'use client';

import { motion } from 'framer-motion';
import { useEnVista } from '@/lib/motion';
import { VIEWBOX_SIMBOLO, LINEAS_SIMBOLO } from '@/lib/simbolo';

// The manual's core metaphor, finally drawn: Complejidad → Enfoque → Claridad.
// Eighteen crossing lines converge in three groups; in the "completa" variant
// each group collapses onto one of the three bars of the ≡, so the mark is
// literally produced by the resolution of the tangle rather than placed next
// to it. The "hero" variant stops at convergence and leaves the tension open —
// FraseAncla pays it off further down the page.

type Variant = 'completa' | 'hero';

// Scattered start positions. Hand-placed rather than random so the tangle is
// identical on every render and between server and client.
const DISPERSAS = [
  { x1: 2, y1: 8, x2: 40, y2: 3, barra: 0 },
  { x1: 20, y1: 2, x2: 61, y2: 24, barra: 0 },
  { x1: 6, y1: 22, x2: 52, y2: 6, barra: 0 },
  { x1: 34, y1: 5, x2: 12, y2: 27, barra: 0 },
  { x1: 48, y1: 2, x2: 58, y2: 30, barra: 0 },
  { x1: 3, y1: 15, x2: 46, y2: 19, barra: 0 },
  { x1: 5, y1: 30, x2: 60, y2: 26, barra: 1 },
  { x1: 14, y1: 40, x2: 55, y2: 20, barra: 1 },
  { x1: 2, y1: 26, x2: 38, y2: 44, barra: 1 },
  { x1: 44, y1: 22, x2: 18, y2: 41, barra: 1 },
  { x1: 30, y1: 18, x2: 62, y2: 40, barra: 1 },
  { x1: 8, y1: 36, x2: 50, y2: 33, barra: 1 },
  { x1: 4, y1: 44, x2: 47, y2: 58, barra: 2 },
  { x1: 24, y1: 62, x2: 60, y2: 42, barra: 2 },
  { x1: 10, y1: 56, x2: 56, y2: 50, barra: 2 },
  { x1: 40, y1: 61, x2: 14, y2: 46, barra: 2 },
  { x1: 2, y1: 50, x2: 44, y2: 62, barra: 2 },
  { x1: 33, y1: 44, x2: 62, y2: 57, barra: 2 },
];

// One line per group survives to become a bar of the ≡; the rest fade as they
// converge — many/disordered becomes few/aligned, per the manual.
const SOBREVIVE = [0, 6, 12];

const EASE = [0.22, 1, 0.36, 1] as const;

export function SecuenciaClaridad({
  variant = 'completa',
  className = '',
}: {
  variant?: Variant;
  className?: string;
}) {
  const { ref, enVista, reduced } = useEnVista(0.35);

  const completa = variant === 'completa';

  // Where each line ends up. In "completa" the survivors land exactly on the
  // symbol's own coordinates; in "hero" they merely tighten toward their
  // group's axis without ever aligning.
  const destino = (i: number) => {
    const { barra } = DISPERSAS[i];
    const linea = LINEAS_SIMBOLO[barra];
    const sobrevive = SOBREVIVE.includes(i);
    if (!completa) {
      const eje = linea.y1;
      const d = DISPERSAS[i];
      // Pulled a good way further in than it used to be: at a third of the way
      // the tangle still read as a scratched-out scribble instead of as lines
      // finding their axis. It must arrive close to aligned and stop short.
      return {
        x1: d.x1 + (26 - d.x1) * 0.5,
        y1: d.y1 + (eje - d.y1) * 0.7,
        x2: d.x2 + (38 - d.x2) * 0.5,
        y2: d.y2 + (eje - d.y2) * 0.7,
        opacity: sobrevive ? 0.95 : 0.28,
      };
    }
    return {
      x1: linea.x1,
      y1: linea.y1,
      x2: linea.x2,
      y2: linea.y2,
      opacity: sobrevive ? 1 : 0,
    };
  };

  const grosor = (i: number) =>
    completa && SOBREVIVE.includes(i) ? LINEAS_SIMBOLO[DISPERSAS[i].barra].grosor : 1.5;

  // Reduced motion renders plain <line> elements: motion.line would apply its
  // own dash scaffolding and leave the drawing invisible (see the same trap in
  // IlustracionInflexion).
  if (reduced) {
    return (
      <svg ref={ref} viewBox={VIEWBOX_SIMBOLO} className={className} aria-hidden="true" focusable="false">
        {DISPERSAS.map((_, i) => {
          const d = destino(i);
          const visible = completa ? SOBREVIVE.includes(i) : true;
          return (
            <line
              key={i}
              {...(completa && SOBREVIVE.includes(i) ? { 'data-resolucion': true } : {})}
              x1={d.x1}
              y1={d.y1}
              x2={d.x2}
              y2={d.y2}
              stroke="currentColor"
              strokeWidth={grosor(i)}
              strokeLinecap="round"
              opacity={visible ? d.opacity : 0}
            />
          );
        })}
      </svg>
    );
  }

  return (
    <svg ref={ref} viewBox={VIEWBOX_SIMBOLO} className={className} aria-hidden="true" focusable="false">
      {DISPERSAS.map(({ barra: _barra, ...inicio }, i) => {
        const d = destino(i);
        // `barra` is grouping metadata, not an SVG attribute — destructured out
        // so it never reaches the DOM.
        const reposo = { ...inicio, opacity: 0.55, strokeWidth: 1.5 };
        return (
          <motion.line
            key={i}
            {...(completa && SOBREVIVE.includes(i) ? { 'data-resolucion': true } : {})}
            stroke="currentColor"
            strokeLinecap="round"
            initial={reposo}
            animate={enVista ? { ...d, strokeWidth: grosor(i) } : reposo}
            transition={{ duration: 1.2, delay: 0.25 + (i % 6) * 0.05, ease: EASE }}
          />
        );
      })}
    </svg>
  );
}