using System;

using System.Collections.Concurrent;

using System.Collections.Generic;

using System.Collections.ObjectModel;

using System.Diagnostics;

using System.Threading.Tasks;

using Avalonia.Threading;

using DesertPaintCodex.Models;

using DesertPaintCodex.Services;

using ReactiveUI;

namespace DesertPaintCodex.ViewModels

{

    public class RecipeGeneratorViewModel : ViewModelBase

    {

        private const long   SaveInterval    = 30000; // ms

        private const string PaintStateFile  = "dp_generator_state";

        private const string RibbonStateFile = "dp_generator_ribbon_state";

        private int _selectedView = 0;

        public int SelectedView { get => _selectedView; private set => this.RaiseAndSetIfChanged(ref _selectedView, value); }

        private float _progress = 0;

        public float Progress { get => _progress; private set => this.RaiseAndSetIfChanged(ref _progress, value); }

        private DateTime _mostRecentTime;

        public DateTime MostRecentTime { get => _mostRecentTime; private set => this.RaiseAndSetIfChanged(ref _mostRecentTime, value); }

        private GeneratorRecipe? _mostRecentRecipe;

        public GeneratorRecipe? MostRecentRecipe { get => _mostRecentRecipe; private set => this.RaiseAndSetIfChanged(ref _mostRecentRecipe, value); }

        private int _productIndex = 0;

        public int ProductIndex { get => _productIndex; private set => this.RaiseAndSetIfChanged(ref _productIndex, value); }

        private int _maxReagents;

        public int MaxReagents { get => _maxReagents; private set => this.RaiseAndSetIfChanged(ref _maxReagents, value); }

        private int _maxConcentration;

        public int MaxConcentration { get => _maxConcentration; private set => this.RaiseAndSetIfChanged(ref _maxConcentration, value); }

        private int _fullQuantity;

        public int FullQuantity { get => _fullQuantity; private set => this.RaiseAndSetIfChanged(ref _fullQuantity, value); }

        private int _fullQuantityDepth;

        public int FullQuantityDepth { get => _fullQuantityDepth; private set => this.RaiseAndSetIfChanged(ref _fullQuantityDepth, value); }

        private int _maxConcentrationMax;

        public int MaxConcentrationMax { get => _maxConcentrationMax; private set => this.RaiseAndSetIfChanged(ref _maxConcentrationMax, value); }

        private int _fullQuantitynMax;

        public int FullQuantityMax { get => _fullQuantitynMax; private set => this.RaiseAndSetIfChanged(ref _fullQuantitynMax, value); }

        #region Flags

        private bool _isPaused = false;

        public bool IsPaused  { get => _isPaused; private set => this.RaiseAndSetIfChanged(ref _isPaused, value); }

        private bool _isInProgress = false;

        public bool IsInProgress { get => _isInProgress; private set => this.RaiseAndSetIfChanged(ref _isInProgress, value); }

        private bool _isRunning = false;

        public bool IsRunning {  get => _isRunning; private set => this.RaiseAndSetIfChanged(ref _isRunning, value); }

        private bool _canStart = false;

        public bool CanStart {  get => _canStart; private set => this.RaiseAndSetIfChanged(ref _canStart, value); }

        private bool _canClear = false;

        public bool CanClear {  get => _canClear; private set => this.RaiseAndSetIfChanged(ref _canClear, value); }

        {

            bool result = await ShowYesNoBox("Clear Recipes", "Are you sure you want to clear your recipes?");

            if (result)

            {

                CanClear = false;

                if (_ribbonMode)

                {

                    _profile.ClearRibbonRecipes();

                }

                else

                {

                    _profile.ClearPaintRecipes();

                }

                foreach (GeneratorRecipe recipe in AllRecipes)

                {

                    recipe.ClearRecipe();

                }

                _generator.Reset();

            }

        }

        private void InitStateForPaint()

        {

            MaxConcentrationMax = 20;

            FullQuantityMax = 20;

            InitState("Paint", PaintRecipe.PaintRecipeMinConcentration, _profile.Recipes, PaintStateFile);

        }

        private void InitStateForRibbons()

        {

            MaxConcentrationMax = 100;

            FullQuantityMax = 100;

            InitState("Ribbon", PaintRecipe.RibbonRecipeMinConcentration, _profile.RibbonRecipes, RibbonStateFile);

        }

        private void InitState(string mode, uint minConcentration, Dictionary<string, PaintRecipe> recipes, string stateFileName)

        {

            _minConcentration = minConcentration;

            _generator.InitRecipes(recipes);

            string stateFile = System.IO.Path.Combine(_profile.Directory, stateFileName);

            if (System.IO.File.Exists(stateFile))

            {

                _generator.LoadState(stateFile);

                if (_generator.CanResume)

                {

                    IsInProgress = true;

                    IsPaused = true;

                    SaveSettings(mode);

                }

                else

                {

                    IsInProgress = false;

                    IsPaused = false;

                    CanClear = true;

                }

            }

            else if (mode == "Paint")

            {

                LoadPaintSettings();

            }

            else

            {

                LoadRibbonSettings();

            }

            AllRecipes.Clear();

            foreach (PaintColor color in PaletteService.Colors)

            {

                GeneratorRecipe genRecipe = new(color);

                if (recipes.TryGetValue(color.Name, out PaintRecipe? recipe)) //  && recipe.IsValidForConcentration(minConcentration)) // This check is redundant, since they're checked when loading.

                {

                    genRecipe.DraftRecipe(recipe);

                }

                AllRecipes.Add(genRecipe);

            }

        }

        #region Event Handlers

        private void OnProgress(object? sender, EventArgs args)

        {

            _newRecipeCount = (int)_generator.RecipeCount;

            _updatesAvailable = true;

        }

        private void OnNewRecipe(object? sender, NewRecipeEventArgs args)

        {

            PaintRecipe recipe = new(args.Recipe);

            _pendingNewRecipes.Enqueue(recipe);

            _updatesAvailable = true;

        }

        private void OnGeneratorStopped(object? sender, EventArgs args)

        {

            SaveState();

            if (_saving)

            {

                _generator.ResumeRecipeGeneration();

                _lastSave = DateTime.Now;

                _saving = false;

                return;

            }

            if (IsPaused) return;

            End();

        }

        private void Update(object? sender, EventArgs e)

        {

            if (!_updatesAvailable) return;

            if (_saving) return;

            _updatesAvailable = false;

            DateTime now = DateTime.Now;

            // Update test count.

            // Pull in new recipes.

            if (!_pendingNewRecipes.IsEmpty)

            {

                GeneratorRecipe? lastRecipe = null;

                while (_pendingNewRecipes.TryDequeue(out PaintRecipe? newRecipe))

                {

                    string recipeColor = PaletteService.FindNearest(newRecipe.ReactedColor);

                    foreach (GeneratorRecipe recipe in AllRecipes)

                    {

                        if (recipe.Color.Name != recipeColor) continue;

                        recipe.DraftRecipe(newRecipe);

                        lastRecipe = recipe;

                        if (_ribbonMode)

                        {

                            _profile.SetRibbonRecipe(recipeColor, newRecipe);

                        }

                        else

                        {

                            _profile.SetRecipe(recipeColor, newRecipe);

                        }

                        break;

                    }

                }

                // If at least one recipe was processed, let's check to see if it's time to save, and

                // highlight that recipe.

                if (lastRecipe != null)

                {

                    _unsavedRecipes = true;

                    MostRecentRecipe = lastRecipe;

                    MostRecentTime = now;

                }

            }

            // Save if it is time.

            if (!((now - _lastSave).TotalMilliseconds > SaveInterval)) return;

            if (_unsavedRecipes)

            {

                _profile.SaveRecipes();

                _unsavedRecipes = false;

            }

            _saving = true;

            _generator.Stop();

        }