import { ReportCategory, SaleRecord } from "@/types/sales";

export const REPORT_CATEGORY_ORDER: ReportCategory[] = [
  "Taxable",
  "Non-Taxable",
  "Unleaded",
  "Unleaded Plus",
  "Diesel",
  "Off Road Diesel",
  "Oil",
  "Hardware",
  "Other",
];

export interface CategoryBreakdown {
  category: ReportCategory;
  cashSales: number;
  cashTax: number;
  creditSales: number;
  creditTax: number;
  totalSales: number;
  totalTax: number;
  grandTotal: number;
}

export interface EndOfDayReport {
  businessDate: string;
  totalTransactions: number;
  totalSales: number;
  totalTax: number;
  cashTotal: number;
  creditTotal: number;
  categoryBreakdown: CategoryBreakdown[];
}

export function formatBusinessDate(value: Date): string {
  const year = value.getFullYear();
  const month = `${value.getMonth() + 1}`.padStart(2, "0");
  const day = `${value.getDate()}`.padStart(2, "0");
  return `${year}-${month}-${day}`;
}

export function normalizeReportCategory(
  label: string,
  taxable: boolean,
): ReportCategory {
  const normalized = label.trim().toLowerCase();

  if (normalized.includes("off road diesel")) return "Off Road Diesel";
  if (normalized.includes("unleaded plus")) return "Unleaded Plus";
  if (normalized.includes("unleaded")) return "Unleaded";
  if (normalized.includes("diesel")) return "Diesel";
  if (normalized.includes("oil")) return "Oil";
  if (normalized.includes("hardware")) return "Hardware";
  if (normalized.includes("taxable")) return "Taxable";
  if (normalized.includes("non-tax")) return "Non-Taxable";
  if (normalized.includes("non tax")) return "Non-Taxable";

  return taxable ? "Taxable" : "Non-Taxable";
}

export function buildEndOfDayReport(sales: SaleRecord[]): EndOfDayReport {
  const businessDate = sales[0]?.businessDate ?? formatBusinessDate(new Date());
  const categoryMap = new Map<ReportCategory, CategoryBreakdown>();

  for (const category of REPORT_CATEGORY_ORDER) {
    categoryMap.set(category, {
      category,
      cashSales: 0,
      cashTax: 0,
      creditSales: 0,
      creditTax: 0,
      totalSales: 0,
      totalTax: 0,
      grandTotal: 0,
    });
  }

  for (const sale of sales) {
    for (const item of sale.items) {
      const entry = categoryMap.get(item.reportCategory) ?? {
        category: item.reportCategory,
        cashSales: 0,
        cashTax: 0,
        creditSales: 0,
        creditTax: 0,
        totalSales: 0,
        totalTax: 0,
        grandTotal: 0,
      };

      if (sale.paymentMethod === "cash") {
        entry.cashSales += item.lineTotal;
        entry.cashTax += item.taxAmount;
      } else {
        entry.creditSales += item.lineTotal;
        entry.creditTax += item.taxAmount;
      }

      entry.totalSales += item.lineTotal;
      entry.totalTax += item.taxAmount;
      entry.grandTotal += item.lineTotal + item.taxAmount;

      categoryMap.set(entry.category, entry);
    }
  }

  const categoryBreakdown = REPORT_CATEGORY_ORDER
    .map((category) => categoryMap.get(category)!)
    .filter((entry) => entry.totalSales > 0 || entry.totalTax > 0);

  const cashTotal = sales
    .filter((sale) => sale.paymentMethod === "cash")
    .reduce((sum, sale) => sum + sale.total, 0);
  const creditTotal = sales
    .filter((sale) => sale.paymentMethod === "credit")
    .reduce((sum, sale) => sum + sale.total, 0);

  return {
    businessDate,
    totalTransactions: sales.length,
    totalSales: sales.reduce((sum, sale) => sum + sale.subtotal, 0),
    totalTax: sales.reduce((sum, sale) => sum + sale.tax, 0),
    cashTotal,
    creditTotal,
    categoryBreakdown,
  };
}