import "server-only";

import { formatCurrency, formatPercentage } from "@/app/utils/formatCurrency";

interface IHealthData {
  total?: number;
  successful?: number;
  acceptance_rate?: number;
  amount?: number;
  atv?: number;
}

interface IStatItem {
  label: string;
  value: string | number;
  change: string;
}

export const transformHealthDataToStats = (
  healthData: IHealthData | null
): IStatItem[] => {
  if (!healthData) {
    return [
      { label: "TOTAL", value: 0, change: "0%" },
      { label: "SUCCESSFUL", value: 0, change: "0%" },
      { label: "ACCEPTANCE RATE", value: "0%", change: "0%" },
      { label: "AMOUNT", value: "€0.00", change: "0%" },
      { label: "ATV", value: "€0.00", change: "0%" },
    ];
  }

  return [
    {
      label: "TOTAL",
      value: healthData.total ?? 0,
      change: "0%",
    },
    {
      label: "SUCCESSFUL",
      value: healthData.successful ?? 0,
      change: "0%",
    },
    {
      label: "ACCEPTANCE RATE",
      value: formatPercentage(healthData.acceptance_rate),
      change: "0%",
    },
    {
      label: "AMOUNT",
      value: formatCurrency(healthData.amount),
      change: "0%",
    },
    {
      label: "ATV",
      value: formatCurrency(healthData.atv),
      change: "0%",
    },
  ];
};

/**
 * Map transaction state to color
 */
const getStateColor = (state: string): string => {
  const normalizedState = state.toLowerCase();

  switch (normalizedState) {
    case "success":
    case "completed":
    case "successful":
      return "#4caf50"; // green
    case "pending":
    case "waiting":
      return "#ff9800"; // orange
    case "failed":
    case "error":
      return "#f44336"; // red
    case "cancelled":
    case "canceled":
      return "#9e9e9e"; // gray
    default:
      return "#9e9e9e"; // gray
  }
};

/**
 * Calculate percentage for each state
 */
const calculatePercentages = (
  items: Array<{ state: string; count: number }>
): Array<{
  state: string;
  count: number;
  percentage: string;
}> => {
  const total = items.reduce((sum, item) => sum + item.count, 0);

  if (total === 0) {
    return items.map(item => ({
      ...item,
      percentage: "0%",
    }));
  }

  return items.map(item => ({
    ...item,
    percentage: `${Math.round((item.count / total) * 100)}%`,
  }));
};

/**
 * Transform API overview data to include colors
 */
const enrichOverviewData = (
  data: Array<{
    state: string;
    count: number;
    percentage: string;
    color?: string;
  }>
): Array<{
  state: string;
  count: number;
  percentage: string;
  color: string;
}> => {
  return data.map(item => ({
    ...item,
    color: item.color || getStateColor(item.state),
  }));
};

/**
 * Transform flat API overview response to enriched array format with percentages and colors
 */
export const transformOverviewResponse = (
  data:
    | {
        cancelled_count?: number;
        failed_count?: number;
        successful_count?: number;
        waiting_count?: number;
      }
    | null
    | undefined
): Array<{
  state: string;
  count: number;
  percentage: string;
  color: string;
}> => {
  if (!data) {
    return [];
  }

  const states = [
    { key: "successful_count", label: "Successful" },
    { key: "waiting_count", label: "Waiting" },
    { key: "failed_count", label: "Failed" },
    { key: "cancelled_count", label: "Cancelled" },
  ];

  const transformed = states
    .map(({ key, label }) => ({
      state: label,
      count: data[key as keyof typeof data] || 0,
    }))
    .filter(item => item.count > 0); // Only include states with counts > 0

  const withPercentages = calculatePercentages(transformed);
  return enrichOverviewData(withPercentages);
};