Hello

Please someone help how to cover the test class and code coverage for the below rest api class?

Thanks in Advance
TH

public class callIwiseAPI {

    //To capture getOauthToken response
    public class tokenResponse{
        public string access_token;
    }
  
  public class OpptyInput{
    String SalesForceId;
        string OpportunityType;
    String Lob;
    String Product;
    String Region;
        String SubRegion;
    String BOTitle;
  //  String BType;
    String DealNature;
  //  String BOCurrency;
    Decimal ContractValue;
    Date EffectiveDate;
    Decimal ContractDuration;
    String ContractDurationUnitOfMesurement;
  //  String AccountCode;
    String Description;
    String SalesPerson1;
    String CreatedBy;
        string ProspectName;
        String ContactPerson;
        String ContactNumber;
        String Competitors;
        String ContactEmail;
        String JobTitle;
        String AccountName;

  }
/******************************************************************************************************************
Method      : getOauthToken
Parameters  : # 
ReturnType  : object
Description : Calling iWise API to get oAuth Token and pass the same token get the BO data
*******************************************************************************************************************/
    public  String getOauthToken(){
        String oAuthToken;
        tokenResponse atResponse = new tokenResponse();
        Http http = new Http();
        HttpRequest request = new HttpRequest();
        request.setEndpoint('callout:iWise_Credentials/token');
        request.setMethod('POST');
        request.setHeader('Content-Type', 'application/json; charset=utf-8');
        request.setHeader('username', '{!$Credential.Username}');
        request.setHeader('password', '{!$Credential.Password}');
        request.setHeader('grant_type', 'password');
    
        System.debug('Request to get oAuth Token:'+request);
        
    
        HttpResponse response = http.send(request);
        system.debug('Response from iWise for OAUTH Token:::'+response.toString());
        // If the request is successful, parse the JSON response.
        if (response.getStatusCode() == 201 || response.getStatusCode() == 200) {
            // Deserialize the JSON string into collections of primitive data types.
            //Map<String, object> results = (Map<String, object>) JSON.deserializeUntyped(response.getBody());
            system.debug(':::: Response::::'+response.getBody());
            atResponse = (tokenResponse)json.deserialize(response.getBody(),tokenResponse.class);
            // get the oAuth tken from the response
            
            oAuthToken = atResponse.access_token;//(String) results.get('access_token');
            System.debug('OAuth Acces Token from response:'+oAuthToken);
            return oAuthToken;
            
        }
        else{
            System.debug('The status code returned was not expected: ' +
            response.getStatusCode() + ' ' + response.getStatus());
            return oAuthToken;
        }
        
    }
    
/******************************************************************************************************************
Method      : sendBoToIwise
Parameters  : oAuthToken 
ReturnType  : object
Description : Calling iWise API to send the BO
*******************************************************************************************************************/
  @future(callout = true)
    public static void sendBoToIwise(set<id> oppIds){
//    system.debug('this');
    list<Opportunity> opty = new list<Opportunity>();
       String oAuthToken;
        
    
    opty = [select Id,Name,TCV__c,IBS_Lob__c,Contract_Type__c,Competitors_Names__c,Products__c,CloseDate,Type_of_Deal__c,Tenure_Unit_of_Measure__c,Tenure__c,Description,Owner.Name,Owner.Email,Account__r.Account_Code__c,Response_from_iWise_System__c,Account.Name,
                ( SELECT contact.firstName,contact.phone,contact.Email,contact.Title,contact.IBS_Region__c,contact.IBS_Sub_Region__c FROM OpportunityContactRoles ),
                (select Name,TeamMemberRole,User.Name,User.Email   from OpportunityTeamMembers where  TeamMemberRole = 'Sales Rep')
                                                from Opportunity where Id IN : oppIds];
            system.debug(opty);
       list<OpptyInput> inputRequest = new list<OpptyInput>();
        callIwiseAPI obj = new callIwiseAPI();
        oAuthToken = obj.getOauthToken();
    if(!opty.isEmpty()){
      for(Opportunity op : opty){
        OpptyInput reqInput  = new OpptyInput();
        reqInput.BOTitle=op.Name;
        reqInput.SalesForceId=op.Id;
                reqInput.OpportunityType=op.Type_of_Deal__c;
        reqInput.Lob = op.IBS_Lob__c;
        reqInput.Product=op.Products__c;
        reqInput.Region=op.OpportunityContactRoles[0].contact.IBS_Region__c;
        reqInput.SubRegion=op.OpportunityContactRoles[0].contact.IBS_Sub_Region__c;
      //  reqInput.BType = 'New BO';
        reqInput.DealNature = op.Contract_Type__c;
      //  reqInput.BOCurrency = 'USD';
        reqInput.ContractValue = op.TCV__c;
                reqInput.EffectiveDate = op.CloseDate;
        reqInput.ContractDuration = op.Tenure__c;
        reqInput.ContractDurationUnitOfMesurement = op.Tenure_Unit_of_Measure__c ;
      //  reqInput.AccountCode= op.Account__r.Account_Code__c;
      //  reqInput.Description= op.Description;
        reqInput.SalesPerson1 =op.OpportunityTeamMembers[0].User.Email;
        reqInput.CreatedBy=op.Owner.Email;
                reqInput.ProspectName= op.Account.Name;
                reqInput.ContactPerson=op.OpportunityContactRoles[0].contact.firstName;
                reqInput.ContactNumber=op.OpportunityContactRoles[0].contact.phone;
                reqInput.Competitors=op.Competitors_Names__c;
                reqInput.ContactEmail = op.OpportunityContactRoles[0].contact.Email;
                reqInput.JobTitle=op.OpportunityContactRoles[0].contact.Title;
                reqInput.AccountName=op.Account.Name;

      inputRequest.add(reqInput);
      
      } 
    }
    String OpportunityInput = Json.serialize(inputRequest);
    System.debug('Input request to send Opportunity to iWise::'+OpportunityInput); 
    Http http = new Http();
        HttpRequest request = new HttpRequest();
        request.setEndpoint('Actual Endpoint to service');// also add this endpoint in remote site settings
        request.setMethod('POST');
        request.setHeader('Content-Type', 'application/json; charset=utf-8');
        request.setHeader('Authorization', oAuthToken);
    request.setBody(OpportunityInput);
    
    System.debug('Request to send Opportunity:'+request);
    System.debug('Request body send Opportunity:'+request.getBody());
    
    HttpResponse response = http.send(request);
        system.debug('Response from iWise for Get Opportunity request:::'+response.toString());
    system.debug('Response from iWise for Get Opportunity request:::'+response.getBody());
        // If the request is successful, parse the JSON response.
        if (response.getStatusCode() == 200) {
      System.debug('Success Response from iWise::'+response.getStatus());
        opty[0].Response_from_iWise_System__c=response.getStatusCode()+' - '+response.getStatus()+' - '+ response.getBody();
    }
    else{
      System.debug('Error Response from iWise::'+response.getStatus());
      opty[0].Response_from_iWise_System__c=response.getStatusCode()+' - '+response.getStatus()+' - '+ response.getBody();
    }
    if(!opty.isEmpty())
      Update opty;  
  }
}