"use client";

import {
  CategoryPieChart,
  type CategoryChartData,
} from "@/components/statistics/category-pie-chart";
import type { BankingData } from "@/lib/types";

interface CategoryBreakdownProps {
  data: BankingData;
}

export function CategoryBreakdown({ data }: CategoryBreakdownProps) {
  // Get current month expenses by category
  const thisMonth = new Date();
  thisMonth.setDate(1);
  const thisMonthStr = thisMonth.toISOString().slice(0, 7);

  const monthExpenses = data.transactions.filter(
    (t) => t.date.startsWith(thisMonthStr) && t.amount < 0,
  );

  const categoryTotals = new Map<string, number>();

  monthExpenses.forEach((t) => {
    const catId = t.categoryId || "uncategorized";
    const current = categoryTotals.get(catId) || 0;
    categoryTotals.set(catId, current + Math.abs(t.amount));
  });

  const chartData: CategoryChartData[] = Array.from(categoryTotals.entries())
    .map(([categoryId, total]) => {
      const category = data.categories.find((c) => c.id === categoryId);
      return {
        name: category?.name || "Non catégorisé",
        value: total,
        color: category?.color || "#94a3b8",
        icon: category?.icon || "HelpCircle",
        categoryId: categoryId === "uncategorized" ? null : categoryId,
      };
    })
    .sort((a, b) => b.value - a.value);

  // Category breakdown grouped by parent
  const categoryTotalsByParent = new Map<string, number>();
  monthExpenses.forEach((t) => {
    const category = data.categories.find((c) => c.id === t.categoryId);
    // Use parent category ID if exists, otherwise use the category itself
    let groupId: string;
    if (!category) {
      groupId = "uncategorized";
    } else if (category.parentId) {
      groupId = category.parentId;
    } else {
      // Category is a parent itself
      groupId = category.id;
    }
    const current = categoryTotalsByParent.get(groupId) || 0;
    categoryTotalsByParent.set(groupId, current + Math.abs(t.amount));
  });

  const chartDataByParent: CategoryChartData[] = Array.from(
    categoryTotalsByParent.entries(),
  )
    .map(([groupId, total]) => {
      const category = data.categories.find((c) => c.id === groupId);
      return {
        name: category?.name || "Non catégorisé",
        value: total,
        color: category?.color || "#94a3b8",
        icon: category?.icon || "HelpCircle",
        categoryId: groupId === "uncategorized" ? null : groupId,
      };
    })
    .sort((a, b) => b.value - a.value);

  const formatCurrency = (value: number) => {
    return new Intl.NumberFormat("fr-FR", {
      style: "currency",
      currency: "EUR",
    }).format(value);
  };

  return (
    <CategoryPieChart
      data={chartData}
      dataByParent={chartDataByParent}
      categories={data.categories}
      formatCurrency={formatCurrency}
      title="Dépenses par catégorie"
      height={250}
      innerRadius={50}
      outerRadius={80}
      emptyMessage="Pas de données ce mois-ci"
    />
  );
}