//
// Copyright (c) 2015-2024 MinIO, Inc.
//
// This file is part of MinIO Object Storage stack
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as
// published by the Free Software Foundation, either version 3 of the
// License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
//

package madmin

import (
	"context"
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"net/url"
	"strings"
	"time"
)

// ServiceType represents service type
type ServiceType string

const (
	// ReplicationService specifies replication service
	ReplicationService ServiceType = "replication"
)

// IsValid returns true if ARN type represents replication
func (t ServiceType) IsValid() bool {
	return t == ReplicationService
}

// ARN is a struct to define arn.
type ARN struct {
	Type   ServiceType
	ID     string
	Region string
	Bucket string
}

// Empty returns true if arn struct is empty
func (a ARN) Empty() bool {
	return !a.Type.IsValid()
}

func (a ARN) String() string {
	return fmt.Sprintf("arn:minio:%s:%s:%s:%s", a.Type, a.Region, a.ID, a.Bucket)
}

// ParseARN return ARN struct from string in arn format.
func ParseARN(s string) (*ARN, error) {
	// ARN must be in the format of arn:minio:<Type>:<REGION>:<ID>:<remote-bucket>
	if !strings.HasPrefix(s, "arn:minio:") {
		return nil, fmt.Errorf("Invalid ARN %s", s)
	}

	tokens := strings.Split(s, ":")
	if len(tokens) != 6 {
		return nil, fmt.Errorf("Invalid ARN %s", s)
	}

	if tokens[4] == "" || tokens[5] == "" {
		return nil, fmt.Errorf("Invalid ARN %s", s)
	}

	return &ARN{
		Type:   ServiceType(tokens[2]),
		Region: tokens[3],
		ID:     tokens[4],
		Bucket: tokens[5],
	}, nil
}

// BucketTarget represents the target bucket and site association.
type BucketTarget struct {
	SourceBucket         string        `json:"sourcebucket"`
	Endpoint             string        `json:"endpoint"`
	Credentials          *Credentials  `json:"credentials"`
	TargetBucket         string        `json:"targetbucket"`
	Secure               bool          `json:"secure"`
	Path                 string        `json:"path,omitempty"`
	API                  string        `json:"api,omitempty"`
	Arn                  string        `json:"arn,omitempty"`
	Type                 ServiceType   `json:"type"`
	Region               string        `json:"region,omitempty"`
	BandwidthLimit       int64         `json:"bandwidthlimit,omitempty"`
	ReplicationSync      bool          `json:"replicationSync"`
	StorageClass         string        `json:"storageclass,omitempty"`
	HealthCheckDuration  time.Duration `json:"healthCheckDuration,omitempty"`
	DisableProxy         bool          `json:"disableProxy"`
	ResetBeforeDate      time.Time     `json:"resetBeforeDate,omitempty"`
	ResetID              string        `json:"resetID,omitempty"`
	TotalDowntime        time.Duration `json:"totalDowntime"`
	LastOnline           time.Time     `json:"lastOnline"`
	Online               bool          `json:"isOnline"`
	Latency              LatencyStat   `json:"latency"`
	DeploymentID         string        `json:"deploymentID,omitempty"`
	Edge                 bool          `json:"edge"`                 // target is recipient of edge traffic
	EdgeSyncBeforeExpiry bool          `json:"edgeSyncBeforeExpiry"` // must replicate to edge before expiry
}

// Clone returns shallow clone of BucketTarget without secret key in credentials
func (t *BucketTarget) Clone() BucketTarget {
	return BucketTarget{
		SourceBucket:         t.SourceBucket,
		Endpoint:             t.Endpoint,
		TargetBucket:         t.TargetBucket,
		Credentials:          &Credentials{AccessKey: t.Credentials.AccessKey},
		Secure:               t.Secure,
		Path:                 t.Path,
		API:                  t.API,
		Arn:                  t.Arn,
		Type:                 t.Type,
		Region:               t.Region,
		BandwidthLimit:       t.BandwidthLimit,
		ReplicationSync:      t.ReplicationSync,
		StorageClass:         t.StorageClass, // target storage class
		HealthCheckDuration:  t.HealthCheckDuration,
		DisableProxy:         t.DisableProxy,
		ResetBeforeDate:      t.ResetBeforeDate,
		ResetID:              t.ResetID,
		TotalDowntime:        t.TotalDowntime,
		LastOnline:           t.LastOnline,
		Online:               t.Online,
		Latency:              t.Latency,
		DeploymentID:         t.DeploymentID,
		Edge:                 t.Edge,
		EdgeSyncBeforeExpiry: t.EdgeSyncBeforeExpiry,
	}
}

// URL returns target url
func (t BucketTarget) URL() *url.URL {
	scheme := "http"
	if t.Secure {
		scheme = "https"
	}
	return &url.URL{
		Scheme: scheme,
		Host:   t.Endpoint,
	}
}

// Empty returns true if struct is empty.
func (t BucketTarget) Empty() bool {
	return t.String() == "" || t.Credentials == nil
}

func (t *BucketTarget) String() string {
	return fmt.Sprintf("%s %s", t.Endpoint, t.TargetBucket)
}

// BucketTargets represents a slice of bucket targets by type and endpoint
type BucketTargets struct {
	Targets []BucketTarget
}

// Empty returns true if struct is empty.
func (t BucketTargets) Empty() bool {
	if len(t.Targets) == 0 {
		return true
	}
	empty := true
	for _, t := range t.Targets {
		if !t.Empty() {
			return false
		}
	}
	return empty
}

// ListRemoteTargets - gets target(s) for this bucket
func (adm *AdminClient) ListRemoteTargets(ctx context.Context, bucket, arnType string) (targets []BucketTarget, err error) {
	queryValues := url.Values{}
	queryValues.Set("bucket", bucket)
	queryValues.Set("type", arnType)

	reqData := requestData{
		relPath:     adminAPIPrefix + "/list-remote-targets",
		queryValues: queryValues,
	}

	// Execute GET on /minio/admin/v3/list-remote-targets
	resp, err := adm.executeMethod(ctx, http.MethodGet, reqData)

	defer closeResponse(resp)
	if err != nil {
		return targets, err
	}

	if resp.StatusCode != http.StatusOK {
		return targets, httpRespToErrorResponse(resp)
	}

	b, err := io.ReadAll(resp.Body)
	if err != nil {
		return targets, err
	}
	if err = json.Unmarshal(b, &targets); err != nil {
		return targets, err
	}
	return targets, nil
}

// SetRemoteTarget sets up a remote target for this bucket
func (adm *AdminClient) SetRemoteTarget(ctx context.Context, bucket string, target *BucketTarget) (string, error) {
	data, err := json.Marshal(target)
	if err != nil {
		return "", err
	}
	encData, err := EncryptData(adm.getSecretKey(), data)
	if err != nil {
		return "", err
	}
	queryValues := url.Values{}
	queryValues.Set("bucket", bucket)

	reqData := requestData{
		relPath:     adminAPIPrefix + "/set-remote-target",
		queryValues: queryValues,
		content:     encData,
	}

	// Execute PUT on /minio/admin/v3/set-remote-target to set a target for this bucket of specific arn type.
	resp, err := adm.executeMethod(ctx, http.MethodPut, reqData)

	defer closeResponse(resp)
	if err != nil {
		return "", err
	}

	if resp.StatusCode != http.StatusOK {
		return "", httpRespToErrorResponse(resp)
	}
	b, err := io.ReadAll(resp.Body)
	if err != nil {
		return "", err
	}
	var arn string
	if err = json.Unmarshal(b, &arn); err != nil {
		return "", err
	}
	return arn, nil
}

// TargetUpdateType -  type of update on the remote target
type TargetUpdateType int

const (
	// CredentialsUpdateType update creds
	CredentialsUpdateType TargetUpdateType = 1 + iota
	// SyncUpdateType update synchronous replication setting
	SyncUpdateType
	// ProxyUpdateType update proxy setting
	ProxyUpdateType
	// BandwidthLimitUpdateType update bandwidth limit
	BandwidthLimitUpdateType
	// HealthCheckDurationUpdateType update health check duration
	HealthCheckDurationUpdateType
	// PathUpdateType update Path
	PathUpdateType
	// ResetUpdateType sets ResetBeforeDate and ResetID on a bucket target
	ResetUpdateType
	// EdgeUpdateType sets bucket target as a recipent of edge traffic
	EdgeUpdateType
	// EdgeExpiryUpdateType sets bucket target to sync before expiry
	EdgeExpiryUpdateType
)

// GetTargetUpdateOps returns a slice of update operations being
// performed with `mc admin bucket remote edit`
func GetTargetUpdateOps(values url.Values) []TargetUpdateType {
	var ops []TargetUpdateType
	if values.Get("update") != "true" {
		return ops
	}
	if values.Get("creds") == "true" {
		ops = append(ops, CredentialsUpdateType)
	}
	if values.Get("sync") == "true" {
		ops = append(ops, SyncUpdateType)
	}
	if values.Get("proxy") == "true" {
		ops = append(ops, ProxyUpdateType)
	}
	if values.Get("healthcheck") == "true" {
		ops = append(ops, HealthCheckDurationUpdateType)
	}
	if values.Get("bandwidth") == "true" {
		ops = append(ops, BandwidthLimitUpdateType)
	}
	if values.Get("path") == "true" {
		ops = append(ops, PathUpdateType)
	}
	if values.Get("edge") == "true" {
		ops = append(ops, EdgeUpdateType)
	}
	if values.Get("edgeSyncBeforeExpiry") == "true" {
		ops = append(ops, EdgeExpiryUpdateType)
	}
	return ops
}

// UpdateRemoteTarget updates credentials for a remote bucket target
func (adm *AdminClient) UpdateRemoteTarget(ctx context.Context, target *BucketTarget, ops ...TargetUpdateType) (string, error) {
	if target == nil {
		return "", fmt.Errorf("target cannot be nil")
	}
	data, err := json.Marshal(target)
	if err != nil {
		return "", err
	}
	encData, err := EncryptData(adm.getSecretKey(), data)
	if err != nil {
		return "", err
	}
	queryValues := url.Values{}
	queryValues.Set("bucket", target.SourceBucket)
	queryValues.Set("update", "true")

	for _, op := range ops {
		switch op {
		case CredentialsUpdateType:
			queryValues.Set("creds", "true")
		case SyncUpdateType:
			queryValues.Set("sync", "true")
		case ProxyUpdateType:
			queryValues.Set("proxy", "true")
		case BandwidthLimitUpdateType:
			queryValues.Set("bandwidth", "true")
		case HealthCheckDurationUpdateType:
			queryValues.Set("healthcheck", "true")
		case PathUpdateType:
			queryValues.Set("path", "true")
		case EdgeUpdateType:
			queryValues.Set("edge", "true")
		case EdgeExpiryUpdateType:
			queryValues.Set("edgeSyncBeforeExpiry", "true")
		}
	}

	reqData := requestData{
		relPath:     adminAPIPrefix + "/set-remote-target",
		queryValues: queryValues,
		content:     encData,
	}

	// Execute PUT on /minio/admin/v3/set-remote-target to set a target for this bucket of specific arn type.
	resp, err := adm.executeMethod(ctx, http.MethodPut, reqData)

	defer closeResponse(resp)
	if err != nil {
		return "", err
	}

	if resp.StatusCode != http.StatusOK {
		return "", httpRespToErrorResponse(resp)
	}
	b, err := io.ReadAll(resp.Body)
	if err != nil {
		return "", err
	}
	var arn string
	if err = json.Unmarshal(b, &arn); err != nil {
		return "", err
	}
	return arn, nil
}

// RemoveRemoteTarget removes a remote target associated with particular ARN for this bucket
func (adm *AdminClient) RemoveRemoteTarget(ctx context.Context, bucket, arn string) error {
	queryValues := url.Values{}
	queryValues.Set("bucket", bucket)
	queryValues.Set("arn", arn)

	reqData := requestData{
		relPath:     adminAPIPrefix + "/remove-remote-target",
		queryValues: queryValues,
	}

	// Execute PUT on /minio/admin/v3/remove-remote-target to remove a target for this bucket
	// with specific ARN
	resp, err := adm.executeMethod(ctx, http.MethodDelete, reqData)
	defer closeResponse(resp)
	if err != nil {
		return err
	}

	if resp.StatusCode != http.StatusNoContent {
		return httpRespToErrorResponse(resp)
	}
	return nil
}
