import type {
  FinanceTransactionFilterState,
  FinanceTransactionListQueryPayload,
  FinanceTransactionQueryPayload,
  QuickDateRangeKey,
} from '../../types';

/**
 * 文件职责：交易流水页面纯函数与数据转换工具。
 */
import type {
  FinanceTransactionChannelFilter,
  FinanceTransactionPaymentFilter,
  FinanceTransactionTypeFilter,
} from '#/api/finance';

function formatDate(date: Date) {
  const year = date.getFullYear();
  const month = `${date.getMonth() + 1}`.padStart(2, '0');
  const day = `${date.getDate()}`.padStart(2, '0');
  return `${year}-${month}-${day}`;
}

function toDateOnly(date: Date) {
  return new Date(date.getFullYear(), date.getMonth(), date.getDate());
}

function shiftDate(date: Date, dayOffset: number) {
  const next = new Date(date);
  next.setDate(next.getDate() + dayOffset);
  return next;
}

function normalizeType(
  value: FinanceTransactionTypeFilter,
): FinanceTransactionTypeFilter | undefined {
  return value === 'all' ? undefined : value;
}

function normalizeChannel(
  value: FinanceTransactionChannelFilter,
): FinanceTransactionChannelFilter | undefined {
  return value === 'all' ? undefined : value;
}

function normalizePayment(
  value: FinanceTransactionPaymentFilter,
): FinanceTransactionPaymentFilter | undefined {
  return value === 'all' ? undefined : value;
}

/** 获取今天日期字符串（yyyy-MM-dd）。 */
export function getTodayDateString() {
  return formatDate(new Date());
}

/** 根据快捷日期键计算筛选起止日期。 */
export function resolveQuickRangeDateRange(value: QuickDateRangeKey) {
  const today = toDateOnly(new Date());
  let start = today;
  let end = today;

  switch (value) {
    case '7d': {
      start = shiftDate(today, -6);

      break;
    }
    case '30d': {
      start = shiftDate(today, -29);

      break;
    }
    case 'month': {
      start = new Date(today.getFullYear(), today.getMonth(), 1);

      break;
    }
    case 'yesterday': {
      start = shiftDate(today, -1);
      end = start;

      break;
    }
    // No default
  }

  return {
    startDate: formatDate(start),
    endDate: formatDate(end),
  };
}

/** 构建交易流水筛选请求。 */
export function buildFilterQueryPayload(
  storeId: string,
  filters: FinanceTransactionFilterState,
): FinanceTransactionQueryPayload {
  return {
    storeId,
    startDate: filters.startDate || undefined,
    endDate: filters.endDate || undefined,
    type: normalizeType(filters.type),
    channel: normalizeChannel(filters.channel),
    paymentMethod: normalizePayment(filters.paymentMethod),
    keyword: filters.keyword.trim() || undefined,
  };
}

/** 构建交易流水列表请求。 */
export function buildListQueryPayload(
  storeId: string,
  filters: FinanceTransactionFilterState,
  page: number,
  pageSize: number,
): FinanceTransactionListQueryPayload {
  return {
    ...buildFilterQueryPayload(storeId, filters),
    page,
    pageSize,
  };
}

/** 判断日期范围是否合法。 */
export function isDateRangeInvalid(filters: FinanceTransactionFilterState) {
  if (!filters.startDate || !filters.endDate) {
    return false;
  }
  return filters.startDate > filters.endDate;
}

/** 货币格式化（人民币）。 */
export function formatCurrency(value: number) {
  return new Intl.NumberFormat('zh-CN', {
    style: 'currency',
    currency: 'CNY',
    minimumFractionDigits: 2,
    maximumFractionDigits: 2,
  }).format(Number.isFinite(value) ? value : 0);
}

/** 交易金额（带符号）格式化。 */
export function formatSignedAmount(value: number, isIncome: boolean) {
  const normalized = Number.isFinite(value) ? value : 0;
  if (normalized === 0) {
    return formatCurrency(0);
  }

  if (normalized > 0 || isIncome) {
    return `+${formatCurrency(Math.abs(normalized))}`;
  }

  return `-${formatCurrency(Math.abs(normalized))}`;
}

/** 金额视觉色调。 */
export function resolveAmountToneClass(value: number, isIncome: boolean) {
  if (value > 0 || isIncome) {
    return 'income';
  }
  if (value < 0) {
    return 'expense';
  }
  return 'neutral';
}

/** 交易类型标签颜色。 */
export function resolveTransactionTypeTagColor(type: string) {
  if (type === 'income') return 'green';
  if (type === 'refund') return 'red';
  if (type === 'stored_card_recharge') return 'blue';
  if (type === 'point_redeem') return 'orange';
  return 'default';
}

function decodeBase64ToBlob(base64: string) {
  const binary = atob(base64);
  const bytes = new Uint8Array(binary.length);
  for (let index = 0; index < binary.length; index += 1) {
    bytes[index] = binary.codePointAt(index) ?? 0;
  }
  return new Blob([bytes], { type: 'text/csv;charset=utf-8;' });
}

/** 下载 Base64 编码文件。 */
export function downloadBase64File(
  fileName: string,
  fileContentBase64: string,
) {
  const blob = decodeBase64ToBlob(fileContentBase64);
  const url = URL.createObjectURL(blob);
  const anchor = document.createElement('a');
  anchor.href = url;
  anchor.download = fileName;
  anchor.click();
  URL.revokeObjectURL(url);
}