import { reactive } from 'vue'
import { resetPickingSession } from '@/stores/picking.js'
import { PLATFORM_API_ROOT } from '@/config/runtime.js'

const SESSION_KEY = 'pda-auth-session'

export const session = reactive({ currentUser: null, token: '', refreshToken: '', tenantId: '', apiBase: PLATFORM_API_ROOT })

function decodeBase64Url(value) {
	const normalized = value.replace(/-/g, '+').replace(/_/g, '/')
	const padded = normalized.padEnd(Math.ceil(normalized.length / 4) * 4, '=')
	if (typeof atob === 'function') return decodeURIComponent(Array.from(atob(padded), (char) => `%${char.charCodeAt(0).toString(16).padStart(2, '0')}`).join(''))
	throw new Error('当前运行环境无法解析登录令牌')
}

export function decodeAccessToken(token) {
	const payload = String(token || '').split('.')[1]
	if (!payload) throw new Error('登录响应中的 accessToken 格式无效')
	try {
		return JSON.parse(decodeBase64Url(payload))
	} catch (error) {
		if (error.message === '当前运行环境无法解析登录令牌') throw error
		throw new Error('登录响应中的 accessToken 无法解析')
	}
}

function storageAvailable() {
	return typeof uni !== 'undefined' && typeof uni.setStorageSync === 'function' && typeof uni.getStorageSync === 'function'
}

function persistSession() {
	if (!storageAvailable()) return
	uni.setStorageSync(SESSION_KEY, {
		currentUser: session.currentUser,
		token: session.token,
		refreshToken: session.refreshToken,
		tenantId: session.tenantId,
		apiBase: session.apiBase
	})
}

export function signIn(account, warehouse, options = {}) {
	session.currentUser = { id: String(account.id), name: account.name, role: account.role, roles: account.roles || [], warehouse, warehouseId: account.warehouseId || null }
	session.token = options.token || account.token || ''
	session.refreshToken = options.refreshToken || account.refreshToken || ''
	session.tenantId = options.tenantId || account.tenantId || ''
	session.apiBase = options.apiBase || account.apiBase || PLATFORM_API_ROOT
	persistSession()
	return session.currentUser
}

export function signInWithTokens(tokens) {
	if (!tokens?.accessToken) throw new Error('登录响应缺少 accessToken')
	const claims = decodeAccessToken(tokens.accessToken)
	if (claims.app_code !== 'PLATFORM') throw new Error('当前账号不属于平台作业端')
	if (claims.exp && claims.exp * 1000 <= Date.now()) throw new Error('登录状态已过期')
	return signIn({
		id: claims.user_id ?? '',
		name: claims.username || '仓库作业员',
		role: Array.isArray(claims.roles) ? claims.roles.join('、') : '',
		roles: claims.roles || []
	}, '', {
		token: tokens.accessToken,
		refreshToken: tokens.refreshToken || '',
		tenantId: claims.tenant_id == null ? '' : String(claims.tenant_id)
	})
}

export function restoreSession() {
	if (!storageAvailable()) return false
	const saved = uni.getStorageSync(SESSION_KEY)
	if (!saved?.token || !saved?.currentUser) return false
	try {
		const claims = decodeAccessToken(saved.token)
		if (claims.exp && claims.exp * 1000 <= Date.now()) return false
		Object.assign(session, saved, { apiBase: saved.apiBase || PLATFORM_API_ROOT })
		return true
	} catch (_) {
		return false
	}
}

export function signOut() {
	session.currentUser = null
	session.token = ''
	session.refreshToken = ''
	session.tenantId = ''
	session.apiBase = PLATFORM_API_ROOT
	if (typeof uni !== 'undefined' && typeof uni.removeStorageSync === 'function') uni.removeStorageSync(SESSION_KEY)
	resetPickingSession()
}

export function requireSession() {
	if (session.currentUser || restoreSession()) return true
	uni.reLaunch({ url: '/pages/login/login' })
	return false
}