using System;
using System.Text.RegularExpressions;
using Godot;
using SpacetimeDB;
using SpacetimeDB.Types;

public class Spacetime
{
    /// The URI of the SpacetimeDB instance hosting our chat database and module.
    const string HOST = "http://localhost:3000";

    /// The database name we chose when we published our module.
    const string DB_NAME = "massive";

    public static Spacetime Instance
    {
        get
        {
            if (_instance == null)
            {
                _instance = new Spacetime(HOST, DB_NAME);
            }
            return _instance;
        }
    }

    // our local client SpacetimeDB identity
    public Identity Identity { get; private set; }
    public DbConnection Connection { get; private set; }
    public User Me
    {
        get => Connection.Db.User.Identity.Find(Identity);
    }

    private static Spacetime _instance;

    string GetClientArg()
    {
        foreach (string arg in OS.GetCmdlineUserArgs())
        {
            GD.Print(arg);
            if (new Regex("--client=.+").IsMatch(arg))
            {
                return arg.Split("=")[1];
            }
        }
        return null;
    }

    public Spacetime(string host, string dbName)
    {
        string client = GetClientArg() ?? "massive";

        // Initialize the `AuthToken` module
        AuthToken.Init($".spacetime/{client}");

        Connection = DbConnection
            .Builder()
            .WithUri(host)
            .WithModuleName(dbName)
            .WithToken(AuthToken.Token)
            .OnConnect(OnConnected)
            .OnConnectError(OnConnectError)
            .OnDisconnect(OnDisconnected)
            .Build();
    }

    /// Our `OnConnected` callback: save our credentials to a file.
    void OnConnected(DbConnection conn, Identity identity, string authToken)
    {
        Identity = identity;
        AuthToken.SaveToken(authToken);

        conn.SubscriptionBuilder().OnApplied(OnSubscriptionApplied).SubscribeToAllTables();
    }

    /// Our `OnSubscriptionApplied` callback:
    /// sort all past messages and print them in timestamp order.
    void OnSubscriptionApplied(SubscriptionEventContext ctx)
    {
        GD.Print("Connected");
    }

    /// Our `OnConnectError` callback: print the error, then exit the process.
    void OnConnectError(Exception e)
    {
        GD.PrintErr($"Error while connecting: {e}");
    }

    /// Our `OnDisconnect` callback: print a note, then exit the process.
    void OnDisconnected(DbConnection conn, Exception? e)
    {
        if (e != null)
        {
            GD.PrintErr($"Disconnected abnormally: {e}");
        }
        else
        {
            GD.Print($"Disconnected normally.");
        }
    }
}