SurvivalFabric/src/main/java/wtf/hak/survivalfabric/mixin/PlayerManagerMixin.java

package wtf.hak.survivalfabric.mixin;

import com.mojang.authlib.minecraft.client.MinecraftClient;
import net.minecraft.network.ClientConnection;
import net.minecraft.network.message.MessageType;
import net.minecraft.network.message.SignedMessage;
import net.minecraft.server.MinecraftServer;
import net.minecraft.server.PlayerManager;
import net.minecraft.server.network.ConnectedClientData;
import net.minecraft.server.network.ServerPlayerEntity;
import net.minecraft.text.Text;
import net.minecraft.world.GameMode;
import org.spongepowered.asm.mixin.Mixin;
import org.spongepowered.asm.mixin.injection.At;
import org.spongepowered.asm.mixin.injection.Inject;
import org.spongepowered.asm.mixin.injection.ModifyArg;
import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
import wtf.hak.survivalfabric.commands.SpectatorCommand;
import wtf.hak.survivalfabric.config.ConfigManager;

import java.awt.*;
import java.beans.Expression;
import java.util.Objects;
import java.util.Set;

@Mixin(PlayerManager.class)
public abstract class PlayerManagerMixin {

    @Inject(method = {"onPlayerConnect"}, at = {@At(value = "INVOKE", target = "Lnet/minecraft/server/PlayerManager;broadcast(Lnet/minecraft/text/Text;Z)V")})
    public void onPlayerConnect(ClientConnection connection, ServerPlayerEntity player, ConnectedClientData clientData, CallbackInfo ci) {
        if(ConfigManager.getConfig().joinMessageEnabled && !player.getServer().isSingleplayer()) {
            Text text = Text.literal(String.format(ConfigManager.getConfig().joinMessage, player.getName().getString()));
            player.sendMessage(text, false);
        }
    }

    @ModifyArg(method = {"onPlayerConnect"}, at = @At(value = "INVOKE", target = "Lnet/minecraft/server/PlayerManager;broadcast(Lnet/minecraft/text/Text;Z)V"))
    private Text onPlayerConnect(Text text) {
        if(ConfigManager.getConfig().joinMessageEnabled) {
            String name = text.getString().split(" ")[0];
            return Text.literal(String.format(ConfigManager.getConfig().joinMessage, name));
        } else
            return text;
    }

    @Inject(method = {"remove"}, at = {@At("HEAD")})
    public void onPlayerLeave(ServerPlayerEntity player, CallbackInfo ci) {
        if(SpectatorCommand.spectating.containsKey(player)) {
            SpectatorCommand.LocationData loc = SpectatorCommand.spectating.remove(player);
            player.teleport(loc.world, loc.x,loc.y,loc.z, Set.of(), loc.yaw, loc.pitch, false);
            player.changeGameMode(GameMode.SURVIVAL);
        }
    }

    @Inject(method = {"broadcast(Lnet/minecraft/network/message/SignedMessage;Lnet/minecraft/server/network/ServerPlayerEntity;Lnet/minecraft/network/message/MessageType$Parameters;)V"}, at = {@At("HEAD")}, cancellable = true)
    private void onBroadcast(SignedMessage message, ServerPlayerEntity sender, MessageType.Parameters parameters, CallbackInfo ci) {
        if(sender != null && ConfigManager.getConfig().chatMessageEnabled) {
            String rawMessage = message.getContent().getString().trim();
            if(sender != null && ConfigManager.getConfig().chatCalcEnabled && rawMessage.endsWith("=")) {
                String expression = rawMessage.substring(0, rawMessage.length() - 1).trim();
                try {
                    String result = String.valueOf(evaluateExpression(expression));
                    if(rawMessage.contains(" ")) rawMessage += " ";
                    rawMessage += (result.endsWith(".0")) ? result.substring(0, result.length() - 2) : result;
                } catch (Exception e) {}
            }
            Text text = Text.literal(String.format(ConfigManager.getConfig().chatMessage, sender.getName().getString(), rawMessage));
            sender.getServer().getPlayerManager().broadcast(text, false);
            ci.cancel();
        } else if (sender != null && ConfigManager.getConfig().chatCalcEnabled) {
            String rawMessage = message.getContent().getString().trim();
            if (rawMessage.endsWith("=")) {
                String expression = rawMessage.substring(0, rawMessage.length() - 1).trim();
                try {
                    String result = String.valueOf(evaluateExpression(expression));
                    if(rawMessage.contains(" ")) rawMessage += " ";
                    rawMessage += (result.endsWith(".0")) ? result.substring(0, result.length() - 2) : result;
                    Text formattedMessage = Text.literal("<" + sender.getName().getString() + "> " + rawMessage);
                    sender.getServer().getPlayerManager().broadcast(formattedMessage, false);
                    ci.cancel();
                } catch (Exception e) {}
            }
        }
    }

    private double evaluateExpression(String expression) {
        return evaluate(expression.replaceAll("\\s", ""), new int[]{0});
    }

    private double evaluate(String expr, int[] index) {
        double value = parseTerm(expr, index);
        while (index[0] < expr.length()) {
            char op = expr.charAt(index[0]);
            if (op != '+' && op != '-') break;
            index[0]++;
            double nextTerm = parseTerm(expr, index);
            value = (op == '+') ? value + nextTerm : value - nextTerm;
        }
        return value;
    }

    private double parseTerm(String expr, int[] index) {
        double value = parseFactor(expr, index);
        while (index[0] < expr.length()) {
            char op = expr.charAt(index[0]);
            if (op != '*' && op != '/') break;
            index[0]++;
            double nextFactor = parseFactor(expr, index);
            value = (op == '*') ? value * nextFactor : value / nextFactor;
        }
        return value;
    }

    private double parseFactor(String expr, int[] index) {
        if (expr.charAt(index[0]) == '(') {
            index[0]++;
            double value = evaluate(expr, index);
            index[0]++; // Skip closing ')'
            return value;
        }

        int start = index[0];
        while (index[0] < expr.length() && (Character.isDigit(expr.charAt(index[0])) || expr.charAt(index[0]) == '.')) {
            index[0]++;
        }
        return Double.parseDouble(expr.substring(start, index[0]));
    }
}