static bool CreateDatabase(ITypeDBDriver driver, string dbName) {
    Console.WriteLine("Creating a new database...");
    driver.Databases.Create(dbName);
    Console.WriteLine("OK");
    using (ITypeDBSession session = driver.Session(dbName, SessionType.Schema)) {
        DbSchemaSetup(session);
    }
    using (ITypeDBSession session = driver.Session(dbName, SessionType.Data)) {
        DbDatasetSetup(session);
    }
    return true;
}

static bool ReplaceDatabase(ITypeDBDriver driver, string dbName) {
    Console.WriteLine("Deleting an existing database...");
    driver.Databases.Get(dbName).Delete();
    Console.WriteLine("OK");
    return CreateDatabase(driver, dbName);
}

static void DbSchemaSetup(ITypeDBSession session, string schemaFile = "iam-schema.tql") {
    string defineQuery;
    try
    {
        defineQuery = File.ReadAllText(schemaFile);
        using (ITypeDBTransaction tx = session.Transaction(TransactionType.Write)) {
            Console.WriteLine("Defining schema...");
            tx.Query.Define(defineQuery).Resolve();
            tx.Commit();
            Console.WriteLine("OK");
        }
    }
    catch (FileNotFoundException)
    {
        Console.WriteLine("Error: File not found.");
        Environment.Exit(1);
    }
    catch (Exception e)
    {
        Console.WriteLine($"An error occurred: {e.Message}");
        Environment.Exit(1);
    }
}

static void DbDatasetSetup(ITypeDBSession session, string dataFile = "iam-data-single-query.tql") {
    string insertQuery = File.ReadAllText(dataFile);
    using (ITypeDBTransaction tx = session.Transaction(TransactionType.Write)) {
        Console.WriteLine("Loading data...");
        IEnumerable<IConceptMap> response = tx.Query.Insert(insertQuery);
        int count = response.Count();
        tx.Commit();
        Console.WriteLine("OK");
    }
}

static bool DbCheck(ITypeDBSession session) {
    using (ITypeDBTransaction tx = session.Transaction(TransactionType.Read)) {
        Console.WriteLine("Testing the database...");
        string testQuery = "match $u isa user; get $u; count;";
        long result = tx.Query.GetAggregate(testQuery).Resolve()!.AsLong();
        if (result == 3) {
            Console.WriteLine("Passed");
            return true;
        } else {
            Console.WriteLine($"Failed with the result: {result}\nExpected result: 3.");
            return false;
        }
    }
}

static List<JObject> FetchAllUsers(ITypeDBDriver driver, string dbName) {
    List<JObject> users = new();
    using (ITypeDBSession session = driver.Session(dbName, SessionType.Data)) {
        using (ITypeDBTransaction tx = session.Transaction(TransactionType.Read)) {
            IEnumerable<JObject> queryResult = tx.Query.Fetch("match $u isa user; fetch $u: full-name, email;");
            int c = 1;
            foreach (JObject user in queryResult) {
                users.Add(user);
                Console.WriteLine($"User #{c++} ");
                Console.WriteLine(JsonConvert.SerializeObject(user, Formatting.Indented));
                Console.WriteLine();
            }
        }
    }
    return users;
}

static IEnumerable<IConceptMap> InsertNewUser(ITypeDBDriver driver, string dbName, string name, string email) {
    List<IConceptMap> response = new List<IConceptMap>();
    using (ITypeDBSession session = driver.Session(dbName, SessionType.Data)) {
        using (ITypeDBTransaction tx = session.Transaction(TransactionType.Write)) {
            string query = $"insert $p isa person, has full-name '{name}', has email '{email}';";
            IEnumerable<IConceptMap> result = tx.Query.Insert(query);
            foreach (IConceptMap conceptMap in result) {
                string retrievedName = conceptMap.Get("_0").AsAttribute().Value.AsString();
                string retrievedEmail = conceptMap.Get("_1").AsAttribute().Value.AsString();
                Console.WriteLine($"Added new user. Name: {retrievedName}, E-mail: {retrievedEmail}");
            }
            tx.Commit();
        }
    }
    return response;
}

static List<string> GetFilesByUser(ITypeDBDriver driver, string dbName, string name, bool inference = false) {
    TypeDBOptions options = new();
    options.Infer(inference);
    List<string> files = new List<string>();
    using (ITypeDBSession session = driver.Session(dbName, SessionType.Data)) {
        using (ITypeDBTransaction tx = session.Transaction(TransactionType.Read, options)) {
            string query = $"match $u isa user, has full-name '{name}'; get;";
            IEnumerable<IConceptMap> users = tx.Query.Get(query);
            int userCount = users.Count();
            if (userCount > 1) {
                Console.WriteLine("Error: Found more than one user with that name.");
            } else if (userCount == 1) {
                string fetchQuery = $@"
                    match
                    $fn == '{name}';
                    $u isa user, has full-name $fn;
                    $p($u, $pa) isa permission;
                    $o isa object, has path $fp;
                    $pa($o, $va) isa access;
                    $va isa action, has name 'view_file';
                    get $fp; sort $fp asc;";
                IEnumerable<IConceptMap> response = tx.Query.Get(fetchQuery);
                int resultCounter = 0;
                foreach (IConceptMap cm in response) {
                    resultCounter++;
                    files.Add(cm.Get("fp").AsAttribute().Value.AsString());
                    Console.WriteLine($"File #{resultCounter}: {cm.Get("fp").AsAttribute().Value.AsString()}");
                }
                if (resultCounter == 0) {
                    Console.WriteLine("No files found. Try enabling inference.");
                }
            } else {
                Console.WriteLine("Error: No users found with that name.");
            }
        }
    }
    return files;
}

static int UpdateFilePath(ITypeDBDriver driver, string dbName, string oldPath, string newPath) {
    int count = 0;
    using (ITypeDBSession session = driver.Session(dbName, SessionType.Data)) {
        using (ITypeDBTransaction tx = session.Transaction(TransactionType.Write)) {
            string updateQuery = $@"
                match
                $f isa file, has path $old;
                $old == '{oldPath}';
                delete
                $f has $old;
                insert
                $f has path '{newPath}';";
            List<IConceptMap> response = tx.Query.Update(updateQuery).ToList();
            count = response.Count();
            if (count > 0) {
                tx.Commit();
                Console.WriteLine($"Total number of paths updated: {count}.");
            } else {
                Console.WriteLine("No matched paths: nothing to update.");
            }
        }
    }
    return count;
}

static bool DeleteFile(ITypeDBDriver driver, string dbName, string path) {
    using (ITypeDBSession session = driver.Session(dbName, SessionType.Data)) {
        using (ITypeDBTransaction tx = session.Transaction(TransactionType.Write)) {
            string matchQuery = $"match $f isa file, has path '{path}'; get;";
            IEnumerable<IConceptMap> response = tx.Query.Get(matchQuery);
            int count = response.Count();
            if (count == 1) {
                tx.Query.Delete($"match $f isa file, has path '{path}'; delete $f isa file;").Resolve();
                tx.Commit();
                Console.WriteLine("The file has been deleted.");
                return true;
            } else if (count > 1) {
                Console.WriteLine("Matched more than one file with the same path.");
                Console.WriteLine("No files were deleted.");
                return false;
            } else {
                Console.WriteLine("No files matched in the database.");
                Console.WriteLine("No files were deleted.");
                return false;
            }
        }
    }
}