public with sharing class SharePointFeature extends CloudStorageBase {
    
    private static final String SHAREPOINT_API_BASE_URL = 'https://graph.microsoft.com/v1.0';
    private static String externalStorage = 'SharePoint';

    //List files
    public override OperationResult listFiles(Map<String, Object> params) {
        try {
            Boolean isServiceMode = (Boolean) params.get('isServiceMode');
            Boolean myDrive = (Boolean) params.get('myDrive');
            Boolean isRootFolder = (Boolean) params.get('isRootFolder');
            String folderId = (String) params.get('folderId');
            String accessToken = (String) params.get('accessToken');
            String level = (String) params.get('level');
            
            //get all sites 
            if (level == 'getAllSite' || level == 'getSites') {
                if(myDrive == true){
                    return getAllFollowedSites(accessToken);
                }
                else {
                    return getAllSharePointSites(accessToken);
                }
            }
            
            else if (level == 'getDocumentDrive') {
                if (String.isBlank(folderId)) {
                    return OperationResult.error('SiteId required ');
                }
                return getAllDocumentDrives(accessToken, folderId);

            } else if (level == 'getFilesInsideDocDrive') {
                if (String.isBlank(folderId)) {
                    return OperationResult.error('DriveId required');
                }
                return getFilesInsideDrive(accessToken, folderId);
            }

            return OperationResult.error('Invalid level provided');

        } catch (Exception e) {
            return OperationResult.error('ERROR: ' + e.getMessage());
        }
    }


    // all sharepoint sites
    private OperationResult getAllSharePointSites(String accessToken) {

        String url = SHAREPOINT_API_BASE_URL + '/sites?search=*';
        HttpRequest req = new HttpRequest();
        req.setEndpoint(url);
        req.setMethod('GET');
        req.setHeader('Authorization', 'Bearer ' + accessToken);
        req.setHeader('Accept', 'application/json');

        Http http = new Http();
        HttpResponse res = http.send(req);

        if (res.getStatusCode() != 200)
            return OperationResult.error('Error fetching SharePoint Sites: ' + res.getBody());

        Map<String,Object> json = (Map<String,Object>) JSON.deserializeUntyped(res.getBody());
        List<Object> siteList = (List<Object>) json.get('value');
        System.debug('siteList: ' + siteList);
        System.debug('siteList: ' + siteList.size());

        List<Map<String,String>> result = new List<Map<String,String>>();
        System.debug('result: ' + result);

        for (Object allsites : siteList) {
            Map<String,Object> site = (Map<String,Object>) allsites;

            Map<String,String> row = new Map<String,String>();

            // getAllSharePointSites  &  getAllFollowedSites
            row.put('id', (String) site.get('id'));
            row.put('name', (String) site.get('displayName'));
            row.put('url', (String) site.get('webUrl'));
            row.put('type', 'site');
            row.put('nextLevel', 'getDocumentDrive');
            row.put('disableCheck', 'true'); 

            result.add(row);
        }

        return OperationResult.success(result);
    }

    
    //get the followed sites
    private OperationResult getAllFollowedSites(String accessToken) {

        String url = SHAREPOINT_API_BASE_URL + '/me/followedSites';

        HttpRequest req = new HttpRequest();
        req.setEndpoint(url);
        req.setMethod('GET');
        req.setHeader('Authorization', 'Bearer ' + accessToken);
        req.setHeader('Accept', 'application/json');

        Http http = new Http();
        HttpResponse res = http.send(req);

        if (res.getStatusCode() != 200) {
            return OperationResult.error(
                'Error fetching followed SharePoint Sites: ' + res.getBody()
            );
        }

        Map<String, Object> resbody = (Map<String, Object>) JSON.deserializeUntyped(res.getBody());
        
        List<Object> siteList = (List<Object>) resbody.get('value');
        List<Map<String, String>> result = new List<Map<String, String>>();
        System.debug('result>>>' + result);

        for (Object obj : siteList) {
            Map<String, Object> s = (Map<String, Object>) obj;

            Map<String, String> row = new Map<String, String>();
            row.put('id', (String) s.get('id'));
            row.put('name', (String) s.get('displayName'));
            row.put('url', (String) s.get('webUrl'));
            row.put('type', 'followedSite');
            row.put('nextLevel', 'getDocumentDrive');
            row.put('disableCheck', 'true');

            result.add(row);
        }

        return OperationResult.success(result);
    }

    // all doc drive
    private OperationResult getAllDocumentDrives(String accessToken, String siteId) {

        String url = SHAREPOINT_API_BASE_URL + '/sites/' + siteId + '/drives';
        HttpRequest req = new HttpRequest();
        req.setEndpoint(url);
        req.setMethod('GET');
        req.setHeader('Authorization', 'Bearer ' + accessToken);
        req.setHeader('Accept', 'application/json');

        Http http = new Http();
        HttpResponse res = http.send(req);

        if (res.getStatusCode() != 200)
            return OperationResult.error('Error fetching drives: ' + res.getBody());

        Map<String,Object> json = (Map<String,Object>) JSON.deserializeUntyped(res.getBody());
        List<Object> driveList = (List<Object>) json.get('value');

        List<Map<String,String>> result = new List<Map<String,String>>();

        for (Object alldrives : driveList) {
            Map<String,Object> drive = (Map<String,Object>) alldrives;

            Map<String,String> row = new Map<String,String>();
            // getAllDocumentDrives
            // row.put('id', (String) drive.get('id'));
            //change
            row.put('id', drive.get('id') + ':' + siteId);

            row.put('name', (String) drive.get('name'));
            row.put('driveType', (String) drive.get('driveType'));
            row.put('type', 'drive');
            row.put('nextLevel', 'getFilesInsideDocDrive');
            row.put('disableCheck', 'true'); 

            result.add(row);
        }

        return OperationResult.success(result);
    }


    private OperationResult getFilesInsideDrive(String accessToken, String compositeId) {

        List<String> parts = compositeId.split(':');

        String driveId = parts[0];
        String siteId  = parts.size() > 1 ? parts[1] : null;
        String itemId  = parts.size() > 2 ? parts[2] : null;

        String url;

        // ROOT of document library
        if (itemId == null) {
            url = SHAREPOINT_API_BASE_URL + '/drives/' + driveId + '/root/children';
        }
        // INSIDE a folder
        else {
            url = SHAREPOINT_API_BASE_URL + '/drives/' + driveId + '/items/' + itemId + '/children';
        }

            HttpRequest req = new HttpRequest();
            req.setEndpoint(url);
            req.setMethod('GET');
            req.setHeader('Authorization', 'Bearer ' + accessToken);
            req.setHeader('Accept', 'application/json');

            Http http = new Http();
            HttpResponse res = http.send(req);

            if (res.getStatusCode() != 200) {
                return OperationResult.error('Error getting drive items: ' + res.getBody());
            }

            Map<String,Object> json = (Map<String,Object>) JSON.deserializeUntyped(res.getBody());
            List<Object> items = (List<Object>) json.get('value');

            List<Map<String,String>> result = new List<Map<String,String>>();

            for (Object obj : items) {
                Map<String,Object> f = (Map<String,Object>) obj;
                Map<String,String> row = new Map<String,String>();

                // Preserve composite ID for next navigation
                // row.put('id', driveId + ':' + (String) f.get('id'));
                //changes
                row.put('id',    driveId + ':' + siteId + ':' + (String) f.get('id'));

                // changes
                //  NORMALIZED ID (used by download/delete/rename)
                // String normalizedFileId = driveId + ':' + (String) f.get('id');
                // row.put('id', normalizedFileId);


                
                // String itemGraphId = (String) f.get('id');

                //  NAVIGATION ID (USED FOR FOLDER CLICK / BACK / BREADCRUMB)
                // String navigationId = driveId + ':' + siteId + ':' + itemGraphId;
                // row.put('id', navigationId);

                //  OPERATION ID (USED FOR DOWNLOAD / DELETE / RENAME)
                // String normalizedId = driveId + ':' + itemGraphId;
                // row.put('normalizedId', normalizedId);


                row.put('name', (String) f.get('name'));
                row.put('openUrl', (String) f.get('webUrl'));  

                row.put('createdTime', (String) f.get('createdDateTime'));
                row.put('disableCheck', 'false');
                row.put('type', f.containsKey('folder') ? 'folder' : 'file');
                row.put('nextLevel', 'getFilesInsideDocDrive');

                if (f.containsKey('folder')) {
                    row.put('mimeType', 'doctype:folder');
                } else {
                    Map<String, Object> fileObj = (Map<String, Object>) f.get('file');
                    row.put('mimeType',
                        fileObj != null && fileObj.containsKey('mimeType')
                        ? (String) fileObj.get('mimeType')
                        : 'doctype:unknown'
                    );
                }

                Map<String, Object> createdBy = (Map<String, Object>) f.get('createdBy');
                if (createdBy != null) {
                    Map<String, Object> userMap = (Map<String, Object>) createdBy.get('user');
                    row.put('displayName', userMap != null ? (String) userMap.get('displayName') : '-');
                }

                result.add(row);
            }

            return OperationResult.success(result);
    }


    //adding method to linkfiles
    // change custom object  -- linkedFolder
    public override OperationResult linkFiles(String recordId) {
        List<Map<String, String>> resultFolders = new List<Map<String, String>>();

        try {
            List<HIC_FilesME__Linked_Folder__c> linkedFolders = [
                SELECT Id,Name,CreatedDate,CreatedBy.Name,HIC_FilesME__External_Folder_ID__c,
                    HIC_FilesME__Folder_Name__c,
                    HIC_FilesME__Folder_URL__c,
                    HIC_FilesME__Storage_Provider__c,
                    HIC_FilesME__Access_Level__c
                FROM HIC_FilesME__Linked_Folder__c
                WHERE HIC_FilesME__Linked_Record__c = :recordId
                AND HIC_FilesME__Is_Active__c = true
            ];

            for (HIC_FilesME__Linked_Folder__c folder : linkedFolders) {

                Map<String, String> folderData = new Map<String, String>();

                folderData.put('id', folder.HIC_FilesME__External_Folder_ID__c);
                folderData.put('recordId', folder.Id);
                folderData.put('name', folder.HIC_FilesME__Folder_Name__c);
                folderData.put('externalStorageType', folder.HIC_FilesME__Storage_Provider__c);
                folderData.put('accessLevel', folder.HIC_FilesME__Access_Level__c);
                folderData.put('createdTime', String.valueOf(folder.CreatedDate));
                folderData.put('createdBy', folder.CreatedBy != null ? folder.CreatedBy.Name : '-');
                folderData.put('url', folder.HIC_FilesME__Folder_URL__c);

                resultFolders.add(folderData);
            }

            return OperationResult.success(resultFolders);

        } catch (Exception e) {FME_Logger.error(e.getMessage(),'LinkedFolderFeature' + e.getLineNumber(),'linkFiles');
            return OperationResult.error('Failed to fetch linked folders. ' + e.getMessage());
        }
    }

    // change custom object  -- linkedFolder
    public override OperationResult toLinkFiles(String recordId,String folderDetails,String providerType) {
        try {
            System.debug('providerType >>>> ' + providerType);
            System.debug('recordId >>>> ' + recordId);
            System.debug('JSON.deserializeUntyped folderDetails  >>>> ' + JSON.deserializeUntyped(folderDetails));
            Map<String, Object> folderMap =
                (Map<String, Object>) JSON.deserializeUntyped(folderDetails);

            HIC_FilesME__Linked_Folder__c linkedFolder = new HIC_FilesME__Linked_Folder__c();

            linkedFolder.HIC_FilesME__Linked_Record__c      = recordId;
            linkedFolder.HIC_FilesME__External_Folder_ID__c = (String) folderMap.get('id');
            linkedFolder.HIC_FilesME__Folder_Name__c        = (String) folderMap.get('name');
            //add
            linkedFolder.HIC_FilesME__Created__c = UserInfo.getUserId();
            linkedFolder.HIC_FilesME__Created_Date__c = System.now();
            linkedFolder.HIC_FilesME__Folder_URL__c         = (String) folderMap.get('url');
            linkedFolder.HIC_FilesME__Storage_Provider__c   =  providerType;
            // linkedFolder.HIC_FilesME__Access_Level__c       = (String) folderMap.get('accessLevel');
            linkedFolder.HIC_FilesME__Is_Active__c          = true;

            String key = providerType +' '+ recordId +' '+ (String) folderMap.get('id');
            linkedFolder.HIC_FilesME__Key__c = key;

            upsert linkedFolder HIC_FilesME__Key__c;
            
            System.debug('linkedFolder >>>> ' + linkedFolder);
            return OperationResult.success(linkedFolder);

        } catch (Exception e) {
            FME_Logger.error(e.getMessage(),'LinkedFolderFeature' + e.getLineNumber(),'toLinkFiles' );
            return OperationResult.error('Error linking folder: ' + e.getMessage());
        }
    }




    //to create folder 
    public override OperationResult createFolder(Map<String, Object> params)
        {
        Map<String, Object> resultMap = new Map<String, Object>();
        OperationResult result;

        try {
            String parentFolderId = (String) params.get('parentFolderId');
            Boolean isServiceMode = (Boolean) params.get('isServiceMode');
            String folderName = (String) params.get('folderName');
            String userId = (String) SalesforceEnvironmentUtil.getUserId();
            String accessToken = (String) params.get('accessToken');

            List<String> ids = parentFolderId != null ? parentFolderId.split(':') : null;
            String driveId  = ids != null ? ids[0] : null;
            String itemId   = (ids != null && ids.size() > 2) ? ids[2] : null;

            if (String.isBlank(driveId)) {
                return OperationResult.error('DriveId is required to create folder in SharePoint');
            }

            String endpoint;
            if (String.isBlank(itemId)) {
                endpoint = SHAREPOINT_API_BASE_URL + '/drives/' + driveId + '/root/children';
            } else {
                endpoint = SHAREPOINT_API_BASE_URL + '/drives/' + driveId + '/items/' + itemId + '/children';
            }

            String folderMetadata = JSON.serialize(new Map<String, Object>{
                'name' => folderName,
                'folder' => new Map<String, Object>(),
                '@microsoft.graph.conflictBehavior' => 'rename'
            });

            Map<String, String> headers = new Map<String, String>{
                'Authorization' => 'Bearer ' + accessToken,
                'Content-Type'  => 'application/json'
            };

            HttpResponse res = CloudStorageUtlilty.makeCallout(folderMetadata,endpoint,headers,'POST');

            if (res.getStatusCode() == 201 || res.getStatusCode() == 200) {
                resultMap = (Map<String, Object>) JSON.deserializeUntyped(res.getBody());
                resultMap.put('code', '200');
                result = OperationResult.success(resultMap);
            } else {
                System.debug('SharePoint create folder failed: ' + res.getBody());
                result = OperationResult.error(res.getBody());
            }

        } catch (Exception e) {
            FME_Logger.error(
                e.getMessage(),
                'SharePointFeature.createFolder line ' + e.getLineNumber(),
                'createFolder'
            );
            result = OperationResult.error('Error creating SharePoint folder: ' + e.getMessage());

        }
        System.debug('resultMap >>> ' + resultMap);
        System.debug('result >>> ' + result);
        return result;
    }

  
    //to delete file or folder
    public override OperationResult deleteFile(Map<String, Object> params) {

        try {
            String fileId = (String) params.get('fileId');
            String userId = SalesforceEnvironmentUtil.getUserId();
            Boolean isServiceMode = (Boolean) params.get('isServiceMode');
            String accessToken = (String) params.get('accessToken');

            System.debug('SharePoint delete >>> fileId=' + fileId);

            if (String.isBlank(fileId)) {
                return OperationResult.error('FileId is required');
            }

            // Parse the complex SharePoint ID format
            // Format: driveId:siteId:itemId
            List<String> ids = fileId.split(':');
            if (ids.size() < 3) {
                return OperationResult.error('Invalid SharePoint fileId format. Expected format: driveId:siteId:itemId');
            }

            String driveId = ids[0];
            String siteId = ids[1];
            String itemId = ids[2];

            // Build the correct endpoint for SharePoint
            String endpoint = SHAREPOINT_API_BASE_URL + '/drives/' + driveId + '/items/' + itemId;
            System.debug('SharePoint delete endpoint >>> ' + endpoint);

            // Headers
            Map<String, String> headers = new Map<String, String>();
            headers.put('Authorization', 'Bearer ' + accessToken);

            HttpResponse res = CloudStorageUtlilty.makeCallout(null,endpoint,headers,'DELETE');
            System.debug('Delete response code >>> ' + res.getStatusCode());

            if (res.getStatusCode() == 204) {
                return OperationResult.success('Deleted successfully');
            } else {
                return OperationResult.error(res.getBody());
            }

        } catch (Exception e) {
            FME_Logger.error(e.getMessage(),'SharePointFeature.deleteFile line ' + e.getLineNumber(),'deleteFile');
            return OperationResult.error(
                'Error deleting SharePoint file: ' + e.getMessage()
            );
        } 
    }

    
    //rename folder -- Done
    public override OperationResult renameFile(Map<String, Object> params) {
        OperationResult result;
        Map<String, String> accessTokenMap = new Map<String, String>();

        try {
            String fileId = (String) params.get('fileId');
            Boolean isServiceMode = (Boolean) params.get('isServiceMode');
            String newFileName = (String) params.get('newFileName');
            String accessToken = (String) params.get('accessToken');

            if (String.isBlank(fileId) || String.isBlank(newFileName)) {
                return OperationResult.error('FileId and newFileName are required');
            }

            // Parse the complex SharePoint ID format
            // Format: driveId:siteId:itemId
            List<String> ids = fileId.split(':');
            if (ids.size() < 3) {
                return OperationResult.error('Invalid SharePoint fileId format. Expected format: driveId:siteId:itemId');
            }

            String driveId = ids[0];
            String siteId = ids[1];  
            String itemId = ids[2];

            String url = SHAREPOINT_API_BASE_URL + '/drives/' + driveId + '/items/' + itemId;

            System.debug('SharePoint rename url >>> ' + url);
            System.debug('New file name >>> ' + newFileName);

            String body = JSON.serialize(new Map<String, Object>{
                'name' => newFileName
            });

            Map<String, String> headers = new Map<String, String>{
                'Authorization' => 'Bearer ' + accessToken,
                'Content-Type'  => 'application/json'
            };

            HttpResponse res = CloudStorageUtlilty.makeCallout(body, url, headers, 'PATCH');

            System.debug('Rename response code >>> ' + res.getStatusCode());

            if (res.getStatusCode() == 200) {
                result = OperationResult.success(res.getBody());
            } else {
                result = OperationResult.error(res.getBody());
            }

        } catch (Exception e) {
            FME_Logger.error(e.getMessage(),'SharePointFeature.renameFile line ' + e.getLineNumber(),'renameFile');
            result = OperationResult.error('Error renaming SharePoint file: ' + e.getMessage());

        }
        System.debug('SharePoint rename result >>> ' + result);
        return result;
    }


    //to share done
    public override OperationResult moveFileAndFolder(Map<String, Object> params) {
        OperationResult result;

        try {
            String fileId        = (String) params.get('fileId');
            Boolean isServiceMode= (Boolean) params.get('isServiceMode');
            String newFolderId   = (String) params.get('newFolderId');
            String oldFolderId   = (String) params.get('oldFolderId');
            String accessToken   = (String) params.get('accessToken');
            String userId        = (String) SalesforceEnvironmentUtil.getUserId();

            System.debug('SharePoint move >>> fileId=' + fileId);
            System.debug('SharePoint move >>> newFolderId=' + newFolderId);
            System.debug('SharePoint move >>> oldFolderId=' + oldFolderId);

        
            List<String> fileIds = fileId.split(':');

            if (fileIds.size() < 3) {
                return OperationResult.error(
                    'Invalid SharePoint fileId format'
                );
            }

            String driveId = fileIds[0];
            String siteId  = fileIds[1];
            String itemId  = fileIds[2];


            List<String> newFolderParts = newFolderId.split(':');

            String newParentId = newFolderParts.size() > 2 ? newFolderParts[2] : null;


            String endpoint =SHAREPOINT_API_BASE_URL + '/drives/' + driveId + '/items/' + itemId;


            Map<String, Object> bodyMap =  new Map<String, Object>();

            if (newParentId != null) {
                bodyMap.put('parentReference',new Map<String, Object>{
                        'id' => newParentId
                    }
                );
            }

            String body = JSON.serialize(bodyMap);

        
            Map<String, String> headers = new Map<String, String>{
                    'Authorization' => 'Bearer ' + accessToken,
                    'Content-Type'  => 'application/json'
                };

            
            HttpResponse res = CloudStorageUtlilty.makeCallout(body,endpoint,headers,'PATCH');

            if (res.getStatusCode() == 200) {
                System.debug('SharePoint move success');
                result = OperationResult.success(res.getBody());
            } else {
                System.debug('SharePoint move failed: ' + res.getBody());
                result = OperationResult.error(res.getBody());
            }

        } catch (Exception e) {
            FME_Logger.error(e.getMessage(),'SharePointFeature ' + e.getLineNumber(),'moveFileAndFolder');

            result = OperationResult.error('Error moving SharePoint item: ' + e.getMessage());
        }

        return result;
    }



    public override OperationResult downloadFile(Map<String, Object> params) {
        // System.debug('SharePointFeature.downloadFile');
        // System.debug('isServiceMode: ' + isServiceMode);
        // System.debug('userId: ' + userId);
        // System.debug('fileId: ' + fileId);
        OperationResult result;
        try {
            Blob fileBlob = fetchFileAndConvertToBase64(params);
            System.debug('fileBlob: ' + fileBlob);
       

            if (fileBlob != null) {
                result = OperationResult.success(EncodingUtil.base64Encode(fileBlob));
                System.debug('SharePoint file downloaded successfully.');
            } else {
                result = OperationResult.error('Failed to download SharePoint file. fileId: ' );
            }
        } catch (Exception e) {
            result = OperationResult.error('Error downloading SharePoint file: ' + e.getMessage());
            FME_Logger.error(e.getMessage(),'SharePointFeature' + e.getLineNumber(),'downloadFile');
        }
        return result;
    }


    public static Blob fetchFileAndConvertToBase64(Map<String, Object> params) {
        Blob fileBlob;

        try {
            Boolean isServiceMode = (Boolean) params.get('isServiceMode');
            String fileId = (String) params.get('fileId');
            String fileName = (String) params.get('fileName');
            String accessToken = (String) params.get('accessToken');
            String userId = (String) SalesforceEnvironmentUtil.getUserId();

            System.debug('isServiceMode: ' + isServiceMode);
            System.debug('fileId: ' + fileId);
            System.debug('fileName: ' + fileName);
            System.debug('accessToken: ' + accessToken);
            
            Map<String, Object> credentials = CloudStorageUtlilty.getAccessToken(isServiceMode, userId, externalStorage);

            // String accessToken  = (String) credentials.get('ACCESS_TOKEN');
            String refreshToken = (String) credentials.get('REFRESH_TOKEN');

            //  Parse the 3-part SharePoint ID correctly
            // Format: driveId:siteId:itemId
            List<String> parts = fileId.split(':');
            if (parts.size() < 3) {
                System.debug('Invalid SharePoint fileId format. Expected: driveId:siteId:itemId');
                return null;
            }
            
            String driveId = parts[0];
            String siteId = parts[1];   
            String itemId = parts[2];   

            Map<String, String> headers = new Map<String, String>{
                'Authorization' => 'Bearer ' + accessToken
            };

            String metaUrl = 'https://graph.microsoft.com/v1.0/drives/' + driveId + '/items/' + itemId + '?select=@microsoft.graph.downloadUrl';
            
            System.debug('SharePoint download URL request: ' + metaUrl);

            HttpResponse metaRes = CloudStorageUtlilty.makeCallout(null, metaUrl, headers, 'GET');

            // 4. Handle token refresh if needed
            if (metaRes.getStatusCode() == 401) {
                SharePointAuth auth = new SharePointAuth();
                String newAccessToken = auth.refreshAccessToken(refreshToken);
                CloudStorageUtlilty.updateAccessToken(isServiceMode, userId, newAccessToken, externalStorage);
                
                headers.put('Authorization', 'Bearer ' + newAccessToken);
                metaRes = CloudStorageUtlilty.makeCallout(null, metaUrl, headers, 'GET');
            }

            if (metaRes.getStatusCode() != 200) {
                System.debug('Failed to fetch SharePoint download URL. Status: ' + metaRes.getStatusCode() + ' Body: ' + metaRes.getBody());
                return null;
            }

            Map<String, Object> meta = (Map<String, Object>) JSON.deserializeUntyped(metaRes.getBody());
            String downloadUrl = (String) meta.get('@microsoft.graph.downloadUrl');

            if (String.isBlank(downloadUrl)) {
                System.debug('No download URL returned from SharePoint');
                return null;
            }

            System.debug('SharePoint download URL obtained successfully');

            HttpResponse fileRes = CloudStorageUtlilty.makeCallout(null, downloadUrl, null, 'GET');

            if (fileRes.getStatusCode() == 200) {
                fileBlob = fileRes.getBodyAsBlob();
                System.debug('SharePoint file downloaded successfully. Size: ' + fileBlob.size() + ' bytes');
            } else {
                System.debug('SharePoint file download failed. Status: ' + fileRes.getStatusCode() + ' Body: ' + fileRes.getBody());
            }

        } catch (Exception e) {
            System.debug('Error in SharePoint fetchFileAndConvertToBase64: ' + e.getMessage() + ' | Line: ' + e.getLineNumber());
        }

        return fileBlob;
    }


    
    public override OperationResult emailFile(Map<String,Object> params) {

        OperationResult result;

        try {

            //maildetails
            Map<String, Object> mailDetails =(Map<String, Object>) JSON.deserializeUntyped(JSON.serialize(params.get('mailDetails')));

            String fileId     = (String) params.get('fileId');
            String fileName   = (String) params.get('fileName');
            String mimeType   = (String) params.get('toSendFileNameMimeType');

            String senderId   = (String) mailDetails.get('fromUser');
            String toUser     = (String) mailDetails.get('toUser');
            String ccUser     = (String) mailDetails.get('ccUser');
            String bccUser    = (String) mailDetails.get('bccUser');
            String subject    = (String) mailDetails.get('subject');
            String body       = (String) mailDetails.get('body');


            Messaging.SingleEmailMessage mail = new Messaging.SingleEmailMessage();

            // Required
            mail.setToAddresses(new List<String>{ toUser });

            // Optional
            if (String.isNotBlank(ccUser))
                mail.setCcAddresses(new List<String>{ ccUser });

            if (String.isNotBlank(bccUser))
                mail.setBccAddresses(new List<String>{ bccUser });

            mail.setSubject(subject);

            // Remove HTML tags safely
            mail.setPlainTextBody(body != null ? body.replaceAll('<[^>]+>', '') : '');

            if (String.isNotBlank(senderId) && senderId.startsWith('0D2')) {
                mail.setOrgWideEmailAddressId(senderId);
            }

            Map<String, Object> downloadParams = new Map<String, Object>(params);
            downloadParams.put('fileId', fileId);
            downloadParams.put('fileName', fileName);

            OperationResult op = downloadFile(downloadParams);

            if (op != null && op.data != null) {

                Blob fileBlob = EncodingUtil.base64Decode((String) op.data);

                Messaging.EmailFileAttachment attachment = new Messaging.EmailFileAttachment();

                attachment.setFileName(fileName);
                attachment.setBody(fileBlob);
                attachment.setContentType(String.isNotBlank(mimeType) ? mimeType: 'application/octet-stream');

                mail.setFileAttachments(new List<Messaging.EmailFileAttachment>{ attachment });
            }


            Messaging.SendEmailResult[] results = Messaging.sendEmail( new List<Messaging.SingleEmailMessage>{ mail });

            if (!results.isEmpty() && results[0].isSuccess()) {
                result = OperationResult.success(null);
                System.debug(' Email sent successfully');

            } else {
                String errMsg = (!results.isEmpty() && results[0].getErrors().size() > 0)? results[0].getErrors()[0].getMessage(): 'Unknown send failure';
                result = OperationResult.error(errMsg);
            }

        } catch (Exception e) {
            FME_Logger.error(e.getMessage(),'EmailFeature ' + e.getLineNumber(),'emailFile');
            result = OperationResult.error('Error sending email: ' + e.getMessage());
        }
        System.debug('result:' + result);
        return result;
    }




    //unlinkfile
    public override OperationResult unlinkFiles(String recordId, String filesId, Boolean deleteFromDrive) {
        System.debug('recordId >>>> ' + recordId);
        System.debug('filesId >>>> ' + filesId);
        System.debug('deleteFromDrive >>>> ' + deleteFromDrive);
        
        OperationResult result;
        try {
            List<HIC_FilesME__Linked_Folder__c> fileLinks = [SELECT Id FROM HIC_FilesME__Linked_Folder__c  WHERE HIC_FilesME__Linked_Record__c = :recordId AND HIC_FilesME__External_Folder_ID__c = :filesId];

                if (fileLinks.size() > 0) {
                    delete fileLinks;

                    // if (deleteFromDrive) {
                    //     deleteFile(filesId, true, null);
                    // }

                    result = OperationResult.success(null);
                } else {
                    result = OperationResult.error('No record found');
                }
            } catch (Exception e) {
                result = OperationResult.error('Error unlinking file: ' + e.getMessage());
                FME_Logger.error(e.getMessage(), 'GoogleDriveFeature' + e.getLineNumber(), 'unlinkFiles');
            } 
            return result;
    }


        
}