/*
Copyright 2021 The KEDA Authors

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package azure

import (
	"context"

	"github.com/Azure/azure-storage-blob-go/azblob"
	"github.com/gobwas/glob"

	kedav1alpha1 "github.com/kedacore/keda/v2/apis/keda/v1alpha1"
	"github.com/kedacore/keda/v2/pkg/util"
)

type BlobMetadata struct {
	TargetBlobCount   int64
	BlobContainerName string
	BlobDelimiter     string
	BlobPrefix        string
	Connection        string
	AccountName       string
	MetricName        string
	EndpointSuffix    string
	ScalerIndex       int
	GlobPattern       *glob.Glob
}

// GetAzureBlobListLength returns the count of the blobs in blob container in int
func GetAzureBlobListLength(ctx context.Context, httpClient util.HTTPDoer, podIdentity kedav1alpha1.PodIdentityProvider, meta *BlobMetadata) (int64, error) {
	credential, endpoint, err := ParseAzureStorageBlobConnection(ctx, httpClient, podIdentity, meta.Connection, meta.AccountName, meta.EndpointSuffix)
	if err != nil {
		return -1, err
	}

	listBlobsSegmentOptions := azblob.ListBlobsSegmentOptions{
		Prefix: meta.BlobPrefix,
	}
	p := azblob.NewPipeline(credential, azblob.PipelineOptions{})
	serviceURL := azblob.NewServiceURL(*endpoint, p)
	containerURL := serviceURL.NewContainerURL(meta.BlobContainerName)

	if meta.GlobPattern != nil {
		props, err := containerURL.ListBlobsFlatSegment(ctx, azblob.Marker{}, azblob.ListBlobsSegmentOptions{})
		if err != nil {
			return -1, err
		}

		var count int64
		globPattern := *meta.GlobPattern
		for _, blobItem := range props.Segment.BlobItems {
			if globPattern.Match(blobItem.Name) {
				count++
			}
		}
		return count, nil
	}

	props, err := containerURL.ListBlobsHierarchySegment(ctx, azblob.Marker{}, meta.BlobDelimiter, listBlobsSegmentOptions)
	if err != nil {
		return -1, err
	}

	return int64(len(props.Segment.BlobItems)), nil
}
