const DEFAULT_SCAN_REGION = {
	width: 0.96,
	height: 0.24,
	centerX: 0.5,
	centerY: 0.5
}

const clamp = (value, min, max, fallback) => {
	const number = Number(value)
	return Number.isFinite(number) ? Math.max(min, Math.min(max, number)) : fallback
}

export function getScanappUserCodes() {
	const user = uni.getStorageSync('scanapp_user') || {}
	const codes = [user.username, user.nickname, user.id, user.userId, user.uid, 'U001']
	return codes.filter((code, index) => code !== undefined && code !== null && code !== '' && codes.indexOf(code) === index).map(String)
}

export function getScanappUserCode() {
	return getScanappUserCodes()[0]
}

export function getScanappSettingsStorageKey() {
	return `scanapp_settings_${getScanappUserCode()}`
}

export function getScanappSettings() {
	for (const userCode of getScanappUserCodes()) {
		const userSettings = uni.getStorageSync(`scanapp_settings_${userCode}`)
		if (userSettings && typeof userSettings === 'object') return userSettings
	}
	const legacySettings = uni.getStorageSync('scanapp_settings')
	return legacySettings && typeof legacySettings === 'object' ? legacySettings : {}
}

/**
 * 读取当前用户的有效识别区域设置，供所有业务扫码入口统一使用。
 */
export function getScanRegionSetting() {
	const settings = getScanappSettings()
	if (!settings.scanRegionPreset && !settings.scanRegion) return {}
	if (settings.scanRegionPreset === 'fullscreen' || (!settings.scanRegionPreset && settings.scanRegion?.fullScreen === true)) {
		return { fullScreen: true }
	}

	const region = settings.scanRegion || {}
	const width = clamp(region.width, 0.1, 1, DEFAULT_SCAN_REGION.width)
	const height = clamp(region.height, 0.1, 1, DEFAULT_SCAN_REGION.height)
	const centerX = clamp(region.centerX, 0, 1, DEFAULT_SCAN_REGION.centerX)
	const minCenterY = Math.min(0.5, height / 2)
	const centerY = clamp(region.centerY, minCenterY, 1 - minCenterY, DEFAULT_SCAN_REGION.centerY)
	return { width, height, centerX, centerY }
}