/*
 * Minio Cloud Storage, (C) 2017 Minio, Inc.
 *
 * 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 cmd

import (
	"io"

	router "github.com/gorilla/mux"
	"github.com/minio/minio-go/pkg/policy"
)

// GatewayLayer - Interface to implement gateway mode.
type GatewayLayer interface {
	ObjectLayer

	MakeBucketWithLocation(bucket, location string) error

	AnonGetObject(bucket, object string, startOffset int64, length int64, writer io.Writer) (err error)
	AnonGetObjectInfo(bucket, object string) (objInfo ObjectInfo, err error)

	AnonPutObject(bucket string, object string, size int64, data io.Reader, metadata map[string]string, sha256sum string) (ObjectInfo, error)

	SetBucketPolicies(string, policy.BucketAccessPolicy) error
	GetBucketPolicies(string) (policy.BucketAccessPolicy, error)
	DeleteBucketPolicies(string) error
	AnonListObjects(bucket, prefix, marker, delimiter string, maxKeys int) (result ListObjectsInfo, err error)
	AnonGetBucketInfo(bucket string) (bucketInfo BucketInfo, err error)
}

// Implements and provides http handlers for S3 API.
// Overrides GetObject HeadObject and Policy related handlers.
type gatewayAPIHandlers struct {
	objectAPIHandlers
	ObjectAPI func() GatewayLayer
}

// registerAPIRouter - registers S3 compatible APIs.
func registerGatewayAPIRouter(mux *router.Router, gw GatewayLayer) {
	// Initialize API.
	api := gatewayAPIHandlers{
		ObjectAPI: func() GatewayLayer { return gw },
		objectAPIHandlers: objectAPIHandlers{
			ObjectAPI: newObjectLayerFn,
		},
	}

	// API Router
	apiRouter := mux.NewRoute().PathPrefix("/").Subrouter()

	// Bucket router
	bucket := apiRouter.PathPrefix("/{bucket}").Subrouter()

	/// Object operations

	// HeadObject
	bucket.Methods("HEAD").Path("/{object:.+}").HandlerFunc(api.HeadObjectHandler)
	// CopyObjectPart
	bucket.Methods("PUT").Path("/{object:.+}").HeadersRegexp("X-Amz-Copy-Source", ".*?(\\/|%2F).*?").HandlerFunc(api.CopyObjectPartHandler).Queries("partNumber", "{partNumber:[0-9]+}", "uploadId", "{uploadId:.*}")
	// PutObjectPart
	bucket.Methods("PUT").Path("/{object:.+}").HandlerFunc(api.PutObjectPartHandler).Queries("partNumber", "{partNumber:[0-9]+}", "uploadId", "{uploadId:.*}")
	// ListObjectPxarts
	bucket.Methods("GET").Path("/{object:.+}").HandlerFunc(api.ListObjectPartsHandler).Queries("uploadId", "{uploadId:.*}")
	// CompleteMultipartUpload
	bucket.Methods("POST").Path("/{object:.+}").HandlerFunc(api.CompleteMultipartUploadHandler).Queries("uploadId", "{uploadId:.*}")
	// NewMultipartUpload
	bucket.Methods("POST").Path("/{object:.+}").HandlerFunc(api.NewMultipartUploadHandler).Queries("uploads", "")
	// AbortMultipartUpload
	bucket.Methods("DELETE").Path("/{object:.+}").HandlerFunc(api.AbortMultipartUploadHandler).Queries("uploadId", "{uploadId:.*}")
	// GetObject
	bucket.Methods("GET").Path("/{object:.+}").HandlerFunc(api.GetObjectHandler)
	// CopyObject
	bucket.Methods("PUT").Path("/{object:.+}").HeadersRegexp("X-Amz-Copy-Source", ".*?(\\/|%2F).*?").HandlerFunc(api.CopyObjectHandler)
	// PutObject
	bucket.Methods("PUT").Path("/{object:.+}").HandlerFunc(api.PutObjectHandler)
	// DeleteObject
	bucket.Methods("DELETE").Path("/{object:.+}").HandlerFunc(api.DeleteObjectHandler)

	/// Bucket operations

	// GetBucketLocation
	bucket.Methods("GET").HandlerFunc(api.GetBucketLocationHandler).Queries("location", "")
	// GetBucketPolicy
	bucket.Methods("GET").HandlerFunc(api.GetBucketPolicyHandler).Queries("policy", "")
	// GetBucketNotification
	bucket.Methods("GET").HandlerFunc(api.GetBucketNotificationHandler).Queries("notification", "")
	// ListenBucketNotification
	bucket.Methods("GET").HandlerFunc(api.ListenBucketNotificationHandler).Queries("events", "{events:.*}")
	// ListMultipartUploads
	bucket.Methods("GET").HandlerFunc(api.ListMultipartUploadsHandler).Queries("uploads", "")
	// ListObjectsV2
	bucket.Methods("GET").HandlerFunc(api.ListObjectsV2Handler).Queries("list-type", "2")
	// ListObjectsV1 (Legacy)
	bucket.Methods("GET").HandlerFunc(api.ListObjectsV1Handler)
	// PutBucketPolicy
	bucket.Methods("PUT").HandlerFunc(api.PutBucketPolicyHandler).Queries("policy", "")
	// PutBucketNotification
	bucket.Methods("PUT").HandlerFunc(api.PutBucketNotificationHandler).Queries("notification", "")
	// PutBucket
	bucket.Methods("PUT").HandlerFunc(api.PutBucketHandler)
	// HeadBucket
	bucket.Methods("HEAD").HandlerFunc(api.HeadBucketHandler)
	// PostPolicy
	bucket.Methods("POST").HeadersRegexp("Content-Type", "multipart/form-data*").HandlerFunc(api.PostPolicyBucketHandler)
	// DeleteMultipleObjects
	bucket.Methods("POST").HandlerFunc(api.DeleteMultipleObjectsHandler)
	// DeleteBucketPolicy
	bucket.Methods("DELETE").HandlerFunc(api.DeleteBucketPolicyHandler).Queries("policy", "")
	// DeleteBucket
	bucket.Methods("DELETE").HandlerFunc(api.DeleteBucketHandler)

	/// Root operation

	// ListBuckets
	apiRouter.Methods("GET").HandlerFunc(api.ListBucketsHandler)
}