database-rules.json

{
    "rules": {
        "level-secrets": {
            "$key": {
                ".read": "true"
            }
        },
        "levels": {
            ".read": true,
            "$level": {
                "$sublevel": {
                    "timesCompleted": {
                        ".validate": "(!data.exists() && newData.val() == 1) || (newData.val() == data.val() + 1)",
                        ".write": true
                    }
                }
            }
        },
        "hall-of-fame": {
            ".read": true,
            "$uid": {
                ".indexOn": [
                    "datetime"
                ],
                ".write": "!data.exists() && $uid === auth.uid && root.child('users/' + $uid + '/' + newData.child('last-level-index').val() + '/' + newData.child('last-sublevel-index').val() + '/answer').exists()",
                ".validate": "newData.hasChildren(['nickname', 'comment', 'datetime'])",
                "nickname": {
                    ".validate": "newData.isString() && newData.val().length >= 1"
                },
                "comment": {
                    ".validate": "newData.isString() && newData.val().length >= 1"
                },
                "datetime": {
                    ".validate": "newData.val() + 10000 >= now && newData.val() - 10000 <= now"
                },
                "last-level-index": {
                    ".validate": "root.child('levels/' + newData.val()).exists() && !root.child('levels/' + (newData.val() + 1)).exists()"
                },
                "last-sublevel-index": {
                    ".validate": "root.child('levels/' + newData.parent().child('last-level-index').val() + '/' + newData.val()).exists() && !root.child('levels/' + newData.parent().child('last-level-index').val() + '/' + (newData.val() + 1)).exists()"
                }
            }
        },
        "users": {
            "$uid": {
                ".read": "$uid === auth.uid",
                "$level_id": {
                    "$sublevel_id": {
                        "answer": {
                            ".write": "$uid === auth.uid && root.child('level-secrets/' + $level_id + '-' + $sublevel_id + '-' + newData.val()).val() == true"
                        },
                        "guesses": {
                            ".write": "$uid === auth.uid"
                        }
                    }
                }
            }
        }
    }
}