package gregtech.common.gui.modularui;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.stream.Collectors;

import javax.annotation.Nullable;
import javax.annotation.ParametersAreNonnullByDefault;

import com.gtnewhorizons.modularui.api.drawable.IDrawable;
import com.gtnewhorizons.modularui.api.math.Pos2d;

import gregtech.api.enums.SteamVariant;
import gregtech.api.gui.modularui.SteamTexture;
import gregtech.api.recipe.BasicUIProperties;
import gregtech.api.util.MethodsReturnNonnullByDefault;

@ParametersAreNonnullByDefault
@MethodsReturnNonnullByDefault
public class UIHelper {

    /**
     * Iterates over candidates for slot placement.
     */
    @SuppressWarnings("SimplifyStreamApiCallChains")
    public static void forEachSlots(ForEachSlot forEachItemInputSlot, ForEachSlot forEachItemOutputSlot,
        ForEachSlot forEachSpecialSlot, ForEachSlot forEachFluidInputSlot, ForEachSlot forEachFluidOutputSlot,
        IDrawable itemSlotBackground, IDrawable fluidSlotBackground, BasicUIProperties uiProperties, int itemInputCount,
        int itemOutputCount, int fluidInputCount, int fluidOutputCount, SteamVariant steamVariant, Pos2d offset) {
        List<Pos2d> itemInputPositions = uiProperties.itemInputPositionsGetter.apply(itemInputCount)
            .stream()
            .map(p -> p.add(offset))
            .collect(Collectors.toList());
        for (int i = 0; i < itemInputPositions.size(); i++) {
            forEachItemInputSlot.accept(
                i,
                getBackgroundsForSlot(itemSlotBackground, uiProperties, false, false, i, false, steamVariant),
                itemInputPositions.get(i));
        }

        List<Pos2d> itemOutputPositions = uiProperties.itemOutputPositionsGetter.apply(itemOutputCount)
            .stream()
            .map(p -> p.add(offset))
            .collect(Collectors.toList());
        for (int i = 0; i < itemOutputPositions.size(); i++) {
            forEachItemOutputSlot.accept(
                i,
                getBackgroundsForSlot(itemSlotBackground, uiProperties, false, true, i, false, steamVariant),
                itemOutputPositions.get(i));
        }

        forEachSpecialSlot.accept(
            0,
            getBackgroundsForSlot(itemSlotBackground, uiProperties, false, false, 0, true, steamVariant),
            uiProperties.specialItemPositionGetter.get()
                .add(offset));

        List<Pos2d> fluidInputPositions = uiProperties.fluidInputPositionsGetter.apply(fluidInputCount)
            .stream()
            .map(p -> p.add(offset))
            .collect(Collectors.toList());
        for (int i = 0; i < fluidInputPositions.size(); i++) {
            forEachFluidInputSlot.accept(
                i,
                getBackgroundsForSlot(fluidSlotBackground, uiProperties, true, false, i, false, steamVariant),
                fluidInputPositions.get(i));
        }

        List<Pos2d> fluidOutputPositions = uiProperties.fluidOutputPositionsGetter.apply(fluidOutputCount)
            .stream()
            .map(p -> p.add(offset))
            .collect(Collectors.toList());
        for (int i = 0; i < fluidOutputPositions.size(); i++) {
            forEachFluidOutputSlot.accept(
                i,
                getBackgroundsForSlot(fluidSlotBackground, uiProperties, true, true, i, false, steamVariant),
                fluidOutputPositions.get(i));
        }
    }

    /**
     * @return Display positions for GUI, including border (18x18 size)
     */
    public static List<Pos2d> getItemInputPositions(int itemInputCount) {
        return switch (itemInputCount) {
            case 0 -> Collections.emptyList();
            case 1 -> getGridPositions(itemInputCount, 52, 24, 1, 1);
            case 2 -> getGridPositions(itemInputCount, 34, 24, 2, 1);
            case 3 -> getGridPositions(itemInputCount, 16, 24, 3, 1);
            case 4 -> getGridPositions(itemInputCount, 34, 15, 2, 2);
            case 5, 6 -> getGridPositions(itemInputCount, 16, 15, 3, 2);
            default -> getGridPositions(itemInputCount, 16, 6, 3);
        };
    }

    /**
     * @return Display positions for GUI, including border (18x18 size)
     */
    public static List<Pos2d> getItemOutputPositions(int itemOutputCount) {
        return switch (itemOutputCount) {
            case 0 -> Collections.emptyList();
            case 1 -> getGridPositions(itemOutputCount, 106, 24, 1, 1);
            case 2 -> getGridPositions(itemOutputCount, 106, 24, 2, 1);
            case 3 -> getGridPositions(itemOutputCount, 106, 24, 3, 1);
            case 4 -> getGridPositions(itemOutputCount, 106, 15, 2, 2);
            case 5, 6 -> getGridPositions(itemOutputCount, 106, 15, 3, 2);
            default -> getGridPositions(itemOutputCount, 106, 6, 3);
        };
    }

    /**
     * @return Display position for GUI, including border (18x18 size)
     */
    public static Pos2d getSpecialItemPosition() {
        return new Pos2d(124, 62);
    }

    /**
     * @return Display positions for GUI, including border (18x18 size)
     */
    public static List<Pos2d> getFluidInputPositions(int fluidInputCount) {
        List<Pos2d> results = new ArrayList<>();
        int base = Math.max(70 - (fluidInputCount * 18), 16);
        int x = 0;
        for (int i = 0; i < fluidInputCount; i++) {
            results.add(new Pos2d(base + x, 62));
            x += 18;
        }
        return results;
    }

    /**
     * @return Display positions for GUI, including border (18x18 size)
     */
    public static List<Pos2d> getFluidOutputPositions(int fluidOutputCount) {
        List<Pos2d> results = new ArrayList<>();
        int x = 106;
        for (int i = 0; i < fluidOutputCount; i++) {
            results.add(new Pos2d(x, 62));
            x += 18;
        }
        return results;
    }

    public static List<Pos2d> getGridPositions(int totalCount, int xOrigin, int yOrigin, int xDirMaxCount,
        int yDirMaxCount) {
        // 18 pixels to get to a new grid for placing an item tile since they are 16x16 and have 1 pixel buffers
        // around them.
        int distance = 18;

        List<Pos2d> results = new ArrayList<>();
        int count = 0;
        loop: for (int j = 0; j < yDirMaxCount; j++) {
            for (int i = 0; i < xDirMaxCount; i++) {
                if (count >= totalCount) break loop;
                results.add(new Pos2d(xOrigin + i * distance, yOrigin + j * distance));
                count++;
            }
        }
        return results;
    }

    public static List<Pos2d> getGridPositions(int totalCount, int xOrigin, int yOrigin, int xDirMaxCount) {
        return getGridPositions(totalCount, xOrigin, yOrigin, xDirMaxCount, 100);
    }

    private static IDrawable[] getBackgroundsForSlot(IDrawable base, BasicUIProperties uiProperties, boolean isFluid,
        boolean isOutput, int index, boolean isSpecial, SteamVariant steamVariant) {
        IDrawable overlay = getOverlay(uiProperties, isFluid, isOutput, index, isSpecial, steamVariant);
        if (overlay != null) {
            return new IDrawable[] { base, overlay };
        } else {
            return new IDrawable[] { base };
        }
    }

    @Nullable
    private static IDrawable getOverlay(BasicUIProperties uiProperties, boolean isFluid, boolean isOutput, int index,
        boolean isSpecial, SteamVariant steamVariant) {
        if (isSpecial && !uiProperties.useSpecialSlot) {
            return null;
        }
        if (steamVariant != SteamVariant.NONE) {
            SteamTexture steamTexture = uiProperties.getOverlayForSlotSteam(index, isFluid, isOutput, isSpecial);
            if (steamTexture != null) {
                return steamTexture.get(steamVariant);
            } else {
                return null;
            }
        } else {
            return uiProperties.getOverlayForSlot(index, isFluid, isOutput, isSpecial);
        }
    }

    @FunctionalInterface
    public interface ForEachSlot {

        void accept(int index, IDrawable[] backgrounds, Pos2d pos);
    }
}