import { useEffect, useRef, useState } from 'react';
import { Animated, Easing, Text, View } from 'react-native';
import Svg, { Circle, Path } from 'react-native-svg';
import { useColors } from '../../lib/theme';

const SIZE = 88;
const STROKE = 11;
const R = (SIZE - STROKE) / 2;

/** Geräte-Kategorie-Farben — auch im Gesamt-Half-Donut (Verteilung). */
export const MOBILE_COLOR = '#22c55e';
export const DESKTOP_COLOR = '#2563eb';

export type SlotSegment = { value: number; color: string };

function polar(cx: number, cy: number, r: number, deg: number) {
  const rad = (deg * Math.PI) / 180;
  return { x: cx + r * Math.cos(rad), y: cy + r * Math.sin(rad) };
}

function arcPath(cx: number, cy: number, r: number, startDeg: number, endDeg: number) {
  const start = polar(cx, cy, r, startDeg);
  const end = polar(cx, cy, r, endDeg);
  const large = endDeg - startDeg > 180 ? 1 : 0;
  return `M ${start.x} ${start.y} A ${r} ${r} 0 ${large} 1 ${end.x} ${end.y}`;
}

/**
 * Slot-Anzeige (react-native-svg, keine Lib), gleiche Größe in beiden Modi:
 * - `half=false` (Default): voller Progress-Ring — eine Kategorie (Mobil/Computer).
 * - `half=true`: Half-Donut für die Gesamt-Verteilung (Mobil-/Computer-Anteil
 *   als zwei farbige Bögen).
 */
export function DeviceSlotDonut({
  segments,
  total,
  label,
  atLimit,
  half = false,
}: {
  segments: SlotSegment[];
  total: number;
  label: string;
  atLimit: boolean;
  half?: boolean;
}) {
  const colors = useColors();
  const cx = SIZE / 2;
  // Half-Donut tiefer setzen, damit der Bogen mittig im SIZE×SIZE-Feld sitzt.
  const cy = half ? SIZE / 2 + R / 2 : SIZE / 2;
  const r = R;
  const safeTotal = Math.max(1, total);
  const used = segments.reduce((s, x) => s + x.value, 0);

  const startAngle = half ? 180 : -90;
  const sweep = half ? 180 : 360;

  const anim = useRef(new Animated.Value(0)).current;
  const [progress, setProgress] = useState(0);

  useEffect(() => {
    anim.setValue(0);
    const l = anim.addListener(({ value }) => setProgress(value));
    Animated.timing(anim, {
      toValue: 1,
      duration: 1400,
      easing: Easing.out(Easing.cubic),
      useNativeDriver: false,
    }).start();
    return () => anim.removeListener(l);
  }, [used, total, anim]);

  let cum = startAngle;
  const arcs = segments.map((seg) => {
    const span = sweep * (seg.value / safeTotal);
    const start = cum;
    const end = cum + span;
    cum = end;
    return { start, end, color: seg.color };
  });

  return (
    <View style={{ alignItems: 'center', flex: 1 }}>
      <View style={{ width: SIZE, height: SIZE }}>
        <Svg width={SIZE} height={SIZE}>
          {half ? (
            <Path
              d={arcPath(cx, cy, r, 180, 360)}
              stroke={colors.surfaceElevated}
              strokeWidth={STROKE}
              fill="none"
              strokeLinecap="round"
            />
          ) : (
            <Circle cx={cx} cy={cy} r={r} stroke={colors.surfaceElevated} strokeWidth={STROKE} fill="none" />
          )}
          {arcs.map((a, i) => {
            const animEnd = a.start + (a.end - a.start) * progress;
            if (animEnd <= a.start + 0.5) return null;
            const drawEnd = Math.min(animEnd, a.start + (half ? 179.99 : 359.99));
            return (
              <Path
                key={i}
                d={arcPath(cx, cy, r, a.start, drawEnd)}
                stroke={a.color}
                strokeWidth={STROKE}
                fill="none"
                strokeLinecap="round"
              />
            );
          })}
        </Svg>
        <View
          pointerEvents="none"
          style={{
            position: 'absolute',
            top: half ? SIZE / 2 - 4 : 0,
            left: 0,
            right: 0,
            bottom: 0,
            alignItems: 'center',
            justifyContent: half ? 'flex-start' : 'center',
          }}
        >
          <Text style={{ fontSize: 22, fontFamily: 'Nunito_900Black', color: colors.text, letterSpacing: -0.5 }}>
            {used}
            <Text style={{ fontSize: 12, fontFamily: 'Nunito_700Bold', color: colors.textMuted }}>
              /{total}
            </Text>
          </Text>
        </View>
      </View>

      <Text
        numberOfLines={1}
        style={{
          fontSize: 11,
          color: atLimit ? colors.brandOrange : colors.textMuted,
          fontFamily: 'Nunito_600SemiBold',
          marginTop: 6,
          textAlign: 'center',
        }}
      >
        {label}
      </Text>
    </View>
  );
}