Chat-Transform/src/client/java/io/gitlab/jfronny/chattransform/mixin/TextFieldWidgetMixin.java

package io.gitlab.jfronny.chattransform.mixin;

import io.gitlab.jfronny.chattransform.*;
import net.minecraft.client.gui.DrawableHelper;
import net.minecraft.client.gui.screen.Screen;
import net.minecraft.client.gui.widget.ClickableWidget;
import net.minecraft.client.gui.widget.TextFieldWidget;
import net.minecraft.client.util.math.MatrixStack;
import net.minecraft.text.Text;
import org.objectweb.asm.Opcodes;
import org.spongepowered.asm.mixin.*;
import org.spongepowered.asm.mixin.injection.*;
import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;

import java.util.Map;
import java.util.Set;
import java.util.function.Predicate;
import java.util.stream.Collectors;

@Mixin(TextFieldWidget.class)
public abstract class TextFieldWidgetMixin extends ClickableWidget implements ITextFieldWidget {
    public TextFieldWidgetMixin(int x, int y, int width, int height, Text message) {
        super(x, y, width, height, message);
    }

    @Shadow public abstract String getText();
    @Shadow private String text;
    @Shadow private int selectionStart;
    @Shadow private int selectionEnd;
    @Shadow private boolean drawsBackground;
    @Shadow public abstract int getCharacterX(int index);
    @Shadow public abstract boolean isVisible();
    @Shadow public abstract void setCursor(int cursor);

    @Shadow private Predicate<String> textPredicate;
    @Unique private boolean chattransform$active = false;
    @Override
    public void chattransform$activate() {
        chattransform$active = true;
        ChatTransform.LOG.info("Activated widget " + this);
    }

    @Unique private boolean chattransform$shouldTransform = false;
    @Redirect(method = "write(Ljava/lang/String;)V", at = @At(value = "FIELD", target = "Lnet/minecraft/client/gui/widget/TextFieldWidget;text:Ljava/lang/String;", opcode = Opcodes.PUTFIELD))
    void transformBeforeWrite(TextFieldWidget instance, String value, String tx) {
        if (chattransform$active) {
            if (selectionStart == selectionEnd && tx.length() == 1 && !Screen.hasAltDown() && !getText().startsWith("/")) {
                chattransform$shouldTransform = true;
            } else {
                chattransform$start = null;
            }
        }
        this.text = value;
    }

    @Inject(method = "write(Ljava/lang/String;)V", at = @At("TAIL"))
    void transformAfterWrite(String text, CallbackInfo ci) {
        if (chattransform$shouldTransform) {
            chattransform$shouldTransform = false;
            transform();
        }
    }

    @Inject(method = "setCursor(I)V", at = @At("TAIL"))
    void updateStartOnSetCursor(int cursor, CallbackInfo ci) {
        chattransform$start = null;
    }

    @Unique private Integer chattransform$start = null;
    void transform() {
        if (chattransform$start == null) chattransform$start = selectionStart - 1;
        if (chattransform$start < 0) chattransform$start = 0;
        if (chattransform$start >= selectionStart) return;
        String currentString = getText().substring(chattransform$start, selectionStart);
        Set<Map.Entry<String, String>> complete = getStartingWith(currentString);
        // Exact match
        if (Cfg.substitutions.containsKey(currentString) && complete.size() == 1
                && substitute(chattransform$start, selectionStart, Cfg.substitutions.get(currentString))) {
            chattransform$start = selectionStart;
            return;
        }
        if (complete.isEmpty()) {
            if (chattransform$start == selectionStart - 1) {
                // Nothing starts with this char
                chattransform$start++;
            } else {
                // Something previously started with this...
                String previousString = getText().substring(chattransform$start, selectionStart - 1);
                if (Cfg.substitutions.containsKey(previousString)
                        // ...and matched -> replace
                        && substitute(chattransform$start, selectionStart - 1, Cfg.substitutions.get(previousString))) {
                    setCursor(selectionStart + 1);
                } else {
                    // ...and didn't match -> move transform start and call transform again (substring might have matched)
                    chattransform$start++;
                    transform();
                }
            }
        }
    }

    @Override
    public String chattransform$finalize() {
        String str = getText();
        if (chattransform$start == null || chattransform$start >= selectionStart) return str;
        String currentString = str.substring(chattransform$start, selectionStart);
        if (!Cfg.substitutions.containsKey(currentString)
                || !substitute(chattransform$start, selectionStart, Cfg.substitutions.get(currentString))) {
            chattransform$start++;
            return chattransform$finalize();
        }
        return str;
    }

    boolean substitute(int start, int end, String substitution) {
        ChatTransform.LOG.info("Transforming " + getText().substring(start, end) + " to " + substitution);
        String sub = text.substring(0, start) + substitution + text.substring(end);
        if (textPredicate.test(sub)) {
            this.text = sub;
            int oldLen = end - start;
            int newLen = substitution.length();
            if (selectionStart > end) selectionStart -= oldLen + newLen;
            else if (selectionStart > start) selectionStart = start + newLen;
            selectionEnd = selectionStart;
            return true;
        } else return false;
    }

    Set<Map.Entry<String, String>> getStartingWith(String start) {
        return Cfg.substitutions.entrySet().stream().filter(s -> s.getKey().startsWith(start)).collect(Collectors.toUnmodifiableSet());
    }

    @Inject(method = "renderButton(Lnet/minecraft/client/util/math/MatrixStack;IIF)V", at = @At(value = "TAIL"))
    void renderTransformStart(MatrixStack matrices, int mouseX, int mouseY, float delta, CallbackInfo ci) {
        if (isVisible() && chattransform$start != null) {
            int x = getCharacterX(chattransform$start);
            int y = this.drawsBackground ? this.getY() + (this.height - 8) / 2 : this.getY();
            DrawableHelper.fill(matrices, x, y - 1, x + 1, y + 1 + 9, 0x7f0000ff);
        }
    }
}