package cz.trask.migration;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.InetSocketAddress;
import java.net.Proxy;
import java.net.URL;
import java.net.URLEncoder;
import java.security.KeyStore;
import java.text.Normalizer;
import java.util.ArrayList;
import java.util.Base64;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.List;
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.APIInfo;
import cz.trask.migration.model.APIList;
import cz.trask.migration.model.ApplicationConfig;
import cz.trask.migration.model.ApplicationConfig.Wso2Settings;
import cz.trask.migration.model.HttpResponse;
import cz.trask.migration.model.RegisterResponse;
import cz.trask.migration.model.TokenResponse;
import cz.trask.migration.model.ZipEntryData;
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.ArtifactReference;
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 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 static Proxy proxy;

	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);
		mapperYaml.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);

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

		setTrustStoreCredentials();
		
		if (config.getProxy() != null && config.getProxy().getHost() != null && !config.getProxy().getHost().isEmpty())
			proxy = new Proxy(Proxy.Type.HTTP, new InetSocketAddress(config.getProxy().getHost(), config.getProxy().getPort()));

		javax.net.ssl.HttpsURLConnection.setDefaultHostnameVerifier(new javax.net.ssl.HostnameVerifier() {
			public boolean verify(String hostname, javax.net.ssl.SSLSession sslSession) {
				return true;
			}
		});
		
	    Map<String, Object> clientConfigs = new HashMap<>();
	    try {
	        SSLContext sslContext = createSSLContext(
	            config.getTrustStore().getPath(), 
	            config.getTrustStore().getPassword()
	        );
	        clientConfigs.put("io.apicurio.rest.client.jdk.sslContext", sslContext);
	    } catch (Exception e) {
	        log.error("Failed to initialize SSL context for Apicurio client", e);
	    }
		
		this.client = RegistryClientFactory.create(config.getApicurio().getApiUrl(), clientConfigs);
		client.listConfigProperties();

	}

	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(Wso2Settings 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(proxy!=null ? proxy : Proxy.NO_PROXY);
		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(proxy!=null ? proxy : Proxy.NO_PROXY);
		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=10&offset=0&query=name:%s", "PTSPaymentHubCZSIT*"));
			String url = publisherurl.concat("/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(proxy!=null ? proxy : Proxy.NO_PROXY);
		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 <= 299) {
			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 int publishApiToWso2(String fileName, byte[] data, TokenResponse tokenResponse) {
		int responseCode = -1;
		try {
			String url = config.getTarget().getPublisherApiUrl()
					.concat(String.format("?preserveProvider=false&overwrite=true"));
			log.info("API Import URL: " + url);
			Map<String, String> httpHeaders = new HashMap<>();
			httpHeaders.put("Authorization", "Bearer " + tokenResponse.getAccess_token());
			HttpResponse response = makeFileRequest("POST", url, httpHeaders, data, fileName);
			responseCode = response.getResponseCode();
			if (response.getResponseCode() != 201 && response.getResponseCode() != 200) {
				log.info("Cannot import API file: " + fileName + ", response code: " + response.getResponseCode());
			}
		} catch (Exception e) {
			log.error("IO error while importing API file: " + fileName + ", error: " + e.getMessage(), e);
		}
		return responseCode;
	}

	protected int publishAppToWso2(String fileName, byte[] data, TokenResponse tokenResponse) {
		int responseCode = -1;
		try {
			String url = config.getTarget().getDevPortalApiUrl().concat(String.format(
					"/v3/applications/import?preserveOwner=true&skipSubscriptions=false&skipApplicationKeys=false&update=true"));
			log.info("App Import URL: " + url);
			Map<String, String> httpHeaders = new HashMap<>();
			httpHeaders.put("Authorization", "Bearer " + tokenResponse.getAccess_token());
			HttpResponse response = makeFileRequest("POST", url, httpHeaders, data, fileName);
			responseCode = response.getResponseCode();
			if (response.getResponseCode() < 200 || response.getResponseCode() > 299) {
				log.info("Cannot import App file: " + fileName + ", response code: " + response.getResponseCode());
			}
		} catch (Exception e) {
			log.error("IO error while importing App file: " + fileName + ", error: " + e.getMessage(), e);
		}
		return responseCode;
	}

	protected void setArtifactMetaData(ArtifactMetaData meta, String name, String description, Map<String, String> props) {
		EditableMetaData metaData = new EditableMetaData();
		metaData.setName(name);
		metaData.setDescription(description);
		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;
	}

	protected void addEndpointsToProps(Map<String, String> props, Map<String, Object> apiMap) {
		if (apiMap == null || !apiMap.containsKey("endpointURLs"))
			return;
		@SuppressWarnings("unchecked")
		List<Map<String, Object>> envs = (List<Map<String, Object>>) apiMap.get("endpointURLs");
		for (Map<String, Object> env : envs) {
			@SuppressWarnings("unchecked")
			Map<String, String> urls = (Map<String, String>) env.get("URLs");
			if (urls == null)
				continue;
			urls.forEach((k, v) -> {
				if (v != null)
					props.put(k + " Endpoint", v);
			});
		}
	}

	protected void addTagsToProps(Map<String, String> props, List<String> tags) {
		if (tags != null && !tags.isEmpty()) {
			props.put("tags", String.join(", ", tags));
		}
	}

	protected List<ArtifactReference> createReferencesFromZip(List<ZipEntryData> zipEntries, APIInfo api)
			throws IOException {

		List<ArtifactReference> references = new ArrayList<>();
		for (ZipEntryData entry : zipEntries) {
			String artifactId = convertToAscii(api.getName() + "/" + api.getVersion() + "/" + entry.getName());

			log.debug("Creating artifact reference for entry: {} with artifactId: {}", entry.getName(), artifactId);

			File tmpFile = new File("tmp/api/", entry.getName());
			FileOutputStream fos = new FileOutputStream(tmpFile);
			fos.write(entry.getContent());
			fos.flush();
			fos.close();

			try (ByteArrayInputStream is = new ByteArrayInputStream(entry.getContent())) {
				ArtifactMetaData meta = client.createArtifactWithVersion(entry.getType().toString(), artifactId, api.getVersion(), is);
				Map<String, String> props = new LinkedHashMap<>();
				props.put(PARAM_SOURCE_APIM, VERSION_32);
				setArtifactMetaData(meta, entry.getName(), null, props);
			}

			ArtifactReference ref = new ArtifactReference();
			ref.setName(entry.getName());
			ref.setGroupId(entry.getType().toString());
			ref.setArtifactId(artifactId);
			ref.setVersion(api.getVersion());
			references.add(ref);
		}
		return references;
	}

	private String convertToAscii(String input) {
		if (input == null) {
			return null;
		}
		String normalized = Normalizer.normalize(input, Normalizer.Form.NFD);
		return normalized.replaceAll("[^\\x00-\\x7F]", "").replace(" ", "_");
	}
}