package s3err

import (
	"encoding/xml"
	"fmt"
	"net/http"
)

// APIError structure
type APIError struct {
	Code           string
	Description    string
	HTTPStatusCode int
}

// RESTErrorResponse - error response format
type RESTErrorResponse struct {
	XMLName   xml.Name `xml:"Error" json:"-"`
	Code      string   `xml:"Code" json:"Code"`
	Message   string   `xml:"Message" json:"Message"`
	Resource  string   `xml:"Resource" json:"Resource"`
	RequestID string   `xml:"RequestId" json:"RequestId"`

	// Underlying HTTP status code for the returned error
	StatusCode int `xml:"-" json:"-"`
}

// Error - Returns S3 error string.
func (e RESTErrorResponse) Error() string {
	if e.Message == "" {
		msg, ok := s3ErrorResponseMap[e.Code]
		if !ok {
			msg = fmt.Sprintf("Error response code %s.", e.Code)
		}
		return msg
	}
	return e.Message
}

// ErrorCode type of error status.
type ErrorCode int

// Error codes, see full list at http://docs.aws.amazon.com/AmazonS3/latest/API/ErrorResponses.html
const (
	ErrNone ErrorCode = iota
	ErrAccessDenied
	ErrMethodNotAllowed
	ErrBucketNotEmpty
	ErrBucketAlreadyExists
	ErrBucketAlreadyOwnedByYou
	ErrNoSuchBucket
	ErrNoSuchKey
	ErrNoSuchUpload
	ErrInvalidBucketName
	ErrInvalidDigest
	ErrInvalidMaxKeys
	ErrInvalidMaxUploads
	ErrInvalidMaxParts
	ErrInvalidPartNumberMarker
	ErrInvalidPart
	ErrInternalError
	ErrInvalidCopyDest
	ErrInvalidCopySource
	ErrInvalidTag
	ErrAuthHeaderEmpty
	ErrSignatureVersionNotSupported
	ErrMalformedPOSTRequest
	ErrPOSTFileRequired
	ErrPostPolicyConditionInvalidFormat
	ErrEntityTooSmall
	ErrEntityTooLarge
	ErrMissingFields
	ErrMissingCredTag
	ErrCredMalformed
	ErrMalformedXML
	ErrMalformedDate
	ErrMalformedPresignedDate
	ErrMalformedCredentialDate
	ErrMissingSignHeadersTag
	ErrMissingSignTag
	ErrUnsignedHeaders
	ErrInvalidQueryParams
	ErrInvalidQuerySignatureAlgo
	ErrExpiredPresignRequest
	ErrMalformedExpires
	ErrNegativeExpires
	ErrMaximumExpires
	ErrSignatureDoesNotMatch
	ErrContentSHA256Mismatch
	ErrInvalidAccessKeyID
	ErrRequestNotReadyYet
	ErrMissingDateHeader
	ErrInvalidRequest
	ErrNotImplemented

	ErrExistingObjectIsDirectory
)

// error code to APIError structure, these fields carry respective
// descriptions for all the error responses.
var errorCodeResponse = map[ErrorCode]APIError{
	ErrAccessDenied: {
		Code:           "AccessDenied",
		Description:    "Access Denied.",
		HTTPStatusCode: http.StatusForbidden,
	},
	ErrMethodNotAllowed: {
		Code:           "MethodNotAllowed",
		Description:    "The specified method is not allowed against this resource.",
		HTTPStatusCode: http.StatusMethodNotAllowed,
	},
	ErrBucketNotEmpty: {
		Code:           "BucketNotEmpty",
		Description:    "The bucket you tried to delete is not empty",
		HTTPStatusCode: http.StatusConflict,
	},
	ErrBucketAlreadyExists: {
		Code:           "BucketAlreadyExists",
		Description:    "The requested bucket name is not available. The bucket namespace is shared by all users of the system. Please select a different name and try again.",
		HTTPStatusCode: http.StatusConflict,
	},
	ErrBucketAlreadyOwnedByYou: {
		Code:           "BucketAlreadyOwnedByYou",
		Description:    "Your previous request to create the named bucket succeeded and you already own it.",
		HTTPStatusCode: http.StatusConflict,
	},
	ErrInvalidBucketName: {
		Code:           "InvalidBucketName",
		Description:    "The specified bucket is not valid.",
		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrInvalidDigest: {
		Code:           "InvalidDigest",
		Description:    "The Content-Md5 you specified is not valid.",
		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrInvalidMaxUploads: {
		Code:           "InvalidArgument",
		Description:    "Argument max-uploads must be an integer between 0 and 2147483647",
		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrInvalidMaxKeys: {
		Code:           "InvalidArgument",
		Description:    "Argument maxKeys must be an integer between 0 and 2147483647",
		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrInvalidMaxParts: {
		Code:           "InvalidArgument",
		Description:    "Argument max-parts must be an integer between 0 and 2147483647",
		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrInvalidPartNumberMarker: {
		Code:           "InvalidArgument",
		Description:    "Argument partNumberMarker must be an integer.",
		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrNoSuchBucket: {
		Code:           "NoSuchBucket",
		Description:    "The specified bucket does not exist",
		HTTPStatusCode: http.StatusNotFound,
	},
	ErrNoSuchKey: {
		Code:           "NoSuchKey",
		Description:    "The specified key does not exist.",
		HTTPStatusCode: http.StatusNotFound,
	},
	ErrNoSuchUpload: {
		Code:           "NoSuchUpload",
		Description:    "The specified multipart upload does not exist. The upload ID may be invalid, or the upload may have been aborted or completed.",
		HTTPStatusCode: http.StatusNotFound,
	},
	ErrInternalError: {
		Code:           "InternalError",
		Description:    "We encountered an internal error, please try again.",
		HTTPStatusCode: http.StatusInternalServerError,
	},

	ErrInvalidPart: {
		Code:           "InvalidPart",
		Description:    "One or more of the specified parts could not be found.  The part may not have been uploaded, or the specified entity tag may not match the part's entity tag.",
		HTTPStatusCode: http.StatusBadRequest,
	},

	ErrInvalidCopyDest: {
		Code:           "InvalidRequest",
		Description:    "This copy request is illegal because it is trying to copy an object to itself without changing the object's metadata, storage class, website redirect location or encryption attributes.",
		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrInvalidCopySource: {
		Code:           "InvalidArgument",
		Description:    "Copy Source must mention the source bucket and key: sourcebucket/sourcekey.",
		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrInvalidTag: {
		Code:           "InvalidArgument",
		Description:    "The Tag value you have provided is invalid",
		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrMalformedXML: {
		Code:           "MalformedXML",
		Description:    "The XML you provided was not well-formed or did not validate against our published schema.",
		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrAuthHeaderEmpty: {
		Code:           "InvalidArgument",
		Description:    "Authorization header is invalid -- one and only one ' ' (space) required.",
		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrSignatureVersionNotSupported: {
		Code:           "InvalidRequest",
		Description:    "The authorization mechanism you have provided is not supported. Please use AWS4-HMAC-SHA256.",
		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrMalformedPOSTRequest: {
		Code:           "MalformedPOSTRequest",
		Description:    "The body of your POST request is not well-formed multipart/form-data.",
		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrPOSTFileRequired: {
		Code:           "InvalidArgument",
		Description:    "POST requires exactly one file upload per request.",
		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrPostPolicyConditionInvalidFormat: {
		Code:           "PostPolicyInvalidKeyName",
		Description:    "Invalid according to Policy: Policy Condition failed",
		HTTPStatusCode: http.StatusForbidden,
	},
	ErrEntityTooSmall: {
		Code:           "EntityTooSmall",
		Description:    "Your proposed upload is smaller than the minimum allowed object size.",
		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrEntityTooLarge: {
		Code:           "EntityTooLarge",
		Description:    "Your proposed upload exceeds the maximum allowed object size.",
		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrMissingFields: {
		Code:           "MissingFields",
		Description:    "Missing fields in request.",
		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrMissingCredTag: {
		Code:           "InvalidRequest",
		Description:    "Missing Credential field for this request.",
		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrCredMalformed: {
		Code:           "AuthorizationQueryParametersError",
		Description:    "Error parsing the X-Amz-Credential parameter; the Credential is mal-formed; expecting \"<YOUR-AKID>/YYYYMMDD/REGION/SERVICE/aws4_request\".",
		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrMalformedDate: {
		Code:           "MalformedDate",
		Description:    "Invalid date format header, expected to be in ISO8601, RFC1123 or RFC1123Z time format.",
		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrMalformedPresignedDate: {
		Code:           "AuthorizationQueryParametersError",
		Description:    "X-Amz-Date must be in the ISO8601 Long Format \"yyyyMMdd'T'HHmmss'Z'\"",
		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrMissingSignHeadersTag: {
		Code:           "InvalidArgument",
		Description:    "Signature header missing SignedHeaders field.",
		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrMissingSignTag: {
		Code:           "AccessDenied",
		Description:    "Signature header missing Signature field.",
		HTTPStatusCode: http.StatusBadRequest,
	},

	ErrUnsignedHeaders: {
		Code:           "AccessDenied",
		Description:    "There were headers present in the request which were not signed",
		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrInvalidQueryParams: {
		Code:           "AuthorizationQueryParametersError",
		Description:    "Query-string authentication version 4 requires the X-Amz-Algorithm, X-Amz-Credential, X-Amz-Signature, X-Amz-Date, X-Amz-SignedHeaders, and X-Amz-Expires parameters.",
		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrInvalidQuerySignatureAlgo: {
		Code:           "AuthorizationQueryParametersError",
		Description:    "X-Amz-Algorithm only supports \"AWS4-HMAC-SHA256\".",
		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrExpiredPresignRequest: {
		Code:           "AccessDenied",
		Description:    "Request has expired",
		HTTPStatusCode: http.StatusForbidden,
	},
	ErrMalformedExpires: {
		Code:           "AuthorizationQueryParametersError",
		Description:    "X-Amz-Expires should be a number",
		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrNegativeExpires: {
		Code:           "AuthorizationQueryParametersError",
		Description:    "X-Amz-Expires must be non-negative",
		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrMaximumExpires: {
		Code:           "AuthorizationQueryParametersError",
		Description:    "X-Amz-Expires must be less than a week (in seconds); that is, the given X-Amz-Expires must be less than 604800 seconds",
		HTTPStatusCode: http.StatusBadRequest,
	},

	ErrInvalidAccessKeyID: {
		Code:           "InvalidAccessKeyId",
		Description:    "The access key ID you provided does not exist in our records.",
		HTTPStatusCode: http.StatusForbidden,
	},

	ErrRequestNotReadyYet: {
		Code:           "AccessDenied",
		Description:    "Request is not valid yet",
		HTTPStatusCode: http.StatusForbidden,
	},

	ErrSignatureDoesNotMatch: {
		Code:           "SignatureDoesNotMatch",
		Description:    "The request signature we calculated does not match the signature you provided. Check your key and signing method.",
		HTTPStatusCode: http.StatusForbidden,
	},

	ErrContentSHA256Mismatch: {
		Code:           "XAmzContentSHA256Mismatch",
		Description:    "The provided 'x-amz-content-sha256' header does not match what was computed.",
		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrMissingDateHeader: {
		Code:           "AccessDenied",
		Description:    "AWS authentication requires a valid Date or x-amz-date header",
		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrInvalidRequest: {
		Code:           "InvalidRequest",
		Description:    "Invalid Request",
		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrNotImplemented: {
		Code:           "NotImplemented",
		Description:    "A header you provided implies functionality that is not implemented",
		HTTPStatusCode: http.StatusNotImplemented,
	},
	ErrExistingObjectIsDirectory: {
		Code:           "ExistingObjectIsDirectory",
		Description:    "Existing Object is a directory.",
		HTTPStatusCode: http.StatusConflict,
	},
}

// GetAPIError provides API Error for input API error code.
func GetAPIError(code ErrorCode) APIError {
	return errorCodeResponse[code]
}