/***************************************************************************************
 * IBM Confidential
 *
 * OCO Source Materials
 *
 * IBM Cognos Products: Moser
 *
 * (C) Copyright IBM Corp. 2020
 *
 * The source code for this program is not published or otherwise
 * divested of its trade secrets, irrespective of what has been
 * deposited with the U.S. Copyright Office.
 * 
 ***************************************************************************************/

package com.ibm.bi.platform.modeling.sdk.examples;

import static com.ibm.bi.platform.modeling.sdk.examples.ModelingRESTEndpoints.filesURL;

import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.util.ArrayList;

import org.apache.commons.io.FilenameUtils;
import org.apache.http.Header;
import org.apache.http.HttpEntity;
import org.apache.http.HttpHeaders;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.methods.HttpPut;
import org.apache.http.client.methods.HttpRequestBase;
import org.apache.http.entity.ContentType;
import org.apache.http.entity.InputStreamEntity;
import org.apache.http.entity.StringEntity;

import com.ibm.bi.platform.modeling.sdk.examples.internal.UnexpectedHTTPResponseException;
import com.ibm.bi.platform.moser.core.tasks.TaskState;
import com.ibm.json.java.JSONObject;

/**
 * Upload new files
 * 
 * Replace existing uploaded files
 * 
 * Append to existing uploaded  files
 *
 */
public class FileImportHelper extends AsynchronousTasksRunner {

	private static final String AFFINITY = "x-ca-affinity";
	private static final String SEGMENT = "index";

	  private static final String CSV_TYPE = "text/csv";
	  private static final String XLS_TYPE = "application/vnd.ms-excel";
	  private static final String XLSX_TYPE =
	      "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet";

	  
	public FileImportHelper(String origin) {
		super(origin);
	}

	
	/**
	 * Upload file
	 * 
	 * @param dir
	 *            directory of the source file relative to current
	 * @param filename
	 *            file name of the file to be uploaded including extension
	 * @param destination
	 *            folder path or store id
	 * @return uploaded file response
	 * 
	 * @throws UnsupportedEncodingException
	 * @throws IOException
	 * @throws UnexpectedHTTPResponseException
	 */
	public String uploadFile(String dir, String filename, String destination)
			throws UnsupportedEncodingException, IOException, UnexpectedHTTPResponseException {
		
		HttpPost initiate = new HttpPost(getOrigin() + filesURL);
		
		JSONObject parameters = new JSONObject();
		parameters.put("filename", filename);
		parameters.put("destination", destination);
		
		HttpEntity entity = new StringEntity(parameters.toString());
		initiate.setEntity(entity);
		initiate.setHeader(HttpHeaders.CONTENT_TYPE, ContentType.APPLICATION_JSON.getMimeType());
		
		String response = executeUploadRequest(initiate, dir + File.separator + filename, filename, null,
				getContentType(filename), 202 );
		
	
		return executeAsychronousTask(response).toString();
	

	}
	
	/**
	 * @param filename
	 * @return
	 */
	private static String getContentType(String filename) {
		switch (FilenameUtils.getExtension(filename)) {

		case "xls":
			return XLS_TYPE;
		case "xlsx":
			return XLSX_TYPE;
		case "csv":
		default:
			return CSV_TYPE;
		}

	}
	
	/**
	 * Replace existing file with new content
	 * 
	 * @param uploadedFileId
	 *            store id of the file to be replaced
	 * @param dir
	 *            directory of the source file relative to current
	 * @param filename
	 *            file name of the file to be uploaded including extension
	 * @return uploaded file response
	 * 
	 * @throws UnsupportedEncodingException
	 * @throws IOException
	 * @throws UnexpectedHTTPResponseException
	 */
	public String replaceFile(String uploadedFileId, String dir, String filename )
			throws UnsupportedEncodingException, IOException, UnexpectedHTTPResponseException {

		HttpPut initiate = new HttpPut(getOrigin() + filesURL + "/" + uploadedFileId + "?append=false&filename="
				+ URLEncoder.encode(filename, "UTF-8"));
		String response =  executeUploadRequest(initiate, dir + File.separator +  filename, filename, null,
				getContentType(filename), 202 );
		

		return executeAsychronousTask(response).toString();
	
		
	}
	
	
	/**
	 * Replace existing file with new content
	 * 
	 * @param uploadedFileId
	 *            store id of the file to be appended
	 * @param dir
	 *            directory of the source file relative to current
	 * @param appendFileName
	 *            file name of the file to be uploaded including extension
	 * @return uploaded file response
	 * 
	 * @throws UnsupportedEncodingException
	 * @throws IOException
	 * @throws UnexpectedHTTPResponseException
	 */
	public String appendFile(String uploadedFileId, String dir, String appendFileName)
			throws UnsupportedEncodingException, IOException, UnexpectedHTTPResponseException {

		
		HttpPut initiate = new HttpPut(getOrigin() + filesURL + "/" + uploadedFileId + "?append=true&filename="
				+ URLEncoder.encode(appendFileName, "UTF-8"));
		String response = executeUploadRequest(initiate, dir + File.separator + appendFileName, appendFileName, null,
				getContentType(appendFileName),  202 );
		
		return executeAsychronousTask(response).toString();
	
	}
	
	/**
	 * @param aRequest
	 *            POST or PUT REST request
	 * @param filename
	 *            name to be used for upload
	 * @param content_path
	 *            relative to project root file to be uploaded path, e.g. resources/pizza.xlsx
	 * @param uploadedId existing file store id for replace and append scenarios, null for new uploads
	 * @param contentType
	 * @return http response body
	 * @throws UnsupportedEncodingException
	 * @throws IOException
	 * @throws UnexpectedHTTPResponseException
	 */
	private String executeUploadRequest(HttpRequestBase aRequest, String content_path, String filename,
			String uploadedId, String contentType, int expectedStatus)
			throws UnsupportedEncodingException, IOException, UnexpectedHTTPResponseException {

		try (InputStream filedata = streamFromFile(content_path)) {

			ArrayList<Header> headers = new ArrayList<>();

//			{
//			  "importPath": "string",
//			  "href": "string",
//			  "taskID": "string"
//		}
			String json = executeHttpRequest(aRequest, expectedStatus, headers);


			if( headers.size() == 0) {
				throw new UnexpectedHTTPResponseException(null, "Response is missing headers");
			}

			Header affinity = null;
			for (Header header : headers) {
				if (AFFINITY.equalsIgnoreCase(header.getName())) {
					affinity = header;
					break;
				}
			}

			if(affinity ==  null) {
				throw new UnexpectedHTTPResponseException(null, "Affinity should have a non null value");
			}

			int length = filedata.available();
			int buffer_size = length / 10;

			JSONObject fileImport = JSONObject.parse(json);
			String path = getOrigin()  + fileImport.get("importPath");
			
			// issue series of segment PUTs
			for (int index = 1; filedata.available() > 0; index++) {
				byte[] buffer = new byte[Math.min(buffer_size, filedata.available())];
				filedata.read(buffer);

				HttpPut request = new HttpPut(path + "?" + SEGMENT + "=" + String.valueOf(index));
				request.setHeader(HttpHeaders.CONTENT_TYPE, contentType);
				request.setHeader(affinity.getName(), affinity.getValue());

				request.setEntity(new InputStreamEntity(new ByteArrayInputStream(buffer)));

				executeHttpRequest(request, Integer.valueOf(202), null);
			}

			// last PUT
			HttpPut request = new HttpPut(path + "?" + SEGMENT + "=" + String.valueOf(-1));
			request.setHeader(HttpHeaders.CONTENT_TYPE, contentType);
			request.setHeader(affinity.getName(), affinity.getValue());
			request.setEntity(null);

			return executeHttpRequest(request, Integer.valueOf(expectedStatus), null);
		}

	}

	@Override
	protected JSONObject executeAsychronousTask(String task){

		JSONObject taskResponse = super.executeAsychronousTask(task);
		if (TaskState.SUCCESS.equals(taskResponse.get("state"))) {
			return  (JSONObject) taskResponse.get("response");
		}
		// return error message
		return taskResponse;
	
	}


	/* (non-Javadoc)
	 * @see com.ibm.bi.platform.modeling.sdk.examples.AsynchronousTasksRunner#getTasksURL()
	 */
	@Override
	public String getTasksURL() {
		return ModelingRESTEndpoints.fileImportTasksURL;
	}
}