package cz.trask.migration.impl.v32;

import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.util.ArrayList;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;

import com.fasterxml.jackson.databind.node.ArrayNode;
import com.fasterxml.jackson.databind.node.ObjectNode;

import cz.trask.migration.AbstractProcess;
import cz.trask.migration.model.APIInfo;
import cz.trask.migration.model.FileType;
import cz.trask.migration.model.ZipEntryData;
import cz.trask.migration.model.v32.ApiDefinition32;
import cz.trask.migration.model.v32.Subscriptions;
import cz.trask.migration.model.v32.Subscriptions.ApplicationInfo;
import cz.trask.migration.model.v32.Subscriptions.Subscription;
import io.apicurio.registry.rest.client.exception.VersionAlreadyExistsException;
import io.apicurio.registry.rest.v2.beans.ArtifactMetaData;
import io.apicurio.registry.rest.v2.beans.ArtifactReference;
import io.apicurio.registry.rest.v2.beans.VersionSearchResults;
import io.apicurio.registry.types.RuleType;
import lombok.extern.log4j.Log4j2;

@Log4j2
public class Wso2v32ToApicurioFromDir extends AbstractProcess {

	private final AtomicInteger apiCounter = new AtomicInteger(1);

	/**
	 * Main entry point for the import process.
	 *
	 * @throws RuntimeException if any error occurs
	 */
	public void process() {
		try {
			log.info("Starting API import to Apicurio from WSO2 Directory...");

			File[] apiFiles = new File(config.getSource().getWso2ApisDir())
					.listFiles((dir, name) -> name.endsWith(".zip"));
			if (apiFiles == null || apiFiles.length == 0) {
				log.warn("No API zip files found in directory: {}", config.getSource().getWso2ApisDir());
				return;
			}

			log.info("Found {} APIs", apiFiles.length);

			int maxThreads = config.getMaxThreads();
			ExecutorService executor = Executors.newFixedThreadPool(maxThreads);

			for (File api : apiFiles) {
				final int index = apiCounter.getAndIncrement();
				executor.submit(() -> processApi(api, index, apiFiles.length));
			}

			executor.shutdown();
			if (!executor.awaitTermination(10, TimeUnit.MINUTES)) {
				log.warn("Timeout waiting for API import tasks to finish");
			}
			log.info("Finished processing APIs.");
		} catch (Exception e) {
			log.error("Error while exporting APIs.", e);
			throw new RuntimeException("Export failed", e);
		}
	}

	/**
	 * Process a single API – fetches the data, creates or updates the corresponding
	 * artifact in Apicurio.
	 */
	private void processApi(File apiFile, int index, int total) {
		long start = System.currentTimeMillis();

		try {
			log.info("Processing API {} of {}", index, total);

			List<ZipEntryData> zipEntries = ZipUtils.extractFilesFromZip(Files.readAllBytes(apiFile.toPath()));

			String swagger = null;
			String apiDefStr = null;

			for (ZipEntryData e : zipEntries) {
				if (swagger != null && apiDefStr != null) {
					break;
				}
				if (e.getType().toString().equals(FileType.OPENAPI.toString())) {
					log.debug("Found main API swagger file: {}", e.getName());
					swagger = new String(e.getContent());
				} else if (e.getType().toString().equals(FileType.APIDEF.toString())) {
					log.debug("Found main API definition file: {}", e.getName());
					apiDefStr = new String(e.getContent());
				}
			}

			ApiDefinition32 apiDef = mapper.readValue(apiDefStr, ApiDefinition32.class);
			Map<String, Object> swaggerMap = mapper.readValue(swagger, Map.class);

			APIInfo api = new APIInfo();
			api.setName(apiDef.getId().getApiName());
			api.setVersion(apiDef.getId().getVersion());
			api.setContext(apiDef.getContext().substring(0, apiDef.getContext().indexOf('/', 1)));
			api.setDescription((String) ((Map<String, Object>) swaggerMap.get("info")).get("description"));
			api.setType(apiDef.getType());
			api.setId(apiDef.getUuid());

			System.out.println("Context: " + apiDef.getContext());

			@SuppressWarnings("unchecked")
			List<String> tagsList = (List<String>) apiDef.getTags();

			Map<String, String> props = new LinkedHashMap<>();
			props.put("version", api.getVersion());
			props.put("status", apiDef.getStatus());
			props.put(PARAM_SOURCE_APIM, VERSION_32);
			// addSubscriptionsToProps(props, subs);
			// addEndpointsToProps(props, apiMap);
			addTagsToProps(props, tagsList);

			String baseDesc = api.getDescription() != null ? api.getDescription() : "";
			String pubUrl = config.getPatterns().getPublisherUrlPattern().replace("{API_ID}",
					api.getId());
			String devPortUrl = config.getPatterns().getDevPortalUrlPattern().replace("{API_ID}",
					api.getId());

			String fullDesc = baseDesc + " ***** PUBLISHER URL ***** " + pubUrl + " ***** DEVPORTAL URL ***** "
					+ devPortUrl;

			ObjectNode swaggerObj = mapperYaml.valueToTree(swaggerMap);
			updateSwagger(swaggerObj, apiDef, fullDesc);

			String group = config.getApicurio().getDefaultApiGroup();
			String mainArtifactId = api.getName() + api.getContext();

			VersionSearchResults existingArtifacts;
			try {
				existingArtifacts = client.listArtifactVersions(group, mainArtifactId, 0,
						Integer.MAX_VALUE);
			} catch (Exception e) {
				log.debug("No API {} exists – will create it", api.getContext());
				existingArtifacts = null;
			}

			if (existingArtifacts == null) {
				// Create new artifact
				List<ArtifactReference> references = createReferencesFromZip(zipEntries,
						api);
				// addSubscriptionsToReferences(references, subs, api);

				ArtifactMetaData meta = client.createArtifact(group, mainArtifactId,
						api.getVersion(), null, null, null,
						api.getName(), fullDesc, null, null, null,
						new ByteArrayInputStream(swaggerObj.toString().getBytes()), references);

				setArtifactMetaData(meta, props);
				// Create the three required rules
				createRule(meta, "NONE", RuleType.COMPATIBILITY);
				createRule(meta, "NONE", RuleType.VALIDITY);
				createRule(meta, "NONE", RuleType.INTEGRITY);

			} else {
				// Artifact exists – check if the version exists
				boolean versionExists = false;
				try {
					client.getArtifactVersionMetaData(group, mainArtifactId, api.getVersion());
					versionExists = true;
				} catch (Exception e) {
					// Version missing – will create it below
				}

				List<ArtifactReference> references = createReferencesFromZip(zipEntries,
						api);
				// addSubscriptionsToReferences(references, subs, api);

				if (!versionExists) {
					ArtifactMetaData meta = client.updateArtifact(group, mainArtifactId,
							api.getVersion(),
							api.getName(), fullDesc, new ByteArrayInputStream(swaggerObj.toString().getBytes()),
							references);
					setArtifactMetaData(meta, props);
				} else {
					// Version already exists – no action needed
					log.warn("API {} with version {} already exists. Skipping import.",
							api.getContext(),
							api.getVersion());
				}
			}

			log.info("Successfully imported API '{}' ({}). Took {} ms", api.getName(),
					api.getVersion(),
					System.currentTimeMillis() - start);
		} catch (IOException e) {
			log.error("IO error while importing API file {}: {}", apiFile.getName(), e.getMessage(), e);
		} catch (VersionAlreadyExistsException e) {
			log.warn("API version already exists for file: {}. Skipping.", apiFile.getName(), e.getMessage(), e);
		} catch (Exception e) {
			log.error("Cannot export API '{}': {}", apiFile.getName(), e.getMessage(), e);
		}
	}

	/* --------------------------------------------------------------------- */
	/* Helper methods */
	/* --------------------------------------------------------------------- */

	private void updateSwagger(ObjectNode swagger, ApiDefinition32 apiDef, String description) {
		// Update "info.description"
		ObjectNode info = (ObjectNode) swagger.get("info");
		if (info != null) {
			info.put("description", description);
		}

		// Build "servers" array
		ArrayNode servers = mapper.createArrayNode();

		Map<String, Object> endpoints = apiDef.getEndpointConfig();
		if (endpoints != null) {

			Map<String, Object> prodEps = (Map<String, Object>) endpoints.get("production_endpoints");
			Map<String, Object> sandEps = (Map<String, Object>) endpoints.get("sandbox_endpoints");

			
			ObjectNode server = mapper.createObjectNode();
			if (k.equals("https") || k.equals("wss")) {
				server.put("url", v);
			}
			server.put("description", "Gateway: " + env.getOrDefault("environmentName", ""));
			servers.add(server);
		}
	}

	// Replace "servers" node
	swagger.set("servers",servers);

	}

	private 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);
			});
		}
	}

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

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

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

			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, 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;
	}
}