database.rules.json

{
  "rules": {
    //".write" : true,
    //".read":true,
      "bets":{
        ".read":true,
        "$match":{
          "$userBet":{
            
            //loggedIn user takes the bet && there is no bet already && in time && has enough coins && email verified
        		".write": "auth.uid === $userBet && !data.exists() && root.child('matches/'+$match+'/begin_at').val()>=now && root.child('users/'+$userBet+'/coins').val()>=newData.child('tip').val() && root.child('users/'+$userBet+'/verified').val() === true"
          }
        }
      },
      "comments":{
        ".read":true,
        "$new":{
          "$comment":{
            //loggedin user comments in his/her name || admin || author
            ".write": "auth.uid === newData.child('userId').val() || root.child('users/'+auth.uid+'/roles/admin').val() == true || root.child('users/'+auth.uid+'/roles/author').val() == true"
          }
        }
      },
      "labels":{
        ".read":true,
        	//only authors can modify labels~categories
        ".write": "root.child('users/'+auth.uid+'/roles/author').val() == true"
      },
      "matches":{
        ".indexOn": ["status", "begin_at"],
        ".read":true,
        	//only the Administrator (not roles/admin) can modify the matches - it means only functions are able to modify it!
        ".write":false
      },
      "news":{
        ".read":true,
        	//only authors can modify news
        ".write": "root.child('users/'+auth.uid+'/roles/author').val() == true"
      },
      "newscontent":{
        ".read":true,
        ".write": "root.child('users/'+auth.uid+'/roles/author').val() == true"
      },
      "statistics":{
        ".read":true,
        ".write": true
      },
      "users":{
        ".read": "root.child('users/'+auth.uid+'/roles/admin').val() === true",
        //".read":true,
        "$userId":{
          ".read":true,
          "email":{
            ".read": "auth.uid === $userId || root.child('users/'+auth.uid+'/roles/admin').val() == true",
          	".write" : "auth.uid === $userId || root.child('users/'+auth.uid+'/roles/admin').val() == true"
          },
          "displayName":{
            ".read":true,
            ".write": "auth.uid === $userId || root.child('users/'+auth.uid+'/roles/admin').val() == true"
          },
          "coins":{
            ".read":"auth.uid === $userId || root.child('users/'+auth.uid+'/roles/admin').val() == true",
            ".write": "auth.uid === $userId || root.child('users/'+auth.uid+'/roles/admin').val() == true"
          },
          "photoURL":{
            ".read": true,
            ".write": "auth.uid === $userId || root.child('users/'+auth.uid+'/roles/admin').val() == true"
          },
          "roles":{
            ".read": "auth.uid === $userId || root.child('users/'+auth.uid+'/roles/admin').val() == true",
            ".write": "auth.uid === $userId || root.child('users/'+auth.uid+'/roles/admin').val() == true"
          },
          "verified":{
            ".read": "auth.uid === $userId || root.child('users/'+auth.uid+'/roles/admin').val() == true",
            ".write": "auth.uid === $userId || root.child('users/'+auth.uid+'/roles/admin').val() == true"
          }
        }
      }
  }
}