import { apiClient } from '@/lib/api-client';

export type FinanceGranularity = 'daily' | 'weekly' | 'monthly';

export interface FinanceSummaryFilters {
  dateFrom: string;
  dateTo: string;
  granularity?: FinanceGranularity;
  originStationId?: string;
  destinationStationId?: string;
  method?: string;
}

export interface FinanceBucketRow {
  period: string;
  originStationId: string;
  destinationStationId: string;
  segmentLabel: string;
  method: string;
  currency: string;
  bookingCount: number;
  revenueMinor: number;
}

/** One roll-up entry. Amounts are never mixed across currencies — `currency` names which one this row is in. */
export interface FinanceRollupRow {
  key: string;
  label: string;
  currency: string;
  revenueMinor: number;
  bookingCount: number;
}

export interface FinanceSummaryReport {
  granularity: FinanceGranularity;
  dateFrom: string;
  dateTo: string;
  /** Grand totals, one entry per currency present — never summed across currencies. */
  totals: FinanceRollupRow[];
  byPeriod: FinanceRollupRow[];
  bySegment: FinanceRollupRow[];
  byMethod: FinanceRollupRow[];
  rows: FinanceBucketRow[];
}

/** Drops blanks so the API applies its own defaults (granularity=daily, no station/method filter). */
function toParams(filters: FinanceSummaryFilters): Record<string, string> {
  const params: Record<string, string> = { dateFrom: filters.dateFrom, dateTo: filters.dateTo };
  if (filters.granularity) params.granularity = filters.granularity;
  if (filters.originStationId) params.originStationId = filters.originStationId;
  if (filters.destinationStationId) params.destinationStationId = filters.destinationStationId;
  if (filters.method) params.method = filters.method;
  return params;
}

export const financeApi = {
  getSummary: (filters: FinanceSummaryFilters) =>
    apiClient.get<FinanceSummaryReport>('/reports/finance', { params: toParams(filters) }),

  /** CSV export. `getRaw` because the endpoint streams a bare CSV body, not the `{success,data}` envelope. */
  exportCsv: (filters: FinanceSummaryFilters) =>
    apiClient.getRaw<string>('/reports/finance/export', { params: toParams(filters) }),
};