/*
 * WorldEdit, a Minecraft world manipulation toolkit
 * Copyright (C) sk89q <http://www.sk89q.com>
 * Copyright (C) WorldEdit team and contributors
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */

package com.sk89q.worldedit.extension.factory.parser.mask;

import com.fastasyncworldedit.core.configuration.Caption;
import com.fastasyncworldedit.core.extension.factory.parser.AliasedParser;
import com.google.common.collect.ImmutableList;
import com.sk89q.worldedit.WorldEdit;
import com.sk89q.worldedit.extension.input.InputParseException;
import com.sk89q.worldedit.extension.input.ParserContext;
import com.sk89q.worldedit.function.mask.ExpressionMask;
import com.sk89q.worldedit.function.mask.Mask;
import com.sk89q.worldedit.internal.expression.Expression;
import com.sk89q.worldedit.internal.expression.ExpressionException;
import com.sk89q.worldedit.internal.registry.InputParser;
import com.sk89q.worldedit.math.Vector3;
import com.sk89q.worldedit.regions.shape.WorldEditExpressionEnvironment;
import com.sk89q.worldedit.session.SessionOwner;
import com.sk89q.worldedit.util.formatting.text.TextComponent;

import java.util.List;
import java.util.function.IntSupplier;
import java.util.stream.Stream;

//FAWE start - aliased
public class ExpressionMaskParser extends InputParser<Mask> implements AliasedParser {

    private final List<String> aliases = ImmutableList.of("=");
    //FAWE end

    public ExpressionMaskParser(WorldEdit worldEdit) {
        super(worldEdit);
    }

    @Override
    public Stream<String> getSuggestions(String input) {
        if (input.isEmpty()) {
            return Stream.of("=");
        }
        return Stream.empty();
    }

    @Override
    public Mask parseFromInput(String input, ParserContext context) throws InputParseException {
        if (!input.startsWith("=")) {
            return null;
        }

        //FAWE start - richer parsing
        if (input.charAt(1) == '[') {
            int end = input.lastIndexOf(']');
            if (end == -1) {
                return null;
            }
            input = input.substring(2, end);
        } else {
            input = input.substring(1);
        }
        //FAWE end

        try {
            //FAWE start - richer parsing
            Expression exp = Expression.compile(input, "x", "y", "z");
            //FAWE end
            WorldEditExpressionEnvironment env = new WorldEditExpressionEnvironment(
                    context.requireExtent(), Vector3.ONE, Vector3.ZERO);
            exp.setEnvironment(env);
            if (context.getActor() != null) {
                SessionOwner owner = context.getActor();
                IntSupplier timeout = () -> WorldEdit.getInstance().getSessionManager().get(owner).getTimeout();
                return new ExpressionMask(exp, timeout);
            }
            return new ExpressionMask(exp);
        } catch (ExpressionException e) {
            throw new InputParseException(Caption.of(
                    "worldedit.error.parser.invalid-expression",
                    TextComponent.of(e.getMessage())
            ));
        }
    }

    //FAWE start - aliased
    @Override
    public List<String> getMatchedAliases() {
        return aliases;
    }
    //FAWE end

}
