/**
 * ShrimpClient — Shrimp 框架前端基类
 * 框架无关层，包含协议通信、模块管理、菜单树操作
 */
import { ShrimpCode, ShrimpRequestFn, IShrimpResponse, IModuleInfo, IMenuItem, ILoginResult, IMeResult, IShrimpClient, ILabel } from './IShrimpType'

/** tip 展示接口（由框架层实现，如 Element Plus）。msg 是 ILabel,实现层负责翻译后展示 */
export interface IShrimpTipper {
    success(msg: ILabel): void
    error(msg: ILabel): void
    alert(msg: ILabel): Promise<any>
}

/** 路由注册信息，子类 addRoute 的参数 */
export interface IRouteInfo {
    moduleKey: string
    name: string
    path?: string
    label: ILabel
    events: string[]
    /** 组件相对 module 目录的路径(不含 .vue),不传则默认 moduleKey。用于子模块嵌套目录定位 */
    componentPath?: string
    /** 子模块跳转按钮图标(element-plus icon 名,仅 sub 模块有意义) */
    icon?: string
}

class ShrimpResponseError extends Error {
    constructor(public data: IShrimpResponse) {
        super(data.code.toString())
        this.name = 'ShrimpResponseError'
    }
}
/**
 * 处理 Shrimp 响应中的 tip 和 log
 * @returns 处理后的响应数据，或抛出错误
 */
export function handleShrimpResponse(
    body: IShrimpResponse,
    tipper: IShrimpTipper,
    onUnauthorized?: () => void,
): any {
    if (body.log) {
        console.warn('[Shrimp]', body.log)
    }

    if (body.code === ShrimpCode.OK) {
        if (body.tip) tipper.success(body.tip)
        return body.data
    }

    // 业务错误：根据 code 决定展示方式
    if (body.tip) {
        if (body.code === ShrimpCode.UNAUTHORIZED) {
            tipper.alert(body.tip).then(() => onUnauthorized?.())
        } else {
            tipper.error(body.tip)
        }
    } else {
        tipper.alert("").then(() => onUnauthorized?.())
        // tipper.error(t('base.fail'))
    }

    const err = new ShrimpResponseError(body) as any
    err.code = body.code
    err.handled = true
    throw err
}

/**
 * 根据协议类型生成类型安全的 API 调用器
 * 用法:
 *   const userApi = getCaller<IUserProto>(request, "user")
 *   const subApi  = getCaller<ISubProto>(request, ["parent", "sub"])
 */
export function getCaller<P extends Record<string, any>>(request: ShrimpRequestFn, moduleKey: string | string[]): P {
    const segments = Array.isArray(moduleKey) ? moduleKey : [moduleKey]
    return new Proxy({} as any, {
        get: (target, prop, receiver) => {
            if (typeof prop === 'symbol' || prop === 'valueOf' || prop === 'toString') {
                return Reflect.get(target, prop, receiver)
            }
            return (...args: any[]) => request([...segments, prop as string], ...args)
        }
    })
}

/**
 * ShrimpClient 基类
 * 封装与 Shrimp 协议相关的公共方法，框架无关
 * 业务层（如 HandAdmin）继承此类并实现底层请求
 */
export abstract class ShrimpClient implements IShrimpClient {
    /** 当前用户的模块权限列表 */
    moduleInfo: IModuleInfo[] = []

    /** 当前用户的菜单树（含层级结构） */
    menuTree: IMenuItem[] = []

    /** 全局选项（/me 返回的 options） */
    globalOptions: Record<string, any> = {}

    private callers: Map<string, any> = new Map()

    /** 子类必须实现：底层 HTTP 请求 */
    abstract rawRequest<T = any>(method: string, url: string, data?: any): Promise<T>

    /** 子类必须实现：路由注册（框架特定，如 Vue Router） */
    abstract registerRoute(info: IRouteInfo): void

    // ---- Shrimp RPC ----

    /** Shrimp RPC 请求（POST /moduleKey/eventName） */
    async doRequest(path: string[], data?: any[]): Promise<IShrimpResponse> {
        return this.rawRequest<IShrimpResponse>('POST', '/' + path.join('/'), data)
    }

    /** 标准 Shrimp 请求函数（过滤 undefined 参数），供 getCaller 使用 */
    async shrimpRequest(path: string[], ...args: any[]): Promise<IShrimpResponse> {
        const filteredArgs = args.filter(arg => arg !== undefined)
        return await this.doRequest(path, filteredArgs.length > 0 ? filteredArgs : undefined)
    }

    // ---- REST 接口 ----

    /** 获取当前用户信息（权限 + 菜单） */
    async fetchMe(): Promise<IMeResult> {
        return this.rawRequest<IMeResult>('GET', '/me')
    }

    /** 用户登录 */
    async fetchLogin(data: { username: string; password: string }): Promise<ILoginResult> {
        return this.rawRequest<ILoginResult>('POST', '/login', data)
    }

    /** 获取后台配置 */
    async fetchConfig(): Promise<Record<string, any>> {
        return this.rawRequest<Record<string, any>>('GET', '/config')
    }

    // ---- 用户信息 ----

    /** 获取当前用户信息（moduleInfo + menuTree）并注册路由 */
    async loadUserInfo(): Promise<IMeResult> {
        const data = await this.fetchMe()
        this.moduleInfo = data.moduleInfo
        this.menuTree = data.menuTree
        this.globalOptions = data.options || {}
        if (this.menuTree.length > 0) {
            this.registerRoutesFromMenuTree(this.menuTree)
        } else {
            this.registerRoutesFromModuleInfo(this.moduleInfo)
        }
        // 子模块永远走 moduleInfo 递归注册(不进 menu)
        this.registerSubModuleRoutes(this.moduleInfo)
        return data
    }

    // ---- 路由注册 ----

    /**
     * 根据 moduleInfo 扁平注册路由
     * 适用于无层级菜单的场景：moduleKey 即路由名，path 为 /moduleKey
     * 子模块（带 parent）不会作为顶层路由，由 registerSubModuleRoutes 处理
     */
    registerRoutesFromModuleInfo(moduleInfo: IModuleInfo[]) {
        moduleInfo.forEach(info => {
            if (info.parent) return
            this.registerRoute({
                moduleKey: info.moduleKey,
                name: info.moduleKey,
                label: info.label,
                path: '/' + info.moduleKey,
                events: info.events,
            })
        })
    }

    /**
     * 根据 menuTree 层级注册路由
     * 遍历菜单树，对每个带 moduleKey 的项调用 addRoute
     */
    registerRoutesFromMenuTree(menuTree: IMenuItem[]) {
        const walk = (items: IMenuItem[]) => {
            items.forEach(item => {
                if (item.moduleKey) {
                    this.registerRoute({
                        moduleKey: item.moduleKey,
                        name: item.name,
                        path: item.path,
                        label: item.label,
                        events: this.getEvents(item.moduleKey),
                    })
                }
                if (item.children) {
                    walk(item.children)
                }
            })
        }
        walk(menuTree)
    }

    /**
     * 注册子模块路由(扁平 moduleInfo,通过 parent 链接)
     * 子模块路径 = /<parent_path>/<sub>,组件文件 = @/module/<parent_path>/<sub>.vue
     */
    registerSubModuleRoutes(moduleInfo: IModuleInfo[]) {
        const byKey = new Map(moduleInfo.map(m => [m.moduleKey, m]))
        const buildSegments = (info: IModuleInfo): string[] => {
            const segs = [info.moduleKey]
            let p = info.parent
            while (p) {
                segs.unshift(p)
                p = byKey.get(p)?.parent
            }
            return segs
        }
        moduleInfo.forEach(info => {
            if (!info.parent) return
            const segments = buildSegments(info)
            this.registerRoute({
                moduleKey: info.moduleKey,
                name: segments.join('.'),
                path: '/' + segments.join('/'),
                label: info.label,
                events: info.events,
                componentPath: segments.join('/'),
                icon: info.icon,
            })
        })
    }

    // ---- 菜单树操作 ----

    /** 获取第一个菜单路径（用于默认跳转） */
    getFirstMenuPath(): string {
        const findFirst = (items: IMenuItem[]): string | null => {
            for (const item of items) {
                if (item.path) return item.path
                if (item.moduleKey) return '/' + item.moduleKey
                if (item.children) {
                    const found = findFirst(item.children)
                    if (found) return found
                }
            }
            return null
        }
        const path = findFirst(this.menuTree)
        if (path) return path
        const top = this.moduleInfo.find(m => !m.parent)
        return '/' + (top?.moduleKey || '')
    }

    /** 根据 path 获取所在顶级菜单的索引 */
    getMenuIndex(path: string): number {
        const findIndex = (items: IMenuItem[], targetPath: string): number => {
            for (let i = 0; i < items.length; i++) {
                const item = items[i]
                if (item.path === targetPath || '/' + item.name === targetPath) return i
                if (item.children) {
                    const childIndex = findIndex(item.children, targetPath)
                    if (childIndex !== -1) return i
                }
            }
            return -1
        }
        return findIndex(this.menuTree, path)
    }

    /** 判断是否为分组菜单（有 children） */
    isGroupMenu(item?: IMenuItem): boolean {
        return item != null && item.children != null && item.children.length > 0
    }

    /** 根据 path 生成面包屑路径(支持子模块: 走 moduleInfo.parent 链) */
    getBreadcrumb(path: string): { key: string; label: ILabel; path?: string }[] {
        const result: { key: string; label: ILabel; path?: string }[] = []
        const findInMenu = (items: IMenuItem[], targetPath: string, out: typeof result): boolean => {
            for (const item of items) {
                const itemPath = item.path || '/' + item.name
                if (itemPath === targetPath) {
                    out.unshift({ key: item.name, label: item.label, path: itemPath })
                    return true
                }
                if (item.children) {
                    if (findInMenu(item.children, targetPath, out)) {
                        out.unshift({ key: item.name, label: item.label, path: item.path })
                        return true
                    }
                }
            }
            return false
        }
        if (findInMenu(this.menuTree, path, result)) return result

        // 子模块 fallback: 沿 moduleInfo.parent 链构建,带累积路径
        const segments = path.split('/').filter(Boolean)
        if (segments.length === 0) return result
        const byKey = new Map(this.moduleInfo.map(m => [m.moduleKey, m]))
        const chain: IModuleInfo[] = []
        let info = byKey.get(segments[segments.length - 1])
        while (info) {
            chain.unshift(info)
            info = info.parent ? byKey.get(info.parent) : undefined
        }
        if (chain.length === 0) return result

        // 顶层模块如果在 menu 分组下, 先把分组上下文放进来
        findInMenu(this.menuTree, '/' + chain[0].moduleKey, result)
        const lastKey = result.length > 0 ? result[result.length - 1].key : ''
        let acc = ''
        chain.forEach(m => {
            acc += '/' + m.moduleKey
            if (m.moduleKey === lastKey) return // 已被 menu 添加
            result.push({ key: m.moduleKey, label: m.label, path: acc })
        })
        return result
    }

    // ---- 模块权限 ----

    /** 获取模块的权限事件列表 */
    getEvents(moduleKey: string): string[] {
        const mod = this.moduleInfo.find(m => m.moduleKey === moduleKey)
        return mod?.events || []
    }

    /** 判断是否有某个事件的权限 */
    hasEvent(moduleKey: string, eventName: string): boolean {
        return this.getEvents(moduleKey).includes(eventName)
    }

    /** 获取绑定到指定模块的权限检查器：const can = client.can('shopAdmin'); can('apply') */
    can(moduleKey: string): (event: string) => boolean {
        return (event: string) => this.hasEvent(moduleKey, event)
    }

    // ---- 模块 API ----

    /** 获取类型安全的模块 API（带缓存,自动沿 parent 链解析嵌套模块路径） */
    getModule<P extends Record<string, any>>(moduleKey: string): P {
        let caller = this.callers.get(moduleKey)
        if (!caller) {
            const segments = this.resolveModulePath(moduleKey)
            caller = getCaller<P>(this.shrimpRequest.bind(this), segments)
            this.callers.set(moduleKey, caller)
        }
        return caller
    }

    /** 从 moduleInfo 沿 parent 链回溯出完整路径(根→自身);找不到时退化为单段 */
    private resolveModulePath(moduleKey: string): string[] {
        const byKey = new Map(this.moduleInfo.map(m => [m.moduleKey, m]))
        const info = byKey.get(moduleKey)
        if (!info) return [moduleKey]
        const segs = [info.moduleKey]
        let p = info.parent
        while (p) {
            segs.unshift(p)
            p = byKey.get(p)?.parent
        }
        return segs
    }

    /** 清除模块 API 缓存 */
    clearModuleCache(moduleKey?: string) {
        if (moduleKey) {
            this.callers.delete(moduleKey)
        } else {
            this.callers.clear()
        }
    }
}