.rules

rules_version = '2';

service cloud.firestore {
    match /databases/{database}/documents {

        function isValidString(field, minSize, maxSize) {
            return field is string && field.size() >= minSize && field.size() <= maxSize;
        }

        function hasRequiredFields(resourceData, fields) {
            return resourceData.keys().hasAll(fields);
        }

        match /users/{userId} {
            allow read;

            allow create: if hasRequiredFields(request.resource.data, ['id', 'name', 'userAgent', 'country', 'createdAt'])
                && request.resource.data.id == userId
                && isValidString(request.resource.data.name, 2, 50)
                && isValidString(request.resource.data.userAgent, 1, 500)
                && isValidString(request.resource.data.country, 2, 20)
                && request.resource.data.createdAt == request.time;
        }

        match /messages/{messageId} {
            allow read;

            allow create: if hasRequiredFields(request.resource.data, ['content', 'userId', 'userName', 'userCountry', 'timestamp'])
                && isValidString(request.resource.data.content, 1, 255)
                && isValidString(request.resource.data.userId, 1, 500) 
                && isValidString(request.resource.data.userName, 2, 50)
                && isValidString(request.resource.data.userCountry, 2, 20)
                && request.resource.data.timestamp == request.time;
        }
    }
}