'use client';

import { useId } from 'react';
import { ArrowDownRight, ArrowUpRight, type LucideIcon } from 'lucide-react';

export type StatsSparklineTone = 'green' | 'violet' | 'orange' | 'blue';

const TONES: Record<
  StatsSparklineTone,
  { stroke: string; iconBox: string; value: string }
> = {
  green: {
    stroke: 'var(--success)',
    iconBox: 'bg-success/10 border-success/25 text-success',
    value: 'text-success',
  },
  violet: {
    stroke: 'var(--info)',
    iconBox: 'bg-info/10 border-info/25 text-info',
    value: 'text-info',
  },
  orange: {
    stroke: 'var(--warning)',
    iconBox: 'bg-warning/10 border-warning/30 text-warning',
    value: 'text-warning',
  },
  blue: {
    stroke: '#3b82f6',
    iconBox: 'bg-[#3b82f6]/10 border-[#3b82f6]/25 text-[#3b82f6]',
    value: 'text-[#3b82f6]',
  },
};

export function datesToSparkline(
  dates: Array<string | Date | null | undefined>,
  days = 7
): number[] {
  const buckets = Array.from({ length: days }, () => 0);
  const today = new Date();
  today.setHours(0, 0, 0, 0);
  for (const raw of dates) {
    if (!raw) continue;
    const d = new Date(raw);
    if (Number.isNaN(d.getTime())) continue;
    d.setHours(0, 0, 0, 0);
    const diff = Math.round((today.getTime() - d.getTime()) / 86400000);
    if (diff >= 0 && diff < days) buckets[days - 1 - diff] += 1;
  }
  return buckets;
}

export function weekOverWeekChange(dates: Array<string | Date | null | undefined>): number {
  const now = Date.now();
  const week = 7 * 86400000;
  let thisWeek = 0;
  let lastWeek = 0;
  for (const raw of dates) {
    if (!raw) continue;
    const t = new Date(raw).getTime();
    if (Number.isNaN(t)) continue;
    const age = now - t;
    if (age >= 0 && age < week) thisWeek += 1;
    else if (age >= week && age < week * 2) lastWeek += 1;
  }
  if (lastWeek === 0) return thisWeek === 0 ? 0 : 100;
  return ((thisWeek - lastWeek) / lastWeek) * 100;
}

function MiniSparkline({ data, color }: { data: number[]; color: string }) {
  const gradientId = useId();
  const width = 118;
  const height = 52;
  const padX = 2;
  const padY = 6;
  const values = data.length > 1 ? data : [0, 0];
  const max = Math.max(...values, 1);
  const points = values.map((value, index) => {
    const x = padX + (index / Math.max(values.length - 1, 1)) * (width - padX * 2);
    const y = height - padY - (value / max) * (height - padY * 2);
    return { x, y };
  });
  const line = points.map((point, index) => `${index === 0 ? 'M' : 'L'}${point.x},${point.y}`).join(' ');
  const area = `${line} L${points[points.length - 1].x},${height - 2} L${points[0].x},${height - 2} Z`;

  return (
    <svg width={width} height={height} viewBox={`0 0 ${width} ${height}`} className="overflow-visible shrink-0">
      <defs>
        <linearGradient id={gradientId} x1="0" y1="0" x2="0" y2="1">
          <stop offset="0%" stopColor={color} stopOpacity="0.32" />
          <stop offset="100%" stopColor={color} stopOpacity="0.02" />
        </linearGradient>
      </defs>
      <line
        x1={padX}
        x2={width - padX}
        y1={height - 4}
        y2={height - 4}
        stroke="currentColor"
        strokeDasharray="3 4"
        className="text-border"
        strokeWidth="1"
      />
      <path d={area} fill={`url(#${gradientId})`} />
      <path d={line} fill="none" stroke={color} strokeWidth="2.25" strokeLinecap="round" strokeLinejoin="round" />
    </svg>
  );
}

interface StatsSparklineCardProps {
  title: string;
  value: string | number;
  icon: LucideIcon;
  tone: StatsSparklineTone;
  series: number[];
  deltaPercent?: number;
  deltaLabel?: string;
  active?: boolean;
  onClick?: () => void;
}

export function StatsSparklineCard({
  title,
  value,
  icon: Icon,
  tone,
  series,
  deltaPercent = 0,
  deltaLabel = 'vs Last Week',
  active = false,
  onClick,
}: StatsSparklineCardProps) {
  const theme = TONES[tone];
  const positive = deltaPercent >= 0;
  const TrendIcon = positive ? ArrowUpRight : ArrowDownRight;
  const deltaText = `${positive ? '+' : ''}${deltaPercent.toFixed(1)}%`;

  return (
    <button
      type="button"
      onClick={onClick}
      className={`bg-card border text-left cursor-pointer transition-colors crm-radius-section p-4 shadow-[0_1px_3px_rgba(16,24,40,0.06)] min-w-0 ${
        active ? 'border-[#b8c0d4]' : 'border-border'
      }`}
    >
      <div className="flex items-center gap-3 min-w-0">
        <div className={`w-10 h-10 crm-radius-section border flex items-center justify-center shrink-0 ${theme.iconBox}`}>
          <Icon className="w-[18px] h-[18px]" strokeWidth={1.75} />
        </div>
        <p className="text-[14px] font-medium text-foreground truncate">{title}</p>
      </div>

      <div className="mt-4 border border-border crm-radius-section px-3.5 py-3 flex items-end justify-between gap-2 min-w-0">
        <div className="min-w-0">
          <p className={`text-[26px] font-bold tracking-tight leading-none ${theme.value}`}>{value}</p>
          <p className="text-[12px] mt-2 leading-none truncate">
            <span className={`font-semibold ${theme.value}`}>{deltaText}</span>
            <span className="text-muted-foreground"> {deltaLabel}</span>
          </p>
        </div>
        <div className="flex items-center gap-0.5 shrink-0">
          <TrendIcon className={`w-4 h-4 mb-3 ${theme.value}`} strokeWidth={2.25} />
          <MiniSparkline data={series} color={theme.stroke} />
        </div>
      </div>
    </button>
  );
}