import { getSystemConfig } from '@/config/api/system.js'

/** 系统配置项 key（与后台一致） */
export const DANA_TOTAL_CONFIG_KEY = 'overseas_payment_dana_total'
export const DANA_SINGLE_CONFIG_KEY = 'overseas_payment_dana_single'

/** 本地缓存 key */
export const DANA_TOTAL_STORAGE_KEY = 'danaPaymentTotal'
export const DANA_SINGLE_STORAGE_KEY = 'danaPaymentSingle'

/** 写入缓存的金额结构（与业务侧约定一致） */
const wrapStorageNumber = (n) => ({ type: 'number', data: n })

/**
 * 从本地缓存读取 DANA 金额；兼容 { type, data }、JSON 字符串、纯数字。
 */
export function parseDanaStorageNumber(raw) {
	if (raw === null || raw === undefined || raw === '') return null
	let value = raw
	if (typeof raw === 'string') {
		const trimmed = raw.trim()
		if (trimmed.startsWith('{')) {
			try {
				const parsed = JSON.parse(trimmed)
				if (parsed && typeof parsed === 'object' && 'data' in parsed) {
					value = parsed.data
				} else {
					value = parsed
				}
			} catch {
				value = raw
			}
		}
	} else if (typeof raw === 'object' && raw !== null && 'data' in raw) {
		value = raw.data
	}
	const num = Number(value)
	return Number.isFinite(num) ? num : null
}

const parseConfigNumber = (rawValue) => {
	if (rawValue === null || rawValue === undefined) return null
	const cleaned = String(rawValue).replace(/[^0-9.]/g, '')
	if (!cleaned) return null
	const num = Number(cleaned)
	return Number.isFinite(num) ? num : null
}

const extractConfigValue = (res, configKey) => {
	if (!res || res.code !== 200) return null
	const row = (res.rows || []).find((item) => item && item.configKey === configKey)
	if (row && row.configValue !== undefined) return row.configValue
	return null
}

/**
 * 拉取 DANA 预扣款 / 单次扣款配置并写入本地缓存。
 * 用于首页及「直达」设备详情、订单详情、支付页等场景，避免仅依赖首页拉取。
 */
export async function fetchAndCacheDanaPaymentConfig() {
	const [totalRes, singleRes] = await Promise.all([
		getSystemConfig({ configKey: DANA_TOTAL_CONFIG_KEY }),
		getSystemConfig({ configKey: DANA_SINGLE_CONFIG_KEY })
	])

	const totalRaw = extractConfigValue(totalRes, DANA_TOTAL_CONFIG_KEY)
	const singleRaw = extractConfigValue(singleRes, DANA_SINGLE_CONFIG_KEY)
	const totalValue = parseConfigNumber(totalRaw)
	const singleValue = parseConfigNumber(singleRaw)

	if (totalValue !== null) {
		uni.setStorageSync(DANA_TOTAL_STORAGE_KEY, wrapStorageNumber(totalValue))
	}
	if (singleValue !== null) {
		uni.setStorageSync(DANA_SINGLE_STORAGE_KEY, wrapStorageNumber(singleValue))
	}

	return { totalValue, singleValue }
}