"use client";

import { RiPieChartLine } from "@remixicon/react";
import { useMemo } from "react";
import {
	Area,
	AreaChart,
	CartesianGrid,
	ResponsiveContainer,
	Tooltip,
	XAxis,
	YAxis,
} from "recharts";
import { EmptyState } from "@/components/empty-state";
import { Card, CardContent, CardHeader, CardTitle } from "@/components/ui/card";
import { currencyFormatter } from "@/lib/lancamentos/formatting-helpers";
import type { CategoryChartData } from "@/lib/relatorios/fetch-category-chart-data";
import { CATEGORY_COLORS } from "@/lib/utils/category-colors";

interface CategoryReportChartProps {
	data: CategoryChartData;
}

const CHART_COLORS = CATEGORY_COLORS;

const MAX_CATEGORIES_IN_CHART = 15;

export function CategoryReportChart({ data }: CategoryReportChartProps) {
	const { chartData, categories } = data;

	// Check if there's no data
	if (categories.length === 0 || chartData.length === 0) {
		return (
			<EmptyState
				title="Nenhum dado disponível"
				description="Não há transações no período selecionado para as categorias filtradas."
				media={<RiPieChartLine className="h-12 w-12" />}
				mediaVariant="icon"
			/>
		);
	}

	// Get top 10 categories by total spending
	const { topCategories, filteredChartData } = useMemo(() => {
		// Calculate total for each category across all periods
		const categoriesWithTotal = categories.map((category) => {
			const total = chartData.reduce((sum, dataPoint) => {
				const value = dataPoint[category.name];
				return sum + (typeof value === "number" ? value : 0);
			}, 0);

			return { ...category, total };
		});

		// Sort by total (descending) and take top 10
		const sorted = categoriesWithTotal
			.sort((a, b) => b.total - a.total)
			.slice(0, MAX_CATEGORIES_IN_CHART);

		// Filter chartData to include only top categories
		const _topCategoryNames = new Set(sorted.map((cat) => cat.name));
		const filtered = chartData.map((dataPoint) => {
			const filteredPoint: { month: string; [key: string]: number | string } = {
				month: dataPoint.month,
			};

			// Only include data for top categories
			for (const cat of sorted) {
				if (dataPoint[cat.name] !== undefined) {
					filteredPoint[cat.name] = dataPoint[cat.name];
				}
			}

			return filteredPoint;
		});

		return { topCategories: sorted, filteredChartData: filtered };
	}, [categories, chartData]);

	return (
		<Card>
			<CardHeader>
				<CardTitle>
					Evolução por Categoria - Top {topCategories.length}
				</CardTitle>
			</CardHeader>
			<CardContent>
				<div className="h-[400px] w-full">
					<ResponsiveContainer width="100%" height="100%">
						<AreaChart data={filteredChartData}>
							<defs>
								{topCategories.map((category, index) => {
									const color = CHART_COLORS[index % CHART_COLORS.length];
									return (
										<linearGradient
											key={category.id}
											id={`gradient-${category.id}`}
											x1="0"
											y1="0"
											x2="0"
											y2="1"
										>
											<stop offset="5%" stopColor={color} stopOpacity={0.3} />
											<stop offset="95%" stopColor={color} stopOpacity={0} />
										</linearGradient>
									);
								})}
							</defs>
							<CartesianGrid strokeDasharray="3 3" className="stroke-muted" />
							<XAxis
								dataKey="month"
								className="text-xs"
								tick={{ fill: "hsl(var(--muted-foreground))" }}
							/>
							<YAxis
								className="text-xs"
								tick={{ fill: "hsl(var(--muted-foreground))" }}
								tickFormatter={(value) => {
									if (value >= 1000) {
										return `${(value / 1000).toFixed(0)}k`;
									}
									return value.toString();
								}}
							/>
							<Tooltip
								content={({ active, payload }) => {
									if (!active || !payload || payload.length === 0) {
										return null;
									}

									return (
										<div className="rounded-lg border bg-background p-3 shadow-md">
											<div className="mb-2 font-semibold">
												{payload[0]?.payload?.month}
											</div>
											<div className="space-y-1">
												{payload.map((entry, index) => {
													if (entry.dataKey === "month") return null;

													return (
														<div
															key={index}
															className="flex items-center justify-between gap-4 text-sm"
														>
															<div className="flex items-center gap-2">
																<div
																	className="h-2 w-2 rounded-full"
																	style={{ backgroundColor: entry.color }}
																/>
																<span className="text-muted-foreground">
																	{entry.name}
																</span>
															</div>
															<span className="font-medium">
																{currencyFormatter.format(
																	Number(entry.value) || 0,
																)}
															</span>
														</div>
													);
												})}
											</div>
										</div>
									);
								}}
							/>
							{topCategories.map((category, index) => {
								const color = CHART_COLORS[index % CHART_COLORS.length];
								return (
									<Area
										key={category.id}
										type="monotone"
										dataKey={category.name}
										stroke={color}
										strokeWidth={2}
										fill={`url(#gradient-${category.id})`}
										fillOpacity={1}
									/>
								);
							})}
						</AreaChart>
					</ResponsiveContainer>
				</div>

				{/* Legend */}
				<div className="mt-4 flex flex-wrap gap-4">
					{topCategories.map((category, index) => {
						const color = CHART_COLORS[index % CHART_COLORS.length];
						return (
							<div key={category.id} className="flex items-center gap-2">
								<div
									className="h-3 w-3 rounded-full"
									style={{ backgroundColor: color }}
								/>
								<span className="text-sm text-muted-foreground">
									{category.name}
								</span>
							</div>
						);
					})}
				</div>
			</CardContent>
		</Card>
	);
}