// Code generated by smithy-go-codegen DO NOT EDIT.

package fsx

import (
	"context"
	"fmt"
	awsmiddleware "github.com/aws/aws-sdk-go-v2/aws/middleware"
	"github.com/aws/aws-sdk-go-v2/service/fsx/types"
	"github.com/aws/smithy-go/middleware"
	smithyhttp "github.com/aws/smithy-go/transport/http"
)

// Returns the description of specific Amazon FSx file systems, if a FileSystemIds
// value is provided for that file system. Otherwise, it returns descriptions of
// all file systems owned by your Amazon Web Services account in the Amazon Web
// Services Region of the endpoint that you're calling.
//
// When retrieving all file system descriptions, you can optionally specify the
// MaxResults parameter to limit the number of descriptions in a response. If more
// file system descriptions remain, Amazon FSx returns a NextToken value in the
// response. In this case, send a later request with the NextToken request
// parameter set to the value of NextToken from the last response.
//
// This operation is used in an iterative process to retrieve a list of your file
// system descriptions. DescribeFileSystems is called first without a NextToken
// value. Then the operation continues to be called with the NextToken parameter
// set to the value of the last NextToken value until a response has no NextToken .
//
// When using this operation, keep the following in mind:
//
//   - The implementation might return fewer than MaxResults file system
//     descriptions while still including a NextToken value.
//
//   - The order of file systems returned in the response of one
//     DescribeFileSystems call and the order of file systems returned across the
//     responses of a multicall iteration is unspecified.
func (c *Client) DescribeFileSystems(ctx context.Context, params *DescribeFileSystemsInput, optFns ...func(*Options)) (*DescribeFileSystemsOutput, error) {
	if params == nil {
		params = &DescribeFileSystemsInput{}
	}

	result, metadata, err := c.invokeOperation(ctx, "DescribeFileSystems", params, optFns, c.addOperationDescribeFileSystemsMiddlewares)
	if err != nil {
		return nil, err
	}

	out := result.(*DescribeFileSystemsOutput)
	out.ResultMetadata = metadata
	return out, nil
}

// The request object for DescribeFileSystems operation.
type DescribeFileSystemsInput struct {

	// IDs of the file systems whose descriptions you want to retrieve (String).
	FileSystemIds []string

	// Maximum number of file systems to return in the response (integer). This
	// parameter value must be greater than 0. The number of items that Amazon FSx
	// returns is the minimum of the MaxResults parameter specified in the request and
	// the service's internal maximum number of items per page.
	MaxResults *int32

	// Opaque pagination token returned from a previous DescribeFileSystems operation
	// (String). If a token present, the operation continues the list from where the
	// returning call left off.
	NextToken *string

	noSmithyDocumentSerde
}

// The response object for DescribeFileSystems operation.
type DescribeFileSystemsOutput struct {

	// An array of file system descriptions.
	FileSystems []types.FileSystem

	// Present if there are more file systems than returned in the response (String).
	// You can use the NextToken value in the later request to fetch the descriptions.
	NextToken *string

	// Metadata pertaining to the operation's result.
	ResultMetadata middleware.Metadata

	noSmithyDocumentSerde
}

func (c *Client) addOperationDescribeFileSystemsMiddlewares(stack *middleware.Stack, options Options) (err error) {
	if err := stack.Serialize.Add(&setOperationInputMiddleware{}, middleware.After); err != nil {
		return err
	}
	err = stack.Serialize.Add(&awsAwsjson11_serializeOpDescribeFileSystems{}, middleware.After)
	if err != nil {
		return err
	}
	err = stack.Deserialize.Add(&awsAwsjson11_deserializeOpDescribeFileSystems{}, middleware.After)
	if err != nil {
		return err
	}
	if err := addProtocolFinalizerMiddlewares(stack, options, "DescribeFileSystems"); err != nil {
		return fmt.Errorf("add protocol finalizers: %v", err)
	}

	if err = addlegacyEndpointContextSetter(stack, options); err != nil {
		return err
	}
	if err = addSetLoggerMiddleware(stack, options); err != nil {
		return err
	}
	if err = addClientRequestID(stack); err != nil {
		return err
	}
	if err = addComputeContentLength(stack); err != nil {
		return err
	}
	if err = addResolveEndpointMiddleware(stack, options); err != nil {
		return err
	}
	if err = addComputePayloadSHA256(stack); err != nil {
		return err
	}
	if err = addRetry(stack, options); err != nil {
		return err
	}
	if err = addRawResponseToMetadata(stack); err != nil {
		return err
	}
	if err = addRecordResponseTiming(stack); err != nil {
		return err
	}
	if err = addClientUserAgent(stack, options); err != nil {
		return err
	}
	if err = smithyhttp.AddErrorCloseResponseBodyMiddleware(stack); err != nil {
		return err
	}
	if err = smithyhttp.AddCloseResponseBodyMiddleware(stack); err != nil {
		return err
	}
	if err = addSetLegacyContextSigningOptionsMiddleware(stack); err != nil {
		return err
	}
	if err = addTimeOffsetBuild(stack, c); err != nil {
		return err
	}
	if err = addUserAgentRetryMode(stack, options); err != nil {
		return err
	}
	if err = stack.Initialize.Add(newServiceMetadataMiddleware_opDescribeFileSystems(options.Region), middleware.Before); err != nil {
		return err
	}
	if err = addRecursionDetection(stack); err != nil {
		return err
	}
	if err = addRequestIDRetrieverMiddleware(stack); err != nil {
		return err
	}
	if err = addResponseErrorMiddleware(stack); err != nil {
		return err
	}
	if err = addRequestResponseLogging(stack, options); err != nil {
		return err
	}
	if err = addDisableHTTPSMiddleware(stack, options); err != nil {
		return err
	}
	return nil
}

// DescribeFileSystemsPaginatorOptions is the paginator options for
// DescribeFileSystems
type DescribeFileSystemsPaginatorOptions struct {
	// Maximum number of file systems to return in the response (integer). This
	// parameter value must be greater than 0. The number of items that Amazon FSx
	// returns is the minimum of the MaxResults parameter specified in the request and
	// the service's internal maximum number of items per page.
	Limit int32

	// Set to true if pagination should stop if the service returns a pagination token
	// that matches the most recent token provided to the service.
	StopOnDuplicateToken bool
}

// DescribeFileSystemsPaginator is a paginator for DescribeFileSystems
type DescribeFileSystemsPaginator struct {
	options   DescribeFileSystemsPaginatorOptions
	client    DescribeFileSystemsAPIClient
	params    *DescribeFileSystemsInput
	nextToken *string
	firstPage bool
}

// NewDescribeFileSystemsPaginator returns a new DescribeFileSystemsPaginator
func NewDescribeFileSystemsPaginator(client DescribeFileSystemsAPIClient, params *DescribeFileSystemsInput, optFns ...func(*DescribeFileSystemsPaginatorOptions)) *DescribeFileSystemsPaginator {
	if params == nil {
		params = &DescribeFileSystemsInput{}
	}

	options := DescribeFileSystemsPaginatorOptions{}
	if params.MaxResults != nil {
		options.Limit = *params.MaxResults
	}

	for _, fn := range optFns {
		fn(&options)
	}

	return &DescribeFileSystemsPaginator{
		options:   options,
		client:    client,
		params:    params,
		firstPage: true,
		nextToken: params.NextToken,
	}
}

// HasMorePages returns a boolean indicating whether more pages are available
func (p *DescribeFileSystemsPaginator) HasMorePages() bool {
	return p.firstPage || (p.nextToken != nil && len(*p.nextToken) != 0)
}

// NextPage retrieves the next DescribeFileSystems page.
func (p *DescribeFileSystemsPaginator) NextPage(ctx context.Context, optFns ...func(*Options)) (*DescribeFileSystemsOutput, error) {
	if !p.HasMorePages() {
		return nil, fmt.Errorf("no more pages available")
	}

	params := *p.params
	params.NextToken = p.nextToken

	var limit *int32
	if p.options.Limit > 0 {
		limit = &p.options.Limit
	}
	params.MaxResults = limit

	optFns = append([]func(*Options){
		addIsPaginatorUserAgent,
	}, optFns...)
	result, err := p.client.DescribeFileSystems(ctx, &params, optFns...)
	if err != nil {
		return nil, err
	}
	p.firstPage = false

	prevToken := p.nextToken
	p.nextToken = result.NextToken

	if p.options.StopOnDuplicateToken &&
		prevToken != nil &&
		p.nextToken != nil &&
		*prevToken == *p.nextToken {
		p.nextToken = nil
	}

	return result, nil
}

// DescribeFileSystemsAPIClient is a client that implements the
// DescribeFileSystems operation.
type DescribeFileSystemsAPIClient interface {
	DescribeFileSystems(context.Context, *DescribeFileSystemsInput, ...func(*Options)) (*DescribeFileSystemsOutput, error)
}

var _ DescribeFileSystemsAPIClient = (*Client)(nil)

func newServiceMetadataMiddleware_opDescribeFileSystems(region string) *awsmiddleware.RegisterServiceMetadata {
	return &awsmiddleware.RegisterServiceMetadata{
		Region:        region,
		ServiceID:     ServiceID,
		OperationName: "DescribeFileSystems",
	}
}