"use strict";
// ===== CONFIGURACIÓN DEL EFECTO =====
const config = {
    TEXTURE_DOWNSAMPLE: 1,
    DENSITY_DISSIPATION: 0.975,
    VELOCITY_DISSIPATION: 0.98,
    PRESSURE_DISSIPATION: 0.8,
    PRESSURE_ITERATIONS: 20,
    CURL: 30,
    SPLAT_RADIUS: 0.003
};

// ===== INICIALIZAR CANVAS =====
let canvas = document.getElementById("fluidCanvas");
if (!canvas) {
    console.error("ERROR CRÍTICO: No se encontró <canvas id='fluidCanvas'> en el HTML");
}

canvas.width = window.innerWidth;
canvas.height = window.innerHeight;

let pointers = [];

function getWebGLContext(canvas) {
    let params = {
        alpha: true,  // ✅ TRANSPARENCIA ACTIVADA
        depth: false,
        stencil: false,
        antialias: false
    };
    
    // ✅ SIN ESPACIOS DENTRO DE LAS COMILLAS
    let gl = canvas.getContext("webgl2", params);
    let isWebGL2 = !!gl;
    
    if (!isWebGL2) {
        gl = canvas.getContext("webgl", params) || canvas.getContext("experimental-webgl", params);
    }
    
    let halfFloat = gl.getExtension("OES_texture_half_float");
    let support_linear_float = gl.getExtension("OES_texture_half_float_linear");
    
    if (isWebGL2) {
        gl.getExtension("EXT_color_buffer_float");
        support_linear_float = gl.getExtension("OES_texture_float_linear");
    }
    
    // ✅ ÚLTIMO 0 = TRANSPARENCIA TOTAL DEL FONDO
    gl.clearColor(0.0, 0.0, 0.0, 0.0);
    
    let internalFormat = isWebGL2 ? gl.RGBA16F : gl.RGBA;
    let internalFormatRG = isWebGL2 ? gl.RG16F : gl.RGBA;
    let formatRG = isWebGL2 ? gl.RG : gl.RGBA;
    let texType = isWebGL2 ? gl.HALF_FLOAT : halfFloat.HALF_FLOAT_OES;
    
    return {
        gl: gl,
        ext: { internalFormat, internalFormatRG, formatRG, texType },
        support_linear_float: support_linear_float
    };
}

let _ctx = getWebGLContext(canvas);
let gl = _ctx.gl;
let ext = _ctx.ext;
let support_linear_float = _ctx.support_linear_float;

// ===== POINTER =====
function pointerPrototype() {
    this.id = -1; this.x = 0; this.y = 0; this.dx = 0; this.dy = 0;
    this.down = false; this.moved = false; this.color = [0.8, 0.2, 0.6];
}
pointers.push(new pointerPrototype());

// ===== SHADERS (Código WebGL estándar) =====
let GLProgram = (function () {
    function GLProgram(vertexShader, fragmentShader) {
        this.uniforms = {};
        this.program = gl.createProgram();
        gl.attachShader(this.program, vertexShader);
        gl.attachShader(this.program, fragmentShader);
        gl.linkProgram(this.program);
        if (!gl.getProgramParameter(this.program, gl.LINK_STATUS)) throw gl.getProgramInfoLog(this.program);
        let uniformCount = gl.getProgramParameter(this.program, gl.ACTIVE_UNIFORMS);
        for (let i = 0; i < uniformCount; i++) {
            let uniformName = gl.getActiveUniform(this.program, i).name;
            this.uniforms[uniformName] = gl.getUniformLocation(this.program, uniformName);
        }
    }
    GLProgram.prototype.bind = function () { gl.useProgram(this.program); };
    return GLProgram;
})();

function compileShader(type, source) {
    let shader = gl.createShader(type);
    gl.shaderSource(shader, source);
    gl.compileShader(shader);
    if (!gl.getShaderParameter(shader, gl.COMPILE_STATUS)) throw gl.getShaderInfoLog(shader);
    return shader;
}

let baseVertexShader = compileShader(gl.VERTEX_SHADER, "precision highp float; precision mediump sampler2D; attribute vec2 aPosition; varying vec2 vUv; varying vec2 vL; varying vec2 vR; varying vec2 vT; varying vec2 vB; uniform vec2 texelSize; void main () { vUv = aPosition * 0.5 + 0.5; vL = vUv - vec2(texelSize.x, 0.0); vR = vUv + vec2(texelSize.x, 0.0); vT = vUv + vec2(0.0, texelSize.y); vB = vUv - vec2(0.0, texelSize.y); gl_Position = vec4(aPosition, 0.0, 1.0); }");
let clearShader = compileShader(gl.FRAGMENT_SHADER, "precision highp float; precision mediump sampler2D; varying vec2 vUv; uniform sampler2D uTexture; uniform float value; void main () { gl_FragColor = value * texture2D(uTexture, vUv); }");
let displayShader = compileShader(gl.FRAGMENT_SHADER, "precision highp float; precision mediump sampler2D; varying vec2 vUv; uniform sampler2D uTexture; void main () { gl_FragColor = texture2D(uTexture, vUv); }");
let splatShader = compileShader(gl.FRAGMENT_SHADER, "precision highp float; precision mediump sampler2D; varying vec2 vUv; uniform sampler2D uTarget; uniform float aspectRatio; uniform vec3 color; uniform vec2 point; uniform float radius; void main () { vec2 p = vUv - point.xy; p.x *= aspectRatio; vec3 splat = exp(-dot(p, p) / radius) * color; vec3 base = texture2D(uTarget, vUv).xyz; gl_FragColor = vec4(base + splat, 1.0); }");
let advectionShader = compileShader(gl.FRAGMENT_SHADER, "precision highp float; precision mediump sampler2D; varying vec2 vUv; uniform sampler2D uVelocity; uniform sampler2D uSource; uniform vec2 texelSize; uniform float dt; uniform float dissipation; void main () { vec2 coord = vUv - dt * texture2D(uVelocity, vUv).xy * texelSize; gl_FragColor = dissipation * texture2D(uSource, coord); }");
let divergenceShader = compileShader(gl.FRAGMENT_SHADER, "precision highp float; precision mediump sampler2D; varying vec2 vUv; varying vec2 vL; varying vec2 vR; varying vec2 vT; varying vec2 vB; uniform sampler2D uVelocity; void main () { float L = texture2D(uVelocity, vL).x; float R = texture2D(uVelocity, vR).x; float T = texture2D(uVelocity, vT).y; float B = texture2D(uVelocity, vB).y; float div = 0.5 * (R - L + T - B); gl_FragColor = vec4(div, 0.0, 0.0, 1.0); }");
let curlShader = compileShader(gl.FRAGMENT_SHADER, "precision highp float; precision mediump sampler2D; varying vec2 vUv; varying vec2 vL; varying vec2 vR; varying vec2 vT; varying vec2 vB; uniform sampler2D uVelocity; void main () { float L = texture2D(uVelocity, vL).y; float R = texture2D(uVelocity, vR).y; float T = texture2D(uVelocity, vT).x; float B = texture2D(uVelocity, vB).x; float vorticity = R - L - T + B; gl_FragColor = vec4(vorticity, 0.0, 0.0, 1.0); }");
let vorticityShader = compileShader(gl.FRAGMENT_SHADER, "precision highp float; precision mediump sampler2D; varying vec2 vUv; varying vec2 vL; varying vec2 vR; varying vec2 vT; varying vec2 vB; uniform sampler2D uVelocity; uniform sampler2D uCurl; uniform float curl; uniform float dt; void main () { float L = texture2D(uCurl, vL).x; float R = texture2D(uCurl, vR).x; float T = texture2D(uCurl, vT).y; float B = texture2D(uCurl, vB).y; float C = texture2D(uCurl, vUv).x; vec2 force = vec2(abs(T) - abs(B), abs(R) - abs(L)); force *= 1.0 / length(force + 0.00001) * curl * C; vec2 vel = texture2D(uVelocity, vUv).xy; gl_FragColor = vec4(vel + force * dt, 0.0, 1.0); }");
let pressureShader = compileShader(gl.FRAGMENT_SHADER, "precision highp float; precision mediump sampler2D; varying vec2 vUv; varying vec2 vL; varying vec2 vR; varying vec2 vT; varying vec2 vB; uniform sampler2D uPressure; uniform sampler2D uDivergence; void main () { float L = texture2D(uPressure, vL).x; float R = texture2D(uPressure, vR).x; float T = texture2D(uPressure, vT).x; float B = texture2D(uPressure, vB).x; float C = texture2D(uPressure, vUv).x; float divergence = texture2D(uDivergence, vUv).x; float pressure = (L + R + B + T - divergence) * 0.25; gl_FragColor = vec4(pressure, 0.0, 0.0, 1.0); }");
let gradientSubtractShader = compileShader(gl.FRAGMENT_SHADER, "precision highp float; precision mediump sampler2D; varying vec2 vUv; varying vec2 vL; varying vec2 vR; varying vec2 vT; varying vec2 vB; uniform sampler2D uPressure; uniform sampler2D uVelocity; void main () { float L = texture2D(uPressure, vL).x; float R = texture2D(uPressure, vR).x; float T = texture2D(uPressure, vT).x; float B = texture2D(uPressure, vB).x; vec2 velocity = texture2D(uVelocity, vUv).xy; velocity.xy -= vec2(R - L, T - B); gl_FragColor = vec4(velocity, 0.0, 1.0); }");

// ===== FRAMEBUFFERS =====
let textureWidth, textureHeight, density, velocity, divergence, curl, pressure;
function initFramebuffers() {
    textureWidth = gl.drawingBufferWidth >> config.TEXTURE_DOWNSAMPLE;
    textureHeight = gl.drawingBufferHeight >> config.TEXTURE_DOWNSAMPLE;
    let iFormat = ext.internalFormat, iFormatRG = ext.internalFormatRG, formatRG = ext.formatRG, texType = ext.texType;
    density = createDoubleFBO(0, textureWidth, textureHeight, iFormat, gl.RGBA, texType, support_linear_float ? gl.LINEAR : gl.NEAREST);
    velocity = createDoubleFBO(2, textureWidth, textureHeight, iFormatRG, formatRG, texType, support_linear_float ? gl.LINEAR : gl.NEAREST);
    divergence = createFBO(4, textureWidth, textureHeight, iFormatRG, formatRG, texType, gl.NEAREST);
    curl = createFBO(5, textureWidth, textureHeight, iFormatRG, formatRG, texType, gl.NEAREST);
    pressure = createDoubleFBO(6, textureWidth, textureHeight, iFormatRG, formatRG, texType, gl.NEAREST);
}
function createFBO(texId, w, h, internalFormat, format, type, param) {
    gl.activeTexture(gl.TEXTURE0 + texId);
    let texture = gl.createTexture();
    gl.bindTexture(gl.TEXTURE_2D, texture);
    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, param);
    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, param);
    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE);
    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE);
    gl.texImage2D(gl.TEXTURE_2D, 0, internalFormat, w, h, 0, format, type, null);
    let fbo = gl.createFramebuffer();
    gl.bindFramebuffer(gl.FRAMEBUFFER, fbo);
    gl.framebufferTexture2D(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.TEXTURE_2D, texture, 0);
    gl.viewport(0, 0, w, h);
    gl.clear(gl.COLOR_BUFFER_BIT);
    return [texture, fbo, texId];
}
function createDoubleFBO(texId, w, h, internalFormat, format, type, param) {
    let fbo1 = createFBO(texId, w, h, internalFormat, format, type, param);
    let fbo2 = createFBO(texId + 1, w, h, internalFormat, format, type, param);
    return {
        get first() { return fbo1; },
        get second() { return fbo2; },
        swap: function () { let temp = fbo1; fbo1 = fbo2; fbo2 = temp; }
    };
}
initFramebuffers();

// ===== PROGRAMS & BLIT =====
let clearProgram = new GLProgram(baseVertexShader, clearShader);
let displayProgram = new GLProgram(baseVertexShader, displayShader);
let splatProgram = new GLProgram(baseVertexShader, splatShader);
let advectionProgram = new GLProgram(baseVertexShader, advectionShader);
let divergenceProgram = new GLProgram(baseVertexShader, divergenceShader);
let curlProgram = new GLProgram(baseVertexShader, curlShader);
let vorticityProgram = new GLProgram(baseVertexShader, vorticityShader);
let pressureProgram = new GLProgram(baseVertexShader, pressureShader);
let gradienSubtractProgram = new GLProgram(baseVertexShader, gradientSubtractShader);

let blit = (function () {
    gl.bindBuffer(gl.ARRAY_BUFFER, gl.createBuffer());
    gl.bufferData(gl.ARRAY_BUFFER, new Float32Array([-1, -1, -1, 1, 1, 1, 1, -1]), gl.STATIC_DRAW);
    gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, gl.createBuffer());
    gl.bufferData(gl.ELEMENT_ARRAY_BUFFER, new Uint16Array([0, 1, 2, 0, 2, 3]), gl.STATIC_DRAW);
    gl.vertexAttribPointer(0, 2, gl.FLOAT, false, 0, 0);
    gl.enableVertexAttribArray(0);
    return function (destination) {
        gl.bindFramebuffer(gl.FRAMEBUFFER, destination);
        gl.drawElements(gl.TRIANGLES, 6, gl.UNSIGNED_SHORT, 0);
    };
})();

function splat(x, y, dx, dy, color) {
    splatProgram.bind();
    gl.uniform1i(splatProgram.uniforms.uTarget, velocity.first[2]);
    gl.uniform1f(splatProgram.uniforms.aspectRatio, canvas.width / canvas.height);
    gl.uniform2f(splatProgram.uniforms.point, x / canvas.width, 1.0 - y / canvas.height);
    gl.uniform3f(splatProgram.uniforms.color, dx, -dy, 1.0);
    gl.uniform1f(splatProgram.uniforms.radius, config.SPLAT_RADIUS);
    blit(velocity.second[1]); velocity.swap();
    gl.uniform1i(splatProgram.uniforms.uTarget, density.first[2]);
    gl.uniform3f(splatProgram.uniforms.color, color[0] * 0.3, color[1] * 0.3, color[2] * 0.3);
    blit(density.second[1]); density.swap();
}

// ===== COLORES DE LA MARCA =====
const brandColors = [[0.874, 0.741, 0.725], [0.729, 0.071, 0.302], [0.000, 0.247, 0.322]];
let currentColor = brandColors[0], targetColor = brandColors[1], transitionProgress = 0;
const transitionSpeed = 0.008;
function lerpColor(a, b, t) { return [a[0] + (b[0] - a[0]) * t, a[1] + (b[1] - a[1]) * t, a[2] + (b[2] - a[2]) * t]; }
let colorArr = currentColor, count = 0;

// ===== EVENTOS =====
canvas.addEventListener("mousemove", function (e) {
    count++;
    if (count > 1) {
        transitionProgress += transitionSpeed;
        if (transitionProgress >= 1) {
            transitionProgress = 0;
            let currentIndex = brandColors.indexOf(currentColor);
            currentColor = targetColor;
            targetColor = brandColors[(currentIndex + 1) % brandColors.length];
        }
        colorArr = lerpColor(currentColor, targetColor, transitionProgress);
        count = 0;
    }
    pointers[0].down = true; pointers[0].color = colorArr; pointers[0].moved = true;
    pointers[0].dx = (e.offsetX - pointers[0].x) * 10.0;
    pointers[0].dy = (e.offsetY - pointers[0].y) * 10.0;
    pointers[0].x = e.offsetX; pointers[0].y = e.offsetY;
});

// ===== LOOP PRINCIPAL =====
let lastTime = Date.now();
function update() {
    if (canvas.width !== canvas.clientWidth || canvas.height !== canvas.clientHeight) {
        canvas.width = canvas.clientWidth; canvas.height = canvas.clientHeight;
        initFramebuffers();
    }
    let dt = Math.min((Date.now() - lastTime) / 1000, 0.016);
    lastTime = Date.now();
    gl.viewport(0, 0, textureWidth, textureHeight);
    
    advectionProgram.bind();
    gl.uniform2f(advectionProgram.uniforms.texelSize, 1.0 / textureWidth, 1.0 / textureHeight);
    gl.uniform1i(advectionProgram.uniforms.uVelocity, velocity.first[2]);
    gl.uniform1i(advectionProgram.uniforms.uSource, velocity.first[2]);
    gl.uniform1f(advectionProgram.uniforms.dt, dt);
    gl.uniform1f(advectionProgram.uniforms.dissipation, config.VELOCITY_DISSIPATION);
    blit(velocity.second[1]); velocity.swap();
    gl.uniform1i(advectionProgram.uniforms.uSource, density.first[2]);
    gl.uniform1f(advectionProgram.uniforms.dissipation, config.DENSITY_DISSIPATION);
    blit(density.second[1]); density.swap();
    
    for (let i = 0; i < pointers.length; i++) {
        if (pointers[i].moved) { splat(pointers[i].x, pointers[i].y, pointers[i].dx, pointers[i].dy, pointers[i].color); pointers[i].moved = false; }
    }
    
    curlProgram.bind(); gl.uniform2f(curlProgram.uniforms.texelSize, 1.0 / textureWidth, 1.0 / textureHeight);
    gl.uniform1i(curlProgram.uniforms.uVelocity, velocity.first[2]); blit(curl[1]);
    
    vorticityProgram.bind(); gl.uniform2f(vorticityProgram.uniforms.texelSize, 1.0 / textureWidth, 1.0 / textureHeight);
    gl.uniform1i(vorticityProgram.uniforms.uVelocity, velocity.first[2]); gl.uniform1i(vorticityProgram.uniforms.uCurl, curl[2]);
    gl.uniform1f(vorticityProgram.uniforms.curl, config.CURL); gl.uniform1f(vorticityProgram.uniforms.dt, dt);
    blit(velocity.second[1]); velocity.swap();
    
    divergenceProgram.bind(); gl.uniform2f(divergenceProgram.uniforms.texelSize, 1.0 / textureWidth, 1.0 / textureHeight);
    gl.uniform1i(divergenceProgram.uniforms.uVelocity, velocity.first[2]); blit(divergence[1]);
    
    clearProgram.bind();
    gl.activeTexture(gl.TEXTURE0 + pressure.first[2]); gl.bindTexture(gl.TEXTURE_2D, pressure.first[0]);
    gl.uniform1i(clearProgram.uniforms.uTexture, pressure.first[2]); gl.uniform1f(clearProgram.uniforms.value, config.PRESSURE_DISSIPATION);
    blit(pressure.second[1]); pressure.swap();
    
    pressureProgram.bind(); gl.uniform2f(pressureProgram.uniforms.texelSize, 1.0 / textureWidth, 1.0 / textureHeight);
    gl.uniform1i(pressureProgram.uniforms.uDivergence, divergence[2]);
    for (let _i = 0; _i < config.PRESSURE_ITERATIONS; _i++) {
        gl.activeTexture(gl.TEXTURE0 + pressure.first[2]); gl.bindTexture(gl.TEXTURE_2D, pressure.first[0]);
        gl.uniform1i(pressureProgram.uniforms.uPressure, pressure.first[2]);
        blit(pressure.second[1]); pressure.swap();
    }
    
    gradienSubtractProgram.bind(); gl.uniform2f(gradienSubtractProgram.uniforms.texelSize, 1.0 / textureWidth, 1.0 / textureHeight);
    gl.uniform1i(gradienSubtractProgram.uniforms.uPressure, pressure.first[2]); gl.uniform1i(gradienSubtractProgram.uniforms.uVelocity, velocity.first[2]);
    blit(velocity.second[1]); velocity.swap();
    
    gl.viewport(0, 0, gl.drawingBufferWidth, gl.drawingBufferHeight);
    displayProgram.bind(); gl.uniform1i(displayProgram.uniforms.uTexture, density.first[2]);
    blit(null);
    requestAnimationFrame(update);
}
update();

window.addEventListener("resize", function() {
    canvas.width = window.innerWidth; canvas.height = window.innerHeight;
    initFramebuffers();
});