using Client.ConsoleForms;
using Client.ConsoleForms.Events;
using Client.ConsoleForms.Graphics;
using Client.ConsoleForms.Parameters;
using Client.Properties;
using ConsoleForms;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Tofvesson.Collections;
using Tofvesson.Common;
using Tofvesson.Crypto;

namespace Client
{
    public sealed class SessionContext : Context
    {
        private readonly BankNetInteractor interactor;
        private bool scheduleDestroy;
        private Promise userDataGetter;
        private Promise accountsGetter;
        private Promise remoteAccountsGetter;
        private Promise remoteUserGetter;
        private List<string> accounts = null;
        private string username;
        private bool isAdministrator = false;
        
        // Stores personal accounts
        private readonly FixedQueue<Tuple<string, decimal>> accountDataCache = new FixedQueue<Tuple<string, decimal>>(64);

        // Stores remote account data
        private readonly FixedQueue<Tuple<string, string>> remoteUserCache = new FixedQueue<Tuple<string, string>>(8);
        private bool accountChange = false;


        public SessionContext(ContextManager manager, BankNetInteractor interactor) : base(manager, "Session", "Common")
        {
            this.interactor = interactor;
            scheduleDestroy = !interactor.IsLoggedIn;

            RegisterAutoHide("account_create", "account_info", "password_update", "exit_prompt", "account_show", "transfer");

            GetView<DialogView>("Success").RegisterSelectListener((v, i, s) => HandleLogout());

            // Menu option setup
            ListView options = GetView<ListView>("menu_options");
            options.GetView<ButtonView>("exit").SetEvent(v => Show("exit_prompt"));

            void SubmitListener(View listener)
            {
                ButtonView view = listener as ButtonView;

                void ShowAccountData(string name, decimal balance)
                {
                    // Build dialog view manually
                    var show = new DialogView(
                        new ViewData("DialogView")

                        // Layout parameters
                        .SetAttribute("padding_left", 2)
                        .SetAttribute("padding_right", 2)
                        .SetAttribute("padding_top", 1)
                        .SetAttribute("padding_bottom", 1)
                        .SetAttribute("border", (int)ConsoleColor.DarkGreen)

                        // Option buttons
                        .AddNested(new ViewData("Options").AddNestedSimple("Option", GetIntlString("GENERIC_dismiss")))

                        // Message
                        .AddNestedSimple("Text", GetIntlString("SE_info").Replace("$0", name).Replace("$1", balance.ToString())),

                        // No translation (it's already handled)
                        LangManager.NO_LANG);

                    show.RegisterSelectListener((_, s, l) => Hide(show));
                    Show(show);
                }

                // TODO: Show account info
                var account = AccountLookup(view.Text);
                if (account == null)
                {
                    // TODO: Get account data from server + cache data
                    Show("data_fetch");
                    Promise info_promise = Promise.AwaitPromise(interactor.AccountInfo(view.Text));
                    info_promise.Subscribe = evt =>
                    {
                        Hide("data_fetch");
                        if (evt.Value.StartsWith("ERROR") || !Account.TryParse(evt.Value, out var act))
                            controller.Popup(GetIntlString("GENERIC_error"), 3000, ConsoleColor.Red);
                        else
                        {
                            accountDataCache.Enqueue(new Tuple<string, decimal>(view.Text, act.balance)); // Cache result
                            ShowAccountData(view.Text, act.balance);
                        }

                    };
                }
                else ShowAccountData(account.Item1, account.Item2);
            }

            options.GetView<ButtonView>("view").SetEvent(v =>
            {
                if (accountChange) RefreshAccountList();
                if (!accountsGetter.HasValue) Show("data_fetch");
                accountsGetter.Subscribe = p =>
                {
                    accountsGetter.Unsubscribe();
                    Hide("data_fetch");
                    
                    Show(GenerateList(p.Value.Split('&').ForEach(Support.FromBase64String), SubmitListener));
                };
            });

            GetView<InputView>("password_update").SubmissionsListener = v =>
            {
                bool hasError = v.Inputs[0].Text.Length == 0;
                if (hasError)
                {
                    // Notify user, as well as mark the errant input field
                    v.Inputs[0].SelectBackgroundColor = ConsoleColor.Red;
                    v.Inputs[0].BackgroundColor = ConsoleColor.DarkRed;
                    controller.Popup(GetIntlString("ERR_empty"), 3000, ConsoleColor.Red);
                }
                if(v.Inputs[1].Text.Length == 0)
                {
                    v.Inputs[1].SelectBackgroundColor = ConsoleColor.Red;
                    v.Inputs[1].BackgroundColor = ConsoleColor.DarkRed;
                    if(!hasError) controller.Popup(GetIntlString("ERR_empty"), 3000, ConsoleColor.Red);
                    return; // No need to continue, we have notified the user. There is no valid information to operate on past this point
                }
                if (!v.Inputs[0].Text.Equals(v.Inputs[1].Text))
                {
                    controller.Popup(GetIntlString("SU_mismatch"), 3000, ConsoleColor.Red);
                    return;
                }
                Show("update_stall");
                Task<Promise> t = interactor.UpdatePassword(v.Inputs[0].Text);
                Promise.AwaitPromise(t).Subscribe = p =>
                {
                    Hide("update_stall");
                    Hide("password_update");
                    v.Inputs[0].ClearText();
                    v.Inputs[1].ClearText();
                    v.SelectedField = 0;
                };
            };

            // Actual "create account" input box thingy
            var input = GetView<InputView>("account_create");
            input.SubmissionsListener = __ =>
            {
                if (input.Inputs[0].Text.Length == 0)
                {
                    input.Inputs[0].SelectBackgroundColor = ConsoleColor.Red;
                    input.Inputs[0].BackgroundColor = ConsoleColor.DarkRed;
                    controller.Popup(GetIntlString("ERR_empty"), 3000, ConsoleColor.Red);
                }
                else
                {
                    void AlreadyExists()
                        => controller.Popup(GetIntlString("SE_account_exists").Replace("$0", input.Inputs[0].Text), 2500, ConsoleColor.Red, () => Hide(input));

                    var act = AccountLookup(input.Inputs[0].Text);
                    if (act != null) AlreadyExists();
                    else
                    {
                        Show("account_stall");
                        Promise accountPromise = Promise.AwaitPromise(interactor.CreateAccount(input.Inputs[0].Text));
                        accountPromise.Subscribe = p =>
                        {
                            if (bool.Parse(p.Value))
                            {
                                controller.Popup(GetIntlString("SE_account_success"), 750, ConsoleColor.Green, () => Hide(input));
                                accountChange = true;
                            }
                            else AlreadyExists();
                            Hide("account_stall");
                        };
                    }
                }
            };
            input.InputListener = (v, c, i, t) =>
            {
                c.BackgroundColor = v.DefaultBackgroundColor;
                c.SelectBackgroundColor = v.DefaultSelectBackgroundColor;
                return true;
            };

            options.GetView<ButtonView>("add").SetEvent(_ => Show(input));

            // Set up a listener to reset color scheme
            GetView<InputView>("password_update").InputListener = (v, c, i, t) =>
            {
                c.BackgroundColor = v.DefaultBackgroundColor;
                c.SelectBackgroundColor = v.DefaultSelectBackgroundColor;
                return true;
            };

            // Update password
            options.GetView<ButtonView>("update").SetEvent(v => Show("password_update"));


            string acc1 = null, acc2 = null, user = null;

            options.GetView<ButtonView>("tx").SetEvent(v =>
            {
                var txView = GetView<InputView>("transfer");
                txView.Inputs[0].Text = GetIntlString("SE_account_select");
                txView.Inputs[1].Text = GetIntlString("SE_user_select");
                txView.Inputs[2].Text = GetIntlString("SE_account_select");
                Show(txView);
            });

            GetView<InputView>("transfer").SubmissionsListener = v =>
            {
                switch (v.SelectedField)
                {
                    case 0:
                        if (accountChange) accountsGetter = Promise.AwaitPromise(interactor.ListUserAccounts());
                        Show("data_fetch");
                        accountsGetter.Subscribe = p =>
                        {
                            accountsGetter.Unsubscribe();
                            Hide("data_fetch");

                            Show(GenerateList(p.Value.Split('&').ForEach(Support.FromBase64String), sel => v.Inputs[0].Text = acc1 = (sel as ButtonView).Text, true));
                        };
                        break;
                    case 1:
                        Show("data_fetch");
                        remoteUserGetter = Promise.AwaitPromise(interactor.ListUsers());
                        remoteUserGetter.Subscribe = p =>
                        {
                            remoteUserGetter.Unsubscribe();
                            Hide("data_fetch");

                            Show(GenerateList(p.Value.Split('&').ForEach(Support.FromBase64String), sel => v.Inputs[1].Text = user = (sel as ButtonView).Text, true));
                        };
                        break;
                    case 2:
                        if (user == null)
                            controller.Popup(GetIntlString("SE_user_noselect"), 2000, ConsoleColor.Red);
                        else
                        {
                            Show("data_fetch");
                            remoteAccountsGetter = Promise.AwaitPromise(interactor.ListAccounts(user));
                            remoteAccountsGetter.Subscribe = p =>
                            {
                                remoteUserGetter.Unsubscribe();
                                Hide("data_fetch");

                                Show(GenerateList(p.Value.Split('&').ForEach(Support.FromBase64String), sel => v.Inputs[2].Text = acc2 = (sel as ButtonView).Text, true));
                            };
                        }
                        break;
                    case 3:
                    case 4:
                        Show("verify_stall");
                        bool error = false;
                        if (acc1==null)
                        {
                            controller.Popup(GetIntlString("SE_account_noselect"), 1500, ConsoleColor.Red);
                            error = true;
                            v.Inputs[0].BackgroundColor = ConsoleColor.Red;
                            v.Inputs[0].SelectBackgroundColor = ConsoleColor.DarkRed;
                        }
                        if (acc2 == null)
                        {
                            if(!error) controller.Popup(GetIntlString("SE_account_noselect"), 1500, ConsoleColor.Red);
                            error = true;
                            v.Inputs[2].BackgroundColor = ConsoleColor.Red;
                            v.Inputs[2].SelectBackgroundColor = ConsoleColor.DarkRed;
                        }
                        if(user == null)
                        {
                            if(!error) controller.Popup(GetIntlString("SE_account_nouser"), 1500, ConsoleColor.Red);
                            error = true;
                            v.Inputs[1].BackgroundColor = ConsoleColor.DarkRed;
                            v.Inputs[1].SelectBackgroundColor = ConsoleColor.Red;
                        }
                        userDataGetter = Promise.AwaitPromise(interactor.UserInfo());
                        userDataGetter.Subscribe = p =>
                        {
                            userDataGetter.Unsubscribe();
                            var account = AccountLookup("SE_balance_toohigh");
                            if (account == null) accountsGetter = Promise.AwaitPromise(interactor.AccountInfo(acc1));
                            accountsGetter.Subscribe = result =>
                            {
                                accountsGetter.Unsubscribe();
                                var resultData = p.Value.Split('&');
                                Hide("verify_stall");
                                decimal d;
                                if (result.Value.StartsWith("ERROR") || !Account.TryParse(result.Value, out var act))
                                    controller.Popup(GetIntlString("GENERIC_error"), 1500, ConsoleColor.Red);
                                else if ((d = decimal.Parse(v.Inputs[3].Text)) > act.balance && (!bool.Parse(resultData[1]) || !acc1.Equals(acc2)))
                                    controller.Popup(GetIntlString("SE_balance_toohigh").Replace("$0", act.balance.ToString()), 3000, ConsoleColor.Red);
                                else
                                {
                                    Promise txPromise = Promise.AwaitPromise(interactor.CreateTransaction(acc1, user, acc2, d, v.Inputs[4].Text.Length == 0 ? null : v.Inputs[4].Text));
                                    accountChange = true;
                                    accountDataCache.Clear();
                                    txPromise.Subscribe = txResult =>
                                    {
                                        if (txResult.Value.StartsWith("ERROR"))
                                            controller.Popup(GetIntlString("GENERIC_error"), 1500, ConsoleColor.Red);
                                        else controller.Popup(GetIntlString("SE_tx_success"), 2000, ConsoleColor.Green, () => Hide("transfer"));
                                    };
                                }
                            };
                        };
                        break;
                }
            };

            GetView<InputView>("transfer").InputListener = (v, i, s, t) =>
            {
                if (t) return false; // Don't handle artificial events
                i.BackgroundColor = v.DefaultBackgroundColor;
                i.SelectBackgroundColor = v.DefaultSelectBackgroundColor;
                if (v.IndexOf(i) < 3)
                {
                    // Trigger a keypress event for key [ENTER]
                    v.TriggerKeyEvent(new ConsoleController.KeyEvent(new ConsoleKeyInfo('\n', ConsoleKey.Enter, false, false, false)));
                    return false; // Don't update input
                }
                return true;
            };

            options.OnBackEvent = v => Show("exit_prompt");

            GetView<DialogView>("exit_prompt").RegisterSelectListener((v, i, s) =>
            {
                if (i == 0) Hide("exit_prompt");
                else HandleLogout();
            });

            if (!scheduleDestroy)
            {
                // We have a valid context!
                RefreshUserInfo();      // Get user info
                RefreshAccountList();   // Get account list for user
            }
        }

        private ListView GenerateList(string[] data, SubmissionEvent onclick, bool exitOnSubmit = false)
        {
            var list = GetView<ListView>("account_show");
            list.RemoveIf(t => !t.Item1.Equals("close"));
            ButtonView exit = list.GetView<ButtonView>("close");
            exit.SetEvent(_ => Hide(list));
            if (data.Length == 1 && data[0].Length == 0) return list;
            bool b = data.Length == 1 && data[0].Length == 0;
            Tuple<string, View>[] listData = new Tuple<string, View>[data.Length - (b ? 1 : 0)];
            if (!b)
                for (int i = 0; i < listData.Length; ++i)
                {
                    ButtonView t = new ButtonView(new ViewData("ButtonView").AddNestedSimple("Text", data[i]), LangManager.NO_LANG); // Don't do translations
                    t.SetEvent(v =>
                    {
                        onclick?.Invoke(v);
                        if (exitOnSubmit) Hide(list);
                    });
                    listData[i] = new Tuple<string, View>(t.Text, t);
                }
            list.RemoveIf(t => !t.Item1.Equals("close"));
            list.AddViews(0, listData); // Insert generated buttons before predefined "close" button
            return list;
        }

        private void RefreshAccountList()
        {
            accountsGetter = Promise.AwaitPromise(interactor.ListUserAccounts()); // Get accounts associated with this user

            accountsGetter.Subscribe = p =>
            {
                var data = p.Value.Split('&');
                accounts = new List<string>();
                accounts.AddRange(data);
            };
        }

        private void RefreshUserInfo()
        {
            userDataGetter = Promise.AwaitPromise(interactor.UserInfo()); // Get basic user info

            userDataGetter.Subscribe = p =>
            {
                var data = p.Value.Split('&');
                username = data[0].FromBase64String();
                isAdministrator = bool.Parse(data[1]);
            };
        }

        private void HandleLogout(bool automatic = false)
        {
#pragma warning disable CS4014 // Because this call is not awaited, execution of the current method continues before the call is completed
            interactor.Logout();
#pragma warning restore CS4014 // Because this call is not awaited, execution of the current method continues before the call is completed
            controller.Popup(GetIntlString($"SE_{(automatic ? "auto" : "")}lo"), 2500, ConsoleColor.DarkMagenta, () => manager.LoadContext(new NetContext(manager)));
        }

        private Tuple<string, decimal> AccountLookup(string name)
        {
            foreach (var cacheEntry in accountDataCache)
                if (cacheEntry.Item1.Equals(name))
                    return cacheEntry;
            return null;
        }

        public override void OnCreate()
        {
            if (scheduleDestroy) manager.LoadContext(new WelcomeContext(manager, interactor));
            else Show("menu_options");
        }

        public override void OnDestroy()
        {
            base.HideAll();
#pragma warning disable CS4014 // Because this call is not awaited, execution of the current method continues before the call is completed
            interactor.CancelAll();
#pragma warning restore CS4014 // Because this call is not awaited, execution of the current method continues before the call is completed
        }
    }
}