/**
 * 把 ShrimpServer 内联的 Express routes 抽成纯函数。
 *
 * routes 完全不知道:
 *   - 数据库类型(只通过 dataSource 抽象访问)
 *   - JWT(只通过 ITokenAuth 注入)
 *   - 自己的字段名(通过 IUserAccessor 适配)
 */

import { Router, Request, Response, NextFunction } from "express"
import { Shrimp } from "../Shrimp/Shrimp"
import { ShrimpCode, IMeResult, IShrimpOperator, ShrimpError } from "../IShrimpType"
import type { IShrimpRouterDeps } from "./types"

declare global {
    namespace Express {
        interface Request {
            user: { _id: string; name: string; power: Set<string>; roleId: string[]; isSuperAdmin: boolean }
        }
    }
}

export function buildShrimpRouter(deps: IShrimpRouterDeps): Router {
    const {
        shrimp, userModule, roleModule, operationLogModule,
        tokenAuth, config, globalOptions, forcedOptionAccess, userAccessor,
    } = deps

    const router = Router()

    router.get("/config", (_req: Request, res: Response) => {
        res.json(shrimp.success(config))
    })

    router.post("/login", async (req: Request, res: Response) => {
        const ip = req.ip || ""
        const { username, password } = req.body
        const args = [{ username, password }]
        try {
            const user = await userModule.getUser(username, password)
            const token = tokenAuth.sign(userAccessor.getJwtPayload(user))
            operationLogModule.record(user._id, ip, ["login"], args, true)
            res.json(shrimp.success({ token }))
        } catch (error: any) {
            const msg = error instanceof ShrimpError ? error.tip : { t: "shrimp.loginFailed" }
            const errMsg = error instanceof ShrimpError ? JSON.stringify(error.tip) : (error?.message || "")
            operationLogModule.record(null, ip, ["login"], args, false, errMsg)
            res.json(shrimp.fail(ShrimpCode.FAIL, msg))
        }
    })

    router.use(async (req: Request, res: Response, next: NextFunction) => {
        try {
            const auth = req.headers.authorization
            if (!auth || !auth.startsWith("Bearer ")) {
                return res.json(shrimp.fail(ShrimpCode.UNAUTHORIZED, { t: "shrimp.relogin" }, "No token"))
            }
            const token = auth.split(" ")[1]
            const decoded = tokenAuth.verify(token)
            const user = await userModule.dataSource.get(decoded._id)
            if (!user || !userAccessor.isUserActive(user)) {
                return res.json(shrimp.fail(ShrimpCode.UNAUTHORIZED, { t: "shrimp.userDisabled" }, "User disabled"))
            }
            const roleIds = userAccessor.getUserRoleIds(user)
            const roles = await Promise.all(roleIds.map(id => roleModule.dataSource.get(id)))
            const isSuperAdmin = roles.some(r => userAccessor.isRoleSuperAdmin(r))
            const powers = isSuperAdmin
                ? new Set((await shrimp.allPower()).map(p => p.key))
                : new Set(roles.flatMap(r => userAccessor.getRolePowers(r)))
            req.user = { _id: user._id, name: userAccessor.getUserDisplayName(user), power: powers, roleId: roleIds, isSuperAdmin }
            next()
        } catch (error: any) {
            const msg = error instanceof ShrimpError ? error.tip : { t: "shrimp.relogin" }
            return res.json(shrimp.fail(ShrimpCode.UNAUTHORIZED, msg))
        }
    })

    router.get("/me", async (req: Request, res: Response) => {
        try {
            const moduleInfo = await userModule.getModule(req.user._id, roleModule)
            const user = await userModule.dataSource.get(req.user._id)
            if (!user) {
                return res.json(shrimp.fail(ShrimpCode.NOT_FOUND, { t: "shrimp.userNotFound" }))
            }
            const roleIds = userAccessor.getUserRoleIds(user)
            const roles = await Promise.all(roleIds.map(id => roleModule.dataSource.get(id)))
            const isSuperAdmin = roles.some(r => userAccessor.isRoleSuperAdmin(r))
            const powers = isSuperAdmin
                ? (await shrimp.allPower()).map(p => p.key)
                : roles.flatMap(r => userAccessor.getRolePowers(r))
            const filteredMenuTree = shrimp.filterMenuTree(shrimp.getMenuTree(), powers)
            const neededKeys = new Set<string>()
            for (const mod of moduleInfo) {
                for (const field of mod.fields || []) {
                    if (typeof field.options === "string") {
                        neededKeys.add(field.options)
                    }
                }
            }
            const filteredOptions: Record<string, any> = {}
            for (const key of neededKeys) {
                if (globalOptions[key] != null) {
                    filteredOptions[key] = globalOptions[key]
                }
            }
            for (const [key, access] of forcedOptionAccess) {
                if (globalOptions[key] != null) {
                    if (isSuperAdmin || powers.includes(access.powerKey)) {
                        filteredOptions[key] = globalOptions[key]
                    }
                }
            }
            res.setHeader("Cache-Control", "no-store, no-cache, must-revalidate")
            res.json(shrimp.success<IMeResult>({
                nickname: userAccessor.getUserDisplayName(user),
                moduleInfo,
                menuTree: filteredMenuTree,
                options: filteredOptions,
            }))
        } catch (error: any) {
            if (error instanceof ShrimpError) {
                res.json(shrimp.fail(error.code, error.tip))
            } else {
                res.json(shrimp.fail(ShrimpCode.FAIL, { t: "shrimp.serverError" }, error.message))
            }
        }
    })

    router.post("/*path", async (req: Request, res: Response) => {
        const raw = req.params.path
        const path = (Array.isArray(raw) ? raw.join("/") : raw).split("/").filter(Boolean)
        const args = Array.isArray(req.body) ? req.body : [req.body]
        const ip = req.ip || ""
        const shouldLog = operationLogModule.shouldLog(path)
        try {
            if (path.length === 0) {
                return res.json(shrimp.fail(ShrimpCode.FAIL, { t: "shrimp.emptyPath" }))
            }
            const powers = req.user.power
            if (!shrimp.checkEvent(powers, path)) {
                return res.json(shrimp.fail(ShrimpCode.FORBIDDEN, { t: "shrimp.forbidden" }))
            }
            const operator: IShrimpOperator = {
                userId: req.user._id,
                roleId: req.user.roleId,
                isSuperAdmin: req.user.isSuperAdmin,
            }
            const result = await Shrimp.asyncLocalStorage.run(operator, () => shrimp.call(path, ...args))
            if (shouldLog) operationLogModule.record(req.user._id, ip, path, args, true)
            res.json(shrimp.success(result))
        } catch (error: any) {
            if (shouldLog) {
                const errMsg = error instanceof ShrimpError ? JSON.stringify(error.tip) : (error?.message || "")
                operationLogModule.record(req.user?._id ?? null, ip, path, args, false, errMsg)
            }
            if (error instanceof ShrimpError) {
                res.json(shrimp.fail(error.code, error.tip))
            } else {
                res.json(shrimp.fail(ShrimpCode.SERVER_ERROR, { t: "shrimp.serverError" }, error.message))
            }
        }
    })

    return router
}