// Copyright (C) 2017 The Android Open Source Project
//
// 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
//
// 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.googlesource.gerrit.plugins.its.base.workflow.action;

import com.google.common.base.Strings;
import com.google.common.io.CharStreams;
import com.google.gerrit.server.config.SitePath;
import com.google.inject.Inject;
import com.google.inject.ProvisionException;
import com.google.template.soy.SoyFileSet;
import com.google.template.soy.data.SanitizedContent;
import com.google.template.soy.tofu.SoyTofu;
import com.googlesource.gerrit.plugins.its.base.its.ItsFacade;
import com.googlesource.gerrit.plugins.its.base.workflow.ActionRequest;
import com.googlesource.gerrit.plugins.its.base.workflow.Property;
import java.io.File;
import java.io.IOException;
import java.io.Reader;
import java.io.StringWriter;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;
import org.apache.commons.lang.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Adds a short predefined comments to an issue.
 *
 * <p>Comments are added for merging, abandoning, restoring of changes and adding of patch sets.
 */
public class AddSoyComment implements Action {
  private static final Logger log = LoggerFactory.getLogger(AddSoyComment.class);

  public interface Factory {
    AddSoyComment create();
  }

  /** Directory (relative to site) to search templates in */
  private static final String ITS_TEMPLATE_DIR =
      "etc" + File.separator + "its" + File.separator + "templates";

  private final ItsFacade its;
  private final Path sitePath;
  protected HashMap<String, Object> soyContext;

  @Inject
  public AddSoyComment(@SitePath Path sitePath, ItsFacade its) {
    this.sitePath = sitePath;
    this.its = its;
  }

  private HashMap getSoyContext(Set<Property> properties) {
    HashMap<String, Object> soyContext = new HashMap<>();
    for (Property property : properties) {
      String key = property.getKey();
      if (!Strings.isNullOrEmpty(key)) {
        String value = property.getValue();
        if (!Strings.isNullOrEmpty(value)) {
          soyContext.put(key, value);
        }
      }
    }

    return soyContext;
  }

  private String soyTemplate(SoyFileSet.Builder builder, String template, SanitizedContent.ContentKind kind, Set<Property> properties) {
    Path templateDir = sitePath.resolve(ITS_TEMPLATE_DIR);
    Path templatePath = templateDir.resolve(template + ".soy");
    String content;

    try (Reader r = Files.newBufferedReader(templatePath, StandardCharsets.UTF_8)) {
       content = CharStreams.toString(r);
    } catch (IOException err) {
      throw new ProvisionException(
          "Failed to read template file " + templatePath.toAbsolutePath().toString(), err);
    }

    builder.add(content, templatePath.toAbsolutePath().toString());

    HashMap context = getSoyContext(properties);

    SoyTofu.Renderer renderer =
        builder
            .build()
            .compileToTofu()
            .newRenderer("etc.its.templates." + template)
            .setContentKind(kind)
            .setData(context);
    return renderer.render();
  }

  protected String soyTextTemplate(SoyFileSet.Builder builder, String template, Set<Property> properties) {
    return soyTemplate(builder, template, SanitizedContent.ContentKind.TEXT, properties);
  }

  @Override
  public void execute(String issue, ActionRequest actionRequest, Set<Property> properties)
      throws IOException {
    SoyFileSet.Builder builder = SoyFileSet.builder();
    String template = null;
    String templateName = actionRequest.getParameter(1);
    if (templateName.isEmpty()) {
      log.error("No template name given in " + actionRequest);
    } else {
      template = templateName;
    }
    if (!Strings.isNullOrEmpty(template)) {
      String comment = soyTextTemplate(builder, template, properties);
      its.addComment(issue, comment);
    }
  }
}