import React, { useState } from 'react';
import Pie, { ProvidedProps, PieArcDatum } from '@visx/shape/lib/shapes/Pie';
import { scaleOrdinal } from '@visx/scale';
import { Group } from '@visx/group';
import { animated, useTransition, interpolate } from '@react-spring/web';
import LoadingSpinner from '@/components/ui/spinner';

// accessor functions
const frequency = (c) => c.percentage;

const defaultMargin = { top: 20, right: 20, bottom: 20, left: 20 };

export type PieProps = {
    data: any
    width: number;
    height: number;
    margin?: typeof defaultMargin;
    animate?: boolean;
};

export default function PieChart({
    data,
    width,
    height,
    margin = defaultMargin,
    animate = true,
}: PieProps) {
    if (width < 10) return null;

    const innerWidth = width - margin.left - margin.right;
    const innerHeight = height - margin.top - margin.bottom;
    const radius = Math.min(innerWidth, innerHeight) / 2;
    const centerY = innerHeight / 2;
    const centerX = innerWidth / 2;

    return data.length == 0 ? <LoadingSpinner /> : (
        <svg width={width} height={height}>
            <rect rx={14} width={width} height={height} fill="transparent" />
            <Group top={centerY + margin.top} left={centerX + margin.left}>
                <Pie
                    data={data}
                    pieValue={frequency}
                    pieSort={(a, b) => b.categoryCode - a.categoryCode}
                    outerRadius={radius}
                    cornerRadius={0}
                >
                    {(pie) => (
                        <AnimatedPie
                            {...pie}
                            animate={false}
                            getKey={(c) => c.data.categoryName}
                            onClickDatum={({ data: category }) =>
                                console.log('clicked: ', category.categoryName)
                            }
                            getColor={(arc) => {
                                if (arc.data.background == "inherit") { return "color-mix(in srgb, hsl(var(--muted)) 95%, black 5%)" };
                                return arc.data.background ?? 'transparent';
                            }}
                        />
                    )}
                </Pie>
            </Group>
        </svg>
    );
}

// react-spring transition definitions
type AnimatedStyles = { startAngle: number; endAngle: number; opacity: number };

const fromLeaveTransition = ({ endAngle }: PieArcDatum<any>) => ({
    // enter from 360° if end angle is > 180°
    startAngle: endAngle > Math.PI ? 2 * Math.PI : 0,
    endAngle: endAngle > Math.PI ? 2 * Math.PI : 0,
    opacity: 0,
});
const enterUpdateTransition = ({ startAngle, endAngle }: PieArcDatum<any>) => ({
    startAngle,
    endAngle,
    opacity: 1,
});

type AnimatedPieProps<Datum> = ProvidedProps<Datum> & {
    animate?: boolean;
    getKey: (d: PieArcDatum<Datum>) => string;
    getColor: (d: PieArcDatum<Datum>) => string;
    onClickDatum: (d: PieArcDatum<Datum>) => void;
    delay?: number;
};

function AnimatedPie<Datum>({
    animate,
    arcs,
    path,
    getKey,
    getColor,
    onClickDatum,
}: AnimatedPieProps<Datum>) {
    const transitions = useTransition<PieArcDatum<Datum>, AnimatedStyles>(arcs, {
        from: animate ? fromLeaveTransition : enterUpdateTransition,
        enter: enterUpdateTransition,
        update: enterUpdateTransition,
        leave: animate ? fromLeaveTransition : enterUpdateTransition,
        keys: getKey,
    });
    return transitions((props, arc, { key }) => {
        const [centroidX, centroidY] = path.centroid(arc);
        const hasSpaceForLabel = arc.endAngle - arc.startAngle >= 0.1;

        return (
            <g key={key}>
                <animated.path
                    // compute interpolated path d attribute from intermediate angle values
                    d={interpolate([props.startAngle, props.endAngle], (startAngle, endAngle) =>
                        path({
                            ...arc,
                            startAngle,
                            endAngle,
                        }),
                    )}
                    fill={getColor(arc)}
                    onClick={() => onClickDatum(arc)}
                    onTouchStart={() => onClickDatum(arc)}
                />
                {hasSpaceForLabel && false && (
                    <animated.g style={{ opacity: props.opacity }}>
                        <text
                            fill={getForeground(arc)}
                            x={centroidX}
                            y={centroidY}
                            dy=".33em"
                            fontSize={9}
                            textAnchor="middle"
                            pointerEvents="none"
                        >
                            {getKey(arc)}
                        </text>
                    </animated.g>
                )}
            </g>
        );
    });

    function getForeground(arc: PieArcDatum<Datum>) {
        return arc.data.foreground;
    }

}