'use client';

import { Component, useEffect, useMemo, useRef, useState, type ReactNode } from 'react';
import { Canvas, useFrame, useThree } from '@react-three/fiber';
import * as THREE from 'three';
import { usePrefersReducedMotion } from '@/lib/motion';

// VISUAL CONCEPT: "Las Tres Líneas" — the brand symbol tells the story.
// 1. Caos: three golden bars drift tangled, each on its own frequencies.
// 2. Claridad: they settle into the "≡" of cre≡er — level, exact, still.
// 3. Dirección: together they tilt ~9° and stagger into a staircase.
// 4. Crecimiento: each line extends forward (the top one the most) with a
//    rising golden glow. The scene then rests, barely alive: a slow camera
//    drift and an almost imperceptible emissive pulse. No loops, no resets.

const DORADO = new THREE.Color('#C4942E');

const suave = (t: number) => 1 - Math.pow(1 - t, 3);
const tramo = (t: number, desde: number, dura: number) =>
  Math.min(1, Math.max(0, (t - desde) / dura));

// Phase timings (seconds), verbatim from the approved preview.
const CAOS_DURA = 3.0;
const CLARIDAD = { desde: 3.0, dura: 2.2 };
const DIRECCION = { desde: 5.2, dura: 2.0 };
const CRECIMIENTO = { desde: 7.2, dura: 2.4 };

// ── Las Tres Líneas ─────────────────────────────────────────────────────────

function TresLineas({ estatico }: { estatico: boolean }) {
  const time = useRef(estatico ? 10 : 0);
  const m1 = useRef<THREE.Mesh>(null);
  const m2 = useRef<THREE.Mesh>(null);
  const m3 = useRef<THREE.Mesh>(null);
  const meshes = [m1, m2, m3];

  // Decoupled drift frequencies per bar, so the chaos never syncs.
  const deriva = useMemo(
    () => [
      { fx: 1.1, fy: 0.9, fz: 0.7, rx: 0.8, ry: 1.1 },
      { fx: 1.47, fy: 1.4, fz: 1.4, rx: 1.1, ry: 0.9 },
      { fx: 1.84, fy: 1.9, fz: 0.7, rx: 1.4, ry: 0.7 },
    ],
    [],
  );

  const geometria = useMemo(() => new THREE.BoxGeometry(2.3, 0.3, 0.3), []);
  const materiales = useMemo(
    () =>
      [0, 1, 2].map(
        () =>
          new THREE.MeshStandardMaterial({
            color: DORADO,
            metalness: 0.8,
            roughness: 0.25,
            emissive: DORADO,
            emissiveIntensity: 0,
          }),
      ),
    [],
  );

  // Final poses: the "≡" (identity rotation) and the tilted staircase.
  const qSimbolo = useMemo(() => new THREE.Quaternion().identity(), []);
  const qEscalera = useMemo(
    () => new THREE.Quaternion().setFromEuler(new THREE.Euler(0, 0, -0.16)),
    [],
  );

  useFrame((_, delta) => {
    if (!estatico) time.current += delta;
    const t = time.current;

    const claridad = suave(tramo(t, CLARIDAD.desde, CLARIDAD.dura));
    const direccion = suave(tramo(t, DIRECCION.desde, DIRECCION.dura));
    const crecimiento = suave(tramo(t, CRECIMIENTO.desde, CRECIMIENTO.dura));
    // "Reposo vivo": a slow emissive breathing once the story is told.
    const pulso = Math.sin(t * 0.8) * 0.03 * crecimiento;

    meshes.forEach((ref, i) => {
      const mesh = ref.current;
      if (!mesh) return;
      const d = deriva[i];

      // Caos: free drift around the frame.
      const posCaos = new THREE.Vector3(
        Math.sin(t * d.fx + i * 2.1) * 1.6,
        Math.cos(t * d.fy + i) * 1.1 + 0.7,
        Math.sin(t * d.fz + i * 3) * 0.9,
      );
      const rotCaos = new THREE.Quaternion().setFromEuler(
        new THREE.Euler(t * d.rx, t * (d.ry - i * 0.2), t * 0.5),
      );

      // Claridad: the "≡" of the wordmark.
      const posSimbolo = new THREE.Vector3(0, 0.7 - i * 0.7, 0);
      // Dirección: the ascending staircase.
      const posEscalera = new THREE.Vector3(i * 1.15 - 1.15, 0.35 + i * 0.8, 0);

      mesh.position.copy(
        posCaos.lerp(posSimbolo, claridad).lerp(posEscalera, direccion),
      );
      mesh.quaternion.slerpQuaternions(rotCaos, qSimbolo, claridad);
      mesh.quaternion.slerp(qEscalera, direccion);

      // Crecimiento: each line extends, the top one the most.
      mesh.scale.set(
        1 + direccion * 0.1 + crecimiento * (0.35 + i * 0.35),
        1,
        1,
      );

      materiales[i].emissiveIntensity = crecimiento * (0.1 + i * 0.06) + pulso;
    });
  });

  return (
    <group>
      {meshes.map((ref, i) => (
        <mesh key={i} ref={ref} geometry={geometria} material={materiales[i]} />
      ))}
    </group>
  );
}

// ── Cámara — frontal, with the preview's gentle drift ───────────────────────

const CAMARA: [number, number, number] = [0, 0.9, 8];
const MIRA: [number, number, number] = [0, 0.7, 0];

function Camara({ estatico }: { estatico: boolean }) {
  const { camera, invalidate } = useThree();
  const time = useRef(estatico ? 10 : 0);

  useEffect(() => {
    camera.position.set(...CAMARA);
    camera.lookAt(...MIRA);
    invalidate();
  }, [camera, invalidate]);

  useFrame((_, delta) => {
    if (estatico) return;
    time.current += delta;
    camera.position.set(
      CAMARA[0] + Math.sin(time.current * 0.25) * 0.5,
      CAMARA[1],
      CAMARA[2],
    );
    camera.lookAt(...MIRA);
  });

  return null;
}

// ── Iluminación — the three lights of the approved preview ──────────────────

function Luces() {
  return (
    <>
      <ambientLight intensity={1.4} color="#ffffff" />
      <directionalLight position={[4, 8, 5]} intensity={2.2} color="#ffffff" />
      <pointLight position={[0, 2, 4]} intensity={10} distance={25} color={DORADO} />
    </>
  );
}

// ── WebGL Guard ─────────────────────────────────────────────────────────────

class SiHayWebGL extends Component<{ children: ReactNode }, { falla: boolean }> {
  state = { falla: false };
  static getDerivedStateFromError() { return { falla: true }; }
  render() { return this.state.falla ? null : this.props.children; }
}

// ── El Componente ───────────────────────────────────────────────────────────

export function EscenaClaridad({ className = '' }: { className?: string }) {
  const reducido = usePrefersReducedMotion();
  const contenedor = useRef<HTMLDivElement>(null);
  const [enVista, setEnVista] = useState(true);

  useEffect(() => {
    const el = contenedor.current;
    if (!el || typeof IntersectionObserver === 'undefined') return;
    const obs = new IntersectionObserver(([entrada]) => setEnVista(entrada.isIntersecting));
    obs.observe(el);
    return () => obs.disconnect();
  }, []);

  const animando = enVista && !reducido;

  return (
    <div ref={contenedor} className={className} aria-hidden="true">
      <SiHayWebGL>
        <Canvas
          dpr={[1, 2]}
          frameloop={animando ? 'always' : 'demand'}
          camera={{ position: CAMARA, fov: 38, near: 0.1, far: 100 }}
          gl={{ antialias: true, alpha: true, powerPreference: 'low-power' }}
          style={{ background: 'transparent' }}
        >
          <Camara estatico={reducido} />
          <Luces />
          <TresLineas estatico={reducido} />
        </Canvas>
      </SiHayWebGL>
    </div>
  );
}