalLight | null = null;
let ambientLight: THREE.AmbientLight | null = null;
let animationId: number | null = null;

type UniformValue = THREE.IUniform<unknown> | unknown;

interface ExtendMaterialConfig {
  header: string;
  vertexHeader?: string;
  fragmentHeader?: string;
  material?: THREE.MeshPhysicalMaterialParameters & { fog?: boolean };
  uniforms?: Record<string, UniformValue>;
  vertex?: Record<string, string>;
  fragment?: Record<string, string>;
}

type ShaderWithDefines = THREE.ShaderLibShader & {
  defines?: Record<string, string | number | boolean>;
};

const hexToNormalizedRGB = (hex: string): [number, number, number] => {
  const clean = hex.replace('#', '');
  const r = parseInt(clean.substring(0, 2), 16);
  const g = parseInt(clean.substring(2, 4), 16);
  const b = parseInt(clean.substring(4, 6), 16);
  return [r / 255, g / 255, b / 255];
};

const noise = `
float random (in vec2 st) {
    return fract(sin(dot(st.xy,
                         vec2(12.9898,78.233)))*
        43758.5453123);
}
float noise (in vec2 st) {
    vec2 i = floor(st);
    vec2 f = fract(st);
    float a = random(i);
    float b = random(i + vec2(1.0, 0.0));
    float c = random(i + vec2(0.0, 1.0));
    float d = random(i + vec2(1.0, 1.0));
    vec2 u = f * f * (3.0 - 2.0 * f);
    return mix(a, b, u.x) +
           (c - a)* u.y * (1.0 - u.x) +
           (d - b) * u.x * u.y;
}
vec4 permute(vec4 x){return mod(((x*34.0)+1.0)*x, 289.0);}
vec4 taylorInvSqrt(vec4 r){return 1.79284291400159 - 0.85373472095314 * r;}
vec3 fade(vec3 t) {return t*t*t*(t*(t*6.0-15.0)+10.0);}
float cnoise(vec3 P){
  vec3 Pi0 = floor(P);
  vec3 Pi1 = Pi0 + vec3(1.0);
  Pi0 = mod(Pi0, 289.0);
  Pi1 = mod(Pi1, 289.0);
  vec3 Pf0 = fract(P);
  vec3 Pf1 = Pf0 - vec3(1.0);
  vec4 ix = vec4(Pi0.x, Pi1.x, Pi0.x, Pi1.x);
  vec4 iy = vec4(Pi0.yy, Pi1.yy);
  vec4 iz0 = Pi0.zzzz;
  vec4 iz1 = Pi1.zzzz;
  vec4 ixy = permute(permute(ix) + iy);
  vec4 ixy0 = permute(ixy + iz0);
  vec4 ixy1 = permute(ixy + iz1);
  vec4 gx0 = ixy0 / 7.0;
  vec4 gy0 = fract(floor(gx0) / 7.0) - 0.5;
  gx0 = fract(gx0);
  vec4 gz0 = vec4(0.5) - abs(gx0) - abs(gy0);
  vec4 sz0 = step(gz0, vec4(0.0));
  gx0 -= sz0 * (step(0.0, gx0) - 0.5);
  gy0 -= sz0 * (step(0.0, gy0) - 0.5);
  vec4 gx1 = ixy1 / 7.0;
  vec4 gy1 = fract(floor(gx1) / 7.0) - 0.5;
  gx1 = fract(gx1);
  vec4 gz1 = vec4(0.5) - abs(gx1) - abs(gy1);
  vec4 sz1 = step(gz1, vec4(0.0));
  gx1 -= sz1 * (step(0.0, gx1) - 0.5);
  gy1 -= sz1 * (step(0.0, gy1) - 0.5);
  vec3 g000 = vec3(gx0.x,gy0.x,gz0.x);
  vec3 g100 = vec3(gx0.y,gy0.y,gz0.y);
  vec3 g010 = vec3(gx0.z,gy0.z,gz0.z);
  vec3 g110 = vec3(gx0.w,gy0.w,gz0.w);
  vec3 g001 = vec3(gx1.x,gy1.x,gz1.x);
  vec3 g101 = vec3(gx1.y,gy1.y,gz1.y);
  vec3 g011 = vec3(gx1.z,gy1.z,gz1.z);
  vec3 g111 = vec3(gx1.w,gy1.w,gz1.w);
  vec4 norm0 = taylorInvSqrt(vec4(dot(g000,g000),dot(g010,g010),dot(g100,g100),dot(g110,g110)));
  g000 *= norm0.x; g010 *= norm0.y; g100 *= norm0.z; g110 *= norm0.w;
  vec4 norm1 = taylorInvSqrt(vec4(dot(g001,g001),dot(g011,g011),dot(g101,g101),dot(g111,g111)));
  g001 *= norm1.x; g011 *= norm1.y; g101 *= norm1.z; g111 *= norm1.w;
  float n000 = dot(g000, Pf0);
  float n100 = dot(g100, vec3(Pf1.x,Pf0.yz));
  float n010 = dot(g010, vec3(Pf0.x,Pf1.y,Pf0.z));
  float n110 = dot(g110, vec3(Pf1.xy,Pf0.z));
  float n001 = dot(g001, vec3(Pf0.xy,Pf1.z));
  float n101 = dot(g101, vec3(Pf1.x,Pf0.y,Pf1.z));
  float n011 = dot(g011, vec3(Pf0.x,Pf1.yz));
  float n111 = dot(g111, Pf1);
  vec3 fade_xyz = fade(Pf0);
  vec4 n_z = mix(vec4(n000,n100,n010,n110),vec4(n001,n101,n011,n111),fade_xyz.z);
  vec2 n_yz = mix(n_z.xy,n_z.zw,fade_xyz.y);
  float n_xyz = mix(n_yz.x,n_yz.y,fade_xyz.x);
  return 2.2 * n_xyz;
}
`;

function extendMaterial<T extends THREE.Material = THREE.Material>(
  BaseMaterial: new (params?: THREE.MaterialParameters) => T,
  cfg: ExtendMaterialConfig
): THREE.ShaderMaterial {
  const physical = THREE.ShaderLib.physical as ShaderWithDefines;
  const { vertexShader: baseVert, fragmentShader: baseFrag, uniforms: baseUniforms } = physical;
  const baseDefines = physical.defines ?? {};

  const uniforms: Record<string, THREE.IUniform> = THREE.UniformsUtils.clone(baseUniforms);

  const defaults = new BaseMaterial(cfg.material || {}) as T & {
    color?: THREE.Color;
    roughness?: number;
    metalness?: number;
    envMap?: THREE.Texture;
    envMapIntensity?: number;
  };

  if (defaults.color) uniforms.diffuse.value = defaults.color;
  if ('roughness' in defaults) uniforms.roughness.value = defaults.roughness;
  if ('metalness' in defaults) uniforms.metalness.value = defaults.metalness;
  if ('envMap' in defaults) uniforms.envMap.value = defaults.envMap;
  if ('envMapIntensity' in defaults) uniforms.envMapIntensity.value = defaults.envMapIntensity;

  Object.entries(cfg.uniforms ?? {}).forEach(([key, u]) => {
    uniforms[key] =
      u !== null && typeof u === 'object' && 'value' in u
        ? (u as THREE.IUniform<unknown>)
        : ({ value: u } as THREE.IUniform<unknown>);
  });

  let vert = `${cfg.header}\n${cfg.vertexHeader ?? ''}\n${baseVert}`;
  let frag = `${cfg.header}\n${cfg.fragmentHeader ?? ''}\n${baseFrag}`;

  for (const [inc, code] of Object.entries(cfg.vertex ?? {})) {
    vert = vert.replace(inc, `${inc}\n${code}`);
  }
  for (const [inc, code] of Object.entries(cfg.fragment ?? {})) {
    frag = frag.replace(inc, `${inc}\n${code}`);
  }

  const mat = new THREE.ShaderMaterial({
    defines: { ...baseDefines },
    uniforms,
    vertexShader: vert,
    fragmentShader: frag,
    lights: true,
    fog: !!cfg.material?.fog
  });

  return mat;
}

function createStackedPlanesBufferGeometry(
  n: number,
  width: number,
  height: number,
  spacing: number,
  heightSegments: number
): THREE.BufferGeometry {
  const geometry = new THREE.BufferGeometry();
  const numVertices = n * (heightSegments + 1) * 2;
  const numFaces = n * heightSegments * 2;
  const positions = new Float32Array(numVertices * 3);
  const indices = new Uint32Array(numFaces * 3);
  const uvs = new Float32Array(numVertices * 2);

  let vertexOffset = 0;
  let indexOffset = 0;
  let uvOffset = 0;
  const totalWidth = n * width + (n - 1) * spacing;
  const xOffsetBase = -totalWidth / 2;

  for (let i = 0; i < n; i++) {
    const xOffset = xOffsetBase + i * (width + spacing);
    const uvXOffset = Math.random() * 300;
    const uvYOffset = Math.random() * 300;

    for (let j = 0; j <= heightSegments; j++) {
      const y = height * (j / heightSegments - 0.5);
      const v0 = [xOffset, y, 0];
      const v1 = [xOffset + width, y, 0];
      positions.set([...v0, ...v1], vertexOffset * 3);

      const uvY = j / heightSegments;
      uvs.set([uvXOffset, uvY + uvYOffset, uvXOffset + 1, uvY + uvYOffset], uvOffset);

      if (j < heightSegments) {
        const a = vertexOffset,
          b = vertexOffset + 1,
          c = vertexOffset + 2,
          d = vertexOffset + 3;
        indices.set([a, b, c, c, b, d], indexOffset);
        indexOffset += 6;
      }
      vertexOffset += 2;
      uvOffset += 4;
    }
  }

  geometry.setAttribute('position', new THREE.BufferAttribute(positions, 3));
  geometry.setAttribute('uv', new THREE.BufferAttribute(uvs, 2));
  geometry.setIndex(new THREE.BufferAttribute(indices, 1));
  geometry.computeVertexNormals();
  return geometry;
}

const beamMaterial = computed(() =>
  extendMaterial(THREE.MeshStandardMaterial, {
    header: `
  varying vec3 vEye;
  varying float vNoise;
  varying vec2 vUv;
  varying vec3 vPosition;
  uniform float time;
  uniform float uSpeed;
  uniform float uNoiseIntensity;
  uniform float uScale;
  ${noise}`,
    vertexHeader: `
  float getPos(vec3 pos) {
    vec3 noisePos =
      vec3(pos.x * 0., pos.y - uv.y, pos.z + time * uSpeed * 3.) * uScale;
    return cnoise(noisePos);
  }
  vec3 getCurrentPos(vec3 pos) {
    vec3 newpos = pos;
    newpos.z += getPos(pos);
    return newpos;
  }
  vec3 getNormal(vec3 pos) {
    vec3 curpos = getCurrentPos(pos);
    vec3 nextposX = getCurrentPos(pos + vec3(0.01, 0.0, 0.0));
    vec3 nextposZ = getCurrentPos(pos + vec3(0.0, -0.01, 0.0));
    vec3 tangentX = normalize(nextposX - curpos);
    vec3 tangentZ = normalize(nextposZ - curpos);
    return normalize(cross(tangentZ, tangentX));
  }`,
    fragmentHeader: '',
    vertex: {
      '#include <begin_vertex>': `transformed.z += getPos(transformed.xyz);`,
      '#include <beginnormal_vertex>': `objectNormal = getNormal(position.xyz);`
    },
    fragment: {
      '#include <dithering_fragment>': `
    float randomNoise = noise(gl_FragCoord.xy);
    gl_FragColor.rgb -= randomNoise / 15. * uNoiseIntensity;`
    },
    material: { fog: true },
    uniforms: {
      diffuse: new THREE.Color(...hexToNormalizedRGB('#000000')),
      time: { shared: true, mixed: true, linked: true, value: 0 },
      roughness: 0.3,
      metalness: 0.3,
      uSpeed: { shared: true, mixed: true, linked: true, value: props.speed },
      envMapIntensity: 10,
      uNoiseIntensity: props.noiseIntensity,
      uScale: props.scale
    }
  })
);

const initThreeJS = () => {
  if (!containerRef.value) return;

  cleanup();

  const container = containerRef.value;

  renderer = new THREE.WebGLRenderer({ antialias: true });
  renderer.setPixelRatio(Math.min(window.devicePixelRatio, 2));
  renderer.setClearColor(0x000000, 1);

  scene = new THREE.Scene();

  camera = new THREE.PerspectiveCamera(30, 1, 0.1, 1000);
  camera.position.set(0, 0, 20);

  const geometry = createStackedPlanesBufferGeometry(props.beamNumber, props.beamWidth, props.beamHeight, 0, 100);

  const material = beamMaterial.value;
  beamMesh = new THREE.Mesh(geometry, material);

  const group = new THREE.Group();
  group.rotation.z = degToRad(props.rotation);
  group.add(beamMesh);
  scene.add(group);

  directionalLight = new THREE.DirectionalLight(new THREE.Color(props.lightColor), 1);
  directionalLight.position.set(0, 3, 10);
  const shadowCamera = directionalLight.shadow.camera as THREE.OrthographicCamera;
  shadowCamera.top = 24;
  shadowCamera.bottom = -24;
  shadowCamera.left = -24;
  shadowCamera.right = 24;
  shadowCamera.far = 64;
  directionalLight.shadow.bias = -0.004;
  scene.add(directionalLight);

  ambientLight = new THREE.AmbientLight(0xffffff, 1);
  scene.add(ambientLight);

  container.appendChild(renderer.domElement);

  const resize = () => {
    if (!container || !renderer || !camera) return;

    const width = container.offsetWidth;
    const height = container.offsetHeight;

    renderer.setSize(width, height);
    camera.aspect = width / height;
    camera.updateProjectionMatrix();
  };

  const resizeObserver = new ResizeObserver(resize);
  resizeObserver.observe(container);

  resize();

  const animate = () => {
    animationId = requestAnimationFrame(animate);

    if (beamMesh && beamMesh.material) {
      beamMesh.material.uniforms.time.value += 0.1 * 0.016;
    }

    if (renderer && scene && camera) {
      renderer.render(scene, camera);
    }
  };

  animationId = requestAnimationFrame(animate);
  (container as HTMLDivElement & { _resizeObserver?: ResizeObserver })._resizeObserver = resizeObserver;
};

const cleanup = () => {
  if (animationId) {
    cancelAnimationFrame(animationId);
    animationId = null;
  }

  if (containerRef.value) {
    const container = containerRef.value as HTMLDivElement & { _resizeObserver?: ResizeObserver };

    if (container._resizeObserver) {
      container._resizeObserver.disconnect();
      delete container._resizeObserver;
    }

    if (renderer && renderer.domElement.parentNode === container) {
      container.removeChild(renderer.domElement);
    }
  }

  if (beamMesh) {
    if (beamMesh.geometry) beamMesh.geometry.dispose();
    if (beamMesh.material) beamMesh.material.dispose();
    beamMesh = null;
  }

  if (renderer) {
    renderer.dispose();
    renderer = null;
  }

  scene = null;
  camera = null;
  directionalLight = null;
  ambientLight = null;
};

watch(
  () => [
    props.beamWidth,
    props.beamHeight,
    props.beamNumber,
    props.lightColor,
    props.speed,
    props.noiseIntensity,
    props.scale,
    props.rotation
  ],
  () => {
    initThreeJS();
  },
  { deep: true }
);

onMounted(() => {
  initThreeJS();
});

onUnmounted(() => {
  cleanup();
});
</script>
