// Copyright (c) 2015-2021 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"
	"io/ioutil"
	"net/http"
	"net/url"
	"time"

	"github.com/minio/minio/pkg/auth"
	iampolicy "github.com/minio/minio/pkg/iam/policy"
)

// AccountAccess contains information about
type AccountAccess struct {
	Read  bool `json:"read"`
	Write bool `json:"write"`
}

// BucketAccessInfo represents bucket usage of a bucket, and its relevant
// access type for an account
type BucketAccessInfo struct {
	Name    string        `json:"name"`
	Size    uint64        `json:"size"`
	Created time.Time     `json:"created"`
	Access  AccountAccess `json:"access"`
}

// AccountInfo represents the account usage info of an
// account across buckets.
type AccountInfo struct {
	AccountName string
	Policy      iampolicy.Policy
	Buckets     []BucketAccessInfo
}

// AccountInfo returns the usage info for the authenticating account.
func (adm *AdminClient) AccountInfo(ctx context.Context) (AccountInfo, error) {
	resp, err := adm.executeMethod(ctx, http.MethodGet, requestData{relPath: adminAPIPrefix + "/accountinfo"})
	defer closeResponse(resp)
	if err != nil {
		return AccountInfo{}, err
	}

	// Check response http status code
	if resp.StatusCode != http.StatusOK {
		return AccountInfo{}, httpRespToErrorResponse(resp)
	}

	// Unmarshal the server's json response
	var accountInfo AccountInfo

	respBytes, err := ioutil.ReadAll(resp.Body)
	if err != nil {
		return AccountInfo{}, err
	}

	err = json.Unmarshal(respBytes, &accountInfo)
	if err != nil {
		return AccountInfo{}, err
	}

	return accountInfo, nil
}

// AccountStatus - account status.
type AccountStatus string

// Account status per user.
const (
	AccountEnabled  AccountStatus = "enabled"
	AccountDisabled AccountStatus = "disabled"
)

// UserInfo carries information about long term users.
type UserInfo struct {
	SecretKey  string        `json:"secretKey,omitempty"`
	PolicyName string        `json:"policyName,omitempty"`
	Status     AccountStatus `json:"status"`
	MemberOf   []string      `json:"memberOf,omitempty"`
}

// RemoveUser - remove a user.
func (adm *AdminClient) RemoveUser(ctx context.Context, accessKey string) error {
	queryValues := url.Values{}
	queryValues.Set("accessKey", accessKey)

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

	// Execute DELETE on /minio/admin/v3/remove-user to remove a user.
	resp, err := adm.executeMethod(ctx, http.MethodDelete, reqData)

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

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

	return nil
}

// ListUsers - list all users.
func (adm *AdminClient) ListUsers(ctx context.Context) (map[string]UserInfo, error) {
	reqData := requestData{
		relPath: adminAPIPrefix + "/list-users",
	}

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

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

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

	data, err := DecryptData(adm.getSecretKey(), resp.Body)
	if err != nil {
		return nil, err
	}

	var users = make(map[string]UserInfo)
	if err = json.Unmarshal(data, &users); err != nil {
		return nil, err
	}

	return users, nil
}

// GetUserInfo - get info on a user
func (adm *AdminClient) GetUserInfo(ctx context.Context, name string) (u UserInfo, err error) {
	queryValues := url.Values{}
	queryValues.Set("accessKey", name)

	reqData := requestData{
		relPath:     adminAPIPrefix + "/user-info",
		queryValues: queryValues,
	}

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

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

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

	b, err := ioutil.ReadAll(resp.Body)
	if err != nil {
		return u, err
	}

	if err = json.Unmarshal(b, &u); err != nil {
		return u, err
	}

	return u, nil
}

// SetUser - sets a user info.
func (adm *AdminClient) SetUser(ctx context.Context, accessKey, secretKey string, status AccountStatus) error {

	if !auth.IsAccessKeyValid(accessKey) {
		return auth.ErrInvalidAccessKeyLength
	}

	if !auth.IsSecretKeyValid(secretKey) {
		return auth.ErrInvalidSecretKeyLength
	}

	data, err := json.Marshal(UserInfo{
		SecretKey: secretKey,
		Status:    status,
	})
	if err != nil {
		return err
	}
	econfigBytes, err := EncryptData(adm.getSecretKey(), data)
	if err != nil {
		return err
	}

	queryValues := url.Values{}
	queryValues.Set("accessKey", accessKey)

	reqData := requestData{
		relPath:     adminAPIPrefix + "/add-user",
		queryValues: queryValues,
		content:     econfigBytes,
	}

	// Execute PUT on /minio/admin/v3/add-user to set a user.
	resp, err := adm.executeMethod(ctx, http.MethodPut, reqData)

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

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

	return nil
}

// AddUser - adds a user.
func (adm *AdminClient) AddUser(ctx context.Context, accessKey, secretKey string) error {
	return adm.SetUser(ctx, accessKey, secretKey, AccountEnabled)
}

// SetUserStatus - adds a status for a user.
func (adm *AdminClient) SetUserStatus(ctx context.Context, accessKey string, status AccountStatus) error {
	queryValues := url.Values{}
	queryValues.Set("accessKey", accessKey)
	queryValues.Set("status", string(status))

	reqData := requestData{
		relPath:     adminAPIPrefix + "/set-user-status",
		queryValues: queryValues,
	}

	// Execute PUT on /minio/admin/v3/set-user-status to set status.
	resp, err := adm.executeMethod(ctx, http.MethodPut, reqData)

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

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

	return nil
}

// AddServiceAccountReq is the request options of the add service account admin call
type AddServiceAccountReq struct {
	Policy     *iampolicy.Policy `json:"policy,omitempty"`
	TargetUser string            `json:"targetUser,omitempty"`
	AccessKey  string            `json:"accessKey,omitempty"`
	SecretKey  string            `json:"secretKey,omitempty"`
}

// AddServiceAccountResp is the response body of the add service account admin call
type AddServiceAccountResp struct {
	Credentials auth.Credentials `json:"credentials"`
}

// AddServiceAccount - creates a new service account belonging to the user sending
// the request while restricting the service account permission by the given policy document.
func (adm *AdminClient) AddServiceAccount(ctx context.Context, opts AddServiceAccountReq) (auth.Credentials, error) {
	if opts.Policy != nil {
		if err := opts.Policy.Validate(); err != nil {
			return auth.Credentials{}, err
		}
	}

	data, err := json.Marshal(opts)
	if err != nil {
		return auth.Credentials{}, err
	}

	econfigBytes, err := EncryptData(adm.getSecretKey(), data)
	if err != nil {
		return auth.Credentials{}, err
	}

	reqData := requestData{
		relPath: adminAPIPrefix + "/add-service-account",
		content: econfigBytes,
	}

	// Execute PUT on /minio/admin/v3/add-service-account to set a user.
	resp, err := adm.executeMethod(ctx, http.MethodPut, reqData)
	defer closeResponse(resp)
	if err != nil {
		return auth.Credentials{}, err
	}

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

	data, err = DecryptData(adm.getSecretKey(), resp.Body)
	if err != nil {
		return auth.Credentials{}, err
	}

	var serviceAccountResp AddServiceAccountResp
	if err = json.Unmarshal(data, &serviceAccountResp); err != nil {
		return auth.Credentials{}, err
	}
	return serviceAccountResp.Credentials, nil
}

// UpdateServiceAccountReq is the request options of the edit service account admin call
type UpdateServiceAccountReq struct {
	NewPolicy    *iampolicy.Policy `json:"newPolicy,omitempty"`
	NewSecretKey string            `json:"newSecretKey,omitempty"`
	NewStatus    string            `json:"newStatus,omityempty"`
}

// UpdateServiceAccount - edit an existing service account
func (adm *AdminClient) UpdateServiceAccount(ctx context.Context, accessKey string, opts UpdateServiceAccountReq) error {
	if opts.NewPolicy != nil {
		if err := opts.NewPolicy.Validate(); err != nil {
			return err
		}
	}

	data, err := json.Marshal(opts)
	if err != nil {
		return err
	}

	econfigBytes, err := EncryptData(adm.getSecretKey(), data)
	if err != nil {
		return err
	}

	queryValues := url.Values{}
	queryValues.Set("accessKey", accessKey)

	reqData := requestData{
		relPath:     adminAPIPrefix + "/update-service-account",
		content:     econfigBytes,
		queryValues: queryValues,
	}

	// Execute POST on /minio/admin/v3/update-service-account to edit a service account
	resp, err := adm.executeMethod(ctx, http.MethodPost, reqData)
	defer closeResponse(resp)
	if err != nil {
		return err
	}

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

	return nil
}

// ListServiceAccountsResp is the response body of the list service accounts call
type ListServiceAccountsResp struct {
	Accounts []string `json:"accounts"`
}

// ListServiceAccounts - list service accounts belonging to the specified user
func (adm *AdminClient) ListServiceAccounts(ctx context.Context, user string) (ListServiceAccountsResp, error) {
	queryValues := url.Values{}
	queryValues.Set("user", user)

	reqData := requestData{
		relPath:     adminAPIPrefix + "/list-service-accounts",
		queryValues: queryValues,
	}

	// Execute GET on /minio/admin/v3/list-service-accounts
	resp, err := adm.executeMethod(ctx, http.MethodGet, reqData)
	defer closeResponse(resp)
	if err != nil {
		return ListServiceAccountsResp{}, err
	}

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

	data, err := DecryptData(adm.getSecretKey(), resp.Body)
	if err != nil {
		return ListServiceAccountsResp{}, err
	}

	var listResp ListServiceAccountsResp
	if err = json.Unmarshal(data, &listResp); err != nil {
		return ListServiceAccountsResp{}, err
	}
	return listResp, nil
}

// InfoServiceAccountResp is the response body of the info service account call
type InfoServiceAccountResp struct {
	ParentUser    string `json:"parentUser"`
	AccountStatus string `json:"accountStatus"`
	ImpliedPolicy bool   `json:"impliedPolicy"`
	Policy        string `json:"policy"`
}

// InfoServiceAccount - returns the info of service account belonging to the specified user
func (adm *AdminClient) InfoServiceAccount(ctx context.Context, accessKey string) (InfoServiceAccountResp, error) {
	queryValues := url.Values{}
	queryValues.Set("accessKey", accessKey)

	reqData := requestData{
		relPath:     adminAPIPrefix + "/info-service-account",
		queryValues: queryValues,
	}

	// Execute GET on /minio/admin/v3/info-service-account
	resp, err := adm.executeMethod(ctx, http.MethodGet, reqData)
	defer closeResponse(resp)
	if err != nil {
		return InfoServiceAccountResp{}, err
	}

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

	data, err := DecryptData(adm.getSecretKey(), resp.Body)
	if err != nil {
		return InfoServiceAccountResp{}, err
	}

	var infoResp InfoServiceAccountResp
	if err = json.Unmarshal(data, &infoResp); err != nil {
		return InfoServiceAccountResp{}, err
	}
	return infoResp, nil
}

// DeleteServiceAccount - delete a specified service account. The server will reject
// the request if the service account does not belong to the user initiating the request
func (adm *AdminClient) DeleteServiceAccount(ctx context.Context, serviceAccount string) error {
	if !auth.IsAccessKeyValid(serviceAccount) {
		return auth.ErrInvalidAccessKeyLength
	}

	queryValues := url.Values{}
	queryValues.Set("accessKey", serviceAccount)

	reqData := requestData{
		relPath:     adminAPIPrefix + "/delete-service-account",
		queryValues: queryValues,
	}

	// Execute DELETE on /minio/admin/v3/delete-service-account
	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
}