package software.amazon.rds.dbproxyendpoint;

import java.util.ArrayList;
import java.util.List;

import com.amazonaws.services.rds.AmazonRDS;
import com.amazonaws.services.rds.AmazonRDSClientBuilder;
import com.amazonaws.services.rds.model.DBProxyEndpoint;
import com.amazonaws.services.rds.model.DBProxyEndpointNotFoundException;
import com.amazonaws.services.rds.model.DescribeDBProxyEndpointsRequest;
import com.amazonaws.services.rds.model.DescribeDBProxyEndpointsResult;
import com.amazonaws.services.rds.model.ListTagsForResourceRequest;
import com.amazonaws.services.rds.model.ListTagsForResourceResult;
import com.amazonaws.services.rds.model.Tag;
import software.amazon.cloudformation.exceptions.CfnNotFoundException;
import software.amazon.cloudformation.proxy.AmazonWebServicesClientProxy;
import software.amazon.cloudformation.proxy.HandlerErrorCode;
import software.amazon.cloudformation.proxy.Logger;
import software.amazon.cloudformation.proxy.OperationStatus;
import software.amazon.cloudformation.proxy.ProgressEvent;
import software.amazon.cloudformation.proxy.ResourceHandlerRequest;

public class ReadHandler extends BaseHandler<CallbackContext> {
    private AmazonWebServicesClientProxy clientProxy;
    private AmazonRDS rdsClient;

    @Override
    public ProgressEvent<ResourceModel, CallbackContext> handleRequest(
            final AmazonWebServicesClientProxy proxy,
            final ResourceHandlerRequest<ResourceModel> request,
            final CallbackContext callbackContext,
            final Logger logger) {

        clientProxy = proxy;
        rdsClient = AmazonRDSClientBuilder.defaultClient();

        final ResourceModel model;
        try {
            model = describeDBProxyEndpoint(request.getDesiredResourceState().getDBProxyEndpointName());
        } catch (DBProxyEndpointNotFoundException | CfnNotFoundException e) {
            return ProgressEvent.defaultFailureHandler(e, HandlerErrorCode.NotFound);
        }

        return ProgressEvent.<ResourceModel, CallbackContext>builder()
                .resourceModel(model)
                .status(OperationStatus.SUCCESS)
                .build();
    }

    private ResourceModel describeDBProxyEndpoint(final String proxyEndpointName) {
        DescribeDBProxyEndpointsRequest request = new DescribeDBProxyEndpointsRequest().withDBProxyEndpointName(proxyEndpointName);

        final DescribeDBProxyEndpointsResult result = clientProxy.injectCredentialsAndInvoke(request, rdsClient::describeDBProxyEndpoints);

        if (result != null && result.getDBProxyEndpoints() != null && result.getDBProxyEndpoints().size() == 1) {
            DBProxyEndpoint proxyEndpoint = result.getDBProxyEndpoints().get(0);
            ResourceModel resourceModel = Utility.resultToModel(proxyEndpoint);
            ListTagsForResourceRequest tagRequest = new ListTagsForResourceRequest().withResourceName(proxyEndpoint.getDBProxyEndpointArn());

            final ListTagsForResourceResult tagResult = clientProxy.injectCredentialsAndInvoke(tagRequest, rdsClient::listTagsForResource);
            if (tagResult != null && tagResult.getTagList()!= null && tagResult.getTagList().size() > 0) {
                resourceModel.setTags(convertTags(tagResult.getTagList()));
            }
            return resourceModel;
        } else {
            throw new CfnNotFoundException(ResourceModel.TYPE_NAME, proxyEndpointName);
        }
    }

    private List<TagFormat> convertTags(List<Tag> tags) {
        List<TagFormat> convertedTags = new ArrayList<>();

        if (tags == null || tags.size() == 0) {
            return convertedTags;
        }

        for(Tag tag : tags){
            convertedTags.add(TagFormat.builder()
                    .key(tag.getKey())
                    .value(tag.getValue())
                    .build());
        }

        return convertedTags;
    }
}