<script module lang="ts">
  import { Renderer, Program, Mesh, Triangle, Texture } from 'ogl';

  const PROJECT_LOGO = '/logo.png';
  const RASTER = 560;
  const CELL = 4;
  const FAR = 1e20;
  const ARCS = 5;
  const PULSES = 3;
  const PIXEL_BUDGET = 4e6;

  type Rgb = [number, number, number];

  export type ElectricLogoProps = {
    src?: string;
    color?: string;
    glowColor?: string;
    scale?: number;
    intensity?: number;
    glow?: number;
    thickness?: number;
    strands?: number;
    bend?: number;
    crackle?: number;
    arcs?: number;
    flicker?: number;
    fill?: number;
    speed?: number;
    interactive?: boolean;
    cursorIntensity?: number;
    cursorRadius?: number;
    theme?: 'dark' | 'light';
    onRender?: (canvas: HTMLCanvasElement) => void;
    class?: string;
    style?: string;
  };

  type Settings = Required<Omit<ElectricLogoProps, 'src' | 'class' | 'style' | 'onRender'>> &
    Pick<ElectricLogoProps, 'onRender'>;

  type Shape = {
    field: Float32Array;
    edges: number[];
    width: number;
    height: number;
    pad: number;
    logoWidth: number;
    logoHeight: number;
    glow: Float32Array;
    glowWidth: number;
    glowHeight: number;
    glowOffset: number;
  };

  type Slot = {
    shape: Shape | null;
    field: Texture;
    glow: Texture;
  };

  type Pulse = {
    x: number;
    y: number;
    born: number;
  };

  type Point = {
    x: number;
    y: number;
  };

  type Focus = {
    x: number;
    y: number;
    radius: number;
  };

  type Spark = {
    ax: number;
    ay: number;
    bx: number;
    by: number;
    bow: number;
    seed: number;
    born: number;
    life: number;
  };

  const hexToRgb = (hex: string): Rgb => {
    let h = (hex || '').replace('#', '');
    if (h.length === 3) h = h.replace(/./g, (c) => c + c);
    const n = parseInt(h.slice(0, 6), 16);
    return Number.isNaN(n) ? [1, 1, 1] : [((n >> 16) & 255) / 255, ((n >> 8) & 255) / 255, (n & 255) / 255];
  };

  const transformLine = (f: Float64Array, d: Float64Array, v: Int32Array, z: Float64Array, n: number) => {
    let k = 0;
    v[0] = 0;
    z[0] = -FAR;
    z[1] = FAR;
    for (let q = 1; q < n; q++) {
      let s = (f[q] + q * q - (f[v[k]] + v[k] * v[k])) / (2 * q - 2 * v[k]);
      while (s <= z[k]) {
        k--;
        s = (f[q] + q * q - (f[v[k]] + v[k] * v[k])) / (2 * q - 2 * v[k]);
      }
      k++;
      v[k] = q;
      z[k] = s;
      z[k + 1] = FAR;
    }
    k = 0;
    for (let q = 0; q < n; q++) {
      while (z[k + 1] < q) k++;
      d[q] = (q - v[k]) * (q - v[k]) + f[v[k]];
    }
  };

  const transformGrid = (grid: Float32Array, w: number, h: number) => {
    const n = Math.max(w, h);
    const f = new Float64Array(n);
    const d = new Float64Array(n);
    const v = new Int32Array(n);
    const z = new Float64Array(n + 1);
    for (let x = 0; x < w; x++) {
      for (let y = 0; y < h; y++) f[y] = grid[y * w + x];
      transformLine(f, d, v, z, h);
      for (let y = 0; y < h; y++) grid[y * w + x] = d[y];
    }
    for (let y = 0; y < h; y++) {
      for (let x = 0; x < w; x++) f[x] = grid[y * w + x];
      transformLine(f, d, v, z, w);
      for (let x = 0; x < w; x++) grid[y * w + x] = d[x];
    }
  };

  const blurLine = (src: Float32Array, dst: Float32Array, offset: number, stride: number, n: number, r: number) => {
    const scale = 1 / (2 * r + 1);
    let sum = 0;
    for (let i = 0; i <= r && i < n; i++) sum += src[offset + i * stride];
    for (let i = 0; i < n; i++) {
      dst[offset + i * stride] = sum * scale;
      if (i + r + 1 < n) sum += src[offset + (i + r + 1) * stride];
      if (i - r >= 0) sum -= src[offset + (i - r) * stride];
    }
  };

  const blurGrid = (grid: Float32Array, w: number, h: number, r: number) => {
    const tmp = new Float32Array(w * h);
    for (let pass = 0; pass < 3; pass++) {
      for (let y = 0; y < h; y++) blurLine(grid, tmp, y * w, 1, w, r);
      for (let x = 0; x < w; x++) blurLine(tmp, grid, x, w, h, r);
    }
  };

  const readCoverage = (data: Uint8ClampedArray, w: number, h: number) => {
    const coverage = new Float32Array(w * h);
    let clear = 0;
    for (let i = 0; i < w * h; i++) if (data[i * 4 + 3] < 250) clear++;
    if (clear > w * h * 0.01) {
      for (let i = 0; i < w * h; i++) coverage[i] = data[i * 4 + 3] / 255;
      return coverage;
    }
    let r = 0;
    let g = 0;
    let b = 0;
    let n = 0;
    const sample = (i: number) => {
      r += data[i * 4];
      g += data[i * 4 + 1];
      b += data[i * 4 + 2];
      n++;
    };
    for (let x = 0; x < w; x++) {
      sample(x);
      sample((h - 1) * w + x);
    }
    for (let y = 0; y < h; y++) {
      sample(y * w);
      sample(y * w + w - 1);
    }
    r /= n;
    g /= n;
    b /= n;
    for (let i = 0; i < w * h; i++) {
      const diff = Math.max(Math.abs(data[i * 4] - r), Math.abs(data[i * 4 + 1] - g), Math.abs(data[i * 4 + 2] - b));
      coverage[i] = Math.min(1, Math.max(0, (diff - 24) / 48));
    }
    return coverage;
  };

  const sampleField = (shape: Shape, x: number, y: number) => {
    const { field, width, height } = shape;
    const cx = Math.min(Math.max(x, 0.5), width - 0.5);
    const cy = Math.min(Math.max(y, 0.5), height - 0.5);
    const x0 = Math.min(Math.floor(cx - 0.5), width - 2);
    const y0 = Math.min(Math.floor(cy - 0.5), height - 2);
    const tx = cx - 0.5 - x0;
    const ty = cy - 0.5 - y0;
    const i = y0 * width + x0;
    const top = field[i] + (field[i + 1] - field[i]) * tx;
    const bottom = field[i + width] + (field[i + width + 1] - field[i + width]) * tx;
    return top + (bottom - top) * ty + Math.hypot(x - cx, y - cy);
  };

  const traceShape = (image: HTMLImageElement): Shape | null => {
    const iw = image.naturalWidth || image.width;
    const ih = image.naturalHeight || image.height;
    if (!iw || !ih) return null;
    const fit = RASTER / Math.max(iw, ih);
    const w = Math.max(2, Math.round(iw * fit));
    const h = Math.max(2, Math.round(ih * fit));
    const canvas = document.createElement('canvas');
    canvas.width = w;
    canvas.height = h;
    const ctx = canvas.getContext('2d', { willReadFrequently: true });
    if (!ctx) return null;
    ctx.drawImage(image, 0, 0, w, h);
    const coverage = readCoverage(ctx.getImageData(0, 0, w, h).data, w, h);

    let left = w;
    let top = h;
    let right = -1;
    let bottom = -1;
    for (let y = 0; y < h; y++) {
      for (let x = 0; x < w; x++) {
        if (coverage[y * w + x] <= 0.01) continue;
        if (x < left) left = x;
        if (x > right) right = x;
        if (y < top) top = y;
        if (y > bottom) bottom = y;
      }
    }
    if (right < 0) return null;

    const logoWidth = right - left + 1;
    const logoHeight = bottom - top + 1;
    const pad = Math.ceil(Math.max(logoWidth, logoHeight) * 0.25) + 2;
    const width = logoWidth + pad * 2;
    const height = logoHeight + pad * 2;
    const outer = new Float32Array(width * height);
    const inner = new Float32Array(width * height);
    for (let y = 0; y < height; y++) {
      for (let x = 0; x < width; x++) {
        const sx = x - pad + left;
        const sy = y - pad + top;
        const a = sx >= 0 && sy >= 0 && sx < w && sy < h ? coverage[sy * w + sx] : 0;
        const i = y * width + x;
        if (a >= 1) {
          outer[i] = 0;
          inner[i] = FAR;
        } else if (a <= 0) {
          outer[i] = FAR;
          inner[i] = 0;
        } else {
          const e = 0.5 - a;
          outer[i] = e > 0 ? e * e : 0;
          inner[i] = e < 0 ? e * e : 0;
        }
      }
    }
    transformGrid(outer, width, height);
    transformGrid(inner, width, height);

    const field = new Float32Array(width * height);
    for (let i = 0; i < width * height; i++) field[i] = Math.sqrt(outer[i]) - Math.sqrt(inner[i]);

    const points: number[] = [];
    for (let y = 1; y < height - 1; y++) {
      for (let x = 1; x < width - 1; x++) {
        const i = y * width + x;
        const d = field[i];
        if (d > 0) continue;
        if (field[i - 1] <= 0 && field[i + 1] <= 0 && field[i - width] <= 0 && field[i + width] <= 0) continue;
        const gx = field[i + 1] - field[i - 1];
        const gy = field[i + width] - field[i - width];
        const len = Math.hypot(gx, gy) || 1;
        points.push(x + 0.5 - (d * gx) / len, y + 0.5 - (d * gy) / len);
      }
    }
    const stride = Math.max(1, Math.ceil(points.length / 2 / 3000)) * 2;
    const edges: number[] = [];
    for (let i = 0; i < points.length; i += stride) edges.push(points[i], points[i + 1]);

    const size = Math.max(logoWidth, logoHeight);
    const glowPad = Math.ceil((size * 0.7) / CELL);
    const glowWidth = Math.ceil(logoWidth / CELL) + glowPad * 2;
    const glowHeight = Math.ceil(logoHeight / CELL) + glowPad * 2;
    const tight = new Float32Array(glowWidth * glowHeight);
    for (let y = 0; y < height; y++) {
      const gy = Math.floor((y - pad) / CELL) + glowPad;
      for (let x = 0; x < width; x++) {
        const gx = Math.floor((x - pad) / CELL) + glowPad;
        tight[gy * glowWidth + gx] += Math.exp(-Math.abs(field[y * width + x]) / 1.5) / (CELL * CELL);
      }
    }
    const wide = tight.slice();
    const tightRadius = Math.max(1, Math.round((size * 0.035) / CELL));
    const wideRadius = Math.max(2, Math.round((size * 0.13) / CELL));
    blurGrid(tight, glowWidth, glowHeight, tightRadius);
    blurGrid(wide, glowWidth, glowHeight, wideRadius);
    const tightNorm = (Math.sqrt(2 * Math.PI * (tightRadius * tightRadius + tightRadius)) * CELL) / 3;
    const wideNorm = (Math.sqrt(2 * Math.PI * (wideRadius * wideRadius + wideRadius)) * CELL) / 3;
    const glow = new Float32Array(glowWidth * glowHeight * 2);
    for (let i = 0; i < glowWidth * glowHeight; i++) {
      glow[i * 2] = tight[i] * tightNorm;
      glow[i * 2 + 1] = wide[i] * wideNorm;
    }

    return {
      field,
      edges,
      width,
      height,
      pad,
      logoWidth,
      logoHeight,
      glow,
      glowWidth,
      glowHeight,
      glowOffset: pad - glowPad * CELL
    };
  };

  const spawnArc = (shape: Shape, time: number, focus: Focus | null): Spark | null => {
    const { edges, logoWidth, logoHeight } = shape;
    const count = edges.length / 2;
    if (count < 2) return null;
    const size = Math.max(logoWidth, logoHeight);
    let i = Math.floor(Math.random() * count);
    if (focus) {
      let found = false;
      for (let attempt = 0; attempt < 40 && !found; attempt++) {
        const j = Math.floor(Math.random() * count);
        if (Math.hypot(edges[j * 2] - focus.x, edges[j * 2 + 1] - focus.y) < focus.radius) {
          i = j;
          found = true;
        }
      }
      if (!found) return null;
    }
    const ax = edges[i * 2];
    const ay = edges[i * 2 + 1];
    for (let attempt = 0; attempt < 24; attempt++) {
      const j = Math.floor(Math.random() * count);
      const bx = edges[j * 2];
      const by = edges[j * 2 + 1];
      const len = Math.hypot(bx - ax, by - ay);
      if (len < size * 0.08 || len > size * 0.3) continue;
      const nx = -(by - ay) / len;
      const ny = (bx - ax) / len;
      const bow = len * (0.2 + Math.random() * 0.3);
      const mx = (ax + bx) / 2;
      const my = (ay + by) / 2;
      const left = sampleField(shape, mx + nx * bow, my + ny * bow);
      const right = sampleField(shape, mx - nx * bow, my - ny * bow);
      if (Math.max(left, right) <= 0) continue;
      return {
        ax,
        ay,
        bx,
        by,
        bow: left >= right ? bow : -bow,
        seed: 1 + Math.random() * 60,
        born: time,
        life: 0.35 + Math.random() * 0.45
      };
    }
    return null;
  };

  const vertex = `#version 300 es
in vec2 position;
in vec2 uv;
out vec2 vUv;
void main() {
  vUv = uv;
  gl_Position = vec4(position, 0.0, 1.0);
}
`;

  const fragment = `#version 300 es
precision highp float;
precision highp int;

uniform sampler2D tFieldFrom;
uniform sampler2D tGlowFrom;
uniform sampler2D tFieldTo;
uniform sampler2D tGlowTo;
uniform vec4 uMapFrom;
uniform vec4 uSizeFrom;
uniform vec4 uMapTo;
uniform vec4 uSizeTo;
uniform float uMorph;
uniform vec2 uResolution;
uniform float uUnit;
uniform float uTime;
uniform float uPresence;
uniform vec3 uHover;
uniform float uHoverRadius;
uniform vec4 uPulses[${PULSES}];
uniform float uPulseBoost;
uniform float uFlash;
uniform vec3 uColor;
uniform vec3 uGlowColor;
uniform float uIntensity;
uniform float uGlow;
uniform float uThickness;
uniform float uStrands;
uniform float uBend;
uniform float uCrackle;
uniform float uFlicker;
uniform float uFill;
uniform float uInk;
uniform vec4 uArcEnds[${ARCS}];
uniform vec4 uArcShape[${ARCS}];

in vec2 vUv;
out vec4 fragColor;

uint scramble(uint x) {
  x ^= x >> 16u;
  x *= 0x7feb352du;
  x ^= x >> 15u;
  x *= 0x846ca68bu;
  x ^= x >> 16u;
  return x;
}

float fieldAt(sampler2D tex, vec4 map, vec4 size, vec2 p) {
  vec2 f = (p - map.xy) / map.z;
  vec2 c = clamp(f, vec2(0.5), size.xy - 0.5);
  return (textureLod(tex, c / size.xy, 0.0).r + length(f - c)) * map.z;
}

vec2 glowAt(sampler2D tex, vec4 map, vec4 size, vec2 p) {
  vec2 f = (p - map.xy) / map.z - map.w;
  return textureLod(tex, f / (size.zw * ${CELL}.0), 0.0).rg;
}

float shape(vec2 p, float k) {
  float to = fieldAt(tFieldTo, uMapTo, uSizeTo, p);
  if (k >= 1.0) return to;
  return mix(fieldAt(tFieldFrom, uMapFrom, uSizeFrom, p), to, k);
}

vec2 aura(vec2 p, float k) {
  vec2 to = glowAt(tGlowTo, uMapTo, uSizeTo, p);
  if (k >= 1.0) return to;
  return mix(glowAt(tGlowFrom, uMapFrom, uSizeFrom, p), to, k);
}

vec4 corner(ivec2 c, uint seed) {
  uint h = scramble(uint(c.x) * 0x8da6b343u + uint(c.y) * 0xd8163841u + seed * 0xcb1ab31fu);
  return vec4(uvec4(h, h >> 8u, h >> 16u, h >> 24u) & 255u) / 127.5 - 1.0;
}

vec2 drift(vec2 p, uint seed, out mat2 jac) {
  vec2 i = floor(p);
  vec2 f = p - i;
  vec2 u = f * f * f * (f * (f * 6.0 - 15.0) + 10.0);
  vec2 du = 30.0 * f * f * (f * (f - 2.0) + 1.0);
  ivec2 c = ivec2(i);
  vec4 ga = corner(c, seed);
  vec4 gb = corner(c + ivec2(1, 0), seed);
  vec4 gc = corner(c + ivec2(0, 1), seed);
  vec4 gd = corner(c + ivec2(1, 1), seed);
  vec2 fb = f - vec2(1.0, 0.0);
  vec2 fc = f - vec2(0.0, 1.0);
  vec2 fd = f - vec2(1.0);
  vec2 va = vec2(dot(ga.xy, f), dot(ga.zw, f));
  vec2 vb = vec2(dot(gb.xy, fb), dot(gb.zw, fb));
  vec2 vc = vec2(dot(gc.xy, fc), dot(gc.zw, fc));
  vec2 vd = vec2(dot(gd.xy, fd), dot(gd.zw, fd));
  vec2 k = va - vb - vc + vd;
  vec4 g = ga + u.x * (gb - ga) + u.y * (gc - ga) + u.x * u.y * (ga - gb - gc + gd);
  jac = mat2(
    g.xy + du * (u.yx * k.x + vec2(vb.x - va.x, vc.x - va.x)),
    g.zw + du * (u.yx * k.y + vec2(vb.y - va.y, vc.y - va.y))
  );
  return va + u.x * (vb - va) + u.y * (vc - va) + u.x * u.y * k;
}

float wobble(vec2 p, uint seed) {
  mat2 jac;
  return drift(p, seed, jac).x;
}

vec2 ripple(vec2 p, out float surge) {
  vec2 push = vec2(0.0);
  surge = 0.0;
  float width = uUnit * 10.0;
  for (int i = 0; i < ${PULSES}; i++) {
    vec4 pulse = uPulses[i];
    if (pulse.w <= 0.0) continue;
    vec2 d = p - pulse.xy;
    float dist = length(d);
    float front = (dist - pulse.z * uUnit * 150.0) / width;
    float env = exp(-front * front) * pulse.w * exp(-pulse.z * 1.7) * smoothstep(0.0, uUnit * 8.0, dist);
    push += d / max(dist, 1.0) * env * cos(front * 2.2) * uUnit * 7.5;
    surge += env;
  }
  return push;
}

vec2 wander(vec2 p, float t, uint seed, float reachScale, out mat2 jac, out vec2 sway) {
  vec2 q = p / uUnit;
  mat2 ja;
  mat2 jb;
  mat2 jc;
  mat2 jd;
  vec2 a = drift(q * 0.028 + vec2(t * 0.29, t * 0.21), seed, ja);
  vec2 b = drift(q * 0.085 + a * 0.4 + vec2(t * 0.83, -t * 0.61) + 17.0, seed + 1u, jb);
  vec2 c = drift(p / 9.0 + b * 0.6 + vec2(t * 1.9, t * 1.3) + 5.0, seed + 2u, jc);
  vec2 d = drift(p / 4.1 + vec2(-t * 2.7, t * 2.2) + 11.0, seed + 3u, jd);
  float bendAmp = uBend * 8.0 * reachScale;
  float rippleAmp = uBend * 3.2 * reachScale;
  float crinkleAmp = uCrackle * 1.5 * reachScale;
  jac = ja * (0.028 * bendAmp) + jb * (0.085 * rippleAmp) + jc * (crinkleAmp / 9.0) + jd * (crinkleAmp * 0.35 / 4.1);
  sway = (a * bendAmp + b * rippleAmp) * uUnit;
  return sway + (c + d * 0.35) * crinkleAmp;
}

vec2 glowShape(float line, float spread, float w) {
  float x = abs(line);
  float y = abs(spread);
  return vec2(exp(-x * x / (w * w * 0.5)) + exp(-y / (w * 2.2)) * 0.6, exp(-y / (w * 4.5)) * 0.5);
}

void addArc(vec2 p, vec4 ends, vec4 info, float t, inout vec3 light, inout float energy, inout float hot) {
  if (info.y < 0.002) return;
  vec2 ab = ends.zw - ends.xy;
  float len = max(length(ab), 1.0);
  vec2 dir = ab / len;
  vec2 rel = p - ends.xy;
  float s = dot(rel, dir);
  float h = dot(rel, vec2(-dir.y, dir.x));
  float margin = abs(info.x) + uCrackle * (2.0 + len * 0.08) + uThickness * 12.0 + 10.0;
  if (s < -margin || s > len + margin || abs(h) > margin) return;
  float u = clamp(s / len, 0.0, 1.0);
  float taper = sin(3.14159265 * u);
  float bendSlope = s > 0.0 && s < len ? 3.14159265 / len * cos(3.14159265 * u) : 0.0;
  float beyond = max(-s, 0.0) + max(s - len, 0.0);
  for (int c = 0; c < 2; c++) {
    uint seed = uint(info.z * 131.0) + uint(c) * 29u + 7u;
    float jag = 0.0;
    float jagSlope = 0.0;
    float wave = max(len * 0.3, 14.0);
    float weight = uCrackle * (1.5 + len * 0.05) * (c == 0 ? 1.0 : 1.5);
    for (int o = 0; o < 3; o++) {
      mat2 jac;
      float n = drift(vec2(s / wave + info.z * 3.0, t * (1.4 + float(o) * 1.1)), seed + uint(o), jac).x;
      jag += n * weight;
      jagSlope += jac[0].x * weight / wave;
      wave *= 0.42;
      weight *= 0.4;
    }
    float offset = (info.x + jag) * taper;
    float offsetSlope = (info.x + jag) * bendSlope + jagSlope * taper;
    float across = (h - offset) / sqrt(1.0 + offsetSlope * offsetSlope);
    float gap = length(vec2(beyond, across));
    float w = uThickness * (c == 0 ? 0.9 : 0.6);
    vec2 g = glowShape(gap, gap, w);
    float k = info.y * (c == 0 ? 1.0 : 0.45);
    light += (uColor * g.x + uGlowColor * g.y * uGlow) * k;
    energy += (g.x + g.y * uGlow) * k;
    hot += exp(-gap * gap / (w * w * 0.16)) * k * (c == 0 ? 1.0 : 0.0);
  }
}

void main() {
  vec2 p = vec2(vUv.x, 1.0 - vUv.y) * uResolution;
  float t = uTime;
  vec3 light = vec3(0.0);
  float energy = 0.0;
  float hot = 0.0;

  float surge;
  vec2 pr = p - ripple(p, surge);
  float k = uMorph >= 1.0 ? 1.0 : smoothstep(0.0, 1.0, clamp(uMorph * 1.7 - 0.35 + 0.35 * wobble(p / uUnit * 0.018, 41u), 0.0, 1.0));
  float transit = uMorph >= 1.0 ? 0.0 : sin(3.14159265 * uMorph);
  float base = shape(pr, k);

  vec2 toHover = p - uHover.xy;
  float heat = min(uHover.z * exp(-dot(toHover, toHover) / (uHoverRadius * uHoverRadius)) + surge * 1.4 + transit * 0.5, 2.0);
  float heatCap = min(uHover.z + uPulseBoost * 1.4 + transit * 0.5, 2.0);
  float breath = 1.0 + uFlicker * 0.6 * wobble(vec2(t * 2.1, 7.0), 3u);
  float grow = uPresence;

  float edge = abs(base);
  vec2 halo = aura(pr, k);
  float ink = uInk;
  float bloom = (halo.x * 0.16 + halo.y * 0.08) * (1.0 - ink * 0.65) * uGlow * (1.0 + heat * 1.2);
  float body = smoothstep(0.75, -0.75, base) * uFill * (0.06 + 1.2 * min(halo.x, 1.0)) * (1.0 + heat * 0.5);
  light += uGlowColor * bloom * grow * grow;
  energy += bloom * grow * grow;

  float reachScale = mix(0.15, 1.0, grow) * (1.0 + heat * 0.9);
  float reach = (uUnit * uBend * 16.0 + uCrackle * 3.0) * (1.0 + heatCap * 0.9) + uThickness * 20.0 + 8.0;
  if (edge < reach && grow > 0.0) {
    float fade = smoothstep(reach, reach * 0.55, edge);
    vec2 q = pr / uUnit;
    float count = min(uStrands + heat * 2.5, 6.0);
    float limit = min(uStrands + heatCap * 2.5, 6.0);
    for (int i = 0; i < 6; i++) {
      float fi = float(i);
      if (fi >= limit) break;
      float present = clamp(count - fi, 0.0, 1.0);
      if (present <= 0.0) continue;
      uint seed = uint(i) * 7u + 3u;
      mat2 jac;
      vec2 sway;
      float lead = i == 0 ? 1.0 : 0.0;
      vec2 warped = pr + wander(pr, t * (1.0 + fi * 0.19), seed, reachScale * mix(0.6 + fi * 0.2, 0.7, lead), jac, sway);
      float dw = shape(warped, k);
      vec2 slope = vec2(shape(warped + vec2(1.0, 0.0), k), shape(warped + vec2(0.0, 1.0), k)) - dw;
      float d = dw / max(length(slope + jac * slope), 0.3);
      float spread = shape(pr + sway, k);
      float swell = 0.5 + 0.5 * wobble(q * 0.06 + vec2(t * 0.9, fi * 5.1 - t * 0.6), seed + 8u);
      float w = uThickness * mix(0.5, 1.0, lead) * (0.5 + swell);
      float vis = mix(0.3 + 0.45 * smoothstep(-0.25, 0.2, wobble(q * 0.035 + vec2(t * 0.21, fi * 3.7), seed + 5u)), 1.0, lead);
      float spark = 1.0 - uFlicker * 0.3 * (0.5 + 0.5 * wobble(vec2(t * 6.0, fi * 2.3), seed + 6u));
      float weight = max(vis, heat * 0.85) * spark * fade * present * (0.7 + 0.6 * swell);
      vec2 g = glowShape(d, spread, w) * weight;
      float soft = mix(1.0, mix(0.5, 1.0, lead), ink);
      vec3 stroke = mix(uColor, uGlowColor, ink * (1.0 - lead) * 0.65);
      float haze = uGlow * (1.0 + heat) * (1.0 - ink * 0.7);
      light += stroke * g.x * soft + uGlowColor * g.y * haze;
      energy += g.x * soft + g.y * haze;
      hot += exp(-d * d / (w * w * 0.16)) * lead * weight;
    }
    light *= grow;
    energy *= grow;
  }

  for (int i = 0; i < ${ARCS}; i++) addArc(pr, uArcEnds[i], uArcShape[i], t, light, energy, hot);

  float gain = uIntensity * breath * (1.0 + heat * 0.45) * (1.0 + uFlash * 0.3) * 1.4;
  float alpha = 1.0 - exp(-energy * gain);
  vec3 color = mix(1.0 - exp(-light * gain), alpha * light / max(energy, 1e-4), ink);
  color = mix(color, vec3(alpha), clamp(hot * grow, 0.0, 1.0) * ink * 0.85);
  float tint = (1.0 - exp(-body * gain * 1.2)) * grow * grow * (1.0 - ink * 0.82);
  color += uGlowColor * tint * (1.0 - alpha);
  alpha += tint * (1.0 - alpha);
  float grain = (fract(52.9829189 * fract(dot(gl_FragCoord.xy, vec2(0.06711056, 0.00583715)))) - 0.5) / 255.0;
  alpha = clamp(alpha + grain, 0.0, 1.0);
  fragColor = vec4(clamp(color + grain, 0.0, alpha), alpha);
}
`;
</script>

<script lang="ts">
  import { onMount } from 'svelte';

  let {
    src = PROJECT_LOGO,
    color = '#ecc7ff',
    glowColor = '#ad6dff',
    scale = 0.7,
    intensity = 1,
    glow = 1,
    thickness = 1.5,
    strands = 4,
    bend = 0.6,
    crackle = 1.5,
    arcs = 1,
    flicker = 0.6,
    fill = 0,
    speed = 2.5,
    interactive = true,
    cursorIntensity = 0.75,
    cursorRadius = 100,
    theme = 'dark',
    onRender,
    class: className = '',
    style
  }: ElectricLogoProps = $props();

  let container: HTMLDivElement;

  // Не реактивное состояние: читается внутри rAF-цикла
  let tracedShape: Shape | null = null;

  // Актуальные настройки на каждый кадр (props в Svelte 5 всегда свежие)
  const getSettings = (): Settings => ({
    color,
    glowColor,
    scale,
    intensity,
    glow,
    thickness,
    strands,
    bend,
    crackle,
    arcs,
    flicker,
    fill,
    speed,
    interactive,
    cursorIntensity,
    cursorRadius,
    theme,
    onRender
  });

  // Трассировка контура при смене src
  $effect(() => {
    const source = src || PROJECT_LOGO;
    let alive = true;
    const image = new Image();
    image.crossOrigin = 'anonymous';
    image.decoding = 'async';
    image.onload = () => {
      if (!alive) return;
      let traced: Shape | null = null;
      try {
        traced = traceShape(image);
      } catch {
        traced = null;
      }
      if (traced) tracedShape = traced;
    };
    image.src = source;
    return () => {
      alive = false;
      image.onload = null;
    };
  });

  onMount(() => {
    const renderer = new Renderer({
      dpr: Math.min(window.devicePixelRatio || 1, 2),
      alpha: true,
      premultipliedAlpha: true,
      antialias: false
    });
    const gl = renderer.gl;
    const gl2 = gl as WebGL2RenderingContext;
    if (!renderer.isWebgl2) {
      gl.getExtension('WEBGL_lose_context')?.loseContext();
      return undefined;
    }
    gl.clearColor(0, 0, 0, 0);
    const canvas = gl.canvas;
    canvas.style.display = 'block';
    canvas.style.width = '100%';
    canvas.style.height = '100%';
    // OGL creates its canvas imperatively and cleanup is handled in onMount.
    // eslint-disable-next-line svelte/no-dom-manipulating
    container.appendChild(canvas);

    const makeSlot = (): Slot => ({
      shape: null,
      field: new Texture(gl, {
        image: new Float32Array([1000]),
        width: 1,
        height: 1,
        internalFormat: gl2.R16F,
        format: gl2.RED,
        type: gl.FLOAT,
        minFilter: gl.LINEAR,
        magFilter: gl.LINEAR,
        generateMipmaps: false,
        flipY: false,
        unpackAlignment: 1
      }),
      glow: new Texture(gl, {
        image: new Float32Array([0, 0]),
        width: 1,
        height: 1,
        internalFormat: gl2.RG16F,
        format: gl2.RG,
        type: gl.FLOAT,
        minFilter: gl.LINEAR,
        magFilter: gl.LINEAR,
        generateMipmaps: false,
        flipY: false,
        unpackAlignment: 1
      })
    });
    const slots = [makeSlot(), makeSlot()];

    const arcEnds = Array.from({ length: ARCS * 4 }, () => 0);
    const arcShape = Array.from({ length: ARCS * 4 }, () => 0);
    const pulseData = Array.from({ length: PULSES * 4 }, () => 0);
    const uniforms = {
      tFieldFrom: { value: slots[1].field },
      tGlowFrom: { value: slots[1].glow },
      tFieldTo: { value: slots[0].field },
      tGlowTo: { value: slots[0].glow },
      uMapFrom: { value: [0, 0, 1, 0] },
      uSizeFrom: { value: [1, 1, 1, 1] },
      uMapTo: { value: [0, 0, 1, 0] },
      uSizeTo: { value: [1, 1, 1, 1] },
      uMorph: { value: 1 },
      uResolution: { value: [1, 1] },
      uUnit: { value: 1 },
      uTime: { value: 0 },
      uPresence: { value: 0 },
      uHover: { value: [0, 0, 0] },
      uHoverRadius: { value: 120 },
      uPulses: { value: pulseData },
      uPulseBoost: { value: 0 },
      uFlash: { value: 0 },
      uColor: { value: [1, 1, 1] },
      uGlowColor: { value: [0.43, 0.48, 1] },
      uIntensity: { value: 1 },
      uGlow: { value: 1 },
      uThickness: { value: 1.8 },
      uStrands: { value: 3 },
      uBend: { value: 1 },
      uCrackle: { value: 1 },
      uFlicker: { value: 0.4 },
      uFill: { value: 0.5 },
      uInk: { value: 0 },
      uArcEnds: { value: arcEnds },
      uArcShape: { value: arcShape }
    };
    const mesh = new Mesh(gl, {
      geometry: new Triangle(gl),
      program: new Program(gl, { vertex, fragment, uniforms, depthTest: false, depthWrite: false })
    });

    const reducedMotion = window.matchMedia?.('(prefers-reduced-motion: reduce)').matches ?? false;
    const pointer = { x: 0, y: 0, over: false };
    const hover = { x: 0, y: 0, vx: 0, vy: 0, power: 0 };
    const sparks: Spark[] = [];
    const pulses: Pulse[] = [];
    let target = 0;
    let pending: Shape | null = null;
    let morph = 1;
    let burst: Point | null = null;
    let progress = 0;
    let ink = 0;
    const hues = [
      [1, 1, 1],
      [1, 1, 1]
    ];
    let settled = false;
    let time = 0;
    let width = 1;
    let height = 1;
    let raf = 0;
    let last = performance.now();
    let visible = true;

    const load = (slot: Slot, next: Shape) => {
      slot.shape = next;
      slot.field.image = next.field;
      slot.field.width = next.width;
      slot.field.height = next.height;
      slot.field.needsUpdate = true;
      slot.glow.image = next.glow;
      slot.glow.width = next.glowWidth;
      slot.glow.height = next.glowHeight;
      slot.glow.needsUpdate = true;
    };

    const place = (shape: Shape, s: Settings) => {
      const fit = Math.max(1e-4, Math.min((width * s.scale) / shape.logoWidth, (height * s.scale) / shape.logoHeight));
      return {
        fit,
        ox: width / 2 - (shape.pad + shape.logoWidth / 2) * fit,
        oy: height / 2 - (shape.pad + shape.logoHeight / 2) * fit,
        unit: (Math.max(shape.logoWidth, shape.logoHeight) * fit) / 100
      };
    };

    const resize = () => {
      width = Math.max(1, container.clientWidth);
      height = Math.max(1, container.clientHeight);
      renderer.dpr = Math.min(window.devicePixelRatio || 1, 2, Math.sqrt(PIXEL_BUDGET / (width * height)));
      renderer.setSize(width, height);
      uniforms.uResolution.value = [width, height];
    };

    const frame = (now: number) => {
      raf = 0;
      const s = getSettings();
      const dt = Math.min(0.05, Math.max(0, (now - last) / 1000));
      last = now;

      const incoming = tracedShape;
      if (incoming && incoming !== slots[target].shape) pending = incoming;
      if (pending && morph >= 1) {
        if (slots[target].shape) {
          target = 1 - target;
          morph = 0;
          sparks.length = 0;
        }
        load(slots[target], pending);
        pending = null;
      }
      if (morph < 1) morph = Math.min(1, morph + dt / (pending ? 0.3 : 1.6));

      const to = slots[target].shape;
      const from = morph < 1 ? slots[1 - target].shape : null;
      if (to) progress = Math.min(1, progress + dt / 1.4);
      const presence = progress * progress * (3 - 2 * progress);

      if (to) {
        const near = place(to, s);
        const far = from ? place(from, s) : near;
        const blend = morph * morph * (3 - 2 * morph);
        const unit = far.unit + (near.unit - far.unit) * blend;

        const engaged = s.interactive && pointer.over;
        if (engaged && hover.power < 0.01) {
          hover.x = pointer.x;
          hover.y = pointer.y;
          hover.vx = 0;
          hover.vy = 0;
        }
        hover.vx += ((pointer.x - hover.x) * 120 - hover.vx * 19) * dt;
        hover.vy += ((pointer.y - hover.y) * 120 - hover.vy * 19) * dt;
        hover.x += hover.vx * dt;
        hover.y += hover.vy * dt;
        hover.power += ((engaged ? 1 : 0) - hover.power) * (1 - Math.exp(-dt / (engaged ? 0.3 : 0.55)));

        const motion = reducedMotion ? 0.2 : 1;
        time += dt * s.speed * motion;

        for (let i = sparks.length - 1; i >= 0; i--) {
          if (time - sparks[i].born > sparks[i].life) sparks.splice(i, 1);
        }
        const focus = (spot: Point): Focus => ({
          x: (spot.x - near.ox) / near.fit,
          y: (spot.y - near.oy) / near.fit,
          radius: Math.max(1, s.cursorRadius) / near.fit
        });
        if (burst && morph >= 1 && s.arcs > 0) {
          for (let i = 0; i < 3 && sparks.length < ARCS; i++) {
            const spark = spawnArc(to, time, focus(burst));
            if (spark) sparks.push(spark);
          }
        }
        burst = null;
        if (!reducedMotion && presence > 0.8 && morph >= 1 && sparks.length < ARCS) {
          const chance = dt * s.speed * s.arcs;
          if (Math.random() < chance * 6 * hover.power * s.cursorIntensity) {
            const spark = spawnArc(to, time, focus(hover));
            if (spark) sparks.push(spark);
          } else if (Math.random() < chance * 2.2) {
            const spark = spawnArc(to, time, null);
            if (spark) sparks.push(spark);
          }
        }

        for (let i = 0; i < ARCS; i++) {
          const o = i * 4;
          const spark = sparks[i];
          if (!spark) {
            arcShape[o + 1] = 0;
            continue;
          }
          const k = (time - spark.born) / spark.life;
          arcEnds[o] = near.ox + spark.ax * near.fit;
          arcEnds[o + 1] = near.oy + spark.ay * near.fit;
          arcEnds[o + 2] = near.ox + spark.bx * near.fit;
          arcEnds[o + 3] = near.oy + spark.by * near.fit;
          arcShape[o] = spark.bow * near.fit;
          arcShape[o + 1] = Math.sin(Math.PI * Math.min(1, Math.max(0, k))) * presence;
          arcShape[o + 2] = spark.seed;
        }

        let boost = 0;
        let flash = 0;
        for (let i = pulses.length - 1; i >= 0; i--) {
          if ((now - pulses[i].born) / 1000 > 2) pulses.splice(i, 1);
        }
        for (let i = 0; i < PULSES; i++) {
          const o = i * 4;
          const pulse = pulses[i];
          if (!pulse) {
            pulseData[o + 3] = 0;
            continue;
          }
          const age = (now - pulse.born) / 1000;
          pulseData[o] = pulse.x;
          pulseData[o + 1] = pulse.y;
          pulseData[o + 2] = age;
          pulseData[o + 3] = 1;
          boost = Math.max(boost, Math.exp(-age * 1.7));
          flash += Math.exp(-age * 7);
        }

        const fromSlot = slots[1 - target];
        uniforms.tFieldTo.value = slots[target].field;
        uniforms.tGlowTo.value = slots[target].glow;
        uniforms.tFieldFrom.value = fromSlot.field;
        uniforms.tGlowFrom.value = fromSlot.glow;
        uniforms.uMapTo.value = [near.ox, near.oy, near.fit, to.glowOffset];
        uniforms.uSizeTo.value = [to.width, to.height, to.glowWidth, to.glowHeight];
        if (from) {
          uniforms.uMapFrom.value = [far.ox, far.oy, far.fit, from.glowOffset];
          uniforms.uSizeFrom.value = [from.width, from.height, from.glowWidth, from.glowHeight];
        }
        uniforms.uMorph.value = morph;
        uniforms.uUnit.value = unit;
        uniforms.uTime.value = time;
        uniforms.uPresence.value = presence;
        uniforms.uHover.value = [hover.x, hover.y, hover.power * Math.max(0, s.cursorIntensity)];
        uniforms.uHoverRadius.value = Math.max(1, s.cursorRadius);
        uniforms.uPulseBoost.value = boost;
        uniforms.uFlash.value = flash;
        const targets = [hexToRgb(s.color), hexToRgb(s.glowColor)];
        const shift = settled ? 1 - Math.exp(-dt / 0.35) : 1;
        settled = true;
        for (let i = 0; i < 2; i++) {
          for (let c = 0; c < 3; c++) hues[i][c] += (targets[i][c] - hues[i][c]) * shift;
        }
        uniforms.uColor.value = hues[0].slice();
        uniforms.uGlowColor.value = hues[1].slice();
        uniforms.uIntensity.value = s.intensity;
        uniforms.uGlow.value = s.glow;
        uniforms.uThickness.value = s.thickness;
        uniforms.uStrands.value = Math.max(1, Math.min(6, Math.round(s.strands)));
        uniforms.uBend.value = s.bend;
        uniforms.uCrackle.value = s.crackle;
        uniforms.uFlicker.value = reducedMotion ? 0 : s.flicker;
        ink += ((s.theme === 'light' ? 1 : 0) - ink) * (1 - Math.exp(-dt / 0.25));
        uniforms.uFill.value = s.fill;
        uniforms.uInk.value = ink;
        renderer.render({ scene: mesh });
        s.onRender?.(canvas);
      }

      if (visible) raf = requestAnimationFrame(frame);
    };

    const start = () => {
      if (raf || !visible) return;
      last = performance.now();
      raf = requestAnimationFrame(frame);
    };

    const onMove = (e: PointerEvent) => {
      const rect = container.getBoundingClientRect();
      pointer.x = e.clientX - rect.left;
      pointer.y = e.clientY - rect.top;
      pointer.over = true;
    };
    const onDown = (e: PointerEvent) => {
      onMove(e);
      if (!interactive || reducedMotion) return;
      pulses.push({ x: pointer.x, y: pointer.y, born: performance.now() });
      if (pulses.length > PULSES) pulses.shift();
      burst = { x: pointer.x, y: pointer.y };
    };
    const onLeave = () => {
      pointer.over = false;
    };
    container.addEventListener('pointermove', onMove);
    container.addEventListener('pointerdown', onDown);
    container.addEventListener('pointerleave', onLeave);
    container.addEventListener('pointercancel', onLeave);

    const resizeObserver = new ResizeObserver(resize);
    resizeObserver.observe(container);
    const intersectionObserver = new IntersectionObserver(([entry]) => {
      visible = entry.isIntersecting;
      start();
    });
    intersectionObserver.observe(container);

    resize();
    start();

    return () => {
      visible = false;
      cancelAnimationFrame(raf);
      resizeObserver.disconnect();
      intersectionObserver.disconnect();
      container.removeEventListener('pointermove', onMove);
      container.removeEventListener('pointerdown', onDown);
      container.removeEventListener('pointerleave', onLeave);
      container.removeEventListener('pointercancel', onLeave);
      gl.getExtension('WEBGL_lose_context')?.loseContext();
      if (canvas.parentNode) canvas.parentNode.removeChild(canvas);
    };
  });
</script>

<div bind:this={container} class="electric-logo {className}" {style}></div>

<style>
  .electric-logo {
    position: relative;
    width: 100%;
    height: 100%;
    overflow: hidden;
  }
</style>