package net.knarcraft.blacksmith.util;

import net.knarcraft.blacksmith.container.ActionCost;
import net.knarcraft.blacksmith.formatting.Translatable;
import net.knarcraft.blacksmith.property.CostModifyAction;
import net.knarcraft.blacksmith.property.CostType;
import net.knarcraft.knarlib.formatting.FormatBuilder;
import net.knarcraft.knarlib.util.TabCompletionHelper;
import org.bukkit.command.CommandSender;
import org.bukkit.entity.Player;
import org.bukkit.inventory.ItemStack;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;

import java.util.Arrays;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

/**
 * A helper class for setting action costs
 */
public final class CostHelper {

    private CostHelper() {

    }

    /**
     * Parses a simple double cost
     *
     * @param commandSender <p>The command sender to notify of any problems</p>
     * @param costString    <p>The string to parse into a cost</p>
     * @return <p>The parsed cost, or null if not a valid number</p>
     */
    @Nullable
    public static Double parseSimpleCost(@NotNull CommandSender commandSender,
                                         @NotNull String costString) throws IllegalArgumentException {
        try {
            double cost = Double.parseDouble(costString);
            if (cost < 0) {
                throw new NumberFormatException();
            }
            return cost;
        } catch (NumberFormatException exception) {
            new FormatBuilder(Translatable.DOUBLE_COST_REQUIRED).error(commandSender);
            return null;
        }
    }

    /**
     * Shows tab-completion actions for altering a cost
     *
     * @param arguments <p>The arguments given by the user</p>
     * @return <p>The available tab-complete options</p>
     */
    public static @Nullable List<String> tabCompleteCost(@NotNull String[] arguments) {
        if (arguments.length == 1) {
            return List.of("simple", "advanced");
        } else if (arguments.length == 2) {
            if (arguments[0].equalsIgnoreCase("simple")) {
                return List.of();
            } else {
                return TabCompletionHelper.filterMatchingStartsWith(TabCompletionHelper.getEnumList(CostModifyAction.class), arguments[1]);
            }
        } else if (arguments.length == 3) {
            if (arguments[0].equalsIgnoreCase("simple")) {
                return List.of();
            } else {
                return TabCompletionHelper.filterMatchingStartsWith(TabCompletionHelper.getEnumList(CostType.class), arguments[2]);
            }
        } else if (arguments.length == 4) {
            CostType costType = CostType.parse(arguments[2]);
            if (costType == null) {
                return null;
            }
            return switch (costType) {
                case PERMISSION -> TabCompletionHelper.tabCompletePermission(arguments[3]);
                case ECONOMY -> List.of("0.5", "1", "10");
                case EXP -> List.of("1, 5, 10");
                case ITEM -> List.of();
            };
        }
        return List.of();
    }

    /**
     * Modifies the cost of an action
     *
     * @param costAction   <p>The action to perform on the cost</p>
     * @param costTypeName <p>The name of the cost to modify, or null if clearing costs</p>
     * @param costValue    <p>The value of the new cost, or null if clearing costs</p>
     * @param oldCost      <p>The previous cost of the action</p>
     * @param player       <p>The player attempting to alter the action cost</p>
     * @return <p>The modified action cost, or null if something went wrong</p>
     */
    @Nullable
    public static ActionCost modifyActionCost(@NotNull String costAction, @Nullable String costTypeName,
                                              @Nullable String costValue, @NotNull ActionCost oldCost,
                                              @NotNull Player player) {
        CostType costType;
        if (costTypeName != null) {
            costType = CostType.parse(costTypeName);
        } else {
            costType = null;
        }

        CostModifyAction action = CostModifyAction.fromString(costAction);
        if (action == null) {
            return null;
        }

        if (action != CostModifyAction.CLEAR && (costType == null || costValue == null)) {
            player.sendMessage("Invalid cost type or value specified!");
            return null;
        }

        return switch (action) {
            case CLEAR -> clearActionCost(costType, oldCost);
            case ADD -> addActionCost(costType, costValue, oldCost, player);
            case SET -> setActionCost(costType, costValue, player);
        };
    }

    /**
     * Sets the cost to the specified value
     *
     * @param costType  <p>The type of cost to set</p>
     * @param costValue <p>The value of the new cost</p>
     * @param player    <p>The player to alert if the cost cannot be properly set</p>
     * @return <p>The new action cost</p>
     */
    public static ActionCost setActionCost(@NotNull CostType costType, @NotNull String costValue,
                                           @NotNull Player player) {
        return parseCost(costType, costValue, new ActionCost(), player);
    }

    /**
     * Modifies a value for the specified action cost
     *
     * @param costType  <p>The type of cost to modify</p>
     * @param costValue <p>The new value of the cost</p>
     * @param oldCost   <p>The cost to modify</p>
     * @param player    <p>The player to alert if the cost cannot be properly set</p>
     * @return <p>The new action cost</p>
     */
    public static ActionCost addActionCost(@NotNull CostType costType, @NotNull String costValue,
                                           @NotNull ActionCost oldCost, @NotNull Player player) {
        return parseCost(costType, costValue, oldCost, player);
    }

    /**
     * Clears an action cost
     *
     * @param costType <p>The type of action cost to clear, or null if clearing all action costs</p>
     * @param oldCost  <p>The old cost to modify, or null if clearing all action costs</p>
     * @return <p>The modified cost</p>
     */
    public static ActionCost clearActionCost(@Nullable CostType costType, @Nullable ActionCost oldCost) {
        // Clears one or all fields of a cost
        if (costType == null || oldCost == null) {
            return new ActionCost();
        } else {
            return switch (costType) {
                case EXP -> oldCost.changeExpCost(0);
                case ITEM -> oldCost.changeItemCost(null);
                case ECONOMY -> oldCost.changeMonetaryCost(0);
                case PERMISSION -> oldCost.changePermissionCost(Set.of());
            };
        }
    }

    /**
     * Parses an advanced action cost
     *
     * @param costType <p>The type of cost to parse</p>
     * @param value    <p>The value to parse</p>
     * @param oldCost  <p>The old cost to modify</p>
     * @param player   <p>The player changing the value</p>
     * @return <p>The new action cost, or null if the process failed.</p>
     */
    @Nullable
    private static ActionCost parseCost(@NotNull CostType costType, @NotNull String value, @NotNull ActionCost oldCost,
                                        @NotNull Player player) {
        switch (costType) {
            case ECONOMY:
                double economyCost = Double.parseDouble(value);
                if (economyCost < 0) {
                    new FormatBuilder("Cost cannot be negative!").error(player);
                    return null;
                }
                return oldCost.changeMonetaryCost(economyCost);
            case ITEM:
                ItemStack itemCost = player.getInventory().getItemInMainHand();
                if (itemCost.getType().isAir()) {
                    new FormatBuilder("You have no item in your main hand").error(player);
                    return null;
                }
                return oldCost.changeItemCost(itemCost);
            case PERMISSION:
                Set<String> permissionSet = new HashSet<>(Arrays.asList(value.split(",")));
                return oldCost.changePermissionCost(permissionSet);
            case EXP:
                int expCost = Integer.parseInt(value);
                if (expCost < 0) {
                    new FormatBuilder("Exp cost cannot be negative!").error(player);
                    return null;
                }
                return oldCost.changeExpCost(expCost);
            default:
                return null;
        }
    }

}