package cz.trask.migration;

import java.io.ByteArrayOutputStream;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.URL;
import java.net.URLEncoder;
import java.security.KeyStore;
import java.util.Base64;
import java.util.HashMap;
import java.util.Map;

import javax.net.ssl.HttpsURLConnection;
import javax.net.ssl.SSLContext;
import javax.net.ssl.TrustManagerFactory;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;

import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.dataformat.yaml.YAMLFactory;
import com.fasterxml.jackson.dataformat.yaml.YAMLGenerator;

import cz.trask.migration.config.ConfigManager;
import cz.trask.migration.model.APIList;
import cz.trask.migration.model.ApplicationConfig;
import cz.trask.migration.model.ApplicationConfig.Wso2Endpoints;
import cz.trask.migration.model.HttpResponse;
import cz.trask.migration.model.RegisterResponse;
import cz.trask.migration.model.TokenResponse;
import io.apicurio.registry.rest.client.RegistryClient;
import io.apicurio.registry.rest.client.RegistryClientFactory;
import io.apicurio.registry.rest.v2.beans.ArtifactMetaData;
import io.apicurio.registry.rest.v2.beans.EditableMetaData;
import io.apicurio.registry.rest.v2.beans.Rule;
import io.apicurio.registry.types.RuleType;

public abstract class AbstractProcess {

	private static Logger log = LogManager.getLogger(AbstractProcess.class);

	protected static final String PARAM_SOURCE_APIM = "source_apim";
	protected static final String VERSION_32 = "v32";

	public static final String PRIVATE_KEY_APIM_32 = "wso2apim32-pk.pem";

	public static final String ARTIFACT_GROUP_SUBSCRIPTIONS = "SUBSCRIPTIONS";
	public static final String ARTIFACT_NAME_SUBSCRIPTIONS = "subs.yaml";

	public static final String ARTIFACT_GROUP_APPLICATIONS = "APPLICATIONS";
	public static final String ARTIFACT_APPLICATION_DEFAULT_VERSION = "1.0.0";

	public static final String DEFAULT_APPLICATION_NAME = "DefaultApplication";
	public static final String ADMIN_USERNAME = "admin";

	public static final String DEFAULT_DOC_FILE_NAME = "document.yaml";

	public static ObjectMapper mapper;
	public static ObjectMapper mapperYaml;

	public final RegistryClient client;

	protected ApplicationConfig config;

	protected AbstractProcess() {
		mapper = new ObjectMapper();
		mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
		YAMLFactory yamlFactory = new YAMLFactory();
		yamlFactory.configure(YAMLGenerator.Feature.WRITE_DOC_START_MARKER, false);
		yamlFactory.configure(YAMLGenerator.Feature.MINIMIZE_QUOTES, true);
		yamlFactory.configure(YAMLGenerator.Feature.SPLIT_LINES, false);
		mapperYaml = new ObjectMapper(yamlFactory);
		mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);

		config = ConfigManager.getInstance().getConfig();

		this.client = RegistryClientFactory.create(config.getApicurio().getApiUrl());

		setTrustStoreCredentials();

		javax.net.ssl.HttpsURLConnection.setDefaultHostnameVerifier(new javax.net.ssl.HostnameVerifier() {
			public boolean verify(String hostname, javax.net.ssl.SSLSession sslSession) {
				return true;
			}
		});
	}

	protected void setTrustStoreCredentials() {
		File trustStoreFile = new File(config.getTrustStore().getPath());
		if (!trustStoreFile.exists() || !trustStoreFile.isFile()) {
			log.warn("Truststore file '{}' does not exist. Skipping truststore setup.",
					config.getTrustStore().getPath());
			return;
		}
		log.info("Setting truststore: " + trustStoreFile.getAbsolutePath());
		System.setProperty("javax.net.ssl.trustStore", trustStoreFile.getAbsolutePath());
		System.setProperty("javax.net.ssl.trustStorePassword", config.getTrustStore().getPassword());
	}

	private SSLContext createSSLContext(String trustStorePath, String trustStorePassword)
			throws Exception {
		// Vytvoříme TrustStore
		KeyStore trustStore = KeyStore.getInstance("JKS");
		try (FileInputStream fis = new FileInputStream(trustStorePath)) {
			trustStore.load(fis, trustStorePassword.toCharArray());
		}

		// Inicializujeme TrustManagerFactory
		TrustManagerFactory tmf = TrustManagerFactory.getInstance("PKIX");
		tmf.init(trustStore);

		// Vytvoříme SSLContext
		SSLContext sslContext = SSLContext.getInstance("TLS");
		sslContext.init(null, tmf.getTrustManagers(), null);

		return sslContext;
	}

	protected void configureHttpsConnection(HttpsURLConnection connection)
			throws Exception {
		SSLContext sslContext = createSSLContext(
				System.getProperty("javax.net.ssl.trustStore"),
				System.getProperty("javax.net.ssl.trustStorePassword"));
		connection.setSSLSocketFactory(sslContext.getSocketFactory());
	}

	protected TokenResponse authenticateToWso2AndGetToken(Wso2Endpoints endpoints) throws Exception {
		RegisterResponse register = register(endpoints.getRegistrationApiUrl(), endpoints.getWso2User());

		String clientId = register.getClientId();
		log.info("Registered with clientId: {}", clientId);

		TokenResponse token = getToken(endpoints.getPublisherTokenUrl(), endpoints.getWso2User(),
				register,
				"apim:api_view apim:api_create apim:api_manage apim:api_delete apim:api_publish apim:subscription_view apim:subscription_block "+
				"apim:subscription_manage apim:external_services_discover apim:threat_protection_policy_create apim:threat_protection_policy_manage "+
				"apim:document_create apim:document_manage apim:mediation_policy_view apim:mediation_policy_create apim:mediation_policy_manage "+
				"apim:client_certificates_view apim:client_certificates_add apim:client_certificates_update apim:ep_certificates_view apim:ep_certificates_add "+
				"apim:ep_certificates_update apim:publisher_settings apim:pub_alert_manage apim:shared_scope_manage apim:app_import_export apim:api_import_export "+
				"apim:api_product_import_export apim:api_generate_key apim:common_operation_policy_view apim:common_operation_policy_manage apim:comment_write "+
				"apim:comment_view apim:admin apim:subscribe apim:api_key apim:app_manage apim:sub_manage apim:store_settings apim:sub_alert_manage");

		log.debug("Access token received – {}", token.getAccess_token());

		return token;
	}

	/**
	 * Retrieve access token based on clientId and clientSecret
	 * 
	 * @param reg   - client application object with clientId and clientSecret
	 * @param scope - requested OAuth2 scope
	 * @throws Exception
	 */
	protected TokenResponse getToken(String publisherurl, String wso2User, RegisterResponse reg, String scope)
			throws Exception {

		byte[] decoded = Base64.getDecoder().decode(wso2User);
		String decodedstring = new String(decoded);
		String[] decodedstringparts = decodedstring.split(":");

		String username = decodedstringparts[0];
		String password = decodedstringparts[1];

		log.debug("Getting token with Username: '" + wso2User + "' URL: " + publisherurl);

		Map<String, String> httpHeaders = new HashMap<>();

		httpHeaders.put("Authorization", "Basic ".concat(Base64.getEncoder()
				.encodeToString(reg.getClientId().concat(":").concat(reg.getClientSecret()).getBytes())));
		httpHeaders.put("Content-Type", "application/x-www-form-urlencoded");

		String data = "grant_type=password&username=".concat(username).concat("&password=")
				.concat(URLEncoder.encode(password, "UTF-8")).concat("&scope=").concat(scope);
		HttpResponse response = makeDataRequest(publisherurl, httpHeaders, data.getBytes());

		log.debug("Token response: HTTP Code " + response.getResponseCode() + " Json: " + response.getResponse());

		TokenResponse resp = mapper.readValue(response.getResponse(), TokenResponse.class);
		return resp;
	}

	/**
	 * Register client application to get clientId and clientSecret
	 * 
	 * @throws Exception
	 */
	protected RegisterResponse register(String publisherurl, String wso2User) throws Exception {

		log.debug("Registering with Username: '" + wso2User + "' URL: " + publisherurl);

		byte[] decodedUserBytes = Base64.getDecoder().decode(wso2User);
		String decodeduserappkey = new String(decodedUserBytes);
		String[] decodeduserparts = decodeduserappkey.split(":");
		String decodeduser = decodeduserparts[0];

		Map<String, String> httpHeaders = new HashMap<>();

		httpHeaders.put("Authorization", "Basic ".concat(wso2User));
		httpHeaders.put("Content-Type", "application/json");

		String data = "{\"callbackUrl\": \"www.google.lk\",\"clientName\": \"rest_api_publisher" + decodeduser
				+ "\",\"owner\": \"" + decodeduser + "\",\"grantType\": \"password refresh_token\",\"saasApp\": true}";
		HttpResponse response = makeDataRequest(publisherurl, httpHeaders, data.getBytes());

		log.debug(
				"Register API response: HTTP Code " + response.getResponseCode() + " Json: " + response.getResponse());

		RegisterResponse resp = mapper.readValue(response.getResponse(), RegisterResponse.class);
		return resp;
	}

	/**
	 * Common function used for http request
	 * 
	 * @param method      - http method
	 * @param urlStr      - url to dev poral
	 * @param httpHeaders
	 * @param params      - currently is not used
	 * @throws Exception
	 */
	protected HttpResponse makeRequest(String method, String urlStr, Map<String, String> httpHeaders,
			Map<String, String> params) throws Exception {
		return makeRequest(method, urlStr, httpHeaders, params, false);
	}

	/**
	 * Common function used for http request
	 *
	 * @param method      - http method
	 * @param urlStr      - url to dev poral
	 * @param httpHeaders
	 * @param data        - request data
	 * @param binary      - binary or text mode
	 * @throws Exception
	 */
	protected HttpResponse makeRequest(String method, String urlStr, Map<String, String> httpHeaders,
			Map<String, String> params, boolean binary) throws Exception {

		log.info("Making {} request to URL: {}", method, urlStr);
		String query = "";
		if (params != null) {
			for (String key : params.keySet()) {
				query = query.concat(URLEncoder.encode(key, "UTF-8")).concat("=")
						.concat(URLEncoder.encode(params.get(key), "UTF-8")).concat("&");
			}
		}

		if (query.length() > 1 && "GET".equals(method)) {
			urlStr = urlStr.concat("?").concat(query);
		}

		URL url = new URL(urlStr);

		HttpsURLConnection con = (HttpsURLConnection) url.openConnection();
		con.setRequestMethod(method);
		con.setDoInput(true);
		configureHttpsConnection(con);

		for (String key : httpHeaders.keySet()) {
			con.addRequestProperty(key, httpHeaders.get(key));
		}

		if (query.length() > 1 && "POST".equals(method)) {
			con.setDoOutput(true);
			OutputStream out = con.getOutputStream();
			out.write(query.getBytes("UTF-8"));
		}

		InputStream in = con.getInputStream();

		String res = "";
		byte[] buf = new byte[4096];
		ByteArrayOutputStream baos = new ByteArrayOutputStream();

		int read = in.read(buf);

		while (read != -1) {
			if (binary)
				baos.write(buf, 0, read);
			else
				res = res.concat(new String(buf, 0, read));

			read = in.read(buf);
		}

		baos.flush();

		HttpResponse resp = new HttpResponse();
		resp.setHeaders(con.getHeaderFields());
		if (binary)
			resp.setResponseBytes(baos.toByteArray());
		else
			resp.setResponse(res);
		resp.setResponseCode(con.getResponseCode());

		con.disconnect();

		log.info("Response code: " + resp.getResponseCode());
		// log.info("Response: " + resp.getResponse());

		return resp;
	}

	/**
	 * Common function used for http request
	 * 
	 * @param urlStr      - url to dev poral
	 * @param httpHeaders
	 * @param data        - request data
	 * @throws Exception
	 */
	protected HttpResponse makeDataRequest(String urlStr, Map<String, String> httpHeaders, byte[] data)
			throws Exception {

		URL url = new URL(urlStr);

		HttpsURLConnection con = (HttpsURLConnection) url.openConnection();
		con.setRequestMethod("POST");
		con.setDoInput(true);
		con.setDoOutput(true);
		configureHttpsConnection(con);

		for (String key : httpHeaders.keySet()) {
			con.addRequestProperty(key, httpHeaders.get(key));
		}

		con.addRequestProperty("Content-Length", "" + data.length);

		OutputStream out = con.getOutputStream();
		out.write(data);
		out.flush();
		out.close();

		InputStream in;

		try {
			in = con.getInputStream();
		} catch (Exception e) {
			in = con.getErrorStream();
		}

		if (in == null) {
			HttpResponse resp = new HttpResponse();
			resp.setHeaders(con.getHeaderFields());
			resp.setResponseCode(con.getResponseCode());
			return resp;
		}

		String res = "";
		byte[] buf = new byte[4096];
		ByteArrayOutputStream baos = new ByteArrayOutputStream();

		int read = in.read(buf);

		while (read != -1) {
			res = res.concat(new String(buf, 0, read));
			read = in.read(buf);
		}

		baos.flush();

		HttpResponse resp = new HttpResponse();
		resp.setHeaders(con.getHeaderFields());
		resp.setResponse(res);
		resp.setResponseCode(con.getResponseCode());

		return resp;
	}

	/**
	 * Retrieve the list of APIs by name.
	 * 
	 * @param tokenResponse - WSO2 APIM access token
	 * @throws Exception
	 */
	protected APIList getList(String publisherurl, TokenResponse tokenResponse) throws Exception {

		APIList listOfApis = null;

		try {
			String url = publisherurl.concat(String.format("/apis?limit=9999&offset=0"));

			log.debug("Getting APIs with token: '" + tokenResponse.getAccess_token() + "' URL: " + url);

			Map<String, String> httpHeaders = new HashMap<>();
			Map<String, String> params = new HashMap<>();

			httpHeaders.put("Authorization", "Bearer ".concat(tokenResponse.getAccess_token()));

			HttpResponse response = makeRequest("GET", url, httpHeaders, params);

			log.debug("Listing APIs: HTTP Code " + response.getResponseCode() + " Data: " + response.getResponse());

			listOfApis = mapper.readValue(response.getResponse(), APIList.class);

			if (response.getResponseCode() != 200)
				log.error("Cannot list API. Something bad happened.");
		} catch (Exception e) {
			log.error("Cannot list API:" + e);
			throw new Exception("Cannot list API:" + e.getMessage());
		}
		return listOfApis;
	}

	/**
	 * Common function used for upload API
	 * 
	 * @param urlStr      - url to dev poral
	 * @param httpHeaders
	 * @param params      - currently is not used
	 * @param api         - zip file to upload
	 * @throws Exception
	 */
	protected HttpResponse makeFileRequest(String method, String urlStr, Map<String, String> httpHeaders, byte[] buff,
			String attachmentFileName) throws Exception {

		if (buff == null) {
			log.error("Cannot send NULL payload to rest service.");
		}

		String crlf = "\r\n";

		String twoHyphens = "--";
		String boundary = "----" + System.currentTimeMillis() + "----";

		URL url = new URL(urlStr);

		HttpsURLConnection con = (HttpsURLConnection) url.openConnection();
		con.setUseCaches(false);
		con.setDoOutput(true);
		configureHttpsConnection(con);

		con.setRequestMethod(method);
		con.setRequestProperty("Content-Type", "multipart/form-data; boundary=" + boundary);
		con.setRequestProperty("User-Agent", "curl/7.55.1");
		con.setRequestProperty("Accept", "*/*");

		for (String key : httpHeaders.keySet()) {
			con.addRequestProperty(key, httpHeaders.get(key));
		}

		DataOutputStream request = new DataOutputStream(con.getOutputStream());
		request.writeBytes(crlf);
		request.writeBytes(twoHyphens + boundary + crlf);
		request.writeBytes(
				"Content-Disposition: form-data; name=\"file\"; filename=\"" + attachmentFileName + "\"" + crlf);
		request.writeBytes("Content-Type: application/octet-stream" + crlf);
		request.writeBytes("Content-Transfer-Encoding: binary" + crlf);
		request.writeBytes(crlf);
		request.write(buff);
		request.writeBytes(crlf);
		request.writeBytes(twoHyphens + boundary + twoHyphens + crlf);
		request.flush();
		request.close();

		String res = "";
		byte[] buf = new byte[4096];

		HttpResponse resp = new HttpResponse();
		InputStream in;
		int responseCode = con.getResponseCode();

		if (responseCode == 200 || responseCode == 201) {
			in = con.getInputStream();
		} else {
			in = con.getErrorStream();
		}

		while (in.available() > 0) {
			int read = in.read(buf);
			res = res.concat(new String(buf, 0, read));
		}

		resp.setHeaders(con.getHeaderFields());
		resp.setResponse(res);
		resp.setResponseCode(responseCode);

		return resp;
	}

	protected void setArtifactMetaData(ArtifactMetaData meta, Map<String, String> props) {
		EditableMetaData metaData = new EditableMetaData();
		metaData.setName(meta.getName());
		metaData.setDescription(meta.getDescription());
		if (props != null)
			metaData.setProperties(props);

		client.updateArtifactMetaData(meta.getGroupId(), meta.getId(), metaData);
	}

	protected void createRule(ArtifactMetaData meta, String config, RuleType type) {
		Rule rule = new Rule();
		rule.setConfig(config);
		rule.setType(type);
		client.createArtifactRule(meta.getGroupId(), meta.getId(), rule);
	}

	protected Map<String, String> createBearerAuthHeaders(TokenResponse tokenResponse) {
		Map<String, String> httpHeaders = new HashMap<>();
		httpHeaders.put("Authorization", "Bearer ".concat(tokenResponse.getAccess_token()));
		return httpHeaders;
	}

	protected Map<String, String> createBasicAuthHeaders(String wso2User) throws Exception {
		Map<String, String> httpHeaders = new HashMap<>();

		byte[] decoded = Base64.getDecoder().decode(wso2User);
		String decodedstring = new String(decoded);
		String[] decodedstringparts = decodedstring.split(":");

		String username = decodedstringparts[0];
		String password = decodedstringparts[1];

		httpHeaders.put("Authorization", "Basic ".concat(Base64.getEncoder()
				.encodeToString(username.concat(":").concat(password).getBytes())));
		return httpHeaders;
	}
}