package world.bentobox.challenges.panel.admin;


import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.function.BiConsumer;
import java.util.function.Consumer;
import java.util.stream.Collectors;

import org.bukkit.Material;
import org.bukkit.event.inventory.InventoryClickEvent;
import org.bukkit.event.inventory.InventoryCloseEvent;
import org.bukkit.inventory.ItemStack;
import org.eclipse.jdt.annotation.Nullable;

import world.bentobox.bentobox.api.panels.PanelItem;
import world.bentobox.bentobox.api.panels.PanelListener;
import world.bentobox.bentobox.api.panels.builders.PanelBuilder;
import world.bentobox.bentobox.api.panels.builders.PanelItemBuilder;
import world.bentobox.bentobox.api.user.User;
import world.bentobox.challenges.config.SettingsUtils.ChallengeLore;
import world.bentobox.challenges.config.SettingsUtils.LevelLore;
import world.bentobox.challenges.panel.CommonGUI;
import world.bentobox.challenges.utils.GuiUtils;


/**
 * This class allows to change Input ItemStacks to different ItemStacks.
 */
public class EditLoreGUI extends CommonGUI
{
    public EditLoreGUI(CommonGUI parent, LoreType loreType)
    {
        super(parent);

        this.lore = loreType;
        this.activeValues = new ArrayList<>();

        switch (this.lore)
        {
        case CHALLENGES:

            for (ChallengeLore lore : this.addon.getChallengesSettings().getChallengeLoreMessage())
            {
                this.activeValues.add(lore.name());
            }

            break;
        case LEVELS:

            for (LevelLore lore : this.addon.getChallengesSettings().getLevelLoreMessage())
            {
                this.activeValues.add(lore.name());
            }

            break;
        }
    }


    /**
     * This is static call method for easier GUI opening.
     * @param parent Parent GUI.
     * @param loreType loreType that will be edited.
     */
    public static void open(CommonGUI parent, LoreType loreType)
    {
        new EditLoreGUI(parent, loreType).build();
    }


    // ---------------------------------------------------------------------
    // Section: Methods
    // ---------------------------------------------------------------------


    /**
     * This method builds panel that allows to change given number value.
     */
    @Override
    public void build()
    {
        PanelBuilder panelBuilder = new PanelBuilder().
                name(this.user.getTranslation("challenges.gui.title.admin.lore-edit")).
                user(this.user).
                listener(new CustomPanelListener());

        GuiUtils.fillBorder(panelBuilder, 5, Material.MAGENTA_STAINED_GLASS_PANE);

        // Define all active buttons
        panelBuilder.item(1, this.getButton(Button.SAVE));

        panelBuilder.item(3, this.getButton(Button.ADD));
        panelBuilder.item(4, this.getButton(Button.REMOVE));

        // TODO: Need 2 View Buttons
        // One for closes / One for opened.
        //		panelBuilder.item(6, this.getButton(Button.VIEW));

        panelBuilder.item(44, this.returnButton);

        // necessary as I have a border around this GUI
        int currentIndex = 10;

        // Only 21 elements will be displayed. On porpoise!
        for (int i = 0; i < this.activeValues.size() || i > 21; i++)
        {
            panelBuilder.item(currentIndex++, this.getLoreButton(this.activeValues.get(i)));

            // Border element
            if (currentIndex % 9 == 8)
            {
                currentIndex += 2;
            }

            // Just in case. Should never occur.
            if (currentIndex % 9 == 0)
            {
                currentIndex++;
            }
        }

        panelBuilder.build();
    }


    /**
     * This method create button that does some functionality in current gui.
     * @param button Button functionality.
     * @return PanelItem.
     */
    private PanelItem getButton(Button button)
    {
        ItemStack icon;
        String name;
        List<String> description;
        PanelItem.ClickHandler clickHandler;

        switch (button)
        {
        case SAVE:
        {
            name = this.user.getTranslation("challenges.gui.buttons.admin.save");
            description = Collections.emptyList();
            icon = new ItemStack(Material.COMMAND_BLOCK);
            clickHandler = (panel, user, clickType, slot) -> {

                switch (this.lore)
                {
                case CHALLENGES:
                {
                    List<ChallengeLore> lore = this.activeValues.stream().
                            map(ChallengeLore::valueOf).
                            collect(Collectors.toCollection(() -> new ArrayList<>(this.activeValues.size())));

                    this.addon.getChallengesSettings().setChallengeLoreMessage(lore);

                    break;
                }
                case LEVELS:
                {
                    List<LevelLore> lore = this.activeValues.stream().
                            map(LevelLore::valueOf).
                            collect(Collectors.toCollection(() -> new ArrayList<>(this.activeValues.size())));

                    this.addon.getChallengesSettings().setLevelLoreMessage(lore);

                    break;
                }
                }

                // Save and return to parent gui.
                this.parentGUI.build();

                return true;
            };
            break;
        }
        case ADD:
        {
            name = this.user.getTranslation("challenges.gui.buttons.admin.add");
            description = Collections.emptyList();
            icon = new ItemStack(Material.GREEN_STAINED_GLASS_PANE);
            clickHandler = (panel, user, clickType, slot) -> {
                new AddLoreElementGUI(element -> {
                    this.activeValues.add(element);
                    this.build();
                });

                return true;
            };

            break;
        }
        case REMOVE:
        {
            name = this.user.getTranslation("challenges.gui.buttons.admin.remove-selected");
            description = Collections.emptyList();
            icon = new ItemStack(Material.RED_STAINED_GLASS_PANE);
            clickHandler = (panel, user, clickType, slot) -> {
                new RemoveLoreElementGUI((element, index) -> {
                    if (this.activeValues.get(index).equals(element))
                    {
                        this.activeValues.remove(element);
                    }

                    this.build();
                });

                return true;
            };

            break;
        }
        case VIEW:
        {
            name = this.user.getTranslation("challenges.gui.buttons.admin.view");
            description = Collections.emptyList();
            icon = new ItemStack(Material.YELLOW_STAINED_GLASS_PANE);
            clickHandler = (panel, user, clickType, slot) -> {
                return true;
            };

            break;
        }
        default:
            return null;
        }

        return new PanelItemBuilder().
                icon(icon).
                name(name).
                description(GuiUtils.stringSplit(description, this.addon.getChallengesSettings().getLoreLineLength())).
                glow(false).
                clickHandler(clickHandler).
                build();
    }


    /**
     * This method creates button for lore element.
     * @param loreElement String that represents current lore element.
     * @return PanelItem.
     */
    @Nullable
    private PanelItem getLoreButton(String loreElement)
    {
        switch (this.lore)
        {
        case CHALLENGES:
            return this.getChallengeLoreButton(loreElement);
        case LEVELS:
            return this.getLevelLoreButton(loreElement);
        default:
            // this should never happen!
            return null;
        }
    }


    /**
     * This method creates button for challenge lore element.
     * @param loreElement String that represents current challenge lore element.
     * @return PanelItem.
     */
    private PanelItem getChallengeLoreButton(String loreElement)
    {
        Material icon;
        String name = loreElement;
        List<String> description = new ArrayList<>();
        description.add(this.user.getTranslation(REFERENCE_DESCRIPTION + "lore." + loreElement.toLowerCase()));

        PanelItem.ClickHandler clickHandler = (panel, user1, clickType, slot) -> true;

        switch (ChallengeLore.valueOf(loreElement))
        {
        case LEVEL:
        {
            icon = Material.DIRT;
            break;
        }
        case STATUS:
        {
            icon = Material.LEVER;
            break;
        }
        case COUNT:
        {
            icon = Material.REPEATER;
            break;
        }
        case DESCRIPTION:
        {
            icon = Material.WRITTEN_BOOK;
            break;
        }
        case WARNINGS:
        {
            icon = Material.LAVA_BUCKET;
            break;
        }
        case ENVIRONMENT:
        {
            icon = Material.GLASS;
            break;
        }
        case REQUIREMENTS:
        {
            icon = Material.HOPPER;
            break;
        }
        case REWARD_TEXT:
        {
            icon = Material.PAPER;
            break;
        }
        case REWARD_OTHER:
        {
            icon = Material.CHEST;
            break;
        }
        case REWARD_ITEMS:
        {
            icon = Material.TRAPPED_CHEST;
            break;
        }
        case REWARD_COMMANDS:
        {
            icon = Material.COMMAND_BLOCK;
            break;
        }
        default:
        {
            icon = Material.BARRIER;
            break;
        }
        }

        return new PanelItemBuilder().
                name(name).
                icon(icon).
                description(GuiUtils.stringSplit(description, this.addon.getChallengesSettings().getLoreLineLength())).
                clickHandler(clickHandler).
                glow(false).
                build();
    }


    /**
     * This method creates button for challenge level lore element.
     * @param loreElement String that represents current challenge level lore element.
     * @return PanelItem.
     */
    private PanelItem getLevelLoreButton(String loreElement)
    {
        Material icon;
        String name = loreElement;
        List<String> description = new ArrayList<>();
        description.add(this.user.getTranslation(REFERENCE_DESCRIPTION + "lore." + loreElement.toLowerCase()));

        PanelItem.ClickHandler clickHandler = (panel, user1, clickType, slot) -> true;

        switch (LevelLore.valueOf(loreElement))
        {
        case LEVEL_STATUS:
        {
            icon = Material.DIRT;
            break;
        }
        case CHALLENGE_COUNT:
        {
            icon = Material.REPEATER;
            break;
        }
        case UNLOCK_MESSAGE:
        {
            icon = Material.WRITTEN_BOOK;
            break;
        }
        case WAIVER_AMOUNT:
        {
            icon = Material.COMPARATOR;
            break;
        }
        case LEVEL_REWARD_TEXT:
        {
            icon = Material.PAPER;
            break;
        }
        case LEVEL_REWARD_OTHER:
        {
            icon = Material.CHEST;
            break;
        }
        case LEVEL_REWARD_ITEMS:
        {
            icon = Material.TRAPPED_CHEST;
            break;
        }
        case LEVEL_REWARD_COMMANDS:
        {
            icon = Material.COMMAND_BLOCK;
            break;
        }
        default:
        {
            icon = Material.BARRIER;
            break;
        }
        }

        return new PanelItemBuilder().
                name(name).
                icon(icon).
                description(GuiUtils.stringSplit(description, this.addon.getChallengesSettings().getLoreLineLength())).
                clickHandler(clickHandler).
                glow(false).
                build();
    }


    // ---------------------------------------------------------------------
    // Section: Select GUI
    // ---------------------------------------------------------------------


    /**
     * This class opens new GUI that add an element from all available lore values.
     */
    private class AddLoreElementGUI
    {
        private AddLoreElementGUI(Consumer<String> selectedElement)
        {
            PanelBuilder panelBuilder = new PanelBuilder().
                    name(EditLoreGUI.this.user.getTranslation("challenges.gui.title.admin.lore-add")).
                    user(EditLoreGUI.this.user);

            GuiUtils.fillBorder(panelBuilder, 5, Material.MAGENTA_STAINED_GLASS_PANE);

            int currentIndex = 10;

            List<String> values = new ArrayList<>();

            // Populate list with all elements.
            switch (EditLoreGUI.this.lore)
            {
            case CHALLENGES:
                for (ChallengeLore value : ChallengeLore.values())
                {
                    values.add(value.name());
                }
                break;
            case LEVELS:
                for (LevelLore value : LevelLore.values())
                {
                    values.add(value.name());
                }
                break;
            }

            for (String value : values)
            {
                PanelItem item = EditLoreGUI.this.getLoreButton(value);
                if (item != null) {
                    item.setClickHandler((panel, user1, clickType, slot) -> {
                        selectedElement.accept(value);
                        return true;
                    });

                    panelBuilder.item(currentIndex++, item);


                    // Border element
                    if (currentIndex % 9 == 8)
                    {
                        currentIndex += 2;
                    }

                    // Just in case. Should never occur.
                    if (currentIndex % 9 == 0)
                    {
                        currentIndex++;
                    }

                    // Just in case. Should never occur.
                    if (currentIndex > 35)
                    {
                        break;
                    }
                }
            }

            panelBuilder.build();
        }
    }


    /**
     * This class opens new GUI that remove an element from all available lore values.
     */
    private class RemoveLoreElementGUI
    {
        private RemoveLoreElementGUI(BiConsumer<String, Integer> selectedElement)
        {
            PanelBuilder panelBuilder = new PanelBuilder().
                    name(EditLoreGUI.this.user.getTranslation("challenges.gui.title.admin.lore-remove")).
                    user(EditLoreGUI.this.user);

            GuiUtils.fillBorder(panelBuilder, 5, Material.MAGENTA_STAINED_GLASS_PANE);

            int currentIndex = 10;

            List<String> values = EditLoreGUI.this.activeValues;

            for (int i = 0; i < values.size(); i++)
            {
                final int counter = i;

                String value = values.get(counter);
                PanelItem item = EditLoreGUI.this.getLoreButton(value);
                if (item != null) {
                    item.setClickHandler((panel, user1, clickType, slot) -> {
                        selectedElement.accept(value, counter);
                        return true;
                    });

                    panelBuilder.item(currentIndex++, item);

                    // Border element
                    if (currentIndex % 9 == 8)
                    {
                        currentIndex += 2;
                    }

                    // Just in case. Should never occur.
                    if (currentIndex % 9 == 0)
                    {
                        currentIndex++;
                    }

                    // Just in case. Should never occur.
                    if (currentIndex > 35)
                    {
                        break;
                    }
                }
            }

            panelBuilder.build();
        }
    }


    // ---------------------------------------------------------------------
    // Section: Private classes
    // ---------------------------------------------------------------------


    /**
     * This CustomPanelListener allows to move items in current panel.
     */
    private class CustomPanelListener implements PanelListener
    {
        @Override
        public void setup()
        {
        }


        @Override
        public void onInventoryClose(InventoryCloseEvent inventoryCloseEvent)
        {
        }


        @Override
        public void onInventoryClick(User user, InventoryClickEvent event)
        {
            // First row of elements should be ignored, as it contains buttons and blocked slots.
            event.setCancelled(event.getRawSlot() < 9 ||
                    event.getRawSlot() < 35 ||
                    event.getRawSlot() % 9 == 0 ||
                    event.getRawSlot() % 9 == 8);
        }
    }


    // ---------------------------------------------------------------------
    // Section: Enums
    // ---------------------------------------------------------------------


    /**
     * This enum holds all button values in current gui.
     */
    private enum Button
    {
        SAVE,
        ADD,
        REMOVE,
        VIEW,
        RETURN
    }


    /**
     * This enum holds which Lore is edited with current GUI.
     */
    public enum LoreType
    {
        CHALLENGES,
        LEVELS,
    }


    // ---------------------------------------------------------------------
    // Section: Variables
    // ---------------------------------------------------------------------

    /**
     * Lore that will be edited with current GUI.
     */
    private final LoreType lore;

    /**
     * List of lore elements that are currently enabled.
     */
    private List<String> activeValues;


    // ---------------------------------------------------------------------
    // Section: Constants
    // ---------------------------------------------------------------------


    private final static String REFERENCE_DESCRIPTION = "challenges.gui.descriptions.admin.";
}