global without sharing class Batch_FixAttachmentToFiles implements Database.Batchable<sObject>{
    // Id batchJobId = Database.executeBatch(new Batch_FixAttachmentToFiles(Datetime.newInstance(2023, 5, 20, 8, 0, 0),'Consumable_order__c'),2000);
    private Datetime endDate = null;
    private String objectApiName = null;
    public Batch_FixAttachmentToFiles(Datetime setTime,String objectType) {
        endDate = setTime;
        objectApiName = objectType;
    }

    global Database.QueryLocator start(Database.BatchableContext BC) {
        String queryObject = 'SELECT Id FROM ' + objectApiName + ' WHERE CreatedDate >=:endDate' + ' order by CreatedDate desc';
        System.debug('queryObject:' + queryObject);
        return Database.getQueryLocator(queryObject);//取指定Object下面的Id或者处理全部
    }

    global void execute(Database.BatchableContext BC, List<sObject> scope) {
        Set<Id> setId = new Set<Id>();
        for(sObject sc: scope){
            setId.add(sc.Id);
        }
        List<ContentVersion> insertContents = new List<ContentVersion>();
        Map<string,id> nameParentMaps = new Map<string,id>();
        for (Attachment att : [select Id,Name ,OwnerId,ParentId, Body, CreatedById from Attachment where ParentId in: setId Order by Name desc]) {
            nameParentMaps.put(att.name, att.ParentId);   
            ContentVersion cVersion = new ContentVersion();
            cVersion.ContentLocation = 'S';     //S-Document is in Salesforce. E-Document is outside of Salesforce. L-Document is on a Social Netork.
            cVersion.PathOnClient = att.Name;   //File name with extention
            cVersion.Origin = 'C';              //C-Content Origin. H-Chatter Origin.   
            cVersion.Title = att.Name;          //Name of the file
            cVersion.VersionData = att.Body;    //File content
            insertContents.add(cVersion);                            
        }
        if(insertContents.isEmpty()){
            return;
        }
        Insert insertContents;
        set<Id> contentIds = new set<Id>();
        for(ContentVersion cv : insertContents){
            contentIds.add(cv.id);
        }
        List<ContentVersion> conDocuments = [SELECT ContentDocumentId, Title FROM ContentVersion WHERE Id in: contentIds];
        List<ContentDocumentLink> insertDocLinks = new List<ContentDocumentLink>();  
        for(ContentVersion cv : conDocuments){
            ContentDocumentLink cDocLink = new ContentDocumentLink();
            cDocLink.ContentDocumentId = cv.ContentDocumentId;          //Add ContentDocumentId
            cDocLink.LinkedEntityId = nameParentMaps.get(cv.Title);     //Add attachment parentId
            cDocLink.ShareType = 'V';                                   //V - Viewer permission. C - Collaborator permission. I - Inferred permission.
            cDocLink.Visibility = 'AllUsers';
            insertDocLinks.add(cDocLink);
        }
        Insert insertDocLinks;
    }

    global void finish(Database.BatchableContext BC) {

    }
}