import { prisma } from './prisma';
import { filterSelectableMaterialTypes, MATERIAL_TYPE_OPTIONS } from './material-type-options';
import { getCompatibleVideoMaterialTypes, isVideoMaterialType } from './video-material-types';

/**
 * 判断是否是超级管理员（从数据库读取）
 */
export async function isSuperAdmin(userId: string | null | undefined): Promise<boolean> {
  if (!userId) {
    return false;
  }
  
  const user = await prisma.user.findUnique({
    where: { id: userId },
    select: { isSuperAdmin: true },
  });
  
  return user?.isSuperAdmin ?? false;
}

/**
 * 同步版本的超级管理员判断（用于已经获取到用户信息的情况）
 */
export function isSuperAdminSync(isSuperAdmin: boolean): boolean {
  return isSuperAdmin;
}

/**
 * 角色权限检查辅助函数（阶段四新增）
 */

/**
 * 判断是否是系统管理员（包括ADMIN和SYSTEM_ADMIN，向后兼容）
 */
export function isSystemAdmin(role: string | null | undefined): boolean {
  if (!role) return false;
  // ADMIN 视为 SYSTEM_ADMIN（向后兼容）
  return role === 'ADMIN' || role === 'SYSTEM_ADMIN';
}

/**
 * 判断是否是部门管理员
 */
export function isDepartmentAdmin(role: string | null | undefined): boolean {
  if (!role) return false;
  return role === 'DEPT_ADMIN';
}

/**
 * 判断是否是管理员（系统管理员或部门管理员）
 */
export function isAdmin(role: string | null | undefined): boolean {
  if (!role) return false;
  // 包括所有管理员角色：ADMIN（兼容）、SYSTEM_ADMIN、DEPT_ADMIN
  return isSystemAdmin(role) || isDepartmentAdmin(role);
}

/**
 * 判断是否有系统管理权限（系统管理员或超级管理员）
 */
export function hasSystemAdminPermission(
  role: string | null | undefined,
  isSuperAdminFlag: boolean = false
): boolean {
  return isSuperAdminFlag || isSystemAdmin(role);
}

/**
 * 判断是否有部门管理权限（部门管理员、系统管理员或超级管理员）
 */
export function hasDepartmentAdminPermission(
  role: string | null | undefined,
  isSuperAdminFlag: boolean = false
): boolean {
  return isSuperAdminFlag || isSystemAdmin(role) || isDepartmentAdmin(role);
}

/**
 * 获取当前超级管理员数量
 */
export async function getSuperAdminCount(): Promise<number> {
  return await prisma.user.count({
    where: { isSuperAdmin: true },
  });
}

/**
 * 检查是否可以添加新的超级管理员（最多4个）
 */
export async function canAddSuperAdmin(): Promise<boolean> {
  const count = await getSuperAdminCount();
  return count < 4;
}

// 默认素材类型列表（作为后备，用于新部门创建默认权限配置时）
// 如果数据库中已有素材，会优先使用数据库中的素材类型
// 已按分类排序
export const DEFAULT_MATERIAL_TYPES = MATERIAL_TYPE_OPTIONS;

/**
 * 从数据库中获取所有素材类型（去重）
 */
export async function getAllMaterialTypes(): Promise<string[]> {
  try {
    // 从materials表中查询所有不重复的materialType
    const materials = await prisma.material.findMany({
      select: {
        materialType: true,
      },
      distinct: ['materialType'],
    });

    const dbTypes = materials.map((m) => m.materialType).filter(Boolean);

    // 合并数据库中的类型和默认类型，去重
    const allTypesSet = new Set([...dbTypes, ...DEFAULT_MATERIAL_TYPES]);
    
    // 按照 DEFAULT_MATERIAL_TYPES 的顺序排序，未在列表中的类型放在最后
    const sortedTypes = [
      ...DEFAULT_MATERIAL_TYPES.filter(type => allTypesSet.has(type)),
      ...Array.from(allTypesSet).filter(type => !DEFAULT_MATERIAL_TYPES.includes(type as any)).sort()
    ];

    return sortedTypes;
  } catch (error) {
    console.error('[getAllMaterialTypes] Error:', error);
    // 如果查询失败，返回默认类型列表
    return [...DEFAULT_MATERIAL_TYPES];
  }
}

export interface DepartmentPermission {
  department: string;
  materialType: string;
  canView: boolean;
  canDownload: boolean;
  canShare: boolean;
  canDownloadSource: boolean;
  linkedToDepartment: string | null;
}

async function findDepartmentPermissionRecord(
  department: string,
  materialType: string
) {
  const normalizedType = String(materialType || '').trim();
  const lookupTypes = isVideoMaterialType(normalizedType)
    ? getCompatibleVideoMaterialTypes(normalizedType)
    : [normalizedType];

  for (const lookupType of lookupTypes) {
    const permission = await prisma.departmentMaterialPermission.findUnique({
      where: {
        department_materialType: {
          department,
          materialType: lookupType,
        },
      },
    });

    if (permission) {
      return permission;
    }
  }

  return null;
}

/**
 * 获取部门的实际权限（考虑关联部门和权限继承）
 * 
 * @param department 部门名称
 * @param materialType 素材类型
 * @param departments 部门列表（用于权限继承检查，可选）
 * @param descendantMap 部门后裔映射（可选，用于加速权限继承检查）
 * @returns 部门权限配置
 */
export async function getDepartmentPermission(
  department: string,
  materialType: string,
  departments?: Array<{ id: string; name: string; parentId?: string | null }>,
  descendantMap?: Map<string, Set<string>>
): Promise<DepartmentPermission | null> {
  // 先查询当前部门的权限配置
  const permission = await findDepartmentPermissionRecord(department, materialType);

  // 如果有关联部门，从关联部门读取权限
  if (permission?.linkedToDepartment) {
    const linkedPermission = await findDepartmentPermissionRecord(
      permission.linkedToDepartment,
      materialType
    );

    if (linkedPermission) {
      return {
        department,
        materialType,
        canView: linkedPermission.canView,
        canDownload: linkedPermission.canDownload,
        canShare: linkedPermission.canShare,
        canDownloadSource: linkedPermission.canDownloadSource,
        linkedToDepartment: permission.linkedToDepartment,
      };
    }
  }

  // 如果当前部门有明确的权限配置，直接返回
  if (permission) {
    return {
      department: permission.department,
      materialType: permission.materialType,
      canView: permission.canView,
      canDownload: permission.canDownload,
      canShare: permission.canShare,
      canDownloadSource: permission.canDownloadSource,
      linkedToDepartment: permission.linkedToDepartment,
    };
  }

  // 权限继承：如果没有找到当前部门的权限配置，尝试从父部门继承
  if (departments && departments.length > 0) {
    const { buildDepartmentDescendants, isDepartmentWithinScope } = await import('@/lib/departments');

    // 构建部门映射
    const deptMap = new Map<string, { id: string; name: string; parentId?: string | null }>();
    departments.forEach(dept => {
      deptMap.set(dept.name, dept);
    });

    // 获取当前部门的父部门链
    const currentDept = deptMap.get(department);
    if (currentDept?.parentId) {
      // 查找父部门
      const parentDept = departments.find(d => d.id === currentDept.parentId);
      if (parentDept) {
        console.log(`[Permission Inheritance] 部门 ${department} 无权限配置，尝试从父部门 ${parentDept.name} 继承 ${materialType} 权限`);

        // 递归获取父部门的权限
        const parentPermission = await getDepartmentPermission(
          parentDept.name,
          materialType,
          departments,
          descendantMap
        );

        // 如果父部门有权限配置，继承父部门的权限
        if (parentPermission) {
          console.log(`[Permission Inheritance] 成功从父部门 ${parentDept.name} 继承权限: canDownload=${parentPermission.canDownload}`);
          return {
            department,
            materialType,
            canView: parentPermission.canView,
            canDownload: parentPermission.canDownload,
            canShare: parentPermission.canShare,
            canDownloadSource: parentPermission.canDownloadSource,
            linkedToDepartment: parentPermission.linkedToDepartment || parentDept.name,
          };
        } else {
          console.log(`[Permission Inheritance] 父部门 ${parentDept.name} 也没有 ${materialType} 权限配置`);
        }
      } else {
        console.log(`[Permission Inheritance] 找不到父部门 (parentId=${currentDept.parentId})`);
      }
    } else {
      console.log(`[Permission Inheritance] 部门 ${department} 没有父部门`);
    }
  }

  // 如果都没有找到，返回 null（表示没有权限配置）
  console.log(`[Permission Inheritance] 部门 ${department} 对于 ${materialType} 没有找到任何权限配置`);
  return null;
}

/**
 * 获取部门所有素材类型的权限（支持权限继承）
 * 
 * @param department 部门名称
 * @param departments 部门列表（用于权限继承检查，可选）
 * @param materialTypes 素材类型列表（可选，如果不提供则从数据库获取）
 * @returns 部门所有素材类型的权限配置
 */
export async function getDepartmentPermissions(
  department: string,
  departments?: Array<{ id: string; name: string; parentId?: string | null }>,
  materialTypes?: string[]
): Promise<Record<string, DepartmentPermission>> {
  // 如果没有提供素材类型列表，从数据库获取所有素材类型
  const allMaterialTypes = materialTypes || await getAllMaterialTypes();
  
  // 获取部门后裔映射（用于加速权限继承检查）
  const { buildDepartmentDescendants } = await import('@/lib/departments');
  const descendantMap = departments && departments.length > 0 
    ? buildDepartmentDescendants(departments)
    : undefined;

  const result: Record<string, DepartmentPermission> = {};

  // 为每种素材类型获取权限（包括继承的权限）
  for (const materialType of allMaterialTypes) {
    const permission = await getDepartmentPermission(
      department,
      materialType,
      departments,
      descendantMap
    );
    
    if (permission) {
      result[materialType] = permission;
    }
  }

  return result;
}

/**
 * 获取用户部门名称（双读：优先使用 departmentId，回退到 department）
 * 阶段二新增：支持外键关联
 */
export async function getUserDepartmentName(
  user: { department?: string | null; departmentId?: string | null; departmentRef?: { name: string } | null } | null | undefined
): Promise<string | null> {
  if (!user) {
    return null;
  }

  // 优先使用新字段（departmentId + departmentRef）
  if (user.departmentRef?.name) {
    return user.departmentRef.name;
  }

  // 回退到旧字段（department）
  return user.department || null;
}

/**
 * 获取用户有查看权限的素材类型列表（支持权限继承）
 */
export async function getUserViewableMaterialTypes(
  userDepartment: string | null | undefined,
  userRole: string,
  managedDepartment: string | null | undefined,
  userId?: string | null | undefined
): Promise<string[]> {
  // 超级管理员可以看到所有素材类型
  if (userId && await isSuperAdmin(userId)) {
    return await getAllMaterialTypes();
  }

  // 如果没有部门信息，返回空数组
  const department = managedDepartment || userDepartment;
  if (!department) {
    return [];
  }

  // 获取部门列表（用于权限继承检查）
  const departments = await prisma.department.findMany({
    select: { id: true, name: true, parentId: true },
  });

  // 获取该部门所有素材类型的权限（包括继承的权限）
  const permissions = await getDepartmentPermissions(department, departments);

  // 获取有查看权限的素材类型
  const viewableTypes = Object.values(permissions)
    .filter((p) => p.canView)
    .map((p) => p.materialType);
  
  // 按照 DEFAULT_MATERIAL_TYPES 的顺序排序
  const sortedTypes = [
    ...DEFAULT_MATERIAL_TYPES.filter(type => viewableTypes.includes(type as string)),
    ...viewableTypes.filter(type => !DEFAULT_MATERIAL_TYPES.includes(type as any)).sort()
  ];
  
  return sortedTypes;
}

/**
 * 检查用户是否有查看权限（支持权限继承）
 */
export async function canUserViewMaterial(
  userDepartment: string | null | undefined,
  userRole: string,
  managedDepartment: string | null | undefined,
  materialType: string,
  userId?: string | null | undefined
): Promise<boolean> {
  // 超级管理员可以查看所有素材
  if (userId && await isSuperAdmin(userId)) {
    return true;
  }

  // 如果没有部门信息，不允许查看
  const department = managedDepartment || userDepartment;
  if (!department) {
    return false;
  }

  // 获取部门列表（用于权限继承检查）
  const departments = await prisma.department.findMany({
    select: { id: true, name: true, parentId: true },
  });

  const permission = await getDepartmentPermission(department, materialType, departments);
  return permission?.canView ?? false;
}

/**
 * 检查用户是否有下载权限（支持权限继承）
 */
export async function canUserDownloadMaterial(
  userDepartment: string | null | undefined,
  userRole: string,
  managedDepartment: string | null | undefined,
  materialType: string,
  userId?: string | null | undefined
): Promise<boolean> {
  // 超级管理员可以下载所有素材
  if (userId && await isSuperAdmin(userId)) {
    console.log(`[Permission] 超级管理员 ${userId} 允许下载 ${materialType}`);
    return true;
  }

  // 如果没有部门信息，不允许下载
  const department = managedDepartment || userDepartment;
  if (!department) {
    console.log(`[Permission] 用户无部门信息，拒绝下载 ${materialType}`);
    return false;
  }

  // 获取部门列表（用于权限继承检查）
  const departments = await prisma.department.findMany({
    select: { id: true, name: true, parentId: true },
  });

  const permission = await getDepartmentPermission(department, materialType, departments);

  // 增强日志：记录权限检查结果
  console.log(`[Permission] 用户部门: ${department}, 素材类型: ${materialType}, 权限: ${permission?.canDownload ?? false}, 继承自: ${permission?.linkedToDepartment || '无'}`);

  return permission?.canDownload ?? false;
}

/**
 * 检查是否是分享链接访问
 */
export function isShareLinkAccess(request: Request): boolean {
  const url = new URL(request.url);
  return url.searchParams.has('share') || url.searchParams.has('shareId');
}

/**
 * 为部门创建默认权限配置
 * 使用数据库中实际存在的所有素材类型
 */
export async function createDefaultPermissionsForDepartment(
  department: string
): Promise<void> {
  const existingPermissions = await prisma.departmentMaterialPermission.findMany({
    where: { department },
  });

    const existingTypes = new Set(existingPermissions.map((p: any) => p.materialType));

  // 获取数据库中所有素材类型
  const allMaterialTypes = filterSelectableMaterialTypes(await getAllMaterialTypes());

  const newPermissions = allMaterialTypes
    .filter((type) => !existingTypes.has(type))
    .map((materialType) => ({
      department,
      materialType,
      canView: false, // 默认不允许查看
      canDownload: false, // 默认不允许下载
      canShare: true, // 默认允许分享
      linkedToDepartment: null,
    }));

  if (newPermissions.length > 0) {
    await prisma.departmentMaterialPermission.createMany({
      data: newPermissions,
    });
  }
}


/**
 * 检查用户是否有下载源文件（PSD）权限
 * 用于任务-详情类型的 PSD 下载权限控制
 */
export async function canUserDownloadSource(
  userDepartment: string | null | undefined,
  userRole: string,
  managedDepartment: string | null | undefined,
  materialType: string,
  userId?: string | null | undefined
): Promise<boolean> {
  // 超级管理员可以下载所有源文件
  if (userId && await isSuperAdmin(userId)) {
    return true;
  }

  // 如果没有部门信息，不允许下载
  const department = managedDepartment || userDepartment;
  if (!department) {
    return false;
  }

  // 查询部门权限配置
  const permission = await prisma.departmentMaterialPermission.findUnique({
    where: {
      department_materialType: {
        department,
        materialType,
      },
    },
    select: {
      canDownloadSource: true,
      linkedToDepartment: true,
    },
  });

  // 如果有关联部门，从关联部门读取权限
  if (permission?.linkedToDepartment) {
    const linkedPermission = await prisma.departmentMaterialPermission.findUnique({
      where: {
        department_materialType: {
          department: permission.linkedToDepartment,
          materialType,
        },
      },
      select: {
        canDownloadSource: true,
      },
    });
    return linkedPermission?.canDownloadSource ?? false;
  }

  return permission?.canDownloadSource ?? false;
}