Hi developers,
I m a beginner, please correct my code.
i have Country__c Object with all Text fields  Name__c,Capital_City__c,Region__c,Sub_Region__c,Regional_Block__c,Country_ISO_Code_2__c,Country_ISO_Code_3__c from Country__c.
this is the Url for integration:  https://restcountries.eu/
I want to create records for each country and populate all fiels in records for JSON
also provide testing code if possible

public class CountryNameWrapper{
	public string name{get;set;}
	public string alpha2Code{get;set;}
	public string alpha3Code{get;set;}
	public string capital{get;set;}
	public string region{get;set;}
	public string subregion{get;set;}
	public List<CountryNameWrapper.RegionalBlocsWrapper> regionalBlocs{get;set;}
	
	public class RegionalBlocsWrapper{
		public String acronym{get;set;}
		public String name{get;set;}
		public List<String> otherAcronyms{get;set;}
		public List<String> otherNames{get;set;}
	}
}


global class Load_Countries_RestApi implements Database.Batchable<sObject>,Database.AllowsCallouts {
 global String query ;
    
 global Database.QueryLocator start(Database.BatchableContext BC) {
     query = 'Select Name__c,Capital_City__c,Region__c,Sub_Region__c,Country_ISO_Code_2__c,Country_ISO_Code_3__c from Country__c';     
        //Query all countries from Country object
        return DataBase.getQueryLocator(query);                                    
    }
    
 global void execute(Database.BatchableContext BC , List <Country__c> contlist) {
     Boolean hasChanged = false;
     Http http = new Http();
     HttpRequest request = new HttpRequest();
     request.setEndpoint('https://restcountries.eu/rest/v2/all');
     request.setMethod('GET');
     HttpResponse response = http.send(request);
     if (response.getStatusCode() == 299) {
     System.debug('response--->'+(List<CountryNameWrapper>)JSON.deserialize(response.getBody(),List<CountryNameWrapper>.class));
     List<CountryNameWrapper> abc = (List<CountryNameWrapper>)JSON.deserialize(response.getBody(),List<CountryNameWrapper>.class);
     List<Country__c> cntList = new List<Country__c>();
     for(CountryNameWrapper cw : abc){
     Country__c cnt = new Country__c();
     cnt.Name__c = cw.name;
     cnt.Capital_City__c = cw.name;
     cnt.Region__c = cw.region;
     cnt.Sub_Region__c = cw.subregion;
  //   cnt.Regional_Block__c = cw.regionalBlocs;
     cnt.Country_ISO_Code_2__c = cw.alpha2Code;
     cnt.Country_ISO_Code_3__c = cw.alpha3Code;
     cntList.add(cnt);
}
insert cntList;
     //Give call to https://restcountries.eu/rest/v2/name/AF
     //AF is country name. It will return you the iterate over the list //(List<CountryNameWrapper>) and see if the information in country is same //as that of object returned from API. If it is not same then set boolean
     //hasChanged to true.
     
     //If has changed is true, then update country object
     }    
 }
 global void finish(Database.BatchableContext BC){
 }   
}