/*
 * Teleport
 * Copyright (C) 2023  Gravitational, Inc.
 *
 * 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 aws

import (
	"errors"
	"net/http"
	"strings"

	awshttp "github.com/aws/aws-sdk-go-v2/aws/transport/http"
	"github.com/aws/aws-sdk-go-v2/config"
	iamTypes "github.com/aws/aws-sdk-go-v2/service/iam/types"
	"github.com/aws/aws-sdk-go/aws/awserr"
	"github.com/aws/aws-sdk-go/service/iam"
	"github.com/aws/aws-sdk-go/service/redshiftserverless"
	"github.com/gravitational/trace"
)

// ConvertRequestFailureError converts `error` into AWS RequestFailure errors
// to trace errors. If the provided error is not an `RequestFailure` it returns
// the error without modifying it.
func ConvertRequestFailureError(err error) error {
	var requestErr awserr.RequestFailure
	if !errors.As(err, &requestErr) {
		return err
	}

	return convertRequestFailureErrorFromStatusCode(requestErr.StatusCode(), requestErr)
}

func convertRequestFailureErrorFromStatusCode(statusCode int, requestErr error) error {
	switch statusCode {
	case http.StatusForbidden:
		return trace.AccessDenied(requestErr.Error())
	case http.StatusConflict:
		return trace.AlreadyExists(requestErr.Error())
	case http.StatusNotFound:
		return trace.NotFound(requestErr.Error())
	case http.StatusBadRequest:
		// Some services like memorydb, redshiftserverless may return 400 with
		// "AccessDeniedException" instead of 403.
		if strings.Contains(requestErr.Error(), redshiftserverless.ErrCodeAccessDeniedException) {
			return trace.AccessDenied(requestErr.Error())
		}
	}

	return requestErr // Return unmodified.
}

// ConvertIAMError converts common errors from IAM clients to trace errors.
func ConvertIAMError(err error) error {
	// By error code.
	var awsErr awserr.Error
	if errors.As(err, &awsErr) {
		switch awsErr.Code() {
		case iam.ErrCodeUnmodifiableEntityException:
			return trace.AccessDenied(awsErr.Error())

		case iam.ErrCodeNoSuchEntityException:
			return trace.NotFound(awsErr.Error())

		case iam.ErrCodeMalformedPolicyDocumentException,
			iam.ErrCodeInvalidInputException,
			iam.ErrCodeDeleteConflictException:
			return trace.BadParameter(awsErr.Error())

		case iam.ErrCodeLimitExceededException:
			return trace.LimitExceeded(awsErr.Error())
		}
	}

	// By status code.
	return ConvertRequestFailureError(err)
}

// parseMetadataClientError converts a failed instance metadata service call to a trace error.
func parseMetadataClientError(err error) error {
	var httpError interface{ HTTPStatusCode() int }
	if errors.As(err, &httpError) {
		return trace.ReadError(httpError.HTTPStatusCode(), nil)
	}
	return trace.Wrap(err)
}

// ConvertIAMv2Error converts common errors from IAM clients to trace errors.
func ConvertIAMv2Error(err error) error {
	if err == nil {
		return nil
	}

	var entityExistsError *iamTypes.EntityAlreadyExistsException
	if errors.As(err, &entityExistsError) {
		return trace.AlreadyExists(*entityExistsError.Message)
	}

	var entityNotFound *iamTypes.NoSuchEntityException
	if errors.As(err, &entityNotFound) {
		return trace.NotFound(*entityNotFound.Message)
	}

	var malformedPolicyDocument *iamTypes.MalformedPolicyDocumentException
	if errors.As(err, &malformedPolicyDocument) {
		return trace.BadParameter(*malformedPolicyDocument.Message)
	}

	var re *awshttp.ResponseError
	if errors.As(err, &re) {
		return convertRequestFailureErrorFromStatusCode(re.HTTPStatusCode(), re.Err)
	}

	return err
}

// ConvertLoadConfigError converts common AWS config loading errors to trace errors.
func ConvertLoadConfigError(configErr error) error {
	var sharedConfigProfileNotExistError config.SharedConfigProfileNotExistError
	switch {
	case errors.As(configErr, &sharedConfigProfileNotExistError):
		return trace.NotFound(configErr.Error())
	}

	return configErr
}