package net.gepafin.tendermanagement.service.impl;

import com.amazonaws.AmazonServiceException;
import com.amazonaws.SdkClientException;
import com.amazonaws.services.s3.AmazonS3;
import com.amazonaws.services.s3.AmazonS3Client;
import com.amazonaws.services.s3.model.GetObjectRequest;
import com.amazonaws.services.s3.model.ObjectMetadata;
import lombok.extern.slf4j.Slf4j;
import net.gepafin.tendermanagement.dao.S3PathConfig;
import net.gepafin.tendermanagement.entities.DocumentEntity;
import net.gepafin.tendermanagement.enums.DocumentSourceTypeEnum;
import net.gepafin.tendermanagement.repositories.ApplicationRepository;
import net.gepafin.tendermanagement.repositories.ApplicationSignedDocumentRepository;
import net.gepafin.tendermanagement.repositories.DocumentRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Service;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.List;

@Slf4j
@Service
public class S3ReUploadMigrationService {

    private static final String OLD_BUCKET = "mementoresources";

    private static final String SECURE_KEY = "267163962963";

    @Autowired
    private DocumentRepository documentRepository;

    @Autowired
    private AmazonS3Client s3Client;

    @Autowired
    private S3PathConfig s3ConfigBean;

    @Autowired
    private ApplicationRepository applicationRepository;

    @Autowired
    private ApplicationSignedDocumentRepository applicationSignedDocumentRepository;

    @Autowired
    private AmazonS3 amazonS3;

    @Value("${aws.s3.url}")
    private String s3Url;

    private boolean migrationCompleted = false;

    public String reUploadAndMigrateDocuments(String providedKey) {

        if (migrationCompleted) {
            return "Migration already completed.";
        }

        // Validate the provided key
        if (!isValidKey(providedKey)) {
            return "Invalid or missing migration key.";
        }

        List<DocumentEntity> documents = documentRepository.findAllByIsDeleteFalse();

        if (documents.isEmpty()) {
            return "No documents found to migrate.";
        }

        for (DocumentEntity document : documents) {
            String oldUrl = document.getFilePath();  // This should contain the full URL
            log.info("Processing {}", oldUrl);

            try {
                File localFile = downloadFileFromS3(oldUrl);
                String newKey = generateNewS3Path(document);  // Make sure this generates the correct new path
                String uploadedPath = uploadFileToNewBucket(localFile, newKey);
                updateDocumentPathAndNameEntry(document, uploadedPath);
            } catch (Exception e) {
                log.error("Error processing document {}: {}", document.getId(), e.getMessage());
            }
        }
        return "Migrated Successfully.";
    }

    private boolean isValidKey(String providedKey) {

        return providedKey != null && providedKey.equals(SECURE_KEY);
    }

    private File downloadFileFromS3(String fileUrl) throws Exception {

        String key = extractS3KeyFromUrl(fileUrl);  // Get the S3 key from the URL
        File localFile = new File("/tmp/" + extractFileName(key));  // Save file locally

        GetObjectRequest getObjectRequest = new GetObjectRequest(OLD_BUCKET, key);  // Use the key

        try (InputStream s3Stream = s3Client.getObject(getObjectRequest).getObjectContent(); FileOutputStream outputStream = new FileOutputStream(localFile)) {
            s3Stream.transferTo(outputStream);
        }

        log.info("Downloaded file from old S3 bucket: {}", key);
        return localFile;
    }

    private String extractS3KeyFromUrl(String url) {
        // Assuming the URL structure is consistent
        return url.replace("https://mementoresources.s3.eu-west-1.amazonaws.com/", "");
    }

    private String uploadFileToNewBucket(File localFile, String s3Folder) {

        InputStream inputStream = null; // Declare the InputStream here for cleanup
        try {
            // Extract file name from the local file
            String fileName = extractFileName(localFile.getAbsolutePath()); // Get the file name
            String path = s3Folder + "/" + fileName; // Construct the S3 path

            // Create InputStream from the local file
            inputStream = new FileInputStream(localFile);

            // Set up object metadata
            ObjectMetadata objectMetadata = new ObjectMetadata();
            objectMetadata.setContentType("application/octet-stream");
            objectMetadata.setContentLength(localFile.length());

            // Upload to S3
            s3Client.putObject(OLD_BUCKET, path, inputStream, objectMetadata);

            // Construct the full S3 URL
            String fullUrl = String.format("https://%s.s3.%s.amazonaws.com/%s", OLD_BUCKET, "eu-west-1", path);
            log.info("File '{}' uploaded successfully to Amazon S3 with URL: {}", fileName, fullUrl);
            return fullUrl;

        } catch (IOException e) {
            log.error("IOException occurred during file upload for '{}': {}", localFile.getName(), e.getMessage());
            throw new RuntimeException("Upload failed for: " + s3Folder + "/" + localFile.getName(), e);
        } catch (AmazonServiceException e) {
            log.error("Amazon service exception while uploading file '{}': {}", localFile.getName(), e.getMessage());
            throw new RuntimeException("Upload failed for: " + s3Folder + "/" + localFile.getName(), e);
        } catch (SdkClientException e) {
            log.error("SDK client exception while uploading file '{}': {}", localFile.getName(), e.getMessage());
            throw new RuntimeException("Upload failed for: " + s3Folder + "/" + localFile.getName(), e);
        } finally {
            // Close InputStream if it was opened
            if (inputStream != null) {
                try {
                    inputStream.close();
                } catch (IOException e) {
                    log.warn("Failed to close InputStream for file '{}': {}", localFile.getName(), e.getMessage());
                }
            }
        }
    }

    private String generateNewS3Path(DocumentEntity document) {

        DocumentSourceTypeEnum sourceType = DocumentSourceTypeEnum.valueOf(document.getSource());
        Long callId;

        if (sourceType.equals(DocumentSourceTypeEnum.CALL)) {
            return s3ConfigBean.generateDocumentPath(sourceType, document.getSourceId(), 0L);
        } else {
            callId = applicationRepository.findCallIdById(document.getSourceId());
            return s3ConfigBean.generateDocumentPath(sourceType, callId, document.getSourceId());
        }
    }

    private String extractFileName(String filePath) {

        String[] parts = filePath.split("/");
        return parts[parts.length - 1];
    }


    private void updateDocumentPathAndNameEntry(DocumentEntity document, String newPath) {

        String fileName = extractFileName(newPath);
        document.setFilePath(newPath);
        document.setFileName(fileName);
        documentRepository.save(document);
        log.info("Migrated document ID: {} to new path: {}", document.getId(), newPath);
    }
}