'use client';

import { useState, useCallback } from 'react';
import { useLocale } from './LocaleProvider';
import { ts } from '@/lib/i18n';
import { getMoonPhaseInfo, getMoonZodiacSign } from '@/lib/lunar';

type PhaseDescKey =
  | 'phase_desc_new'
  | 'phase_desc_waxing_crescent'
  | 'phase_desc_first_quarter'
  | 'phase_desc_waxing_gibbous'
  | 'phase_desc_full'
  | 'phase_desc_waning_gibbous'
  | 'phase_desc_last_quarter'
  | 'phase_desc_waning_crescent';

const PHASE_DESC_MAP: Record<string, PhaseDescKey> = {
  new_moon: 'phase_desc_new',
  waxing_crescent: 'phase_desc_waxing_crescent',
  first_quarter: 'phase_desc_first_quarter',
  waxing_gibbous: 'phase_desc_waxing_gibbous',
  full_moon: 'phase_desc_full',
  waning_gibbous: 'phase_desc_waning_gibbous',
  last_quarter: 'phase_desc_last_quarter',
  waning_crescent: 'phase_desc_waning_crescent',
};

const ZODIAC_EMOJI: Record<string, string> = {
  Aries: '♈', Taurus: '♉', Gemini: '♊', Cancer: '♋',
  Leo: '♌', Virgo: '♍', Libra: '♎', Scorpio: '♏',
  Sagittarius: '♐', Capricorn: '♑', Aquarius: '♒', Pisces: '♓',
};

function MoonVisual({ phase, size = 160 }: { phase: number; size?: number }) {
  const drawMoon = useCallback((ctx: CanvasRenderingContext2D) => {
    const w = size;
    const h = size;
    const margin = 14;
    const r = w / 2 - margin;
    const cx = w / 2;
    const cy = h / 2;

    ctx.clearRect(0, 0, w, h);

    // Moon shadow (dark side)
    ctx.beginPath();
    ctx.arc(cx, cy, r, 0, Math.PI * 2);
    ctx.fillStyle = '#1a1a2e';
    ctx.fill();

    // Lit surface
    ctx.beginPath();
    const angleRad = phase * 2 * Math.PI;

    if (phase <= 0.5) {
      // Waxing: right side lit
      ctx.arc(cx, cy, r, -Math.PI / 2, Math.PI / 2, false);
      const sweep = Math.cos(angleRad);
      ctx.ellipse(cx, cy, Math.abs(sweep) * r, r, 0, Math.PI / 2, -Math.PI / 2, sweep < 0);
    } else {
      // Waning: left side lit
      ctx.arc(cx, cy, r, Math.PI / 2, -Math.PI / 2, false);
      const sweep = Math.cos(angleRad);
      ctx.ellipse(cx, cy, Math.abs(sweep) * r, r, 0, -Math.PI / 2, Math.PI / 2, sweep > 0);
    }

    ctx.closePath();

    // Gradient for realistic look
    const grad = ctx.createRadialGradient(cx - r * 0.3, cy - r * 0.3, 0, cx, cy, r);
    grad.addColorStop(0, '#fef9c3');
    grad.addColorStop(0.5, '#fbbf24');
    grad.addColorStop(1, '#b45309');
    ctx.fillStyle = grad;
    ctx.fill();

    // Surface texture (craters)
    const craters = [
      { x: 0.3, y: 0.35, r: 0.08 },
      { x: 0.6, y: 0.25, r: 0.06 },
      { x: 0.45, y: 0.6, r: 0.1 },
      { x: 0.7, y: 0.55, r: 0.05 },
      { x: 0.35, y: 0.75, r: 0.07 },
      { x: 0.55, y: 0.45, r: 0.04 },
    ];

    craters.forEach(crater => {
      ctx.beginPath();
      ctx.arc(cx + (crater.x - 0.5) * 2 * r, cy + (crater.y - 0.5) * 2 * r, crater.r * r, 0, Math.PI * 2);
      ctx.fillStyle = 'rgba(0, 0, 0, 0.1)';
      ctx.fill();
    });

    // Glow
    ctx.beginPath();
    ctx.arc(cx, cy, r + 8, 0, Math.PI * 2);
    const glowGrad = ctx.createRadialGradient(cx, cy, r - 2, cx, cy, r + 15);
    glowGrad.addColorStop(0, 'rgba(251, 191, 36, 0.15)');
    glowGrad.addColorStop(1, 'rgba(251, 191, 36, 0)');
    ctx.fillStyle = glowGrad;
    ctx.fill();
  }, [phase, size]);

  const canvasRef = useCallback((node: HTMLCanvasElement | null) => {
    if (node) {
      const ctx = node.getContext('2d');
      if (ctx) drawMoon(ctx);
    }
  }, [drawMoon]);

  return (
    <canvas
      ref={canvasRef}
      width={size}
      height={size}
      className="mx-auto"
      style={{ width: size, height: size }}
    />
  );
}

export default function PhaseSimulator() {
  const { locale } = useLocale();
  const [date, setDate] = useState(() => {
    const d = new Date();
    return `${d.getFullYear()}-${String(d.getMonth() + 1).padStart(2, '0')}-${String(d.getDate()).padStart(2, '0')}`;
  });

  const selectedDate = new Date(date + 'T12:00:00');
  const phaseInfo = getMoonPhaseInfo(selectedDate);
  const zodiac = getMoonZodiacSign(selectedDate);
  const phaseDescKey: PhaseDescKey = PHASE_DESC_MAP[phaseInfo.phaseName] || 'phase_desc_full';

  return (
    <section id="simulator" aria-label="Interactive Moon Phase Simulator" className="section-container">
      <div className="text-center mb-10">
        <h2 className="section-title">{ts('simulator_title', locale)}</h2>
        <p className="section-subtitle mx-auto">{ts('simulator_subtitle', locale)}</p>
      </div>

      <div className="glass-card max-w-2xl mx-auto p-4 sm:p-6 md:p-8">
        <div className="flex flex-col md:flex-row items-center gap-6 md:gap-8">
          {/* Moon visual */}
          <div className="shrink-0">
            <MoonVisual phase={phaseInfo.phase} size={160} />
          </div>

          {/* Controls & info */}
          <div className="flex-1 w-full space-y-6">
            <div>
              <label className="block text-sm text-white/50 mb-2">{ts('simulator_date', locale)}</label>
              <input
                type="date"
                value={date}
                onChange={(e) => setDate(e.target.value)}
                className="w-full px-4 py-3 rounded-xl bg-white/5 border border-white/10 text-white focus:border-indigo-400/50 focus:outline-none transition-all"
              />
            </div>

            <div className="grid grid-cols-2 gap-4">
              <div className="p-3 rounded-xl bg-white/5">
                <p className="text-xs text-white/40 mb-1">{ts('current_phase', locale)}</p>
                <p className="font-semibold flex items-center gap-2">
                  <span className="text-xl">{phaseInfo.emoji}</span>
                  {ts(phaseInfo.phaseName, locale)}
                </p>
              </div>

              <div className="p-3 rounded-xl bg-white/5">
                <p className="text-xs text-white/40 mb-1">{ts('simulator_illumination', locale)}</p>
                <p className="font-semibold text-yellow-200">{phaseInfo.illumination}%</p>
                <div className="w-full h-1.5 bg-white/10 rounded-full mt-2">
                  <div
                    className="h-full gradient-bar-illumination rounded-full transition-all duration-500"
                    style={{ width: `${phaseInfo.illumination}%` }}
                  />
                </div>
              </div>

              <div className="p-3 rounded-xl bg-white/5">
                <p className="text-xs text-white/40 mb-1">{ts('simulator_age', locale)}</p>
                <p className="font-semibold">{phaseInfo.age.toFixed(1)} {ts('simulator_days', locale)}</p>
              </div>

              <div className="p-3 rounded-xl bg-white/5">
                <p className="text-xs text-white/40 mb-1">{ts('simulator_zodiac', locale)}</p>
                <p className="font-semibold text-purple-300">{ZODIAC_EMOJI[zodiac] || '♈'} {zodiac}</p>
              </div>
            </div>

            {/* Phase description */}
            <div className="p-4 rounded-xl bg-indigo-500/10 border border-indigo-500/20">
              <p className="text-sm text-white/70 leading-relaxed">
                {ts(phaseDescKey, locale)}
              </p>
            </div>
          </div>
        </div>
      </div>
    </section>
  );
}