// Copyright 2020 Google LLC.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package googleapis

import (
	"context"
	"io"
	"net/http"

	"google.golang.org/api/googleapi"
	"google.golang.org/api/option"
	htransport "google.golang.org/api/transport/http"
)

const basePath = "https://sts.googleapis.com/"

type V1betaService struct {
	client    *http.Client
	BasePath  string // API endpoint base URL
	UserAgent string // optional additional User-Agent fragment
}

// NewStsService creates an STS service, this function is modified a bit from the original version
// We do not need authentication for this function.
func NewStsService(ctx context.Context) (*V1betaService, error) {
	opts := []option.ClientOption{
		option.WithEndpoint(basePath),
		option.WithoutAuthentication(),
	}
	client, endpoint, err := htransport.NewClient(ctx, opts...)
	if err != nil {
		return nil, err
	}
	s := &V1betaService{client: client}
	if endpoint != "" {
		s.BasePath = endpoint
	}
	return s, nil
}

func (s *V1betaService) userAgent() string {
	if s.UserAgent == "" {
		return googleapi.UserAgent
	}
	return googleapi.UserAgent + " " + s.UserAgent
}

// GoogleIdentityStsV1betaExchangeTokenRequest: Request message for
// ExchangeToken.
type GoogleIdentityStsV1betaExchangeTokenRequest struct {
	// Audience: The full resource name of the identity provider. For
	// example,
	// `//iam.googleapis.com/projects//workloadIdentityPools//providers/`.
	// Required when exchanging an external credential for a Google access
	// token.
	Audience string `json:"audience,omitempty"`

	// GrantType: Required. The grant type. Must be
	// `urn:ietf:params:oauth:grant-type:token-exchange`, which indicates a
	// token exchange.
	GrantType string `json:"grantType,omitempty"`

	// Options: A set of features that Security Token Service supports, in
	// addition to the standard OAuth 2.0 token exchange, formatted as a
	// serialized JSON object of Options.
	Options string `json:"options,omitempty"`

	// RequestedTokenType: Required. The type of security token. Must be
	// `urn:ietf:params:oauth:token-type:access_token`, which indicates an
	// OAuth 2.0 access token.
	RequestedTokenType string `json:"requestedTokenType,omitempty"`

	// Scope: The OAuth 2.0 scopes to include on the resulting access token,
	// formatted as a list of space-delimited, case-sensitive strings.
	// Required when exchanging an external credential for a Google access
	// token.
	Scope string `json:"scope,omitempty"`

	// SubjectToken: Required. The input token. This token is a either an
	// external credential issued by a workload identity pool provider, or a
	// short-lived access token issued by Google. If the token is an OIDC
	// JWT, it must use the JWT format defined in [RFC
	// 7523](https://tools.ietf.org/html/rfc7523), and the
	// `subject_token_type` must be `urn:ietf:params:oauth:token-type:jwt`.
	// The following headers are required: - `kid`: The identifier of the
	// signing key securing the JWT. - `alg`: The cryptographic algorithm
	// securing the JWT. Must be `RS256`. The following payload fields are
	// required. For more information, see [RFC 7523, Section
	// 3](https://tools.ietf.org/html/rfc7523#section-3): - `iss`: The
	// issuer of the token. The issuer must provide a discovery document at
	// the URL `/.well-known/openid-configuration`, where `` is the value of
	// this field. The document must be formatted according to section 4.2
	// of the [OIDC 1.0 Discovery
	// specification](https://openid.net/specs/openid-connect-discovery-1_0.h
	// tml#ProviderConfigurationResponse). - `iat`: The issue time, in
	// seconds, since the Unix epoch. Must be in the past. - `exp`: The
	// expiration time, in seconds, since the Unix epoch. Must be less than
	// 48 hours after `iat`. Shorter expiration times are more secure. If
	// possible, we recommend setting an expiration time less than 6 hours.
	// - `sub`: The identity asserted in the JWT. - `aud`: Configured by the
	// mapper policy. The default value is the service account's unique ID.
	// Example header: ``` { "alg": "RS256", "kid": "us-east-11" } ```
	// Example payload: ``` { "iss": "https://accounts.google.com", "iat":
	// 1517963104, "exp": 1517966704, "aud": "113475438248934895348", "sub":
	// "113475438248934895348", "my_claims": { "additional_claim": "value" }
	// } ``` If `subject_token` is an AWS token, it must be a serialized,
	// [signed](https://docs.aws.amazon.com/general/latest/gr/signing_aws_api
	// _requests.html) request to the AWS
	// [`GetCallerIdentity()`](https://docs.aws.amazon.com/STS/latest/APIRefe
	// rence/API_GetCallerIdentity) method. Format the request as
	// URL-encoded JSON, and set the `subject_token_type` parameter to
	// `urn:ietf:params:aws:token-type:aws4_request`. The following
	// parameters are required: - `url`: The URL of the AWS STS endpoint for
	// `GetCallerIdentity()`, such as
	// `https://sts.amazonaws.com?Action=GetCallerIdentity&Version=2011-06-15
	// `. Regional endpoints are also supported. - `method`: The HTTP
	// request method: `POST`. - `headers`: The HTTP request headers, which
	// must include: - `Authorization`: The request signature. -
	// `x-amz-date`: The time you will send the request, formatted as an
	// [ISO8601
	// Basic](https://docs.aws.amazon.com/general/latest/gr/sigv4_elements.ht
	// ml#sigv4_elements_date) string. This is typically set to the current
	// time and used to prevent replay attacks. - `host`: The hostname of
	// the `url` field; for example, `sts.amazonaws.com`. -
	// `x-goog-cloud-target-resource`: The full, canonical resource name of
	// the workload identity pool provider, with or without an `https:`
	// prefix. To help ensure data integrity, we recommend including this
	// header in the `SignedHeaders` field of the signed request. For
	// example:
	// //iam.googleapis.com/projects//locations//workloadIdentityPools//provi
	// ders/
	// https://iam.googleapis.com/projects//locations//workloadIdentityPools//providers/ If you are using temporary security credentials provided by AWS, you must also include the header `x-amz-security-token`, with the value ``. The following example shows a signed, serialized request: ``` { "headers":[ {"key": "x-amz-date", "value": "20200815T015049Z"}, {"key": "Authorization", "value": "AWS4-HMAC-SHA256+Credential=$credential,+SignedHeaders=host;x-amz-date;x-goog-cloud-target-resource,+Signature=$signature"}, {"key": "x-goog-cloud-target-resource", "value": "//iam.googleapis.com/projects//locations//workloadIdentityPools//providers/"}, {"key": "host", "value": "sts.amazonaws.com"} . ], "method":"POST", "url":"https://sts.amazonaws.com?Action=GetCallerIdentity&Version=2011-06-15" } ``` You can also use a Google-issued OAuth 2.0 access token with this field to obtain an access token with new security attributes applied, such as a Credential Access Boundary. In this case, set `subject_token_type` to `urn:ietf:params:oauth:token-type:access_token`. If an access token already contains security attributes, you cannot apply additional security
	// attributes.
	SubjectToken string `json:"subjectToken,omitempty"`

	// SubjectTokenType: Required.
	// `urn:ietf:params:oauth:token-type:access_token`.
	SubjectTokenType string `json:"subjectTokenType,omitempty"`

	// ForceSendFields is a list of field names (e.g. "Audience") to
	// unconditionally include in API requests. By default, fields with
	// empty values are omitted from API requests. However, any non-pointer,
	// non-interface field appearing in ForceSendFields will be sent to the
	// server regardless of whether the field is empty or not. This may be
	// used to include empty fields in Patch requests.
	ForceSendFields []string `json:"-"`

	// NullFields is a list of field names (e.g. "Audience") to include in
	// API requests with the JSON null value. By default, fields with empty
	// values are omitted from API requests. However, any field with an
	// empty value appearing in NullFields will be sent to the server as
	// null. It is an error if a field in this list has a non-empty value.
	// This may be used to include null fields in Patch requests.
	NullFields []string `json:"-"`
}

func (s *GoogleIdentityStsV1betaExchangeTokenRequest) MarshalJSON() ([]byte, error) {
	type NoMethod GoogleIdentityStsV1betaExchangeTokenRequest
	raw := NoMethod(*s)
	return MarshalJSON(raw, s.ForceSendFields, s.NullFields)
}

// GoogleIdentityStsV1betaExchangeTokenResponse: Response message for
// ExchangeToken.
type GoogleIdentityStsV1betaExchangeTokenResponse struct {
	// AccessToken: An OAuth 2.0 security token, issued by Google, in
	// response to the token exchange request. Tokens can vary in size,
	// depending in part on the size of mapped claims, up to a maximum of
	// 12288 bytes (12 KB). Google reserves the right to change the token
	// size and the maximum length at any time.
	AccessToken string `json:"access_token,omitempty"`

	// ExpiresIn: The amount of time, in seconds, between the time when the
	// `access_token` was issued and the time when the `access_token` will
	// expire. This field is absent when the `subject_token` in the request
	// is a Google-issued, short-lived access token. In this case, the
	// `access_token` has the same expiration time as the `subject_token`.
	ExpiresIn int64 `json:"expires_in,omitempty"`

	// IssuedTokenType: The token type. Always matches the value of
	// `requested_token_type` from the request.
	IssuedTokenType string `json:"issued_token_type,omitempty"`

	// TokenType: The type of `access_token`. Always has the value `Bearer`.
	TokenType string `json:"token_type,omitempty"`

	// ServerResponse contains the HTTP response code and headers from the
	// server.
	googleapi.ServerResponse `json:"-"`

	// ForceSendFields is a list of field names (e.g. "AccessToken") to
	// unconditionally include in API requests. By default, fields with
	// empty values are omitted from API requests. However, any non-pointer,
	// non-interface field appearing in ForceSendFields will be sent to the
	// server regardless of whether the field is empty or not. This may be
	// used to include empty fields in Patch requests.
	ForceSendFields []string `json:"-"`

	// NullFields is a list of field names (e.g. "AccessToken") to include
	// in API requests with the JSON null value. By default, fields with
	// empty values are omitted from API requests. However, any field with
	// an empty value appearing in NullFields will be sent to the server as
	// null. It is an error if a field in this list has a non-empty value.
	// This may be used to include null fields in Patch requests.
	NullFields []string `json:"-"`
}

func (s *GoogleIdentityStsV1betaExchangeTokenResponse) MarshalJSON() ([]byte, error) {
	type NoMethod GoogleIdentityStsV1betaExchangeTokenResponse
	raw := NoMethod(*s)
	return MarshalJSON(raw, s.ForceSendFields, s.NullFields)
}

// method id "sts.token":

type V1betaTokenCall struct {
	s                                           *V1betaService
	googleidentitystsv1betaexchangetokenrequest *GoogleIdentityStsV1betaExchangeTokenRequest
	urlParams_                                  URLParams
	ctx_                                        context.Context
	header_                                     http.Header
}

// Token: Exchanges a credential for a Google OAuth 2.0 access token.
// The token asserts an external identity within a workload identity
// pool, or it applies a Credential Access Boundary to a Google access
// token.
func (s *V1betaService) Token(googleidentitystsv1betaexchangetokenrequest *GoogleIdentityStsV1betaExchangeTokenRequest) *V1betaTokenCall {
	c := &V1betaTokenCall{s: s, urlParams_: make(URLParams)}
	c.googleidentitystsv1betaexchangetokenrequest = googleidentitystsv1betaexchangetokenrequest
	return c
}

// Fields allows partial responses to be retrieved. See
// https://developers.google.com/gdata/docs/2.0/basics#PartialResponse
// for more information.
func (c *V1betaTokenCall) Fields(s ...googleapi.Field) *V1betaTokenCall {
	c.urlParams_.Set("fields", googleapi.CombineFields(s))
	return c
}

// Context sets the context to be used in this call's Do method. Any
// pending HTTP request will be aborted if the provided context is
// canceled.
func (c *V1betaTokenCall) Context(ctx context.Context) *V1betaTokenCall {
	c.ctx_ = ctx
	return c
}

// Header returns an http.Header that can be modified by the caller to
// add HTTP headers to the request.
func (c *V1betaTokenCall) Header() http.Header {
	if c.header_ == nil {
		c.header_ = make(http.Header)
	}
	return c.header_
}

func (c *V1betaTokenCall) doRequest(alt string) (*http.Response, error) {
	reqHeaders := make(http.Header)
	reqHeaders.Set("x-goog-api-client", "gl-go/"+GoVersion()+" gdcl/20201210")
	for k, v := range c.header_ {
		reqHeaders[k] = v
	}
	reqHeaders.Set("User-Agent", c.s.userAgent())
	var body io.Reader
	body, err := googleapi.WithoutDataWrapper.JSONReader(c.googleidentitystsv1betaexchangetokenrequest)
	if err != nil {
		return nil, err
	}
	reqHeaders.Set("Content-Type", "application/json")
	c.urlParams_.Set("alt", alt)
	c.urlParams_.Set("prettyPrint", "false")
	urls := googleapi.ResolveRelative(c.s.BasePath, "v1beta/token")
	urls += "?" + c.urlParams_.Encode()
	req, err := http.NewRequest("POST", urls, body)
	if err != nil {
		return nil, err
	}
	req.Header = reqHeaders
	return SendRequest(c.ctx_, c.s.client, req)
}

// Do executes the "sts.token" call.
// Exactly one of *GoogleIdentityStsV1ExchangeTokenResponse or error
// will be non-nil. Any non-2xx status code is an error. Response
// headers are in either
// *GoogleIdentityStsV1ExchangeTokenResponse.ServerResponse.Header or
// (if a response was returned at all) in
// error.(*googleapi.Error).Header. Use googleapi.IsNotModified to check
// whether the returned error was because http.StatusNotModified was
// returned.
func (c *V1betaTokenCall) Do(opts ...googleapi.CallOption) (*GoogleIdentityStsV1betaExchangeTokenResponse, error) {
	SetOptions(c.urlParams_, opts...)
	res, err := c.doRequest("json")
	if res != nil && res.StatusCode == http.StatusNotModified {
		if res.Body != nil {
			res.Body.Close() //nolint:errcheck,gosec
		}
		return nil, &googleapi.Error{
			Code:   res.StatusCode,
			Header: res.Header,
		}
	}
	if err != nil {
		return nil, err
	}
	defer googleapi.CloseBody(res)
	if err := googleapi.CheckResponse(res); err != nil {
		return nil, err
	}
	ret := &GoogleIdentityStsV1betaExchangeTokenResponse{
		ServerResponse: googleapi.ServerResponse{
			Header:         res.Header,
			HTTPStatusCode: res.StatusCode,
		},
	}
	target := &ret
	if err := DecodeResponse(target, res); err != nil {
		return nil, err
	}
	return ret, nil
	// {
	//   "description": "Exchanges a credential for a Google OAuth 2.0 access token.",
	//   "flatPath": "v1/token",
	//   "httpMethod": "POST",
	//   "id": "sts.token",
	//   "parameterOrder": [],
	//   "parameters": {},
	//   "path": "v1/token",
	//   "request": {
	//     "$ref": "GoogleIdentityStsV1ExchangeTokenRequest"
	//   },
	//   "response": {
	//     "$ref": "GoogleIdentityStsV1ExchangeTokenResponse"
	//   }
	// }

}