import {
  Cell,
  Pie,
  PieChart,
  ResponsiveContainer,
  Tooltip,
} from "recharts";
import { Box, Group, Paper, Stack, Text } from "@mantine/core";

import { overviewChartColors } from "./overview.styles";

export interface DonutChartItem {
  name: string;
  value: number;
}

interface OverviewDonutChartProps {
  title: string;
  data: DonutChartItem[];
  emptyMessage?: string;
}

export function OverviewDonutChart({
  title,
  data,
  emptyMessage = "No data available",
}: OverviewDonutChartProps) {
  const filtered = data.filter((item) => item.value > 0);
  const hasData = filtered.length > 0;
  const total = filtered.reduce((sum, item) => sum + item.value, 0);

  return (
    <Paper p="md" radius="lg" withBorder h="100%">
      <Stack gap="sm" h="100%">
        <Text fw={600} size="sm">
          {title}
        </Text>
        {!hasData ? (
          <Text size="sm" c="dimmed" ta="center" py="lg">
            {emptyMessage}
          </Text>
        ) : (
          <Group gap="md" wrap="nowrap" align="center" style={{ flex: 1 }}>
            {/* Compact donut with the total in its center */}
            <Box style={{ position: "relative", width: 132, height: 132, flexShrink: 0 }}>
              <ResponsiveContainer width="100%" height="100%">
                <PieChart>
                  <Pie
                    data={filtered}
                    dataKey="value"
                    nameKey="name"
                    cx="50%"
                    cy="50%"
                    innerRadius={42}
                    outerRadius={62}
                    paddingAngle={2}
                    stroke="none"
                  >
                    {filtered.map((entry, index) => (
                      <Cell
                        key={entry.name}
                        fill={
                          overviewChartColors.pipeline[
                            index % overviewChartColors.pipeline.length
                          ]
                        }
                      />
                    ))}
                  </Pie>
                  <Tooltip formatter={(value) => [value, "Count"]} />
                </PieChart>
              </ResponsiveContainer>
              <Box
                style={{
                  position: "absolute",
                  inset: 0,
                  display: "flex",
                  flexDirection: "column",
                  alignItems: "center",
                  justifyContent: "center",
                  pointerEvents: "none",
                }}
              >
                <Text fw={800} size="xl" lh={1} style={{ color: "#0f172a" }}>
                  {total}
                </Text>
                <Text size="10px" c="dimmed" fw={600} tt="uppercase" style={{ letterSpacing: 0.4 }}>
                  Total
                </Text>
              </Box>
            </Box>

            {/* Legend fills the space — color, name, count and share */}
            <Stack gap={6} style={{ flex: 1, minWidth: 0 }}>
              {filtered.map((entry, index) => {
                const color =
                  overviewChartColors.pipeline[index % overviewChartColors.pipeline.length];
                const pct = total > 0 ? Math.round((entry.value / total) * 100) : 0;
                return (
                  <Group key={entry.name} gap={8} wrap="nowrap" justify="space-between">
                    <Group gap={8} wrap="nowrap" style={{ minWidth: 0 }}>
                      <Box
                        w={9}
                        h={9}
                        style={{ borderRadius: 3, background: color, flexShrink: 0 }}
                      />
                      <Text size="xs" c="dimmed" truncate>
                        {entry.name}
                      </Text>
                    </Group>
                    <Group gap={6} wrap="nowrap" style={{ flexShrink: 0 }}>
                      <Text size="xs" fw={700} c="dark.5">
                        {entry.value}
                      </Text>
                      <Text size="xs" c="dimmed" style={{ width: 34, textAlign: "right" }}>
                        {pct}%
                      </Text>
                    </Group>
                  </Group>
                );
              })}
            </Stack>
          </Group>
        )}
      </Stack>
    </Paper>
  );
}