package com.ctrip.framework.apollo.portal.service;

import com.google.common.base.Preconditions;
import com.google.common.base.Splitter;
import com.google.common.base.Strings;
import com.google.common.collect.FluentIterable;
import com.google.common.collect.HashMultimap;
import com.google.common.collect.Lists;
import com.google.common.collect.Multimap;
import com.google.common.collect.Sets;

import com.ctrip.framework.apollo.portal.entity.po.Permission;
import com.ctrip.framework.apollo.portal.entity.po.Role;
import com.ctrip.framework.apollo.portal.entity.po.RolePermission;
import com.ctrip.framework.apollo.portal.entity.po.UserInfo;
import com.ctrip.framework.apollo.portal.entity.po.UserRole;
import com.ctrip.framework.apollo.portal.repository.PermissionRepository;
import com.ctrip.framework.apollo.portal.repository.RolePermissionRepository;
import com.ctrip.framework.apollo.portal.repository.RoleRepository;
import com.ctrip.framework.apollo.portal.repository.UserRoleRepository;

import org.springframework.beans.factory.InitializingBean;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.util.CollectionUtils;

import java.util.Collection;
import java.util.Collections;
import java.util.Date;
import java.util.List;
import java.util.Set;

/**
 * @author Jason Song(song_s@ctrip.com)
 */
@Service
public class RolePermissionService implements InitializingBean {

  @Autowired
  private RoleRepository roleRepository;
  @Autowired
  private RolePermissionRepository rolePermissionRepository;
  @Autowired
  private UserRoleRepository userRoleRepository;
  @Autowired
  private PermissionRepository permissionRepository;
  @Autowired
  private ServerConfigService serverConfigService;


  private List<String> superAdminUsers;
  private Splitter configSplitter;

  public RolePermissionService() {
    superAdminUsers = Lists.newArrayList();
    configSplitter = Splitter.on(",").omitEmptyStrings().trimResults();
  }

  /**
   * Create role with permissions, note that role name should be unique
   */
  @Transactional
  public Role createRoleWithPermissions(Role role, Set<Long> permissionIds) {
    Role current = findRoleByRoleName(role.getRoleName());
    Preconditions.checkState(current == null, "Role %s already exists!", role.getRoleName());

    Role createdRole = roleRepository.save(role);

    if (!CollectionUtils.isEmpty(permissionIds)) {
      Iterable<RolePermission> rolePermissions = FluentIterable.from(permissionIds).transform(
          permissionId -> {
            RolePermission rolePermission = new RolePermission();
            rolePermission.setRoleId(createdRole.getId());
            rolePermission.setPermissionId(permissionId);
            rolePermission.setDataChangeCreatedBy(createdRole.getDataChangeCreatedBy());
            rolePermission.setDataChangeLastModifiedBy(createdRole.getDataChangeLastModifiedBy());
            return rolePermission;
          });
      rolePermissionRepository.save(rolePermissions);
    }

    return createdRole;
  }

  /**
   * Assign role to users
   *
   * @return the users assigned roles
   */
  @Transactional
  public Set<String> assignRoleToUsers(String roleName, Set<String> userIds,
                                       String operatorUserId) {
    Role role = findRoleByRoleName(roleName);
    Preconditions.checkState(role != null, "Role %s doesn't exist!", roleName);

    List<UserRole> existedUserRoles =
        userRoleRepository.findByUserIdInAndRoleId(userIds, role.getId());
    Set<String> existedUserIds =
        FluentIterable.from(existedUserRoles).transform(userRole -> userRole.getUserId()).toSet();

    Set<String> toAssignUserIds = Sets.difference(userIds, existedUserIds);

    Iterable<UserRole> toCreate = FluentIterable.from(toAssignUserIds).transform(userId -> {
      UserRole userRole = new UserRole();
      userRole.setRoleId(role.getId());
      userRole.setUserId(userId);
      userRole.setDataChangeCreatedBy(operatorUserId);
      userRole.setDataChangeLastModifiedBy(operatorUserId);
      return userRole;
    });

    userRoleRepository.save(toCreate);
    return toAssignUserIds;
  }

  /**
   * Remove role from users
   */
  @Transactional
  public void removeRoleFromUsers(String roleName, Set<String> userIds, String operatorUserId) {
    Role role = findRoleByRoleName(roleName);
    Preconditions.checkState(role != null, "Role %s doesn't exist!", roleName);

    List<UserRole> existedUserRoles =
        userRoleRepository.findByUserIdInAndRoleId(userIds, role.getId());

    for (UserRole userRole : existedUserRoles) {
      userRole.setDeleted(true);
      userRole.setDataChangeLastModifiedTime(new Date());
      userRole.setDataChangeLastModifiedBy(operatorUserId);
    }

    userRoleRepository.save(existedUserRoles);
  }

  /**
   * Query users with role
   */
  public Set<UserInfo> queryUsersWithRole(String roleName) {
    Role role = findRoleByRoleName(roleName);

    if (role == null) {
      return Collections.emptySet();
    }

    List<UserRole> userRoles = userRoleRepository.findByRoleId(role.getId());

    Set<UserInfo> users = FluentIterable.from(userRoles).transform(userRole -> {
      UserInfo userInfo = new UserInfo();
      userInfo.setUserId(userRole.getUserId());
      return userInfo;
    }).toSet();

    return users;
  }

  /**
   * Find role by role name, note that roleName should be unique
   */
  public Role findRoleByRoleName(String roleName) {
    return roleRepository.findTopByRoleName(roleName);
  }

  /**
   * Check whether user has the permission
   */
  public boolean userHasPermission(String userId, String permissionType, String targetId) {
    Permission permission =
        permissionRepository.findTopByPermissionTypeAndTargetId(permissionType, targetId);
    if (permission == null) {
      return false;
    }

    if (isSuperAdmin(userId)) {
      return true;
    }

    List<UserRole> userRoles = userRoleRepository.findByUserId(userId);
    if (CollectionUtils.isEmpty(userRoles)) {
      return false;
    }

    Set<Long> roleIds =
        FluentIterable.from(userRoles).transform(userRole -> userRole.getRoleId()).toSet();
    List<RolePermission> rolePermissions = rolePermissionRepository.findByRoleIdIn(roleIds);
    if (CollectionUtils.isEmpty(rolePermissions)) {
      return false;
    }

    for (RolePermission rolePermission : rolePermissions) {
      if (rolePermission.getPermissionId() == permission.getId()) {
        return true;
      }
    }

    return false;
  }

  public boolean isSuperAdmin(String userId) {
    return superAdminUsers.contains(userId);
  }

  /**
   * Create permission, note that permissionType + targetId should be unique
   */
  @Transactional
  public Permission createPermission(Permission permission) {
    String permissionType = permission.getPermissionType();
    String targetId = permission.getTargetId();
    Permission current =
        permissionRepository.findTopByPermissionTypeAndTargetId(permissionType, targetId);
    Preconditions.checkState(current == null,
        "Permission with permissionType %s targetId %s already exists!", permissionType, targetId);

    return permissionRepository.save(permission);
  }

  /**
   * Create permissions, note that permissionType + targetId should be unique
   */
  @Transactional
  public Set<Permission> createPermissions(Set<Permission> permissions) {
    Multimap<String, String> targetIdPermissionTypes = HashMultimap.create();
    for (Permission permission : permissions) {
      targetIdPermissionTypes.put(permission.getTargetId(), permission.getPermissionType());
    }

    for (String targetId : targetIdPermissionTypes.keySet()) {
      Collection<String> permissionTypes = targetIdPermissionTypes.get(targetId);
      List<Permission> current =
          permissionRepository.findByPermissionTypeInAndTargetId(permissionTypes, targetId);
      Preconditions.checkState(CollectionUtils.isEmpty(current),
          "Permission with permissionType %s targetId %s already exists!", permissionTypes,
          targetId);
    }

    Iterable<Permission> results = permissionRepository.save(permissions);
    return FluentIterable.from(results).toSet();
  }

  @Override
  public void afterPropertiesSet() throws Exception {
    String superAdminConfig = serverConfigService.getValue("superAdmin");
    if (Strings.isNullOrEmpty(superAdminConfig)) {
      return;
    }
    superAdminUsers = configSplitter.splitToList(superAdminConfig);
  }
}
