com.google.api.codegen.configgen.ConfigGenerator.java Source code

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Here is the source code for com.google.api.codegen.configgen.ConfigGenerator.java

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/* Copyright 2017 Google LLC
 *
 * Licensed 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
 *
 *      https://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.google.api.codegen.configgen;

import static com.google.common.base.CharMatcher.whitespace;

import com.google.api.codegen.configgen.nodes.ConfigNode;
import com.google.api.codegen.configgen.nodes.FieldConfigNode;
import com.google.api.codegen.configgen.nodes.ListItemConfigNode;
import com.google.api.codegen.configgen.nodes.ScalarConfigNode;
import com.google.api.tools.framework.util.VisitsBefore;
import com.google.common.base.Splitter;
import com.google.common.base.Strings;
import java.util.ArrayList;
import java.util.List;

/** Generates the text of the gapic yaml file from a ConfigNode representation. */
public class ConfigGenerator extends NodeVisitor {
    private static final int MAX_LINE_WIDTH = 78;

    private static final int TAB_WIDTH = 2;

    private final int indent;

    private final StringBuilder configBuilder = new StringBuilder();

    public ConfigGenerator(int indent) {
        this.indent = indent;
    }

    @VisitsBefore
    void generate(FieldConfigNode node) {
        appendComment(node.getComment().generate());
        appendIndent();

        if (node.getText().isEmpty()) {
            configBuilder.append(visitFieldValue(indent, node.getChild()).trim());
        } else {
            configBuilder.append(node.getText()).append(":")
                    .append(visitFieldValue(indent + TAB_WIDTH, node.getChild()));
        }
    }

    @VisitsBefore
    void generate(ListItemConfigNode node) {
        appendComment(node.getComment().generate());
        ConfigGenerator childGenerator = new ConfigGenerator(indent);
        childGenerator.visit(node.getChild());
        String child = childGenerator.toString().trim();
        boolean isFirst = true;
        for (String line : Splitter.on(System.lineSeparator()).split(child)) {
            if (!isFirst) {
                configBuilder.append(whitespace().trimTrailingFrom(line));
            } else if (line.trim().startsWith("#")) {
                appendIndent().append(whitespace().trimTrailingFrom(line));
            } else {
                configBuilder.append(Strings.repeat(" ", indent - TAB_WIDTH)).append("- ").append(line.trim());
                isFirst = false;
            }
            configBuilder.append(System.lineSeparator());
        }
    }

    @VisitsBefore
    void generate(ScalarConfigNode node) {
        appendIndent().append(node.getText()).append(System.lineSeparator());
    }

    private void appendComment(String comment) {
        if (comment.isEmpty()) {
            return;
        }

        for (String commentLine : Splitter.on("\n").split(comment)) {
            int startIndex = whitespace().negate().indexIn(commentLine);
            if (startIndex < 0) {
                appendIndent().append("#").append(System.lineSeparator());
                continue;
            }

            for (String line : breakLine(commentLine.trim(), MAX_LINE_WIDTH - indent - startIndex)) {
                appendIndent().append("# ");
                appendIndent(startIndex).append(line).append(System.lineSeparator());
            }
        }
    }

    private List<String> breakLine(String line, int maxWidth) {
        List<String> lines = new ArrayList<>();
        while (line.length() > maxWidth) {
            int split = lineWrapIndex(line, maxWidth);
            lines.add(line.substring(0, split).trim());
            line = line.substring(split).trim();
        }
        lines.add(line.trim());
        return lines;
    }

    private int lineWrapIndex(String line, int maxWidth) {
        int index = whitespace().lastIndexIn(line.substring(0, maxWidth + 1));
        if (index >= 0) {
            return index;
        }

        index = whitespace().indexIn(line, maxWidth);
        if (index >= 0) {
            return index;
        }

        return line.length();
    }

    private StringBuilder appendIndent() {
        return appendIndent(indent);
    }

    private StringBuilder appendIndent(int indent) {
        return configBuilder.append(Strings.repeat(" ", indent));
    }

    private String visitFieldValue(int indent, ConfigNode childNode) {
        if (!childNode.isPresent()) {
            return String.format(" []%n");
        }

        ConfigGenerator childGenerator = new ConfigGenerator(indent);
        childGenerator.visit(childNode);
        String child = childGenerator.toString();
        if (childNode instanceof ScalarConfigNode) {
            return String.format(" %s%n", child.trim());
        }

        return System.lineSeparator() + child;
    }

    @Override
    public String toString() {
        return configBuilder.toString();
    }
}