/*
 * Copyright (c) 2015, Jason Maltzen

 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
 in the Software without restriction, including without limitation the rights
 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 copies of the Software, and to permit persons to whom the Software is
 furnished to do so, subject to the following conditions:

 The above copyright notice and this permission notice shall be included in
 all copies or substantial portions of the Software.

 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 THE SOFTWARE.
*/

using System;
using System.Collections.Generic;
using System.Collections.Concurrent;

namespace DesertPaintLab
{
    public partial class RecipeGeneratorWindow : Gtk.Window
    {
        RecipeGenerator generator;
        PlayerProfile profile;
        bool canceling = false;
        bool running = false;
        bool pauseForCheckpoint = false;

        const long RECIPE_SAVE_INTERVAL = 30000; // msec between saving recipes
        const long CHECKPOINT_INTERVAL = 17000; // msec between saving out generator state
        const string STATE_FILE = "dp_generator_state";

        static Gtk.ListStore colorStore = new Gtk.ListStore(typeof(string));

        List<KeyValuePair<string, string>> missingReactions = new List<KeyValuePair<string, string>>();

        long lastProgressUpdate;
        long lastStatusUpdate;
        long lastProfileSave;
        long lastCheckpoint;

        static public Gtk.ListStore RecipeModel
        {
            get
            {
                return colorStore;   
            }
        }

        Gtk.ThreadNotify notifyFinished;
        Gtk.ThreadNotify notifyProgress;
        Gtk.ThreadNotify notifyNewRecipe;

        ConcurrentQueue<PaintRecipe> pendingNewRecipes = new ConcurrentQueue<PaintRecipe>();

        public RecipeGeneratorWindow(PlayerProfile profile) : base(Gtk.WindowType.Toplevel)
        {
            this.profile = profile;
            this.Build();
            maxIngredientsSpinButton.Value = 5; // TODO: read/save profile info
            maxRecipeSpinButton.Value = 20; // TODO: read/save profile info
            fullQuantitySpinButton.Value = 20; // TODO: read/save profile info
            fullQuantityDepthSpinButton.Value = 4; // TODO: read/save profile info

            fullQuantityDepthSpinButton.SetRange(0, ReagentManager.Names.Count);
            maxIngredientsSpinButton.SetRange(0, ReagentManager.Names.Count);

            Gtk.TreeViewColumn recipeColorColumn = new Gtk.TreeViewColumn();
            Gtk.CellRendererText recipeColumnCell = new Gtk.CellRendererText();
            recipeColorColumn.PackStart(recipeColumnCell, true);       
            recipeColorColumn.Title = "Color";

            recipeList.AppendColumn(recipeColorColumn);
            recipeColorColumn.AddAttribute(recipeColumnCell, "text", 0);

            colorStore.Clear();

            colorStore.SetSortColumnId(0, Gtk.SortType.Ascending);
            recipeList.Model = RecipeModel;

            recipeList.Selection.Changed += OnColorSelected;

            profile.LoadRecipes();

            // init UI
            foreach (KeyValuePair<string, PaintRecipe> pair in profile.Recipes)
            {
                if (pair.Value.IsValid)
                {
                    string colorName = pair.Key;
                    colorStore.AppendValues(colorName);
                }
            }

            canceling = false;
            running = false;
            pauseForCheckpoint = false;

            generator = new RecipeGenerator(profile.Reactions);
            generator.InitRecipes(profile.Recipes);

            generator.Progress += OnProgress;
            generator.Finished += OnFinished;
            generator.NewRecipe += OnNewRecipe;

            string stateFile = System.IO.Path.Combine(profile.Directory, STATE_FILE);
            if (System.IO.File.Exists(stateFile))
            {
                generator.LoadState(stateFile);
                if (generator.CanResume)
                {
                    beginButton.Label = "Restart";
                    stopResumeButton.Label = "Resume";
                    stopResumeButton.Sensitive = true;
                }
            }
            countLabel.Text = String.Format("{0} / {1}", profile.RecipeCount, Palette.Count);

            Destroyed += OnDestroyed;

            notifyFinished = new Gtk.ThreadNotify(new Gtk.ReadyEvent(HandleFinished));
            notifyProgress = new Gtk.ThreadNotify(new Gtk.ReadyEvent(HandleProgress));
            notifyNewRecipe = new Gtk.ThreadNotify(new Gtk.ReadyEvent(HandleNewRecipe));
        }

        protected void OnMaxIngredientsChanged(object sender, EventArgs e)
        {
            // TODO: save profile setting
            // TODO: no longer permit resume
        }

        protected void OnMaxRecipeChanged(object sender, EventArgs e)
        {
            // TODO: save profile setting
            // TODO: no longer permit resume
        }

        protected void OnFullQuantityDepthChanged(object sender, EventArgs e)
        {
            // TODO: save profile setting
            // TODO: no longer permit resume
        }

        protected void OnFullQuantityChanged(object sender, EventArgs e)
        {
            // TODO: save profile setting
            // TODO: no longer permit resume
        }

        protected void OnBegin(object sender, EventArgs e)
        {
            maxIngredientsSpinButton.Sensitive = false;
            ExportToWikiAction.Sensitive = false;
            IngredientsAction.Sensitive = false;
            maxRecipeSpinButton.Sensitive = false;
            beginButton.Sensitive = false; // TODO: change to "pause"?
            stopResumeButton.Sensitive = true;
            fullQuantitySpinButton.Sensitive = false;
            fullQuantityDepthSpinButton.Sensitive = false;

            countLabel.Text = String.Format("{0} / {1}", profile.RecipeCount, Palette.Count);

            // TODO: hook up event notifications
            // - progress
            // - complete
            // - new recipe / recipe update

            // Total recipe search count
            //int current = ReagentManager.Names.Count;
            //long recipePermutations = 1;
            //for (int i = 0; i < maxIngredientsSpinButton.ValueAsInt; ++i)
            //{
            //    recipePermutations *= current;
            //    --current;
            //}
            //System.Console.WriteLine("Will search {0} reagent permutations.", recipePermutations);

            lastProgressUpdate = DateTime.Now.Ticks / TimeSpan.TicksPerMillisecond;
            lastStatusUpdate = lastProgressUpdate;

            lastProfileSave = lastProgressUpdate;
            lastCheckpoint = lastProgressUpdate;

            running = true;
            canceling = false;
            pauseForCheckpoint = false;
            stopResumeButton.Label = "Pause";

            generator.BeginRecipeGeneration((uint)maxRecipeSpinButton.ValueAsInt, (uint)maxIngredientsSpinButton.ValueAsInt, (uint)fullQuantityDepthSpinButton.ValueAsInt, (uint)fullQuantitySpinButton.ValueAsInt);
        }

        protected void OnStopResume(object sender, EventArgs e)
        {
            if (generator != null)
            {
                if (running)
                {
                    canceling = true;
                    pauseForCheckpoint = false;
                    generator.Stop();
                }
                else
                {
                    // Resume previous run
                    ExportToWikiAction.Sensitive = false;
                    IngredientsAction.Sensitive = false;
                    lastProgressUpdate = DateTime.Now.Ticks / TimeSpan.TicksPerMillisecond;
                    lastStatusUpdate = lastProgressUpdate;
                    lastProfileSave = lastProgressUpdate;
                    lastCheckpoint = lastProgressUpdate;

                    canceling = false;
                        pauseForCheckpoint = false;
                    running = true;
        
                    stopResumeButton.Label = "Pause";
                    generator.ResumeRecipeGeneration();
                }
            }
        }

        private void HandleFinished()
        {
            generator.Wait();
            if (pauseForCheckpoint)
            {
                pauseForCheckpoint = false;
                generator.SaveState(System.IO.Path.Combine(profile.Directory, STATE_FILE));
                generator.ResumeRecipeGeneration();
            }
            else
            {
                running = false;
                beginButton.Sensitive = true;
                ExportToWikiAction.Sensitive = true;
                IngredientsAction.Sensitive = true;
                stopResumeButton.Sensitive = false;
                maxIngredientsSpinButton.Sensitive = true;
                maxRecipeSpinButton.Sensitive = true;
                fullQuantitySpinButton.Sensitive = true;
                fullQuantityDepthSpinButton.Sensitive = true;
                //generator = null; // don't. Hang on to generator for resume.
                profile.SaveRecipes();
                if (canceling)
                {
                    generator.SaveState(System.IO.Path.Combine(profile.Directory, STATE_FILE));
                    stopResumeButton.Label = "Resume";
                    stopResumeButton.Sensitive = true;
                    beginButton.Label = "Restart";
                }
                else
                {
                    System.IO.File.Delete(System.IO.Path.Combine(profile.Directory, STATE_FILE));
                }
            }
        }

        protected void OnFinished(object sender, EventArgs args)
        {
            notifyFinished.WakeupMain();
            //Gtk.Application.Invoke(delegate {
            //    HandleFinished();
            //});
        }

        private void HandleNewRecipe()
        {
            progressBar.Pulse();
            
            PaintRecipe recipe = null;
            if (pendingNewRecipes.TryDequeue(out recipe))
            {
                string recipeColor = Palette.FindNearest(recipe.ReactedColor);
                // TODO: Add item to recipe list only if not already listed
                bool exists = false;
                Gtk.TreeIter iter;
                if (colorStore.GetIterFirst(out iter))
                {
                    do
                    {
                        string color = (string)colorStore.GetValue(iter, 0);
                        if (color.Equals(recipeColor))
                        {
                            exists = true;
                            break;
                        }
                    } while (colorStore.IterNext(ref iter));
                }
                if (!exists)
                {
                    //Console.WriteLine("Add new recipe for {0}", args.Color);
                    //    bool isMissingReactions = args.Recipe.CheckMissingReactions(ref missingReactions);
                    //    string missingReactionLabel = isMissingReactions ? "X" : "";
                    colorStore.AppendValues(recipeColor); // , missingReactionLabel);
                    countLabel.Text = String.Format("{0} / {1}", profile.RecipeCount+1, Palette.Count);
                }
                profile.SetRecipe(recipe);
    
                long progressTime = DateTime.Now.Ticks / TimeSpan.TicksPerMillisecond;
                long delta = progressTime - lastProfileSave;
                if (delta >= RECIPE_SAVE_INTERVAL)
                {
                    profile.SaveRecipes();
                    lastProfileSave = progressTime;
                }
            }
        }

        protected void OnNewRecipe(object sender, NewRecipeEventArgs args)
        {
            PaintRecipe recipe = new PaintRecipe(args.Recipe); // copy it, so the worker thread can release
            lock(this) {
                pendingNewRecipes.Enqueue(recipe);
            }
            notifyNewRecipe.WakeupMain();
            //Gtk.Application.Invoke(delegate {
            //    HandleNewRecipe();
            //});
        }

        private void HandleProgress()
        {
            long progressTime = DateTime.Now.Ticks / TimeSpan.TicksPerMillisecond;
            long delta = progressTime - lastProgressUpdate;
            if (delta > 30)
            {
                lastProgressUpdate = progressTime;
                progressBar.Pulse();
            }
            delta = progressTime - lastStatusUpdate;
            if (delta > 500)
            {
                lastStatusUpdate = progressTime;
                statusLabel.Text = String.Format("Recipes searched: {0:N00}", generator.RecipeCount);
            }
            delta = progressTime - lastCheckpoint;
            if (delta > CHECKPOINT_INTERVAL)
            {
                lastCheckpoint = progressTime;
                pauseForCheckpoint = true;
                generator.Stop();
            }
        }

        protected void OnProgress(object sender, EventArgs args)
        {
            notifyProgress.WakeupMain();
        }

        protected void OnColorSelected(object o, EventArgs args)
        {
            Gtk.TreeModel model;
            Gtk.TreeIter iter;
            Gtk.TreeSelection selection = recipeList.Selection;
            if ((selection != null) && selection.GetSelected(out model, out iter))
            {
                string colorName = (string)colorStore.GetValue(iter, 0);
                PaintRecipe recipe;
                if (profile.Recipes.TryGetValue(colorName, out recipe))
                {
                    foreach (Gtk.Widget child in recipeListBox.AllChildren)
                    {
                        recipeListBox.Remove(child);
                    }
                    if (recipe.CheckMissingReactions(ref missingReactions))
                    {
                        statusLabel.Text = "WARNING: This recipe includes reactions that have not yet been recorded.";
                    }
                    foreach (PaintRecipe.RecipeIngredient ingredient in recipe.Ingredients)
                    {
                        Gtk.Label label = new Gtk.Label(ingredient.quantity.ToString() + " " + ingredient.name);
                        recipeListBox.PackStart(label);
                        label.Show();
                    }
                }
                paintSwatch.Color = recipe.ReactedColor;
            }
        }

        protected void OnExportToWiki(object sender, EventArgs e)
        {
            Gtk.FileChooserDialog fileDialog =
                new Gtk.FileChooserDialog("Select destination file.",
                        this, Gtk.FileChooserAction.Save,
                        Gtk.Stock.Cancel, Gtk.ResponseType.Cancel,
                        Gtk.Stock.Save, Gtk.ResponseType.Accept);
            Gtk.ResponseType resp = (Gtk.ResponseType)fileDialog.Run();
            if (resp == Gtk.ResponseType.Accept)
            {
                string fileName = fileDialog.Filename;
                string directory = fileDialog.CurrentFolder;
                profile.ExportWikiRecipes(System.IO.Path.Combine(directory, fileName));
            }
            fileDialog.Destroy();
        }

        protected void OnShowIngredients(object sender, EventArgs e)
        {
            ReagentWindow win = new ReagentWindow(profile);
            win.Show();
        }

        protected void OnDestroyed(object o, EventArgs args)
        {
            if (running)
            {
                // window closed while generator running: stop and save
                generator.Finished -= OnFinished;
                generator.Progress -= OnProgress;
                generator.NewRecipe -= OnNewRecipe;
                generator.Stop();
                generator.Wait();
                generator.SaveState(System.IO.Path.Combine(profile.Directory, STATE_FILE));
            }
        }
    }
}