ParseQuery.java

/*
 * Copyright (c) 2015 Spotify AB.
 *
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package com.spotify.heroic.shell.task;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializationFeature;
import com.google.common.base.Joiner;
import com.spotify.heroic.dagger.CoreComponent;
import com.spotify.heroic.grammar.DefaultScope;
import com.spotify.heroic.grammar.Expression;
import com.spotify.heroic.grammar.QueryParser;
import com.spotify.heroic.shell.AbstractShellTaskParams;
import com.spotify.heroic.shell.ShellIO;
import com.spotify.heroic.shell.ShellTask;
import com.spotify.heroic.shell.TaskName;
import com.spotify.heroic.shell.TaskParameters;
import com.spotify.heroic.shell.TaskUsage;
import com.spotify.heroic.time.Clock;
import dagger.Component;
import eu.toolchain.async.AsyncFramework;
import eu.toolchain.async.AsyncFuture;
import java.util.ArrayList;
import java.util.List;
import java.util.stream.Collectors;
import javax.inject.Inject;
import javax.inject.Named;
import org.kohsuke.args4j.Argument;
import org.kohsuke.args4j.Option;

@TaskUsage("Parse a given expression as a query and print their structure")
@TaskName("parse-query")
public class ParseQuery implements ShellTask {
    private final Clock clock;
    private final QueryParser parser;
    private final AsyncFramework async;
    private final ObjectMapper mapper;

    @Inject
    public ParseQuery(
        Clock clock, QueryParser parser, AsyncFramework async,
        @Named("application/json") ObjectMapper mapper
    ) {
        this.clock = clock;
        this.parser = parser;
        this.async = async;
        this.mapper = mapper;
    }

    @Override
    public TaskParameters params() {
        return new Parameters();
    }

    @Override
    public AsyncFuture<Void> run(final ShellIO io, final TaskParameters base) throws Exception {
        final Parameters params = (Parameters) base;
        final ObjectMapper m = mapper.copy();

        if (!params.noIndent) {
            m.enable(SerializationFeature.INDENT_OUTPUT);
        }

        List<Expression> statements = parser.parse(Joiner.on(" ").join(params.query));

        if (params.eval) {
            final Expression.Scope scope = new DefaultScope(clock.currentTimeMillis());
            statements = statements.stream().map(s -> s.eval(scope)).collect(Collectors.toList());
        }

        io.out().println(m.writeValueAsString(statements));
        return async.resolved();
    }

    private static class Parameters extends AbstractShellTaskParams {
        @Option(name = "--no-indent", usage = "Do not indent output")
        private boolean noIndent = false;

        @Option(name = "-e", aliases = "--eval", usage = "Evaluate output")
        private boolean eval = false;

        @Argument(usage = "Query to parse")
        private List<String> query = new ArrayList<>();
    }

    public static ParseQuery setup(final CoreComponent core) {
        return DaggerParseQuery_C.builder().coreComponent(core).build().task();
    }

    @Component(dependencies = CoreComponent.class)
    interface C {
        ParseQuery task();
    }
}