// Copyright (C) 2015 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.github.replication;

import static java.nio.file.StandardOpenOption.CREATE;
import static java.nio.file.StandardOpenOption.TRUNCATE_EXISTING;
import static java.nio.file.StandardOpenOption.WRITE;

import java.io.IOException;
import java.io.Reader;
import java.nio.charset.StandardCharsets;
import java.nio.file.FileVisitResult;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.SimpleFileVisitor;
import java.nio.file.attribute.BasicFileAttributes;
import java.util.ArrayList;
import java.util.List;

import com.google.gerrit.extensions.annotations.PluginData;
import com.google.gerrit.reviewdb.client.Project;
import com.google.gson.Gson;
import com.google.gson.JsonObject;
import com.google.inject.Inject;
import com.google.inject.Provider;

public class ReplicationStatusFlatFile implements ReplicationStatusStore {
  private final Path pluginData;
  private final Gson gson;

  @Inject
  public ReplicationStatusFlatFile(@PluginData Path pluginData,
      Provider<Gson> gsonProvider) {
    this.pluginData = pluginData;
    this.gson = gsonProvider.get();
  }

  @Override
  public void set(Project.NameKey projectKey, String refKey,
      JsonObject statusEvent) throws IOException {
    Path replicationStatusPath =
        getReplicationStatusPath(projectKey.get() + "/" + refKey);
    Files.write(replicationStatusPath, statusEvent.toString().getBytes(),
        TRUNCATE_EXISTING, CREATE, WRITE);
  }

  private Path getReplicationStatusPath(String key) throws IOException {
    Path projectPath =
        pluginData.resolve(getSanitizedKey(key) + ".replication-error.json");
    Files.createDirectories(projectPath.getParent());
    return projectPath;
  }

  private String getSanitizedKey(String key) {
    String sanitizedKey = key.replace(".", "_").replace(" ", "_");
    return sanitizedKey;
  }

  @Override
  public List<JsonObject> list(Project.NameKey parentKey) throws IOException {
    Path projectPath = pluginData.resolve(getSanitizedKey(parentKey.get()));
    final List<JsonObject> entries = new ArrayList<>();
    Files.walkFileTree(projectPath, new SimpleFileVisitor<Path>() {

      @Override
      public FileVisitResult visitFile(Path file, BasicFileAttributes attrs)
          throws IOException {
        try (Reader fileReader =
            Files.newBufferedReader(file, StandardCharsets.UTF_8)) {
          JsonObject json = gson.fromJson(fileReader, JsonObject.class);
          entries.add(json);
        }
        return FileVisitResult.CONTINUE;
      }
    });
    return entries;
  }

}