package org.hathitrust;

import java.io.Serializable;
import org.apache.commons.cli.*;

import org.apache.spark.api.java.*;
import org.apache.spark.util.DoubleAccumulator;
import org.apache.spark.SparkConf;

public class PrepareForIngest implements Serializable
{
	private static final long serialVersionUID = 1L;

	public static final int NUM_PARTITIONS = 6; // default would appear to be 2
	
	protected String _input_dir;
	protected String _json_list_filename;
	protected String _solr_url;
	protected String _output_dir;
	
	protected int    _verbosity;

	public PrepareForIngest(String input_dir, String json_list_filename, 
							String solr_url, String output_dir, int verbosity)
	{
		_input_dir = input_dir;
		_json_list_filename = (json_list_filename != null) ? json_list_filename : input_dir;

		_solr_url   = solr_url;
		_output_dir = output_dir;
		_verbosity  = verbosity;
	}

	public void exec()
	{	
		String spark_app_name = "HathiTrust Extract Features: Prepare for Solr Ingest";
		spark_app_name += " [" + _json_list_filename + "]";

		SparkConf conf = new SparkConf().setAppName(spark_app_name);
		JavaSparkContext jsc = new JavaSparkContext(conf);
		
		if (_verbosity >= 2) {
			System.out.println("Default Minimum Partions: " + jsc.defaultMinPartitions());
			System.out.println("Default Parallelism: " + jsc.defaultParallelism());
		}
				
		JavaRDD<String> json_list_data = jsc.textFile(_json_list_filename,NUM_PARTITIONS).cache();

		long num_volumes = json_list_data.count();
		double per_vol = 100.0/(double)num_volumes;
		
		DoubleAccumulator progress_accum = jsc.sc().doubleAccumulator("Progress Percent");
		
		PagedJSON paged_json = new PagedJSON(_input_dir,_solr_url,_output_dir,_verbosity, progress_accum,per_vol);
		//JavaRDD<String> json_ids = json_list_data.flatMap(paged_json).cache();

		json_list_data.foreach(paged_json);

	
/*
		System.out.println("");
		System.out.println("############");
		System.out.println("# Progress Accumulator: " + progress_accum.value());
		System.out.println("############");
		System.out.println("");
*/
		
		//long num_ids = json_ids.count();
		long num_ids = num_volumes;
		
		System.out.println("");
		System.out.println("############");
		System.out.println("# Number of page ids: " + num_ids);
		System.out.println("############");
		System.out.println("");

		/*
		if (_output_dir != null) {
			String rdd_save_file = "rdd-solr-json-page-files";
			json_ids.saveAsTextFile(rdd_save_file);
			System.out.println("############");
			System.out.println("# Saved RDD of Solr JSON page files, top-level, as:");
			System.out.println("#  " + rdd_save_file);
			System.out.println("############");
			System.out.println("");
		}
		*/
		
		jsc.close();
	}

	public static void print_usage(HelpFormatter formatter, Options options)
	{
		formatter.printHelp("RUN.bash [options] input-dir json-filelist.txt", options);
	}
	public static void main(String[] args) {


		Options options = new Options();

		Option verbosity_opt = new Option("v", "verbosity", true, 
				"Set to control the level of debugging output [0=none, 1=some, 2=lots]");
		verbosity_opt.setRequired(false);
		options.addOption(verbosity_opt);
		
		Option output_dir_opt = new Option("o", "output-dir", true, 
				"If specified, save BZipped Solr JSON files to this directory");
		output_dir_opt.setRequired(false);
		options.addOption(output_dir_opt);
		
		Option solr_url_opt = new Option("u", "solr-url", true, 
				"If specified, the URL to post the Solr JSON data to");
		solr_url_opt.setRequired(false);
		options.addOption(solr_url_opt);
		
		Option read_only_opt = new Option("r", "read-only", false, 
				"Used to initiate a run where the files are all read in, but nothing is ingested/saved");
		read_only_opt.setRequired(false);
		options.addOption(read_only_opt);
		
		// Need to work with CLI v1.2 as this is the JAR that is bundled with Hadoop/Spark 
		CommandLineParser parser = new GnuParser(); 
		//CommandLineParser parser = new DefaultParser(); // if working with CLI v1.3 and above
		
		HelpFormatter formatter = new HelpFormatter();
		CommandLine cmd = null;

		try {
			cmd = parser.parse(options, args);
		}
		catch (ParseException e) {
			System.err.println(e.getMessage());
			print_usage(formatter,options);
			System.exit(1);
		}

		
		String verbosity_str = cmd.getOptionValue("verbosity","0");
		int verbosity = Integer.parseInt(verbosity_str);

		String output_dir = cmd.getOptionValue("output-dir",null);
		String solr_url   = cmd.getOptionValue("solr-url",null);
		boolean dry_run   = cmd.hasOption("dry-run");
		
		String[] filtered_args = cmd.getArgs();

		if (filtered_args.length != 2) {
			print_usage(formatter,options);
			System.exit(1);
		}
		
		if (!dry_run && ((output_dir == null) && (solr_url==null))) {
			System.err.println("Need to specify either --solr-url or --output-dir otherwise generated files are not ingested/saved");
			print_usage(formatter,options);
			System.exit(1);
		}
		
		String input_dir  = filtered_args[0];
		String json_list_filename = filtered_args[1];
		
		PrepareForIngest prep_for_ingest 
			= new PrepareForIngest(input_dir,json_list_filename,solr_url,output_dir,verbosity);
		prep_for_ingest.exec();

	}
}