import { getInvoicePeriodDate, matchesInvoicePeriod } from "./invoicePeriod";

export type AnalyticsInvoice = {
  invoiceDate?: Date | string | number | null;
  createdAt?: Date | string | number | null;
  isSubscription?: number | null;
  status?: string | null;
  supplierName?: string | null;
  totalAmount?: number | string | null;
};

export type AnnualInvoiceSummary = {
  year: number;
  bapCount: number;
  bapAmount: number;
  subscriptionCount: number;
  subscriptionAmount: number;
  totalAmount: number;
};

export type SupplierBudgetSummary = {
  supplierName: string;
  subscriptionCount: number;
  subscriptionAmount: number;
  nonSubscriptionCount: number;
  nonSubscriptionAmount: number;
  totalAmount: number;
};

function getAmount(value: AnalyticsInvoice["totalAmount"]): number {
  const amount = Number(value);
  return Number.isFinite(amount) ? amount : 0;
}

/**
 * Agrège les factures finalisées par année métier. « BAP » désigne ici les
 * factures hors abonnement, éligibles au circuit BAP, validées ou non.
 */
export function buildAnnualInvoiceSummary(invoices: AnalyticsInvoice[]): AnnualInvoiceSummary[] {
  const summaryByYear = new Map<number, AnnualInvoiceSummary>();

  for (const invoice of invoices) {
    if (invoice.status !== "completed") continue;
    const date = getInvoicePeriodDate(invoice);
    if (!date) continue;

    const year = date.getFullYear();
    const current = summaryByYear.get(year) ?? {
      year,
      bapCount: 0,
      bapAmount: 0,
      subscriptionCount: 0,
      subscriptionAmount: 0,
      totalAmount: 0,
    };
    const amount = getAmount(invoice.totalAmount);

    if (invoice.isSubscription === 1) {
      current.subscriptionCount += 1;
      current.subscriptionAmount += amount;
    } else {
      current.bapCount += 1;
      current.bapAmount += amount;
    }
    current.totalAmount += amount;
    summaryByYear.set(year, current);
  }

  return Array.from(summaryByYear.values()).sort((a, b) => b.year - a.year);
}

/** Agrège le budget réellement facturé par fournisseur sur la période choisie. */
export function buildSupplierBudgetSummary(
  invoices: AnalyticsInvoice[],
  year: string,
  month: string,
): SupplierBudgetSummary[] {
  const summaryBySupplier = new Map<string, SupplierBudgetSummary>();

  for (const invoice of invoices) {
    if (invoice.status !== "completed" || !matchesInvoicePeriod(invoice, year, month)) continue;

    const supplierName = invoice.supplierName?.trim() || "Fournisseur inconnu";
    const current = summaryBySupplier.get(supplierName) ?? {
      supplierName,
      subscriptionCount: 0,
      subscriptionAmount: 0,
      nonSubscriptionCount: 0,
      nonSubscriptionAmount: 0,
      totalAmount: 0,
    };
    const amount = getAmount(invoice.totalAmount);

    if (invoice.isSubscription === 1) {
      current.subscriptionCount += 1;
      current.subscriptionAmount += amount;
    } else {
      current.nonSubscriptionCount += 1;
      current.nonSubscriptionAmount += amount;
    }
    current.totalAmount += amount;
    summaryBySupplier.set(supplierName, current);
  }

  return Array.from(summaryBySupplier.values()).sort((a, b) =>
    b.totalAmount - a.totalAmount || a.supplierName.localeCompare(b.supplierName, "fr"),
  );
}