/*
 * 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 org.apache.samza.sql.client.cli;

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;

import org.apache.samza.sql.client.exceptions.CommandHandlerException;
import org.apache.samza.sql.client.exceptions.ExecutorException;
import org.apache.samza.sql.client.util.CliUtil;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Main entry of the program.
 */
public class Main {
  private static final Logger LOG = LoggerFactory.getLogger(Main.class);

  public static void main(String[] args) {
    // Get configuration file path
    String configFilePath = null;
    for (int i = 0; i < args.length; ++i) {
      switch (args[i]) {
        case "-conf":
          if (i + 1 < args.length) {
            configFilePath = args[i + 1];
            i++;
          }
          break;
        default:
          LOG.warn("Unknown parameter {}", args[i]);
          break;
      }
    }

    CliEnvironment environment = new CliEnvironment();
    StringBuilder messageBuilder = new StringBuilder();

    if (!CliUtil.isNullOrEmpty(configFilePath)) {
      LOG.info("Configuration file path is: {}", configFilePath);
      try {
        FileReader fileReader = new FileReader(configFilePath);
        BufferedReader bufferedReader = new BufferedReader(fileReader);
        String line;
        while ((line = bufferedReader.readLine()) != null) {
          if (line.startsWith("#") || line.startsWith("[")) {
            continue;
          }
          String[] strs = line.split("=");
          if (strs.length != 2) {
            continue;
          }
          String key = strs[0].trim().toLowerCase();
          String value = strs[1].trim();
          try {
            LOG.info("Configuration: setting {} = {}", key, value);
            int result = environment.setEnvironmentVariable(key, value);
            if (result == -1) { // CliEnvironment doesn't recognize the key.
              LOG.warn("Unknowing shell environment variable: {}", key);
            } else if (result == -2) { // Invalid value
              LOG.warn("Unknowing shell environment value: {}", value);
            }
          } catch (ExecutorException e) {
            messageBuilder.append("Warning: Failed to create executor: ").append(value).append('\n');
            messageBuilder.append("Warning: Using default executor " + CliConstants.DEFAULT_EXECUTOR_CLASS);
            LOG.error("Failed to create user specified executor {}", value, e);
          } catch (CommandHandlerException e) {
            messageBuilder.append("Warning: Failed to create CommandHandler: ").append(value).append('\n');
            LOG.error("Failed to create user specified CommandHandler {}", value, e);
          }
        }
      } catch (IOException e) {
        LOG.error("Error in opening and reading the configuration file {}", e.toString());
      }
    }

    environment.finishInitialization();
    CliShell shell;
    try {
      shell = new CliShell(environment);
    } catch (ExecutorException e) {
      System.out.println("Unable to initialize executor. Shell must exit. ");
      LOG.error("Unable to initialize executor.", e);
      return;
    }

    shell.open(messageBuilder.toString());
  }
}