const (
	// ErrNotHTTPS is returned when trying to fetch resources from a non-secure
	// URI.
	ErrNotHTTPS xerrors.Error = "uri is not secure; must use HTTPS"

	// ErrDomainNotTrusted is returned when trying to fetch resources from a
	// domain outside the list of allowed domains.
	ErrDomainNotTrusted xerrors.Error = "domain is not trusted"

	// ErrNilHTTPClient is returned when trying to fetch resources without an
	// HTTP client.
	ErrNilHTTPClient xerrors.Error = "HTTP client cannot be nil"

	// ErrRequestFailed is returned when a request fails for unknown reasons.
	ErrRequestFailed xerrors.Error = "request failed with status code"

	// ErrExceededMaxContentLength is returned when trying to fetch resources
	// bigger than the allowed MaxContentLength.
	ErrExceededMaxContentLength xerrors.Error = "response body exceeds maximum content length"
)

const (
	Age                           string = "Age"
	AltSCV                        string = "Alt-Svc"
	Accept                        string = "Accept"
	AcceptCharset                 string = "Accept-Charset"
	AcceptPatch                   string = "Accept-Patch"
	AcceptRanges                  string = "Accept-Ranges"
	AcceptedLanguage              string = "Accept-Language"
	AcceptEncoding                string = "Accept-Encoding"
	Authorization                 string = "Authorization"
	CrossOriginResourcePolicy     string = "Cross-Origin-Resource-Policy"
	CacheControl                  string = "Cache-Control"
	Connection                    string = "Connection"
	ContentDisposition            string = "Content-Disposition"
	ContentEncoding               string = "Content-Encoding"
	ContentLength                 string = "Content-Length"
	ContentType                   string = "Content-Type"
	ContentLanguage               string = "Content-Language"
	ContentLocation               string = "Content-Location"
	ContentRange                  string = "Content-Range"
	Date                          string = "Date"
	DeltaBase                     string = "Delta-Base"
	ETag                          string = "ETag"
	Expires                       string = "Expires"
	Host                          string = "Host"
	IM                            string = "IM"
	IfMatch                       string = "If-Match"
	IfModifiedSince               string = "If-Modified-Since"
	IfNoneMatch                   string = "If-None-Match"
	IfRange                       string = "If-Range"
	IfUnmodifiedSince             string = "If-Unmodified-Since"
	KeepAliveK                    string = "Keep-Alive"
	LastModified                  string = "Last-Modified"
	Link                          string = "Link"
	Pragma                        string = "Pragma"
	ProxyAuthenticate             string = "Proxy-Authenticate"
	ProxyAuthorization            string = "Proxy-Authorization"
	PublicKeyPins                 string = "Public-Key-Pins"
	RequestID                     string = "Request-Id"
	RetryAfter                    string = "Retry-After"
	Referer                       string = "Referer"
	Server                        string = "Server"
	SetCookie                     string = "Set-Cookie"
	StrictTransportSecurity       string = "Strict-Transport-Security"
	Trailer                       string = "Trailer"
	TK                            string = "Tk"
	TransferEncoding              string = "Transfer-Encoding"
	Location                      string = "Location"
	Upgrade                       string = "Upgrade"
	Vary                          string = "Vary"
	Via                           string = "Via"
	Warning                       string = "Warning"
	WWWAuthenticate               string = "WWW-Authenticate"
	XForwardedFor                 string = "X-Forwarded-For"
	XForwardedHost                string = "X-Forwarded-Host"
	XForwardedProto               string = "X-Forwarded-Proto"
	XRealIP                       string = "X-Real-Ip"
	XContentTypeOptions           string = "X-Content-Type-Options"
	XFrameOptions                 string = "X-Frame-Options"
	XXSSProtection                string = "X-XSS-Protection"
	XDNSPrefetchControl           string = "X-DNS-Prefetch-Control"
	Allow                         string = "Allow"
	Origin                        string = "Origin"
	AccessControlAllowOrigin      string = "Access-Control-Allow-Origin"
	AccessControlAllowCredentials string = "Access-Control-Allow-Credentials"
	AccessControlAllowHeaders     string = "Access-Control-Allow-Headers"
	AccessControlAllowMethods     string = "Access-Control-Allow-Methods"
	AccessControlExposeHeaders    string = "Access-Control-Expose-Headers"
	AccessControlMaxAge           string = "Access-Control-Max-Age"
	AccessControlRequestHeaders   string = "Access-Control-Request-Headers"
	AccessControlRequestMethod    string = "Access-Control-Request-Method"
	TimingAllowOrigin             string = "Timing-Allow-Origin"
	UserAgent                     string = "User-Agent"
)

const (
	NoCache               string = "no-cache"
	KeepAliveV            string = "keep-alive"
	Close                 string = "close"
	ApplicationJSON       string = "application/json"
	FormData              string = "multipart/form-data"
	TextHTML              string = "text/html"
	TextPlain             string = "text/plain"
	TextCSS               string = "text/css"
	TextJavascript        string = "text/javascript"
	ApplicationJavascript string = "application/javascript"
	ApplicationXML        string = "application/xml"
	ImageJPEG             string = "image/jpeg"
	ImagePNG              string = "image/png"
	ImageGIF              string = "image/gif"
	ImageSVG              string = "image/svg+xml"
	CharsetUTF8           string = "charset=utf-8"
	Gzip                  string = "gzip"
	Deflate               string = "deflate"
	Brotli                string = "br"
	Wildcard              string = "*"
	SameOrigin            string = "same-origin"
	Deny                  string = "deny"
	SameSiteLax           string = "Lax"
	SameSiteStrict        string = "Strict"
	SameSiteNone          string = "None"
	Secure                string = "secure"
	NoTransform           string = "no-transform"
	Chunked               string = "chunked"
	True                  string = "true"
	False                 string = "false"
)

const (
	// ErrMissingRequest indicates that a nil http.Request was provided to the
	// ClientIP function.
	ErrMissingRequest xerrors.Error = "missing http.Request"

	// ErrInvalidIP indicates that no valid IP address could be extracted from
	// the given http.Request.
	ErrInvalidIP xerrors.Error = "invalid IP address"
)

const (
	// ErrCannotDrainResponse is returned when a response body cannot be drained.
	ErrCannotDrainResponse xerrors.Error = "cannot drain response body"

	// ErrCannotCloseResponse is returned when a response body cannot be closed.
	ErrCannotCloseResponse xerrors.Error = "cannot close response body"
)

const (
	// DefaultMaxRetries is the default maximum number of times a request will
	// be retried.
	DefaultMaxRetries int = 3

	// DefaultMinRetryDelay is the default minimum duration to wait before
	// retrying a request.
	DefaultMinRetryDelay time.Duration = 1 * time.Second

	// DefaultMaxRetryDelay is the default maximum duration to wait before
	// retrying a request.
	DefaultMaxRetryDelay time.Duration = 30 * time.Second
)

const (
	// DefaultTransportMaxIddleConns is the default maximum number of idle
	// connections in the pool.
	DefaultTransportMaxIddleConns int = 100

	// DefaultTransportIdleConnTimeout is the default maximum amount of time a
	// connection can remain idle before being closed.
	DefaultTransportIdleConnTimeout = 90 * time.Second

	// DefaultTransportTLSHandshakeTimeout is the default maximum amount of time
	// allowed to complete a TLS handshake.
	DefaultTransportTLSHandshakeTimeout = 10 * time.Second

	// DefaultTransportExpectContinueTimeout is the default maximum amount of
	// time to wait for a server's first response headers after fully writing
	// the request headers if the request has an "Expect: 100-continue" header.
	DefaultTransportExpectContinueTimeout = 1 * time.Second
)

const (
	UAEdgeWindows    = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/119.0.0.0 Safari/537.36 Edg/119.0.0.0"
	UAChromeWindows  = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/119.0.0.0 Safari/537.36"
	UAFirefoxWindows = "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:109.0) Gecko/20100101 Firefox/119.0"
	UASafariMacOS    = "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/17.1 Safari/605.1.1"
)

const DefaultClientTimeout = 15 * time.Second

const ErrExceededMaxRetries xerrors.Error = "exceeded max retries"

type Fetcher interface {
	// Fetch fetches the resource at the given URL and returns the response as
	// a byte array.
	Fetch(ctx context.Context, uri string) ([]byte, error)
}

type ResponseError struct {
	// Message is a human-readable message describing the error.
	Message string `json:"message"`

	// Documentation is a link to documentation describing the error.
	Documentation string `json:"documentation,omitempty"`

	// Code is a machine-readable code describing the error.
	Code int `json:"code"`
}

type RetryPolicy struct {
	// IsRetryable determines whether a given response and error combination
	// should be retried.
	IsRetryable func(*http.Response, error) bool

	// MaxRetries is the maximum number of times a request will be retried.
	MaxRetries int

	// MinRetryDelay is the minimum duration to wait before retrying a request.
	MinRetryDelay time.Duration

	// MaxRetryDelay is the maximum duration to wait before retrying a request.
	MaxRetryDelay time.Duration
}

type RetryRoundTripper struct {
	// Policy defines the retry behavior.
	Policy *RetryPolicy

	// Logger is used for structured logging. It should be provided if logging
	// of the retry process is required. If nil, logging is disabled.
	Logger *slog.Logger
	// contains filtered or unexported fields
}

type SafeFetcher struct {
	// Client is the underlying HTTP client. If nil, ErrNilHTTPClient is
	// returned.
	Client *http.Client

	// Logger is the logger to use when logging events. If nil, no events are
	// logged.
	Logger *slog.Logger

	// Header specifies additional headers to be included in each request.
	Header http.Header

	// TrustedDomain specifies domains from which fetching is permitted.
	TrustedDomain []string

	// MaxContentLength limits the size of the response body. Fetch operations
	// exceeding this limit are aborted to prevent potential resource exhaustion
	// attacks.
	MaxContentLength int64
}