import React from 'react';
import {
  AbsoluteFill,
  Sequence,
  Video,
  Img,
  interpolate,
  useCurrentFrame,
  useVideoConfig,
} from 'remotion';

// CapCut-style template presets.
// Each preset defines pacing, visual behavior, typography, and motion — not just colors.
export const TEMPLATE_PRESETS = {
  viral: {
    clipDuration: 5,
    transitionDuration: 0.3,
    zoom: { start: 1.05, end: 1.15 },
    overlay: { color: '#000000', opacity: 0.12 },
    subtitle: {
      fontFamily: '"Impact", "Arial Black", sans-serif',
      fontSize: 52,
      fontWeight: '900',
      color: '#FFE600',
      stroke: '#000000',
      strokeWidth: 5,
      position: 'bottom',
      animation: 'pop',
      letterSpacing: '1px',
      textTransform: 'uppercase',
    },
    cinematicBars: false,
    vignette: false,
    grain: false,
  },

  luxury: {
    clipDuration: 7,
    transitionDuration: 1.0,
    zoom: { start: 1.0, end: 1.08 },
    overlay: { color: '#0d0800', opacity: 0.38 },
    subtitle: {
      fontFamily: '"Georgia", "Palatino Linotype", serif',
      fontSize: 38,
      fontWeight: 'normal',
      color: '#D4AF37',
      stroke: '#1a1000',
      strokeWidth: 2,
      position: 'bottom',
      animation: 'fade',
      letterSpacing: '3px',
      textTransform: 'uppercase',
    },
    cinematicBars: true,
    vignette: true,
    grain: false,
  },

  business: {
    clipDuration: 6,
    transitionDuration: 0.5,
    zoom: { start: 1.0, end: 1.05 },
    overlay: { color: '#001020', opacity: 0.22 },
    subtitle: {
      fontFamily: '"Helvetica Neue", "Arial", sans-serif',
      fontSize: 42,
      fontWeight: '700',
      color: '#FFFFFF',
      stroke: '#003399',
      strokeWidth: 3,
      position: 'bottom',
      animation: 'slide',
      letterSpacing: '0.5px',
      textTransform: 'none',
    },
    cinematicBars: false,
    vignette: false,
    grain: false,
  },

  gym: {
    clipDuration: 3,
    transitionDuration: 0.12,
    zoom: { start: 1.0, end: 1.22 },
    overlay: { color: '#200000', opacity: 0.28 },
    subtitle: {
      fontFamily: '"Impact", "Arial Black", sans-serif',
      fontSize: 56,
      fontWeight: '900',
      color: '#FF2020',
      stroke: '#000000',
      strokeWidth: 6,
      position: 'middle',
      animation: 'slam',
      letterSpacing: '2px',
      textTransform: 'uppercase',
    },
    cinematicBars: false,
    vignette: false,
    grain: false,
  },

  cinematic: {
    clipDuration: 8,
    transitionDuration: 1.2,
    zoom: { start: 1.0, end: 1.06 },
    overlay: { color: '#050510', opacity: 0.45 },
    subtitle: {
      fontFamily: '"Georgia", "Times New Roman", serif',
      fontSize: 34,
      fontWeight: 'normal',
      color: '#EEE0C0',
      stroke: '#000000',
      strokeWidth: 1,
      position: 'bottom',
      animation: 'fade',
      letterSpacing: '2px',
      textTransform: 'none',
    },
    cinematicBars: true,
    vignette: true,
    grain: true,
  },

  motivation: {
    clipDuration: 5,
    transitionDuration: 0.4,
    zoom: { start: 1.02, end: 1.12 },
    overlay: { color: '#0a0020', opacity: 0.2 },
    subtitle: {
      fontFamily: '"Impact", "Arial Black", sans-serif',
      fontSize: 50,
      fontWeight: '900',
      color: '#FFFFFF',
      stroke: '#6600CC',
      strokeWidth: 4,
      position: 'bottom',
      animation: 'pop',
      letterSpacing: '1px',
      textTransform: 'uppercase',
    },
    cinematicBars: false,
    vignette: false,
    grain: false,
  },

  dark: {
    clipDuration: 4,
    transitionDuration: 0.25,
    zoom: { start: 1.0, end: 1.10 },
    overlay: { color: '#000000', opacity: 0.55 },
    subtitle: {
      fontFamily: '"Impact", "Arial Black", sans-serif',
      fontSize: 48,
      fontWeight: '900',
      color: '#FFFFFF',
      stroke: '#000000',
      strokeWidth: 4,
      position: 'bottom',
      animation: 'fade',
      letterSpacing: '2px',
      textTransform: 'uppercase',
    },
    cinematicBars: true,
    vignette: true,
    grain: false,
  },
};

// Calculate composition duration based on template + clip count.
export const calculateMetadata = ({ props }) => {
  const fps = 30;
  const preset = TEMPLATE_PRESETS[props.template] || TEMPLATE_PRESETS.viral;
  const clips = props.clips || [];
  const clipCount = Math.max(clips.length, 1);
  const transSec = preset.transitionDuration;
  const totalSec = Math.min(
    clipCount * preset.clipDuration - Math.max(0, clipCount - 1) * transSec,
    30
  );
  return {
    fps,
    durationInFrames: Math.max(Math.round(totalSec * fps), fps),
    width: 540,
    height: 960,
  };
};

// ─── Clip with zoom + fade transitions ───────────────────────────────────────

const ClipLayer = ({ src, preset, clipDurFrames }) => {
  const frame = useCurrentFrame();
  const fps = 30;
  const transFrames = Math.round(preset.transitionDuration * fps);

  const fadeIn = interpolate(frame, [0, Math.max(transFrames, 1)], [0, 1], {
    extrapolateLeft: 'clamp',
    extrapolateRight: 'clamp',
  });
  const fadeOut = interpolate(
    frame,
    [clipDurFrames - Math.max(transFrames, 1), clipDurFrames],
    [1, 0],
    { extrapolateLeft: 'clamp', extrapolateRight: 'clamp' }
  );
  const opacity = Math.min(fadeIn, fadeOut);

  const scale = interpolate(frame, [0, clipDurFrames], [preset.zoom.start, preset.zoom.end], {
    extrapolateLeft: 'clamp',
    extrapolateRight: 'clamp',
  });

  return (
    <AbsoluteFill
      style={{
        opacity,
        transform: `scale(${scale})`,
        transformOrigin: 'center center',
        overflow: 'hidden',
      }}
    >
      <Video
        src={src}
        style={{ width: '100%', height: '100%', objectFit: 'cover' }}
        muted
        volume={0}
      />
    </AbsoluteFill>
  );
};

// ─── Subtitle overlay with template-specific animation ───────────────────────

const SubtitleLayer = ({ subtitles, preset }) => {
  const frame = useCurrentFrame();
  const fps = 30;
  const currentTime = frame / fps;

  const activeSub = subtitles.find(
    (s) => currentTime >= s.start && currentTime < s.end
  );
  if (!activeSub) return null;

  const style = preset.subtitle;
  const subStartFrame = Math.round(activeSub.start * fps);
  const subFrame = frame - subStartFrame;
  const IN_FRAMES = 7;

  let opacity = 1;
  let scale = 1;
  let translateY = 0;

  if (style.animation === 'pop') {
    opacity = interpolate(subFrame, [0, 3], [0, 1], {
      extrapolateLeft: 'clamp',
      extrapolateRight: 'clamp',
    });
    scale = interpolate(
      subFrame,
      [0, Math.round(IN_FRAMES * 0.6), IN_FRAMES],
      [0.5, 1.12, 1.0],
      { extrapolateLeft: 'clamp', extrapolateRight: 'clamp' }
    );
  } else if (style.animation === 'fade') {
    opacity = interpolate(subFrame, [0, IN_FRAMES], [0, 1], {
      extrapolateLeft: 'clamp',
      extrapolateRight: 'clamp',
    });
  } else if (style.animation === 'slide') {
    opacity = interpolate(subFrame, [0, IN_FRAMES], [0, 1], {
      extrapolateLeft: 'clamp',
      extrapolateRight: 'clamp',
    });
    translateY = interpolate(subFrame, [0, IN_FRAMES], [24, 0], {
      extrapolateLeft: 'clamp',
      extrapolateRight: 'clamp',
    });
  } else if (style.animation === 'slam') {
    opacity = interpolate(subFrame, [0, 2], [0, 1], {
      extrapolateLeft: 'clamp',
      extrapolateRight: 'clamp',
    });
    scale = interpolate(
      subFrame,
      [0, Math.round(IN_FRAMES * 0.4), IN_FRAMES],
      [2.2, 0.88, 1.0],
      { extrapolateLeft: 'clamp', extrapolateRight: 'clamp' }
    );
  }

  const topPct =
    style.position === 'top'
      ? '18%'
      : style.position === 'middle'
      ? '50%'
      : '82%';

  return (
    <AbsoluteFill style={{ pointerEvents: 'none' }}>
      <div
        style={{
          position: 'absolute',
          left: '50%',
          top: topPct,
          width: '88%',
          transform: `translate(-50%, -50%) scale(${scale}) translateY(${translateY}px)`,
          opacity,
          textAlign: 'center',
          fontFamily: style.fontFamily,
          fontSize: style.fontSize,
          fontWeight: style.fontWeight,
          color: style.color,
          letterSpacing: style.letterSpacing,
          textTransform: style.textTransform,
          WebkitTextStroke: `${style.strokeWidth}px ${style.stroke}`,
          paintOrder: 'stroke fill',
          lineHeight: 1.25,
          wordBreak: 'break-word',
          textShadow: '0 2px 12px rgba(0,0,0,0.9)',
          padding: '6px 10px',
        }}
      >
        {activeSub.text}
      </div>
    </AbsoluteFill>
  );
};

// ─── Cinematic letterbox bars ────────────────────────────────────────────────

const CinematicBars = () => (
  <>
    <div
      style={{
        position: 'absolute',
        top: 0,
        left: 0,
        right: 0,
        height: 70,
        backgroundColor: '#000',
        zIndex: 10,
      }}
    />
    <div
      style={{
        position: 'absolute',
        bottom: 0,
        left: 0,
        right: 0,
        height: 70,
        backgroundColor: '#000',
        zIndex: 10,
      }}
    />
  </>
);

// ─── Film grain (CSS noise simulation) ───────────────────────────────────────

const FilmGrain = () => {
  const frame = useCurrentFrame();
  // Alternate between two grain seeds per frame for animation feel
  const opacity = 0.04 + (frame % 2) * 0.02;
  return (
    <AbsoluteFill
      style={{
        backgroundImage: `url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='200' height='200'%3E%3Cfilter id='noise'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='200' height='200' filter='url(%23noise)' opacity='1'/%3E%3C/svg%3E")`,
        opacity,
        pointerEvents: 'none',
        mixBlendMode: 'overlay',
      }}
    />
  );
};

// ─── Main composition ─────────────────────────────────────────────────────────

export const ReelsComposition = ({
  clips = [],
  subtitles = [],
  template = 'viral',
  backgroundImage = null,
  backgroundVideo = null,
}) => {
  const { fps, durationInFrames } = useVideoConfig();
  const preset = TEMPLATE_PRESETS[template] || TEMPLATE_PRESETS.viral;
  const clipDurFrames = Math.round(preset.clipDuration * fps);
  const transFrames = Math.round(preset.transitionDuration * fps);

  return (
    <AbsoluteFill style={{ backgroundColor: '#000000', overflow: 'hidden' }}>

      {/* ── LAYER 1: Background content ── */}
      {backgroundVideo ? (
        <AbsoluteFill>
          <Video
            src={backgroundVideo}
            style={{ width: '100%', height: '100%', objectFit: 'cover' }}
            muted
            volume={0}
            loop
          />
        </AbsoluteFill>
      ) : backgroundImage ? (
        <AbsoluteFill>
          <Img
            src={backgroundImage}
            style={{ width: '100%', height: '100%', objectFit: 'cover' }}
          />
        </AbsoluteFill>
      ) : (
        // Stock clips with template-driven transitions + zoom
        clips.map((clip, i) => {
          const from = i * (clipDurFrames - transFrames);
          return (
            <Sequence
              key={i}
              from={from}
              durationInFrames={clipDurFrames + transFrames}
            >
              <ClipLayer src={clip} preset={preset} clipDurFrames={clipDurFrames} />
            </Sequence>
          );
        })
      )}

      {/* ── LAYER 2: Template color grade overlay ── */}
      <AbsoluteFill
        style={{
          backgroundColor: preset.overlay.color,
          opacity: preset.overlay.opacity,
          pointerEvents: 'none',
        }}
      />

      {/* ── LAYER 3: Vignette ── */}
      {preset.vignette && (
        <AbsoluteFill
          style={{
            background:
              'radial-gradient(ellipse at 50% 50%, transparent 35%, rgba(0,0,0,0.75) 100%)',
            pointerEvents: 'none',
          }}
        />
      )}

      {/* ── LAYER 4: Film grain ── */}
      {preset.grain && <FilmGrain />}

      {/* ── LAYER 5: Subtitles ── */}
      <SubtitleLayer subtitles={subtitles} preset={preset} />

      {/* ── LAYER 6: Cinematic bars (on top of subtitles for consistency) ── */}
      {preset.cinematicBars && <CinematicBars />}

    </AbsoluteFill>
  );
};