package io.gitlab.jfronny.libjf.config.impl.ui.tiny.entry;

import io.gitlab.jfronny.commons.throwable.Try;
import io.gitlab.jfronny.libjf.LibJf;
import io.gitlab.jfronny.libjf.config.api.v1.ConfigCategory;
import io.gitlab.jfronny.libjf.config.api.v1.EntryInfo;
import io.gitlab.jfronny.libjf.config.api.v1.type.Type;
import io.gitlab.jfronny.libjf.config.api.v1.ui.tiny.WidgetFactory;
import io.gitlab.jfronny.libjf.config.impl.ui.tiny.WidgetState;
import net.fabricmc.api.EnvType;
import net.fabricmc.api.Environment;
import net.minecraft.client.gui.widget.ButtonWidget;
import net.minecraft.client.gui.widget.TextFieldWidget;
import net.minecraft.text.Text;
import net.minecraft.util.Formatting;

import java.util.LinkedList;
import java.util.List;
import java.util.function.Function;
import java.util.function.UnaryOperator;
import java.util.regex.Pattern;

@Environment(EnvType.CLIENT)
public class EntryInfoWidgetBuilder {
    private static final Pattern INTEGER_ONLY = Pattern.compile("(-?\\d*)");
    private static final Pattern DECIMAL_ONLY = Pattern.compile("-?(\\d+\\.?\\d*|\\d*\\.?\\d+|\\.)");

    public static List<WidgetState<?>> buildWidgets(ConfigCategory config, List<WidgetState<?>> knownStates) {
        List<WidgetState<?>> knownStates2 = new LinkedList<>();
        for (EntryInfo<?> info : config.getEntries()) {
            WidgetState<?> state = initEntry(config, info, knownStates);
            knownStates.add(state);
            knownStates2.add(state);
        }
        return knownStates2;
    }

    private static <T> WidgetState<T> initEntry(ConfigCategory config, EntryInfo<T> info, List<WidgetState<?>> knownStates) {
        Type type = info.getValueType();
        WidgetState<T> state = new WidgetState<>();
        WidgetFactory factory;

        if (type.isInt()) {
            factory = isDiscrete(info)
                    ? slider(info, state, t -> (double)(int)t, Double::intValue, true)
                    : textField(info, state, INTEGER_ONLY, Integer::parseInt, true, info.getMinValue(), info.getMaxValue());
        } else if (type.isLong()) {
            factory = isDiscrete(info)
                    ? slider(info, state, t -> (double)(long)t, Double::longValue, true)
                    : textField(info, state, INTEGER_ONLY, Long::parseLong, true, info.getMinValue(), info.getMaxValue());
        } else if (type.isFloat()) {
            factory = isDiscrete(info)
                    ? slider(info, state, t -> (double)(float)t, Double::floatValue, false)
                    : textField(info, state, DECIMAL_ONLY, Float::parseFloat, false, info.getMinValue(), info.getMaxValue());
        } else if (type.isDouble()) {
            factory = isDiscrete(info)
                    ? slider(info, state, t -> t, t -> t, false)
                    : textField(info, state, DECIMAL_ONLY, Double::parseDouble, false, info.getMinValue(), info.getMaxValue());
        } else if (type.isString()) {
            factory = textField(info, state, null, String::length, true, Math.min(info.getMinValue(), 0), Math.max(info.getMaxValue(), 1));
        } else if (type.isBool()) {
            factory = toggle((EntryInfo<Boolean>) info, (WidgetState<Boolean>) state,
                    value -> !(Boolean) value,
                    value -> Text.literal(value ? "True" : "False").formatted(value ? Formatting.GREEN : Formatting.RED));
        } else if (type.isEnum()) {
            T[] values = type.<T>asEnum().options();
            factory = toggle(info, state, value -> {
                int index = indexOf(values, value) + 1;
                return values[index >= values.length ? 0 : index];
            }, value -> {
                if (type.asClass() == null) {
                    return Text.translatable(config.getTranslationPrefix() + info.getName() + "." + state.cachedValue);
                } else {
                    return Text.translatable(config.getTranslationPrefix() + "enum." + type.getName() + "." + state.cachedValue);
                }
            });
        } else {
            LibJf.LOGGER.error("Unsupported entry type in " + info.getName() + ": " + type.getName() + " - not displaying config control");
            factory = null;
        }

        Try.orThrow(() -> state.initialize(info, knownStates, factory, config.getTranslationPrefix()));
        return state;
    }

    private static int indexOf(Object[] array, Object value) {
        for (int i = 0; i < array.length; i++) {
            if (array[i] == value) return i;
        }
        return -1;
    }

    private static <T> WidgetFactory toggle(EntryInfo<T> info, WidgetState<T> state, UnaryOperator<T> increment, Function<T, Text> valueToText) {
        return (screen, textRenderer) -> {
            final ButtonWidget button = ButtonWidget.builder(valueToText.apply(state.cachedValue), btn -> {
                state.updateCache(increment.apply(state.cachedValue));
                btn.setMessage(valueToText.apply(state.cachedValue));
            }).position(screen.width - 110, 0).size(info.getWidth(), 20).build();
            return new WidgetFactory.Widget(() -> button.setMessage(valueToText.apply(state.cachedValue)), button);
        };
    }

    /**
     * @param info The entry to generate a widget for
     * @param state The state representation of this widget
     * @param pattern The pattern a valid value must abide to
     * @param sizeFetcher A function to get a number for size constraints
     * @param wholeNumber Whether size constraints are whole numbers
     * @param min The minimum size of a valid value
     * @param max The maximum size of a valid value
     */
    private static <T> WidgetFactory textField(EntryInfo<T> info, WidgetState<T> state, Pattern pattern, Function<String, Number> sizeFetcher, boolean wholeNumber, double min, double max) {
        boolean isNumber = pattern != null;
        return (screen, textRenderer) -> {
            TextFieldWidget widget = new TextFieldWidget(textRenderer, screen.width - 110, 0, info.getWidth(), 20, null);

            widget.setText(state.tempValue);
            widget.setTextPredicate(currentInput -> {
                currentInput = currentInput.trim();
                if (!(currentInput.isEmpty() || !isNumber || pattern.matcher(currentInput).matches())) return false;

                Number value = 0;
                boolean inLimits = false;
                state.error = null;
                if (!(isNumber && currentInput.isEmpty()) && !currentInput.equals("-") && !currentInput.equals(".")) {
                    value = sizeFetcher.apply(currentInput);
                    inLimits = value.doubleValue() >= min && value.doubleValue() <= max;
                    state.error = inLimits ? null : Text.literal(value.doubleValue() < min ?
                            "§cMinimum " + (isNumber? "value" : "length") + (wholeNumber ? " is " + (int) min : " is " + min) :
                            "§cMaximum " + (isNumber? "value" : "length") + (wholeNumber ? " is " + (int) max : " is " + max))
                            .formatted(Formatting.RED);
                }

                state.tempValue = currentInput;
                widget.setEditableColor(inLimits? 0xFFFFFFFF : 0xFFFF7777);
                state.inLimits = inLimits;
                screen.done.active = state.knownStates.stream().allMatch(st -> st.inLimits);

                if (inLimits) {
                    state.cachedValue = isNumber ? (T) value : (T) currentInput;
                }

                return true;
            });

            return new WidgetFactory.Widget(() -> widget.setText(state.cachedValue == null ? "" : state.cachedValue.toString()), widget);
        };
    }

    private static <T extends Number> WidgetFactory slider(EntryInfo info, WidgetState state, Function<T, Double> t2d, Function<Double, T> d2t, boolean wholeNumber) {
        double min = info.getMinValue();
        double max = info.getMaxValue();
        if (!isDiscrete(min)) throw new IllegalArgumentException("Attempted to create slider with indiscrete minimum");
        if (!isDiscrete(max)) throw new IllegalArgumentException("Attempted to create slider with indiscrete maximum");
        return (screen, textRenderer) -> {
            CustomSlider slider = new CustomSlider(screen.width - 110, 0, info.getWidth(), 20, Double.parseDouble(state.tempValue), min, max, v -> {
                state.updateCache(d2t.apply(v));
            }, wholeNumber);

            return new WidgetFactory.Widget(() -> slider.setValue(t2d.apply((T) state.cachedValue)), slider);
        };
    }

    private static boolean isDiscrete(EntryInfo<?> info) {
        return isDiscrete(info.getMinValue()) && isDiscrete(info.getMaxValue());
    }

    private static boolean isDiscrete(double number) {
        return !Double.isNaN(number) && Double.isFinite(number);
    }
}