/**
 * 路由权限配置表（对齐 CICD 项目 route-permissions.ts）
 *
 * 4 张表按优先级顺序匹配（精确 > 前缀 > 仪表盘 > API）：
 * 1. EXACT_ROUTE_PERMISSIONS：精确路由（如 /shell/admin/users）
 * 2. PREFIX_ROUTE_PERMISSIONS：前缀路由（如 /shell/admin/*）
 * 3. DASHBOARD_ROUTE_PERMISSIONS：仪表盘路由（按角色分发）
 * 4. API_ROUTE_PERMISSIONS：Next.js API Route（/api/*）
 *
 * 三层安全边界（portal-shell README v2.0 §3.3）：
 * - L1 角色门禁：requiredRoles（4 角色之一）
 * - L2 权限点门禁：requiredPermissions（AND 语义，必须全部满足）
 * - L3 数据范围：运行时由插件/page 内 usePermission 校验
 *
 * 使用方式（middleware / page / layout）：
 * ```ts
 * import { checkRoutePermission } from "@/shared/lib/route-permissions";
 *
 * const result = checkRoutePermission(pathname, userBitmap, userRole);
 * if (!result.allowed) redirect("/shell/forbidden");
 * ```
 *
 * 关联：portal-shell README v2.0 §3.3、project_rules §3.1（禁止 role === "xxx" 硬编码）
 */

import type { Role } from "@edu/shared-ts/contracts";
import {
  hasAllPermissionsInBitmap,
  hasAnyPermissionInBitmap,
  isValidPermission,
} from "@edu/shared-ts/permission-bitmap";

/**
 * 路由权限配置项
 */
export interface RoutePermissionConfig {
  /** 所需角色（任一满足即可；空数组表示不限制角色） */
  requiredRoles?: Role[];
  /**
   * 所需权限点（AND 语义，必须全部满足）
   * 权限点必须来自 PERMISSION_BITMAP_ORDER
   */
  requiredPermissions?: string[];
  /**
   * 所需权限点（OR 语义，任一满足即可）
   * 与 requiredPermissions 同时存在时，先 AND 再 OR
   */
  anyOfPermissions?: string[];
}

/**
 * 路由权限检查结果
 */
export interface RoutePermissionResult {
  /** 是否允许访问 */
  allowed: boolean;
  /** 拒绝原因（allowed=false 时填充） */
  reason?: "missing_role" | "missing_permission" | "no_config";
  /** 匹配到的配置（用于调试） */
  matchedPath?: string;
  /** 缺失的权限点（allowed=false 且 reason=missing_permission 时填充） */
  missingPermissions?: string[];
}

/**
 * 1. 精确路由权限表
 *
 * 高优先级，pathname 完全匹配时生效。
 * 适用于功能明确、URL 固定的页面（用户管理、RBAC、审计日志等）。
 */
export const EXACT_ROUTE_PERMISSIONS: Record<string, RoutePermissionConfig> = {
  // ── admin 专属 ────────────────────────────────────────────
  "/shell/admin/users": {
    requiredRoles: ["admin"],
    requiredPermissions: ["USER_MANAGE"],
  },
  "/shell/admin/roles": {
    requiredRoles: ["admin"],
    requiredPermissions: ["ROLE_MANAGE"],
  },
  "/shell/admin/permissions": {
    requiredRoles: ["admin"],
    requiredPermissions: ["PERMISSION_MANAGE"],
  },
  "/shell/admin/audit-logs": {
    requiredRoles: ["admin"],
    requiredPermissions: ["AUDIT_LOG_READ"],
  },
  "/shell/admin/school": {
    requiredRoles: ["admin"],
    requiredPermissions: ["SCHOOL_MANAGE"],
  },
  "/shell/admin/plugins": {
    requiredRoles: ["admin"],
    requiredPermissions: ["PLUGIN_REGISTRY_MANAGE"],
  },
  "/shell/admin/invitation-codes": {
    requiredRoles: ["admin"],
    anyOfPermissions: ["INVITATION_CODE_MANAGE", "INVITATION_CODE_CREATE"],
  },
  // P1-1：列表页根路由（无尾斜杠）需在 EXACT 表登记，
  // 否则 middleware checkRoutePermission 落入 /shell/** catch-all 拒绝
  "/shell/admin/announcements": {
    requiredRoles: ["admin"],
    requiredPermissions: ["ANNOUNCEMENT_MANAGE"],
  },
  "/shell/admin/classes": {
    requiredRoles: ["admin"],
    anyOfPermissions: ["CLASS_READ", "CLASS_MANAGE"],
  },

  // ── teacher 专属 ──────────────────────────────────────────
  "/shell/teacher/lesson-plans": {
    requiredRoles: ["teacher"],
    anyOfPermissions: [
      "LESSON_PLAN_READ",
      "LESSON_PLAN_CREATE",
      "LESSON_PLAN_UPDATE",
    ],
  },
  "/shell/teacher/question-bank": {
    requiredRoles: ["teacher"],
    anyOfPermissions: ["QUESTION_READ", "QUESTION_CREATE"],
  },
  "/shell/teacher/textbooks": {
    requiredRoles: ["teacher", "admin"],
    requiredPermissions: ["TEXTBOOK_READ"],
  },
  "/shell/teacher/scheduling-rules": {
    requiredRoles: ["teacher", "admin"],
    anyOfPermissions: ["SCHEDULE_AUTO", "SCHEDULE_ADJUST", "SCHEDULE_MANAGE"],
  },
  // P1-1：列表页根路由（无尾斜杠）需在 EXACT 表登记，
  // 与 PREFIX 表（带尾斜杠，匹配子路由如 /shell/teacher/exams/123）互补
  "/shell/teacher/exams": {
    requiredRoles: ["teacher", "admin"],
    anyOfPermissions: ["EXAM_READ", "EXAM_CREATE", "EXAM_UPDATE", "EXAM_GRADE"],
  },
  "/shell/teacher/homework": {
    requiredRoles: ["teacher", "admin"],
    anyOfPermissions: ["HOMEWORK_READ", "HOMEWORK_CREATE", "HOMEWORK_GRADE"],
  },
  "/shell/teacher/grades": {
    requiredRoles: ["teacher", "admin"],
    anyOfPermissions: ["GRADE_RECORD_MANAGE", "GRADE_RECORD_READ"],
  },
  "/shell/teacher/attendance": {
    requiredRoles: ["teacher", "admin"],
    anyOfPermissions: ["ATTENDANCE_READ", "ATTENDANCE_MANAGE"],
  },
  "/shell/teacher/diagnostics": {
    requiredRoles: ["teacher", "admin"],
    anyOfPermissions: ["DIAGNOSTIC_READ", "DIAGNOSTIC_MANAGE"],
  },

  // ── student 专属 ──────────────────────────────────────────
  "/shell/student/error-book": {
    requiredRoles: ["student"],
    requiredPermissions: ["ERROR_BOOK_READ"],
  },
  "/shell/student/learning-path": {
    requiredRoles: ["student"],
    requiredPermissions: ["LEARNING_PATH_READ"],
  },
  "/shell/student/electives": {
    requiredRoles: ["student"],
    anyOfPermissions: ["ELECTIVE_READ", "ELECTIVE_SELECT"],
  },
  "/shell/student/ai-tutor": {
    requiredRoles: ["student"],
    requiredPermissions: ["AI_TUTOR_USE"],
  },

  // ── parent 专属 ───────────────────────────────────────────
  "/shell/parent/children": {
    requiredRoles: ["parent"],
    requiredPermissions: ["GRADE_READ_CHILD"],
  },
  "/shell/parent/leave-approval": {
    requiredRoles: ["parent"],
    requiredPermissions: ["LEAVE_APPROVAL_MANAGE"],
  },
};

/**
 * 2. 前缀路由权限表
 *
 * 中优先级，pathname 以指定前缀开头时生效。
 * 适用于功能集合下的所有子路由（/shell/admin/* /shell/teacher/exams/* 等）。
 *
 * 注意：前缀必须以 / 结尾，避免误匹配（如 /shell/admin 不能匹配 /shell/admin-users）。
 */
export const PREFIX_ROUTE_PERMISSIONS: Array<{
  prefix: string;
  config: RoutePermissionConfig;
}> = [
  // admin 区所有子路由默认要求 admin 角色
  {
    prefix: "/shell/admin/",
    config: { requiredRoles: ["admin"] },
  },
  // 考试管理
  {
    prefix: "/shell/teacher/exams/",
    config: {
      requiredRoles: ["teacher", "admin"],
      anyOfPermissions: [
        "EXAM_READ",
        "EXAM_CREATE",
        "EXAM_UPDATE",
        "EXAM_GRADE",
      ],
    },
  },
  // 作业管理
  {
    prefix: "/shell/teacher/homework/",
    config: {
      requiredRoles: ["teacher", "admin"],
      anyOfPermissions: ["HOMEWORK_READ", "HOMEWORK_CREATE", "HOMEWORK_GRADE"],
    },
  },
  // 教案管理（P2 迁移）
  {
    prefix: "/shell/teacher/lesson-plans/",
    config: {
      requiredRoles: ["teacher", "admin"],
      anyOfPermissions: [
        "LESSON_PLAN_READ",
        "LESSON_PLAN_CREATE",
        "LESSON_PLAN_UPDATE",
      ],
    },
  },
  // 成绩录入
  {
    prefix: "/shell/teacher/grades/",
    config: {
      requiredRoles: ["teacher", "admin"],
      anyOfPermissions: ["GRADE_RECORD_MANAGE", "GRADE_RECORD_READ"],
    },
  },
  // 考勤
  {
    prefix: "/shell/teacher/attendance/",
    config: {
      requiredRoles: ["teacher", "admin"],
      anyOfPermissions: ["ATTENDANCE_READ", "ATTENDANCE_MANAGE"],
    },
  },
  // 班级管理
  {
    prefix: "/shell/admin/classes/",
    config: {
      requiredRoles: ["admin"],
      anyOfPermissions: ["CLASS_READ", "CLASS_MANAGE"],
    },
  },
  // 学情诊断
  {
    prefix: "/shell/teacher/diagnostics/",
    config: {
      requiredRoles: ["teacher", "admin"],
      anyOfPermissions: ["DIAGNOSTIC_READ", "DIAGNOSTIC_MANAGE"],
    },
  },
  // 公告管理
  {
    prefix: "/shell/admin/announcements/",
    config: {
      requiredRoles: ["admin"],
      requiredPermissions: ["ANNOUNCEMENT_MANAGE"],
    },
  },
  // P1-3：dev 模板预览页（仅登录可访问，运行时由 notFound() 拒绝生产访问）
  // ARCHITECTURE.md §10 P1-3：/shell/dev/templates/* 仅 dev 可见
  // 注：Next.js 私有文件夹以 _ 开头会被排除路由，故使用 `dev` 而非 `_dev`
  {
    prefix: "/shell/dev/",
    config: {}, // 空 config = 仅校验登录身份
  },
];

/**
 * 3. 仪表盘路由权限表
 *
 * 低优先级，按角色分发的根仪表盘。
 * 当 pathname 不匹配前两张表时，检查是否为角色仪表盘根路径。
 */
export const DASHBOARD_ROUTE_PERMISSIONS: Record<
  string,
  RoutePermissionConfig
> = {
  "/shell/admin": {
    requiredRoles: ["admin"],
    requiredPermissions: ["DASHBOARD_ADMIN_READ"],
  },
  "/shell/teacher": {
    requiredRoles: ["teacher"],
    requiredPermissions: ["DASHBOARD_TEACHER_READ"],
  },
  "/shell/student": {
    requiredRoles: ["student"],
    requiredPermissions: ["DASHBOARD_STUDENT_READ"],
  },
  "/shell/parent": {
    requiredRoles: ["parent"],
    requiredPermissions: ["DASHBOARD_PARENT_READ"],
  },
  // 通用仪表盘
  "/shell": {
    requiredPermissions: ["DASHBOARD_READ"],
  },
};

/**
 * 4. Next.js API Route 权限表
 *
 * 用于 /api/* 路径的权限校验。
 * 注意：API Route 通常需要更严格的权限校验，因为它们直接操作数据。
 *
 * P0-2（ARCHITECTURE.md §6.2 §3.4 V3-A3）：新增 auth/graphql 公开端点。
 */
export const API_ROUTE_PERMISSIONS: Record<string, RoutePermissionConfig> = {
  // 错误上报端点：所有登录用户可访问（空 config 表示登录即可）
  "/api/log": {},
  // 健康检查：公开
  "/api/healthz": {},
  "/api/health": {},
  "/api/ready": {},
  // 认证端点：公开（未登录也要能调登录接口）
  "/api/auth/login": {},
  "/api/auth/logout": {},
  // GraphQL 同域代理：登录即可（细粒度由后端 resolver 把关）
  "/api/graphql": {},
};

/**
 * 5. 公共路由白名单（P0-2，ARCHITECTURE.md §6.2 §3.4 V3-A3 / §11.7 红线 #5）
 *
 * 这些路由允许匿名访问（登录前/无身份也能访问）。
 * middleware 对白名单路由跳过身份校验，直接放行。
 *
 * 注意：白名单外的路由，未登录访问 → middleware 重定向到 /login。
 */
export const PUBLIC_ROUTES: readonly string[] = [
  "/",
  "/login",
  "/shell/forbidden",
  "/api/health",
  "/api/healthz",
  "/api/ready",
  "/api/log",
  "/api/auth/login",
  "/api/auth/logout",
  "/api/graphql",
];

/**
 * 校验权限配置的合法性（开发时辅助）
 *
 * 检查所有声明的权限点是否在 PERMISSION_BITMAP_ORDER 中。
 * 在 dev 模式下打 warning，生产构建时可阻断。
 *
 * @returns 非法权限点列表（空数组表示全部合法）
 */
export function validateRoutePermissionConfigs(): string[] {
  const invalid: string[] = [];
  const allConfigs: Array<{ source: string; config: RoutePermissionConfig }> = [
    ...Object.entries(EXACT_ROUTE_PERMISSIONS).map(([path, config]) => ({
      source: `EXACT:${path}`,
      config,
    })),
    ...PREFIX_ROUTE_PERMISSIONS.map(({ prefix, config }) => ({
      source: `PREFIX:${prefix}`,
      config,
    })),
    ...Object.entries(DASHBOARD_ROUTE_PERMISSIONS).map(([path, config]) => ({
      source: `DASHBOARD:${path}`,
      config,
    })),
    ...Object.entries(API_ROUTE_PERMISSIONS).map(([path, config]) => ({
      source: `API:${path}`,
      config,
    })),
  ];

  for (const { source, config } of allConfigs) {
    for (const perm of config.requiredPermissions ?? []) {
      if (!isValidPermission(perm)) {
        invalid.push(`${source}:requiredPermissions:${perm}`);
      }
    }
    for (const perm of config.anyOfPermissions ?? []) {
      if (!isValidPermission(perm)) {
        invalid.push(`${source}:anyOfPermissions:${perm}`);
      }
    }
  }

  return invalid;
}

/**
 * 路由权限检查主函数
 *
 * 按优先级顺序匹配 4 张表，返回检查结果。
 *
 * @param pathname 当前路径（如 /shell/admin/users）
 * @param userBitmap 用户权限位图（base36 字符串，从 JWT cookie 解析）
 * @param userRole 用户角色
 * @returns 检查结果，allowed=true 表示放行
 *
 * @example
 * ```ts
 * const result = checkRoutePermission("/shell/admin/users", "abc123", "admin");
 * if (!result.allowed) {
 *   redirect("/shell/forbidden");
 * }
 * ```
 */
export function checkRoutePermission(
  pathname: string,
  userBitmap: string,
  userRole: Role,
): RoutePermissionResult {
  // 0. 公共路由白名单优先（含 /shell/forbidden 自身，避免循环重定向）
  if (PUBLIC_ROUTES.includes(pathname)) {
    return { allowed: true, matchedPath: "PUBLIC" };
  }

  // 1. 匹配精确路由
  const exactConfig = EXACT_ROUTE_PERMISSIONS[pathname];
  if (exactConfig) {
    return evaluateConfig(exactConfig, userBitmap, userRole, pathname);
  }

  // 2. 匹配前缀路由
  for (const { prefix, config } of PREFIX_ROUTE_PERMISSIONS) {
    if (pathname.startsWith(prefix)) {
      return evaluateConfig(config, userBitmap, userRole, prefix);
    }
  }

  // 3. 匹配仪表盘路由
  const dashboardConfig = DASHBOARD_ROUTE_PERMISSIONS[pathname];
  if (dashboardConfig) {
    return evaluateConfig(dashboardConfig, userBitmap, userRole, pathname);
  }

  // 4. 匹配 API 路由
  if (pathname.startsWith("/api/")) {
    const apiConfig = API_ROUTE_PERMISSIONS[pathname];
    if (apiConfig) {
      return evaluateConfig(apiConfig, userBitmap, userRole, pathname);
    }
    // 未配置的 API 路由默认拒绝（fail-closed，§11.7 红线 #5）
    return {
      allowed: false,
      reason: "no_config",
    };
  }

  // 5. /shell/** 下未登记路由 → 默认拒绝（fail-closed，§3.4 V3-A3 / §11.7 红线 #5）
  //    防止"幽灵路由"绕过门禁；新增路由必须显式登记到 EXACT/PREFIX/DASHBOARD 表
  if (pathname.startsWith("/shell/") || pathname === "/shell") {
    return {
      allowed: false,
      reason: "no_config",
    };
  }

  // 6. 其他未匹配路由（如 /favicon.ico / 静态资源）默认放行
  return { allowed: true };
}

/**
 * 评估单个权限配置
 */
function evaluateConfig(
  config: RoutePermissionConfig,
  userBitmap: string,
  userRole: Role,
  matchedPath: string,
): RoutePermissionResult {
  // L1 角色门禁
  if (config.requiredRoles && config.requiredRoles.length > 0) {
    if (!config.requiredRoles.includes(userRole)) {
      return {
        allowed: false,
        reason: "missing_role",
        matchedPath,
      };
    }
  }

  // L2 权限点门禁 - AND 语义
  const missingPermissions: string[] = [];
  if (config.requiredPermissions && config.requiredPermissions.length > 0) {
    for (const perm of config.requiredPermissions) {
      // 使用 hasAllPermissionsInBitmap 不合适（它返回 boolean 不告知哪些缺失）
      // 这里手动遍历以便收集缺失项
      const bit = hasPermissionInBitmapSimple(userBitmap, perm);
      if (!bit) {
        missingPermissions.push(perm);
      }
    }
    if (missingPermissions.length > 0) {
      return {
        allowed: false,
        reason: "missing_permission",
        matchedPath,
        missingPermissions,
      };
    }
  }

  // L2 权限点门禁 - OR 语义
  if (config.anyOfPermissions && config.anyOfPermissions.length > 0) {
    if (!hasAnyPermissionInBitmap(userBitmap, config.anyOfPermissions)) {
      return {
        allowed: false,
        reason: "missing_permission",
        matchedPath,
        missingPermissions: config.anyOfPermissions,
      };
    }
  }

  return { allowed: true, matchedPath };
}

/**
 * 简化版单权限检查（避免循环依赖 hasAllPermissionsInBitmap）
 *
 * 直接调用 hasAllPermissionsInBitmap 检查单个权限点
 */
function hasPermissionInBitmapSimple(
  bitmap: string,
  permission: string,
): boolean {
  return hasAllPermissionsInBitmap(bitmap, [permission]);
}

/**
 * 批量检查用户是否拥有所有指定路由的访问权限
 *
 * 用于侧边栏导航项过滤：一次性检查多个路由，避免重复调用。
 *
 * @param paths 路径列表
 * @param userBitmap 用户权限位图
 * @param userRole 用户角色
 * @returns 路径 → 是否允许 的映射
 */
export function batchCheckRoutePermission(
  paths: readonly string[],
  userBitmap: string,
  userRole: Role,
): Record<string, boolean> {
  const result: Record<string, boolean> = {};
  for (const path of paths) {
    result[path] = checkRoutePermission(path, userBitmap, userRole).allowed;
  }
  return result;
}