find consolidated permissions

find permissions

# # There are many users, many roles, and many modules in  a system
# # - 1 User can have multipple roles
# # - 1 role can have permission to multiple module

# # The task is to simplify the data of user and roles into single JSON object 

# # explanation :
# let roles = [
#     {
#         name: 'access-manager',
#         modulePermsiion : {
#             'role_management' : ['read', 'write'],
#             'content_management' : ['update']
#             # can have more module and their permission
#         }
#     },
#     {
#         name: 'content-manager',
#         modulePermsiion : {
#             'content_management' : ['read', 'write']
#             # can have more module and their permission
#         }
#     }
# ]

# let users = {
#     name: 'meraj',
#     roles: ['access-manager', 'content-manager']
# } 

# # Write a program to take the above inputs  and give a simplified output  as given in below example
# let output =  {
#     name: 'meraj',
#     modulePermsiion: {
#          'content_management' : ['read', 'write', 'update'],
#          'role_management' : ['read', 'write']
#     }
# }

ROLES = [
          {
            :name=>"access-manager", 
            :modulePermsiion=>{:role_management=>["read", "write"], :content_management=>["update"]}
          },                                                                    
          {
            :name=>"content-manager", 
            :modulePermsiion=>{:content_management=>["read", "write"]}
          }
        ]

def permissions(user)
  users_permissions = ROLES.select{|r| user[:roles].include?(r[:name])}
                           .collect{|r| r[:modulePermsiion]}
                           .inject({}) do |result, element| 
                             result.merge(element){|key, a_item, b_item| (a_item || [])+(b_item||[])}
                           end
  {name: user[:name], modulePermsiion: users_permissions}
end

user = {:name=>"meraj", :roles=>["access-manager", "content-manager"]}
permissions(user)