package org.embulk.formatter.poi_excel;

import java.io.IOException;
import java.text.MessageFormat;
import java.util.Map;

import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.SpreadsheetVersion;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
import org.embulk.config.Config;
import org.embulk.config.ConfigDefault;
import org.embulk.config.ConfigInject;
import org.embulk.config.ConfigSource;
import org.embulk.config.Task;
import org.embulk.config.TaskSource;
import org.embulk.formatter.poi_excel.visitor.PoiExcelColumnVisitor;
import org.embulk.spi.BufferAllocator;
import org.embulk.spi.FileOutput;
import org.embulk.spi.FormatterPlugin;
import org.embulk.spi.Page;
import org.embulk.spi.PageOutput;
import org.embulk.spi.PageReader;
import org.embulk.spi.Schema;
import org.embulk.spi.time.TimestampFormatter;
import org.embulk.spi.time.TimestampFormatter.TimestampColumnOption;
import org.embulk.spi.util.FileOutputOutputStream;
import org.embulk.spi.util.FileOutputOutputStream.CloseMode;

import com.google.common.base.Optional;

public class PoiExcelFormatterPlugin implements FormatterPlugin {
	public interface PluginTask extends Task, TimestampFormatter.Task {
		@Config("spread_sheet_version")
		@ConfigDefault("\"EXCEL2007\"")
		public SpreadsheetVersion getSpreadsheetVersion();

		@Config("sheet_name")
		@ConfigDefault("\"Sheet1\"")
		public String getSheetName();

		@Config("column_options")
		@ConfigDefault("{}")
		public Map<String, ColumnOption> getColumnOptions();

		@ConfigInject
		public BufferAllocator getBufferAllocator();
	}

	public interface ColumnOption extends Task, TimestampColumnOption {

		@Config("data_format")
		@ConfigDefault("null")
		public Optional<String> getDataFormat();
	}

	@Override
	public void transaction(ConfigSource config, Schema schema, FormatterPlugin.Control control) {
		PluginTask task = config.loadConfig(PluginTask.class);

		control.run(task.dump());
	}

	@Override
	public PageOutput open(TaskSource taskSource, final Schema schema, FileOutput output) {
		final PluginTask task = taskSource.loadTask(PluginTask.class);

		final Sheet sheet = newWorkbook(task);

		final FileOutputOutputStream stream = new FileOutputOutputStream(output, task.getBufferAllocator(),
				CloseMode.CLOSE);
		stream.nextFile();

		return new PageOutput() {
			private final PageReader pageReader = new PageReader(schema);

			@Override
			public void add(Page page) {
				pageReader.setPage(page);
				PoiExcelColumnVisitor visitor = new PoiExcelColumnVisitor(task, schema, sheet, pageReader);
				while (pageReader.nextRecord()) {
					schema.visitColumns(visitor);
					visitor.endRecord();
				}
			}

			@Override
			public void finish() {
				Workbook book = sheet.getWorkbook();
				try (FileOutputOutputStream os = stream) {
					book.write(os);
					os.finish();
				} catch (IOException e) {
					throw new RuntimeException(e);
				}
			}

			@Override
			public void close() {
				stream.close();
			}
		};
	}

	@SuppressWarnings("resource")
	protected Sheet newWorkbook(PluginTask task) {
		Workbook book;
		{
			SpreadsheetVersion version = task.getSpreadsheetVersion();
			switch (version) {
			case EXCEL97:
				book = new HSSFWorkbook();
				break;
			case EXCEL2007:
				book = new XSSFWorkbook();
				break;
			default:
				throw new UnsupportedOperationException(MessageFormat.format("unsupported spread_sheet_version={0}",
						version));
			}
		}

		String sheetName = task.getSheetName();
		return book.createSheet(sheetName);
	}
}