import type {
	CustomerPackageItem,
	CustomerPackageStatus,
	DeliveryOperationType,
	DeliveryStatus,
	FundOperationType,
	FundRecordStatus,
	PackageConfigStatus,
	PaymentStatus,
	RefundStatus
} from "@/types/Package";

/** 生成套餐业务幂等请求号。每次新操作必须重新生成。 */
export function createPackageRequestNo(): string {
	return window.crypto.randomUUID();
}

/** 将分转换为金额展示文本，不用浮点数做金额格式化。 */
export function formatPackageAmount(cents?: number | null): string {
	if (cents === undefined || cents === null) {
		return "未设置";
	}
	const negative = cents < 0;
	const absolute = Math.abs(Math.trunc(cents));
	const yuan = Math.floor(absolute / 100);
	const fen = String(absolute % 100).padStart(2, "0");
	return `${negative ? "-" : ""}${yuan}.${fen} 元`;
}

/** 将分转换为金额输入框文本。 */
export function formatPackageAmountInput(cents?: number | null): string {
	if (cents === undefined || cents === null) {
		return "";
	}
	const negative = cents < 0;
	const absolute = Math.abs(Math.trunc(cents));
	return `${negative ? "-" : ""}${Math.floor(absolute / 100)}.${String(absolute % 100).padStart(2, "0")}`;
}

/** 将用户输入的元金额精确转换为后端要求的分。 */
export function parsePackageAmount(value: string): number | undefined {
	const text = value.trim();
	if (!/^\d+(?:\.\d{1,2})?$/.test(text)) {
		return undefined;
	}
	const [yuanText, fenText = ""] = text.split(".");
	const cents = BigInt(yuanText) * 100n + BigInt(fenText.padEnd(2, "0") || "0");
	const result = Number(cents);
	return Number.isSafeInteger(result) ? result : undefined;
}

/** 规范化最多三位小数的非负定点数量。 */
export function normalizePackageQuantity(value: number | string): string | undefined {
	const text = String(value).trim();
	if (!/^\d+(?:\.\d{1,3})?$/.test(text)) {
		return undefined;
	}
	const [integerText, fractionText = ""] = text.split(".");
	const integer = integerText.replace(/^0+(?=\d)/, "") || "0";
	const fraction = fractionText.replace(/0+$/, "");
	return fraction ? `${integer}.${fraction}` : integer;
}

/** 使用 BigInt 比较定点数量，避免 JavaScript 二进制浮点误差。 */
export function comparePackageQuantity(left: number | string, right: number | string): number {
	const leftParts = toQuantityParts(left);
	const rightParts = toQuantityParts(right);
	if (!leftParts || !rightParts) {
		return 0;
	}
	const scale = Math.max(leftParts.scale, rightParts.scale);
	const leftValue = leftParts.value * 10n ** BigInt(scale - leftParts.scale);
	const rightValue = rightParts.value * 10n ** BigInt(scale - rightParts.scale);
	return leftValue < rightValue ? -1 : rightValue < leftValue ? 1 : 0;
}

export function getPackageQuantityText(value?: number | string | null): string {
	if (value === undefined || value === null || value === "") {
		return "0";
	}
	return normalizePackageQuantity(value) || "0";
}

export function getPackageConfigStatusText(status?: PackageConfigStatus): string {
	return ({ DRAFT: "草稿", ACTIVE: "启用", INACTIVE: "停用" } as Record<string, string>)[status || ""] || "未知";
}

export function getCustomerPackageStatusText(status?: CustomerPackageStatus): string {
	return ({ ACTIVE: "进行中", FULFILLED: "已履约", CANCELLED: "已取消" } as Record<string, string>)[status || ""] || "未知";
}

export function getPaymentStatusText(status?: PaymentStatus): string {
	return ({ UNPAID: "未收款", PARTIALLY_PAID: "部分收款", PAID: "已收款" } as Record<string, string>)[status || ""] || "未知";
}

export function getRefundStatusText(status?: RefundStatus): string {
	return ({ NOT_REQUIRED: "无需退款", PENDING: "待退款", REFUNDED: "已退款" } as Record<string, string>)[status || ""] || "未知";
}

export function getDeliveryStatusText(status?: DeliveryStatus): string {
	return ({ PENDING: "待核销", VERIFIED: "已核销", REJECTED: "已拒绝", CANCELLED: "已撤销", REVOKED: "已冲正" } as Record<string, string>)[status || ""] || "未知";
}

export function getDeliveryOperationText(type?: DeliveryOperationType): string {
	return type === "REVOKE" ? "发放冲正" : "正常发放";
}

export function getFundOperationText(type?: FundOperationType): string {
	return ({ RECEIVE: "线下收款", REFUND: "退款", CONFIRM_NO_REFUND: "确认无需退款", REVOKE: "资金冲正" } as Record<string, string>)[type || ""] || "未知";
}

export function getFundStatusText(status?: FundRecordStatus): string {
	return ({ PENDING: "待核销", VERIFIED: "已核销", REJECTED: "已拒绝", CANCELLED: "已撤销" } as Record<string, string>)[status || ""] || "未知";
}

export function getPackageItemAvailableQuantity(item: CustomerPackageItem): string {
	return getPackageQuantityText(item.availableQuantity);
}

function toQuantityParts(value: number | string): { value: bigint; scale: number } | undefined {
	const normalized = normalizePackageQuantity(value);
	if (!normalized) {
		return undefined;
	}
	const [integerText, fractionText = ""] = normalized.split(".");
	return {
		value: BigInt(`${integerText}${fractionText}`),
		scale: fractionText.length
	};
}