/** 本地存储：为 true 时用系统浏览器打开链接，否则用内置 WebView */
export const OPEN_URL_IN_SYSTEM_BROWSER_KEY = 'open_url_in_system_browser'

/** 是否已做过「首次启动弱机默认」检测（全应用仅一次） */
export const OPEN_URL_DEVICE_DEFAULT_APPLIED_KEY = 'open_url_device_default_applied'

/** 用户在「应用设置」里手动改过开关后为 true，不再自动覆盖 */
export const OPEN_URL_USER_EXPLICIT_SET_KEY = 'open_url_user_explicit_set'

/** 首次/刷新时写入的检测结果（JSON） */
export const OPEN_URL_DEVICE_SNAPSHOT_KEY = 'open_url_device_snapshot'

/** Android 12 对应 API 31 */
const ANDROID_12_API_LEVEL = 31
/** 物理内存低于此值（GB）视为弱机，默认用系统浏览器打开链接 */
const WEAK_DEVICE_RAM_GB = 8

/**
 * Java Long / 任意桥接值为字节数
 * @param {*} v
 * @returns {number}
 */
function javaLongishToNumber(v) {
	if (v == null || v === undefined) return 0
	if (typeof v === 'number' && Number.isFinite(v)) return v
	if (typeof v === 'string') {
		const n = parseFloat(v)
		return Number.isFinite(n) ? n : 0
	}
	try {
		if (typeof plus !== 'undefined' && plus.android && plus.android.invoke) {
			const lv = plus.android.invoke(v, 'longValue')
			if (typeof lv === 'number' && Number.isFinite(lv)) return lv
		}
	} catch (e) {}
	try {
		const n = Number(v)
		return Number.isFinite(n) ? n : 0
	} catch (e2) {}
	return 0
}

/**
 * 读取 /proc/meminfo 中 MemTotal（kB）换算为字节（多数机型可用，作 ActivityManager 失败时的回退）
 * @returns {number}
 */
function readMemTotalBytesFromProc() {
	// #ifdef APP-PLUS
	let br = null
	try {
		const FileReader = plus.android.importClass('java.io.FileReader')
		const BufferedReader = plus.android.importClass('java.io.BufferedReader')
		const fr = new FileReader('/proc/meminfo')
		br = new BufferedReader(fr)
		let line = br.readLine()
		let guard = 0
		while (line != null && guard < 400) {
			guard++
			const s = String(line)
			if (s.indexOf('MemTotal:') === 0) {
				const parts = s.trim().split(/\s+/)
				const kb = parseInt(parts[1], 10)
				if (Number.isFinite(kb) && kb > 0) return kb * 1024
				return 0
			}
			line = br.readLine()
		}
	} catch (e) {
	} finally {
		try {
			if (br) br.close()
		} catch (e2) {}
	}
	// #endif
	return 0
}

/**
 * 物理内存总字节数（Android App）
 * @returns {{ bytes: number, source: string }}
 */
function readAndroidTotalRamBytes() {
	const empty = { bytes: 0, source: '' }
	// #ifdef APP-PLUS
	try {
		const main = plus.android.runtimeMainActivity()
		const ActivityManager = plus.android.importClass('android.app.ActivityManager')
		const Context = plus.android.importClass('android.content.Context')
		const MemoryInfo = plus.android.importClass('android.app.ActivityManager$MemoryInfo')
		const am = main.getSystemService(Context.ACTIVITY_SERVICE)
		const memInfo = new MemoryInfo()

		try {
			plus.android.invoke(am, 'getMemoryInfo', memInfo)
		} catch (e) {
			try {
				am.getMemoryInfo(memInfo)
			} catch (e2) {}
		}

		let raw = null
		try {
			raw = plus.android.invoke(memInfo, 'totalMem')
		} catch (e) {}
		if (raw == null || raw === undefined) {
			try {
				raw = memInfo.totalMem
			} catch (e2) {}
		}

		const fromAm = javaLongishToNumber(raw)
		if (fromAm > 0) return { bytes: fromAm, source: 'ActivityManager' }

		const fromProc = readMemTotalBytesFromProc()
		if (fromProc > 0) return { bytes: fromProc, source: '/proc/meminfo' }

		return empty
	} catch (e) {
		const fromProc = readMemTotalBytesFromProc()
		if (fromProc > 0) return { bytes: fromProc, source: '/proc/meminfo' }
		return empty
	}
	// #endif
	return empty
}

/**
 * 读取 Android 设备信息（App 端）。用于快照与弱机判断。
 * @returns {object|null}
 */
function collectAndroidSnapshot() {
	// #ifdef APP-PLUS
	try {
		if (uni.getSystemInfoSync().platform !== 'android') return null

		const out = {
			platform: 'android',
			at: Date.now(),
			androidSdkInt: null,
			androidRelease: '',
			totalRamBytes: null,
			totalRamGb: null,
			ramSource: '',
			weakOs: false,
			weakRam: false,
			weakDevice: false
		}

		const VERSION = plus.android.importClass('android.os.Build$VERSION')
		out.androidSdkInt = Number(VERSION.SDK_INT)
		out.androidRelease = String(VERSION.RELEASE || '')
		out.weakOs = out.androidSdkInt < ANDROID_12_API_LEVEL

		const ram = readAndroidTotalRamBytes()
		if (ram.bytes > 0) {
			out.totalRamBytes = ram.bytes
			out.totalRamGb = Math.round((ram.bytes / (1024 * 1024 * 1024)) * 100) / 100
			out.weakRam = out.totalRamGb < WEAK_DEVICE_RAM_GB
			out.ramSource = ram.source || ''
		}

		out.weakDevice = !!(out.weakOs || out.weakRam)
		return out
	} catch (e) {
		return {
			platform: 'android',
			at: Date.now(),
			error: String((e && e.message) || e)
		}
	}
	// #endif
	return null
}

function persistSnapshot(snap) {
	if (!snap) return
	try {
		uni.setStorageSync(OPEN_URL_DEVICE_SNAPSHOT_KEY, JSON.stringify(snap))
	} catch (e) {}
}

/**
 * 供应用设置页展示多行说明
 * @param {object|null} s getOpenUrlDeviceSnapshot() 返回值
 * @returns {string[]}
 */
export function formatOpenUrlDeviceSnapshotLines(s) {
	if (!s || typeof s !== 'object') return []
	if (s.platform === 'android') {
		const lines = ['本机检测（已保存；进入本页会刷新内存与系统信息）']
		if (s.androidSdkInt != null) {
			lines.push(`Android API：${s.androidSdkInt}（低于 31 视为系统版本偏低）`)
		}
		lines.push(`Android 版本：${s.androidRelease || '—'}`)
		if (s.totalRamGb != null) {
			const src = s.ramSource ? `，来源：${s.ramSource}` : ''
			lines.push(`物理内存：约 ${s.totalRamGb} GB（低于 8 GB 视为内存偏低）${src}`)
		} else {
			lines.push('物理内存：未能读取（ActivityManager 与 /proc/meminfo 均失败）')
		}
		lines.push(`弱机判定：${s.weakDevice ? '是' : '否'}（系统偏低或内存偏低）`)
		if (s.error) lines.push(`读取异常：${s.error}`)
		return lines
	}
	if (s.note) return [String(s.note)]
	return []
}

/**
 * 进入应用设置等页面时刷新并保存检测快照（不改变首次默认逻辑）。
 */
export function refreshAndroidOpenUrlDeviceSnapshot() {
	// #ifdef APP-PLUS
	const snap = collectAndroidSnapshot()
	persistSnapshot(snap)
	// #endif
}

/**
 * @returns {object|null}
 */
export function getOpenUrlDeviceSnapshot() {
	try {
		const raw = uni.getStorageSync(OPEN_URL_DEVICE_SNAPSHOT_KEY)
		if (raw == null || raw === '') return null
		if (typeof raw === 'object') return raw
		return JSON.parse(String(raw))
	} catch (e) {
		return null
	}
}

function userHasExplicitOpenUrlPreference() {
	try {
		return !!uni.getStorageSync(OPEN_URL_USER_EXPLICIT_SET_KEY)
	} catch (e) {
		return false
	}
}

/**
 * 应用首次启动执行一次（见 App.vue onLaunch）：
 * 仅 Android：系统版本低于 12 或物理内存低于 8GB 时，若用户未在设置里手动改过，则默认开启「用手机浏览器打开」。
 */
export function maybeApplyAndroidWeakDeviceOpenUrlDefault() {
	// #ifdef APP-PLUS
	try {
		if (uni.getStorageSync(OPEN_URL_DEVICE_DEFAULT_APPLIED_KEY)) return

		const platform = uni.getSystemInfoSync().platform
		if (platform !== 'android') {
			try {
				uni.setStorageSync(OPEN_URL_DEVICE_SNAPSHOT_KEY, JSON.stringify({
					platform,
					at: Date.now(),
					note: '弱机默认仅 Android 检测'
				}))
			} catch (e) {}
			uni.setStorageSync(OPEN_URL_DEVICE_DEFAULT_APPLIED_KEY, true)
			return
		}

		const snap = collectAndroidSnapshot()
		persistSnapshot(snap)

		const weak =
			snap &&
			!snap.error &&
			(snap.weakOs || snap.weakRam)

		if (weak && !userHasExplicitOpenUrlPreference()) {
			setOpenUrlInSystemBrowser(true)
		}
		uni.setStorageSync(OPEN_URL_DEVICE_DEFAULT_APPLIED_KEY, true)
	} catch (e) {
		try {
			uni.setStorageSync(OPEN_URL_DEVICE_DEFAULT_APPLIED_KEY, true)
		} catch (e2) {}
	}
	// #endif
}

export function getOpenUrlInSystemBrowser() {
	try {
		const v = uni.getStorageSync(OPEN_URL_IN_SYSTEM_BROWSER_KEY)
		return v === true || v === 'true' || v === 1
	} catch (e) {
		return false
	}
}

/**
 * @param {boolean} value
 * @param {{ fromUser?: boolean }} [options] fromUser 为 true 时表示用户在应用设置中操作，之后不再被弱机默认覆盖
 */
export function setOpenUrlInSystemBrowser(value, options) {
	try {
		uni.setStorageSync(OPEN_URL_IN_SYSTEM_BROWSER_KEY, !!value)
		if (options && options.fromUser) {
			uni.setStorageSync(OPEN_URL_USER_EXPLICIT_SET_KEY, true)
		}
	} catch (e) {}
}

/**
 * 按用户偏好：系统浏览器或内置 WebView。
 * @param {string} url
 * @param {string} [title] 内置 WebView 标题
 */
export function openEmbeddedOrSystemBrowser(url, title) {
	const u = String(url || '').trim()
	if (!u) return
	const encTitle = encodeURIComponent(title || '页面')
	const pageUrl =
		'/pages/webview/index?url=' + encodeURIComponent(u) + '&title=' + encTitle

	if (getOpenUrlInSystemBrowser()) {
		// #ifdef APP-PLUS
		try {
			if (typeof plus !== 'undefined' && plus.runtime && typeof plus.runtime.openURL === 'function') {
				plus.runtime.openURL(u)
				return
			}
		} catch (e) {}
		// #endif
		// #ifdef H5
		if (typeof window !== 'undefined' && typeof window.open === 'function') {
			window.open(u, '_blank')
			return
		}
		// #endif
	}
	uni.navigateTo({ url: pageUrl })
}